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Sample records for plasma platelet-activating factor

  1. Elevated plasma phospholipase A2 and platelet-activating factor acetylhydrolase activity in colorectal cancer

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    Yves Denizot

    2004-01-01

    Full Text Available This clinical study reports that blood levels of the pro-inflammatory mediator platelet-activating factor (PAF did not change in colorectal cancer patients. In contrast, plasma levels of two enzymatic activities, one implicated in PAF production (i.e. phospholipase A2 and one in PAF degradation (i.e. PAF acetylhydrolase activity were significantly elevated.

  2. Perbedaan Kadar Platelet Activating Factor Plasma antara Penderita Demam Berdarah Dengue dan Demam Dengue

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    Djatnika Setiabudi

    2013-12-01

    Full Text Available Dengue virus infection can manifest as dengue fever and, more severely, as dengue hemorrhagic fever. Their pathogenesis until now is not fully understood. One of the most favorable theories stated the presence of increasing titer of pro-inflammatory mediator in severe dengue. The aim of this study was to determine the difference of plasma platelet activating factor titer between dengue hemorrhagic fever and dengue fever patients. This observational study with cross sectional design was conducted during January–February 2013. Subjects were dengue patients, 1 to 14 years old, hospitalized at Dr. Hasan Sadikin General Hospital, Bandung District Hospital (Ujungberung, and Cimahi District Hospital (Cibabat. Dengue cases were confirmed based on nonstructural-1 antigen and/or immunoglobulin M and G rapid test. Blood samples from febrile, critical and recovery phase were drawn for the examination of platelet activating factor titer using the enzyme-linked immunosorbent assay method. There were 26 dengue cases (14 as dengue fever and 12 as dengue hemorrhagic fever. Plasma platelet activating factor titer at the critical phase was significantly higher in dengue hemorrhagic fever patients [541.45 (239.30–2,449.00] pg/mL compared to dengue fever patients [289.55 (149.50–961.50] pg/mL; p=0.007. In conclusion, plasma platelet activating factor titer at the critical phase is higher in dengue hemorrhagic fever patients than in dengue fever patients.

  3. Decrease in platelet activating factor stimulated phosphoinositide turnover during storage of human platelets in plasma

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    Carter, M.G.; Shukla, S.D. (Univ. of Missouri School of Medicine, Columbia (USA))

    1987-05-01

    Human platelet concentrate from the American Red Cross Blood Center was stored at 24{degree}C in a shaker and aliquots were taken out at time intervals aseptically. Platelet activating factor (PAF) stimulated turnover of phosphoinositide (PPI) was monitored by assaying {sup 32}P incorporation into phosphoinositides using platelet rich plasma (PRP). Platelets in PRP were incubated with 1 {times} 10{sup {minus}7} M PAF at 37{degree}C with gentle shaking and after 5 min their lipids were extracted and analysed by TLC for {sup 32}P-phosphoinositides. The percent stimulation of {sup 32}P incorporation by PAF (over control) into PPI was approximately 250, 100, 60, 25 and 20 on days 1, 2, 3, 5 and 6, respectively. This indicated a dramatic decrease in PAF responsive turnover of platelet PPI during storage. These findings have important implications in relation to PAF receptor activity and viability of platelets at different periods of storage.

  4. Increase in plasma platelet-activating factor levels in enterally fed preterm infants.

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    MacKendrick, W; Hill, N; Hsueh, W; Caplan, M

    1993-01-01

    Because platelet-activating factor (PAF) has been implicated in the pathogenesis of neonatal necrotizing enterocolitis (NEC), we designed a prospective study to examine plasma PAF levels during the first 14 days of feeding in a population of neonates of less than 32 weeks gestation. We found that significantly more patients had detectable plasma PAF levels on days 3 and 14 of feeding when compared to their prefeeding levels (7% on day 0 vs. 26% at day 3, p = 0.04; none on day 0 vs. 18.5% at day 14, p = 0.01). This finding could not be explained by decreased plasma activity of acetylhydrolase, the PAF breakdown enzyme, spontaneous endotoxinemia or a maturational effect. None of the infants who developed detectable PAF levels after feedings were begun went on to develop NEC. We conclude that our findings may reflect increased intestinal PAF production with the provision of feedings to some premature infants. However, this phenomenon by itself does not appear to be a sufficient condition for the subsequent development of NEC.

  5. Human plasma platelet-activating factor acetylhydrolase. Oxidatively fragmented phospholipids as substrates.

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    Stremler, K E; Stafforini, D M; Prescott, S M; McIntyre, T M

    1991-06-15

    Human plasma platelet-activating factor (PAF) acetylhydrolase hydrolyzes the sn-2 acetyl residue of PAF, but not phospholipids with long chain sn-2 residues. It is associated with low density lipoprotein (LDL) particles, and is the LDL-associated phospholipase A2 activity that specifically degrades oxidatively damaged phospholipids (Stremler, K. E., Stafforini, D. M., Prescott, S. M., Zimmerman, G. A., and McIntyre, T. M. (1989) J. Biol. Chem. 264, 5331-5334). To identify potential substrates, we synthesized phosphatidylcholines with sn-2 residues from two to nine carbon atoms long, and found the V/k ratio decreased as the sn-2 residue was lengthened: the C5 homolog was 50%, the C6 20%, while the C9 homolog was only 2% as efficient as PAF. However, the presence of an omega-oxo function radically affected hydrolysis: the half-life of the sn-2 9-aldehydic homolog was identical to that of PAF. We oxidized [2-arachidonoyl]phosphatidylcholine and isolated a number of more polar phosphatidylcholines. We treated these with phospholipase C, derivatized the resulting diglycerides for gas chromatographic/mass spectroscopic analysis, and found a number of diglycerides where the m/z ratio was consistent with a series of short to medium length sn-2 residues. We treated the polar phosphatidylcholines with acetylhydrolase and derivatized the products for analysis by gas chromatography/mass spectroscopy. The liberated residues were more polar than straight chain standards and had m/z ratios from 129 to 296, consistent with short to medium chain residues. Therefore, oxidation fragments the sn-2 residue of phospholipids, and the acetylhydrolase specifically degrades such oxidatively fragmented phospholipids.

  6. Platelet-rich plasma stimulated by pulse electric fields: Platelet activation, procoagulant markers, growth factor release and cell proliferation.

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    Frelinger, A L; Torres, A S; Caiafa, A; Morton, C A; Berny-Lang, M A; Gerrits, A J; Carmichael, S L; Neculaes, V B; Michelson, A D

    2016-01-01

    Therapeutic use of activated platelet-rich plasma (PRP) has been explored for wound healing, hemostasis and antimicrobial wound applications. Pulse electric field (PEF) stimulation may provide more consistent platelet activation and avoid complications associated with the addition of bovine thrombin, the current state of the art ex vivo activator of therapeutic PRP. The aim of this study was to compare the ability of PEF, bovine thrombin and thrombin receptor activating peptide (TRAP) to activate human PRP, release growth factors and induce cell proliferation in vitro. Human PRP was prepared in the Harvest SmartPreP2 System and treated with vehicle, PEF, bovine thrombin, TRAP or Triton X-100. Platelet activation and procoagulant markers and microparticle generation were measured by flow cytometry. Released growth factors were measured by ELISA. The releasates were tested for their ability to stimulate proliferation of human epithelial cells in culture. PEF produced more platelet-derived microparticles, P-selectin-positive particles and procoagulant annexin V-positive particles than bovine thrombin or TRAP. These differences were associated with higher levels of released epidermal growth factor after PEF than after bovine thrombin or TRAP but similar levels of platelet-derived, vascular-endothelial, and basic fibroblast growth factors, and platelet factor 4. Supernatant from PEF-treated platelets significantly increased cell proliferation compared to plasma. In conclusion, PEF treatment of fresh PRP results in generation of microparticles, exposure of prothrombotic platelet surfaces, differential release of growth factors compared to bovine thrombin and TRAP and significant cell proliferation. These results, together with PEF's inherent advantages, suggest that PEF may be a superior alternative to bovine thrombin activation of PRP for therapeutic applications.

  7. An oxidized derivative of phosphatidylcholine is a substrate for the platelet-activating factor acetylhydrolase from human plasma.

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    Stremler, K E; Stafforini, D M; Prescott, S M; Zimmerman, G A; McIntyre, T M

    1989-04-05

    Platelet-activating factor (PAF) is a glycerophospholipid that has diverse potent biological actions. A plasma enzyme catalyzes the hydrolysis of the sn-2 acetoyl group of PAF and thereby abolishes its bioactivity. This PAF acetylhydrolase is specific for phospholipids, such as PAF, with a short acyl group at the sn-2 position. The majority of it (60-70%) is associated with low density lipoprotein (LDL), and the remainder is with high density lipoprotein (HDL). LDL also has a phospholipase A2 activity that is specific for oxidized polyunsaturated fatty acids, which may be important in determining how LDL is recognized by cellular receptors. We previously have purified and characterized the PAF acetylhydrolase from human plasma. We now have found that the purified PAF acetylhydrolase catalyzes the hydrolysis of the oxidized fragments of arachidonic acid from the sn-2 position of phosphatidylcholine. One of the preferred substrates appeared by mass spectrometry to have 5-oxovalerate at the sn-2 position. We synthesized 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine and found that the PAF acetylhydrolase had the same apparent Km for it (11.3 microM) as for PAF (12.5 microM), with Vmax values of 100 and 167 mumol/h/mg of protein, respectively. We also conclude that the PAF acetylhydrolase is the sole activity in LDL that degrades oxidized phospholipids since we found co-localization of the activity against both substrates to LDL and HDL, and precipitation of enzyme activity with an antibody to the PAF acetylhydrolase. Thus, the PAF acetylhydrolase in human plasma degrades oxidized phospholipids, which may be involved in the modification of apolipoprotein B100 and other pathological processes.

  8. Influence of platelet-activating factor, lyso-platelet-activating factor and edelfosine on Langmuir monolayers imitating plasma membranes of cell lines differing in susceptibility to anti-cancer treatment: the effect of plasmalogen level.

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    Flasiński, Michał; Hąc-Wydro, Katarzyna; Wydro, Paweł; Dynarowicz-Łątka, Patrycja

    2014-06-01

    Three structurally related but differing in biological activities single-chained ether phospholipids (PAF (platelet-activating factor) and lyso-PAF) and an anti-cancer drug (edelfosine (ED)) were investigated in Langmuir monolayers imitating natural membranes. The aim of the undertaken experiments was to study the influence of these lipids on monolayers mimicking plasma membranes of cell lines differing in susceptibility to the anti-cancer activity of ED, i.e. promyelocytic leukaemia cells (HL-60) and promyeloblastic leukaemia cells (K-562). As these cells differ essentially in the cholesterol/phospholipid ratio and plasmalogen concentration in the membrane, we have carried out systematic investigations in artificial systems of various compositions. The results for model leukaemia cell membrane were compared with data acquired for systems imitating normal leucocytes. Our results show that the level of plasmalogens significantly modulates the influence of the single-chained phospholipids on the investigated systems. The experiments confirmed also that the interactions of ether lipids with a model membrane of HL-60 cells (in biological tests sensitive to ED) have opposite character when compared with K-562, being resistant to ED. Moreover, the values of the parameters characterizing monolayers serving as membrane models (strength of interactions, monolayers fluidity and morphology) proved both sensitivity of these cells to ED and lack of their susceptibility towards PAF. Interestingly, it has been found that lyso-PAF, which is usually described as an inactive precursor of PAF, displays a stronger effect on HL-60 model membranes than ED.

  9. Factors Associated with Early Platelet Activation in Obese Children

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    García, Anel Gómez; Núñez, Guillermina García; Sandoval, Martha Eva Viveros; Castellanos, Sergio Gutierrez; Aguilar, Cleto Alvarez

    2014-01-01

    Objective To investigate the factors associated with platelet activation in obese children. Design Cross-sectional study. Setting Department of Pediatrics of Regional Hospital N∘ 1 of Mexican Institute of Social Security in Morelia, Michoacán, Mexico. Participants 79 obese and 64 non-obese children between the ages of 5 and 10 years. Main Outcomes Measures Obese children (body mass index [BMI] >85 in growth curves for Centers for Disease Control/National Center for Health Statistics), and the control group of 64 non-obese children (percentile <85), % body fat, platelet activation was assessed by sP-selectin. Other measures were leptin, uric acid (UA), von Willebrand Factor (vWF), plasminogen activator inhibitor (PAI-1), lipid profile, and glucose. Results Obese children displayed higher plasma sP-selectin, leptin, PAI-1, and vWF than non-obese children. In the univariate logistic regression analysis, leptin, vWF, UA, and high density lipoprotein (HDL), but not with PAI-1, were factors associated with platelet activation. By stepwise linear regression analysis adjusted by sex and age, the best predictor variables for platelet activation were leptin (β:0.381; t:4.665; P=0.0001), vWF (β:0.211; t:2.926; P=0.004), UA (β:0.166; t:2.146; P=0.034), and HDL (β:−0.215; t:−2.819; P=0.006). Conclusions Obese children have a higher risk of developing early platelet activation. Factors associated with platelet activation were Leptin, vWF, UA, and HDL. Further studies involving larger numbers of patients over a longer duration are needed to understand the possible molecular mechanism underlying the association between leptin, vWF, and UA and endothelial activation and/or endothelial damage/dysfunction in obese children and its influence in cardiovascular disease in adults. PMID:24415745

  10. Platelet-rich plasma preparation using three devices : Implications for platelet activation and platelet growth factor release

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    Everts, Peter A. M.; Mahoney, Christine Brown; Hoffmann, Johannes J. M. L.; Schonberger, Jacques P. A. M.; Box, Henk A. M.; Van Zundert, Andre; Knape, Johannes T. A.

    2006-01-01

    Background: In this study, three commercial systems for the preparation of platelet-rich plasma (PRP) were compared and platelet growth factors release was measured. Methods: Ten healthy volunteers donated whole blood that was fractionated by a blood cell separator, and a table-top centrifuge to pre

  11. Higher plasma platelet-activating factor levels are associated with increased risk of vertebral fracture and lower bone mineral density in postmenopausal women.

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    Kim, Hyeonmok; Kim, Beom-Jun; Ahn, Seong Hee; Lee, Seung Hun; Koh, Jung-Min

    2015-11-01

    Despite experimental and animal evidence showing the detrimental effects of platelet-activating factor (PAF) on bone metabolism, there are no clinical studies relating PAF to osteoporosis-related phenotypes. This case-control study investigates the association between plasma PAF, osteoporotic vertebral fracture (VF), and bone mineral density (BMD) in postmenopausal Korean women. Among 474 eligible women not taking any drug or having any disease that could affect bone metabolism, we identified 73 cases defined as subjects with radiological VF. The controls were randomly selected from the remaining 401 subjects and matched 1:1 to cases in terms of both age and body mass index (BMI). Lateral thoracolumbar radiographs, BMD, and plasma PAF levels were determined for all subjects. Postmenopausal women with VF demonstrated 34.6 % higher plasma PAF levels than subjects without VF after adjusting for age, BMI, smoking habits, alcohol intake, regular exercise, and parental history of osteoporotic fractures (P = 0.021). Multiple logistic regression analyses revealed that the odds ratio for VF linearly increased across increasing PAF quartiles (P for trend = 0.040) and the odds for VF were 2.88-fold higher in subjects in the highest quartile in comparison with those in the lowest quartile (95 % CI 1.04-8.01). Plasma PAF levels were inversely correlated with BMD at various sites (γ = -0.253 to -0.176, P = 0.003-0.041). These findings suggest that plasma PAF may be a potential biomarker for predicting poor bone health in postmenopausal women.

  12. Role of platelet activating factor in pathogenesis of acute pancreatitis in rats.

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    Konturek, S J; Dembinski, A; Konturek, P J; Warzecha, Z; Jaworek, J; Gustaw, P; Tomaszewska, R; Stachura, J

    1992-01-01

    The importance of platelet activating factor in acute pancreatitis was examined by determining the tissue content of endogenous platelet activating factor and the protective effects of TCV-309, a highly selective platelet activating factor blocker, against caerulein induced pancreatitis in rats. Infusion of caerulein (10 micrograms/kg/h) for five hours resulted in about 70% increase in pancreatic weight, 22% rise in protein content, 50% reduction in tissue blood flow, nine fold increase in tissue level of platelet activating factor and 165% rise in plasma amylase as well as histological evidence of acute pancreatitis. Such infusion of caerulein in chronic pancreatic fistula rats caused a marked increase in protein output from basal secretion of 10 mg/30 minutes to 40 mg/30 minutes in the first hour of infusion followed by a decline in protein output to 15-20 mg/30 minutes in the following hours of the experiment. Exogenous platelet activating factor (50 micrograms/kg) injected ip produced similar alterations in weight, protein content, blood flow, and histology of the pancreas but the increment in serum amylase was significantly smaller and pancreatic secretion was reduced below the basal level. TCV-309 (50 micrograms/kg) given ip before caerulein or platelet activating factor administration significantly reduced the biochemical and morphological alterations caused by caerulein and abolished those induced by exogenous platelet activating factor. These results indicate that platelet activating factor plays an important role in the pathogenesis of acute pancreatitis probably by reducing the blood flow and increasing vascular permeability in the pancreas. PMID:1385272

  13. Response to platelet-activating factor in human platelets stored and aged in plasma. Decrease in aggregation, phosphoinositide turnover, and receptor affinity

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    Shukla, S.D.; Morrison, W.J.; Klachko, D.M.

    1989-07-01

    Human platelet concentrates were stored in polyolefin bags at 22 to 24 degrees C on a horizontal shaker for up to 8 days. At different intervals, aliquots of platelet-rich plasma (PRP) were removed aseptically and five variables, i.e., platelet counts, morphology, platelet-activating factor (PAF)-stimulated aggregation, phosphoinositide turnover, and (3H)PAF binding to platelet receptors, were studied. The number of platelets did not change during the 8 days of storage. Scanning electron microscopy of the platelets revealed a gradual morphologic change from biconcave flat discs to irregular, crenated forms. The PAF-induced aggregation of platelets declined with time of storage. A decrease to 50 percent of the Day 1 aggregatory response to PAF was evident on Day 2, and there was a further decline to about 20 percent by Day 6. Similarly, PAF receptor-coupled phosphoinositide turnover, as monitored by 32P incorporation into individual phosphoinositides, decreased dramatically with storage. After 2 to 3 days of storage, the phosphoinositide turnover was reduced to 50 percent of the original response, and it continued to decline to about 25 percent of original response by Day 5 or 6. The binding of (3H)PAF to washed human platelets indicated subtle changes between Days 2 and 4, which became more noticeable by Day 6. These results have raised the possibility of changes in the number of the receptors and/or their affinity for the ligand during storage. We conclude that although the number of platelets was maintained during storage for 8 days, a general deterioration of their responses to PAF occurred at the levels of cell surface receptor, transmembrane signaling (phosphoinositide turnover), and response (aggregation).

  14. Platelet activation using electric pulse stimulation: growth factor profile and clinical implications.

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    Torres, Andrew S; Caiafa, Antonio; Garner, Allen L; Klopman, Steve; LaPlante, Nicole; Morton, Christine; Conway, Kenneth; Michelson, Alan D; Frelinger, Andrew L; Neculaes, V Bogdan

    2014-09-01

    Autologous platelet gel therapy using platelet-rich plasma has emerged as a promising alternative for chronic wound healing, hemostasis, and wound infection control. A critical step for this therapeutic approach is platelet activation, typically performed using bovine thrombin (BT) and calcium chloride. However, exposure of humans to BT can stimulate antibody formation, potentially resulting in severe hemorrhagic or thrombotic complications. Electric pulse stimulation using nanosecond PEFs (pulse electric fields) is an alternative, nonbiochemical platelet activation method, thereby avoiding exposure to xenogeneic thrombin and associated risks. In this study, we identified specific requirements for a clinically relevant activator instrument by dynamically measuring current, voltage, and electric impedance for platelet-rich plasma samples. From these samples, we investigated the profile of growth factors released from human platelets with electric pulse stimulation versus BT, specifically platelet-derived growth factor, transforming growth factor β, and epidermal growth factor, using commercial enzyme-linked immunosorbent assay kits. Electric pulse stimulation triggers growth factor release from platelet α-granules at the same or higher level compared with BT. Electric pulse stimulation is a fast, inexpensive, easy-to-use platelet activation method for autologous platelet gel therapy.

  15. Effect of montelukast on platelet activating factor- and tachykinin induced mucus secretion in the rat

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    Groneberg David A

    2008-02-01

    Full Text Available Abstract Background Platelet activating factor and tachykinins (substance P, neurokinin A, neurokinin B are important mediators contributing to increased airway secretion in the context of different types of respiratory diseases including acute and chronic asthma. Leukotriene receptor antagonists are recommended as add-on therapy for this disease. The cys-leukotriene-1 receptor antagonist montelukast has been used in clinical asthma therapy during the last years. Besides its inhibitory action on bronchoconstriction, only little is known about its effects on airway secretions. Therefore, the aim of this study was to evaluate the effects of montelukast on platelet activating factor- and tachykinin induced tracheal secretory activity. Methods The effects of montelukast on platelet activating factor- and tachykinin induced tracheal secretory activity in the rat were assessed by quantification of secreted 35SO4 labelled mucus macromolecules using the modified Ussing chamber technique. Results Platelet activating factor potently stimulated airway secretion, which was completely inhibited by the platelet activating factor receptor antagonist WEB 2086 and montelukast. In contrast, montelukast had no effect on tachykinin induced tracheal secretory activity. Conclusion Cys-leukotriene-1 receptor antagonism by montelukast reverses the secretagogue properties of platelet activating factor to the same degree as the specific platelet activating factor antagonist WEB 2086 but has no influence on treacheal secretion elicited by tachykinins. These results suggest a role of montelukast in the signal transduction pathway of platelet activating factor induced secretory activity of the airways and may further explain the beneficial properties of cys-leukotriene-1 receptor antagonists.

  16. Platelet-Activating Factor Induces Th17 Cell Differentiation

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    Anne-Marie Drolet

    2011-01-01

    Full Text Available Th17 cells have been implicated in a number of inflammatory and autoimmune diseases. The phospholipid mediator platelet-activating factor (PAF is found in increased concentrations in inflammatory lesions and has been shown to induce IL-6 production. We investigated whether PAF could affect the development of Th17 cells. Picomolar concentrations of PAF induced IL-23, IL-6, and IL-1β expression in monocyte-derived Langerhans cells (LCs and in keratinocytes. Moreover, when LC were pretreated with PAF and then cocultured with anti-CD3- and anti-CD28-activated T cells, the latter developed a Th17 phenotype, with a significant increase in the expression of the transcriptional regulator RORγt and enhanced expression of IL-17, IL-21, and IL-22. PAF-induced Th17 development was prevented by the PAF receptor antagonist WEB2086 and by neutralizing antibodies to IL-23 and IL-6R. This may constitute a previously unknown stimulus for the development and persistence of inflammatory processes that could be amenable to pharmacologic intervention.

  17. Platelet-activating factor in cirrhotic liver and hepatocellular carcinoma

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    Muriel Mathonnet; Bernard Descottes; Denis Valleix; Véronique Truffinet; Francois Labrousse; Yves Denizot

    2006-01-01

    AIM: Platelet-activating factor (PAF) is a pro-inflammatory and angiogenic lipid mediator. Here we aimed to investigate levels of PAF, lyso-PAF (the PAF precursor),phospholipase A2 (PLA2, the enzymatic activity generating lyso-PAF), acetylhydrolase activity (AHA, the PAF degrading enzyme) and PAF receptor (PAF-R) transcripts in cirrhotic liver and hepatocellular carcinoma (HCC).METHODS: Twenty-nine patients with HCC were ehrolled in this study. Cirrhosis was present in fourteen patients and seven had no liver disease. Tissue PAF levels were investigated by a platelet-aggregation assay. LysoPAF was assessed after its chemical acetylation into PAF.AHA was determined by degradation of [3H]-PAF. PLA2 levels were assessed by EIA. PAF-R transcripts were investigated using RT-PCR.RESULTS: Elevated amounts of PAF and PAF-R transcripts 1 (leukocyte-type) were found in cirrhotic tissues as compared with non-cirrhotic ones. Higher amounts of PAF and PAF-R transcripts 1 and 2 (tissue-type) were found in HCC tissues as compared with non-tumor tissues. PLA2, lyso-PAF and AHA levels were not changed in cirrhotic tissues and HCC.CONCLUSION: While the role of PAF is currently unknown in liver physiology, this study suggests its potential involvement in the inflammatory network found in the cirrhotic liver and in the angiogenic response during HCC.

  18. Identification of platelet-activating factor acetylhydrolase II in human skin.

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    Marques, Mariangela; Pei, Yong; Southall, Michael D; Johnston, John M; Arai, Hiroyuki; Aoki, Junken; Inoue, Takao; Seltmann, Holger; Zouboulis, Christos C; Travers, Jeffrey B

    2002-10-01

    Platelet-activating factor acetylhydrolases are a family of specialized phospholipase A2 enzymes. They serve an anti-inflammatory function by converting the proinflammatory autocoid, PAF, into biologically inactive lyso-PAF, by the removal of the sn-2 acetyl group of this glycerophospholipid. Similarly, platelet-activating factor acetylhydrolases can also degrade oxidatively modified sn-2 polyunsaturated-fatty-acid-containing phospholipids, which are toxic to cells. Platelet-activating factor acetylhydrolase II is a recently cloned member of this family of specialized phospholipases. Consistent with a potential role of this intracellular enzyme in protecting membrane phospholipids against oxidative stress, platelet-activating factor acetylhydrolase II has been shown to translocate from cytosol to membranes in response to pro-oxidative stressors, and overexpression of this enzyme decreases the cytotoxic effects of these agents. The objective of this study was to assess whether platelet-activating factor acetylhydrolase II is involved in protecting skin against oxidative stress. Platelet-activating factor acetylhydrolase II protein was demonstrated in human skin by immunohistochemistry, with the highest levels of the enzyme found in sebaceous glands and lesser amounts in epidermal keratinocytes. Treatment of epidermal cells with t-butylhydroperoxide or ultraviolet B radiation resulted in platelet-activating factor acetylhydrolase II translocation from cytosol to membranes. To assess the role of this enzyme in epidermal function, a recombinant retroviral strategy was used to overexpress platelet-activating factor acetylhydrolase II in the human keratinocyte-derived cell line HaCaT. Overexpression of platelet-activating factor acetylhydrolase II protected HaCaT cells against apop tosis induced by oxidative stressors t-butylhydroperoxide and ultraviolet B radiation. Similar levels of apoptosis, however, were seen in both control and platelet-activating-factor

  19. Creation of reversed phase high-performance liquid chromatographic technique to assay platelet-activating factor

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    杨云梅; 曹红翠; 徐哲荣; 陈晓明

    2004-01-01

    Objective: To establish a new assay for platelet-activating factor (PAF), to compare it with bio-assay; and to discuss its significance in some elderly people diseases such as cerebral infarction and coronary heart disease. Methods: To measure PAF levels in 100 controls, 23 elderly patients with cerebral infarction and 65 cases with coronary heart disease by reversed phase high-performance liquid chromatographic technique (rHPLC). Results: rHPLC is more convenient, sensitive, specific, and less confusing, compared with bio-assay. The level of plasma PAF in patients with cerebral infarction was higher than that in the controls (P<0.01), and in patients with coronary heart disease. Conclusion: Detection of PAF with rHPLC is more reliable and more accurate. The new assay has important significance in PAF research.

  20. Creation of reversed phase high-performance liquid chromatographic technique to assay platelet-activating factor

    Institute of Scientific and Technical Information of China (English)

    杨云梅; 曹红翠; 徐哲荣; 陈晓明

    2004-01-01

    Objective: To establish a new assay for platelet-activating factor (PAF), to compare it with bio-assay; and to discuss its significance in some elderly people diseases such as cerebral infarction and coronary heart disease. Methods: To measure PAF levels in 100 controls, 23 elderly patients with cerebral infarction and 65 cases with coronary heart disease by reversed phase high-performance liquid chromatographic technique (rHPLC). Results:rHPLC is more convenient, sensitive,specific, and less confusing, compared with bio-assay. The level of plasma PAF in patients with cerebral infarction was higher than that in the controls (P<0.01), and in patients with coronary heart disease. Conclusion: Detection of PAF with rHPLC is more reliable and more accurate. The new assay has important significance in PAF research.

  1. Effect of safflower yellow on platelet activating factor mediated platelet activation in patients with coronary heart disease

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    Damin Huang

    2012-06-01

    Full Text Available The platelet aggregation and 5-HT release by washed platelet from coronary heart disease patients following platelet activating factor (PAF treatment were detected by turbidimetry and O-phthalaldehyde assay. The free calcium concentration in the platelets was measured with the fura-2/AM probe fluorescent technique. Results showed safflower yellow could inhibit the PAF induced washed platelet aggregation and 5-HT release, which were in a safflor-yellow-dose dependent manner. When the PAF was 2.0×10-9 mol/L, the inhibition rate of platelet aggregation was 26.2%, 41.3%, 58.1%, 81.2%, and the inhibition rate of 5-HT release was 3.7%, 11.9%, 29.9% and 54.4% after treatment with safflower yellow at 0.21, 0.42, 0.85 and 1.69 g/L, respectively. The study concludes safflower yellow can inhibit the PAF induced platelet aggregation, 5-HT release by platelets and elevation of free calcium in platelets.

  2. Relationship of plasma levels of LP-PLA2, GMP, LPA and platelet activation markers with transient ischemic attack

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    Hang Li

    2015-01-01

    Objective:To explore the relationship of plasma levels of LP-PLA2, GMP, LPA and platelet activation markers with transient ischemic attack(TIA).Methods:A total of 87 cases with TIA were collected, and all patients were treated with ozagrel (120mg/times/day for 2 weeks). Fasting blood were collected in 24 h after attack and 7d, 14 days after treatment respectively, then flow cytometry was used to detect indicators of platelet activation, such as CD63, PAC-1, GPⅡb /Ⅲa, and the plasma levels of LP-PLA2, GMP, LPA. The dynamic changes of the such indexes and the differences between different populations were analyzed.Results:The plasma levels of LP-PLA2, GMP, LPA and the platelet activation indexes including CD63, PAC-1, GPⅡb/Ⅲa of patients with TIA were all significantly higher than control group (allP<0.05). One day after treatment of sodium Ozagrel, the plasma levels of LP-PLA2, GMP, LPA and the platelet activation indexes such as CD63, PAC-1, GPⅡb/Ⅲa of patients with TIA began to decline, and returned to normal in the treatment of 7 d or 14 d.Conclusions:Platelet activation plays an important role in the occurrence of TIA, and antiplatelet therapy can effectively inhibit platelet activation, which has positive significance in the treatment of TIA.

  3. Platelet-activating factor acetylhydrolase and haemophagocytosis in the sepsis syndrome

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    Franck Trimoreau

    2000-01-01

    Full Text Available Sepsis syndrome (SS is associated with depressed PAF acetylhydrolase, the enzyme responsible for the degradation of platelet activating factor. PAF acetylhydrolase is in a large part produced by macrophages, whose inadequate activation with haemophagocytosis is frequent in patients with SS.

  4. Mechanism of platelet activation induced by endocannabinoids in blood and plasma.

    Science.gov (United States)

    Brantl, S Annette; Khandoga, Anna L; Siess, Wolfgang

    2014-01-01

    Platelets play a central role in atherosclerosis and atherothrombosis, and circulating endocannabinoids might modulate platelet function. Previous studies concerning effects of anandamide (N-arachidonylethanolamide) and 2-arachidonoylglycerol (2-AG) on platelets, mainly performed on isolated cells, provided conflicting results. We therefore investigated the action of three main endocannabinoids [anandamide, 2-AG and virodhamine (arachidonoylethanolamine)] on human platelets in blood and platelet-rich plasma (PRP). 2-AG and virodhamine induced platelet aggregation in blood, and shape change, aggregation and adenosine triphosphate (ATP) secretion in PRP. The EC50 of 2-AG and virodhamine for platelet aggregation in blood was 97 and 160 µM, respectively. Lower concentrations of 2-AG (20 µM) and virodhamine (50 µM) synergistically induced aggregation with other platelet stimuli. Platelet activation induced by 2-AG and virodhamine resembled arachidonic acid (AA)-induced aggregation: shape change, the first platelet response, ATP secretion and aggregation induced by 2-AG and virodhamine were all blocked by acetylsalicylic acid (ASA) or the specific thromboxane A2 (TXA2) antagonist daltroban. In addition, platelet activation induced by 2-AG and virodhamine in blood and PRP were inhibited by JZL184, a selective inhibitor of monoacylglycerol lipase (MAGL). In contrast to 2-AG and virodhamine, anandamide, a substrate of fatty acid amidohydrolase, was inactive. Synthetic cannabinoid receptor subtype 1 (CB1) and 2 (CB2) agonists lacked stimulatory as well as inhibitory platelet activity. We conclude that 2-AG and virodhamine stimulate platelets in blood and PRP by a MAGL-triggered mechanism leading to free AA and its metabolism by platelet cyclooxygenase-1/thromboxane synthase to TXA2. CB1, CB2 or non-CB1/CB2 receptors are not involved. Our results imply that ASA and MAGL inhibitors will protect platelets from activation by high endocannabinoid levels, and that

  5. Effect of platelet activating factor antagonist treatment on gentamicin nephrotoxicity

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    A. Rodriguez-Barbero

    1992-01-01

    Full Text Available To assess whether PAF could be involved in the gentamicin-induced nephrotoxicity, we have studied the effect of PAF antagonist BN-52021 on renal function in rats after gentamicin (GENTA treatment. Experiments were completed in 21 Wistar rats divided into three groups: group GENTA was injected with gentamicin 100 mg kg−1 body wt/day s.c. for 6 days. Group GENTA + BN received gentamicin and BN-52021 i.p. 5 mg kg−1 body wt/day. A third group served as control. Rats were placed in meta-bolic cages and plasma creatinine and creatinine clearance were measured daily. GENTA group showed a progressive increase in plasma creatinine, a drop in creatinine clearance and an increase in urinary excretion of N-acetyl-β-D-glucosaminidase and alkaline phosphatase. GENTA + BN group showed a lesser change in plasma creatinine and a creatinine clearance, but no difference with GENTA group in urinary excretion of NAG and AP were observed. Histological examination revealed a massive cortical tubular necrosis in rats treated with gentamicin, whereas in BN-52021 injected animals tubular damage was markedly attenuated. The present results suggest a role for PAF in the gentamicininduced nephro-toxicity.

  6. Platelet-activating factor in liver injury: A relational scope

    Institute of Scientific and Technical Information of China (English)

    Nikolaos P Karidis; Gregory Kouraklis; Stamatios E Theocharis

    2006-01-01

    The hepatocyte, the main cellular component of the liver, exhibits variable susceptibility to different types of injury induced by endogenous or exogenous factors.Hepatocellular dysfunction or death and regeneration are dependent upon the complicated interactions between numerous biologically active molecules. Plateletactivating factor (PAF) seems to play a pivotal role as the key mediator of liver injury in the clinical and experimental setting, as implied by the beneficial effects of its receptor antagonists. A comprehensive up-todate overview of the specific functional and regulatory properties of PAF in conditions associated with liver injury is attempted in this review.

  7. Thrombin generation by activated factor VII on platelet activated by different agonists. Extending the cell-based model of hemostasis

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    Herrera Maria

    2006-04-01

    Full Text Available Abstract Background Platelet activation is crucial in normal hemostasis. Using a clotting system free of external tissue factor, we investigated whether activated Factor VII in combination with platelet agonists increased thrombin generation (TG in vitro. Methods and results TG was quantified by time parameters: lag time (LT and time to peak (TTP, and by amount of TG: peak of TG (PTG and area under thrombin formation curve after 35 minutes (AUC→35min in plasma from 29 healthy volunteers using the calibrated automated thrombography (CAT technique. TG parameters were measured at basal conditions and after platelet stimulation by sodium arachidonate (AA, ADP, and collagen (Col. In addition, the effects of recombinant activated FVII (rFVIIa alone or combined with the other platelet agonists on TG parameters were investigated. We found that LT and TTP were significantly decreased (p 35min were significantly increased (p 35min (but not PTG when compared to platelet rich plasma activated with agonists in the absence of rFVIIa. Conclusion Platelets activated by AA, ADP, Col or rFVIIa triggered TG. This effect was increased by combining rFVIIa with other agonists. Our intrinsic coagulation system produced a burst in TG independent of external tissue factor activity an apparent hemostatic effect with little thrombotic capacity. Thus we suggest a modification in the cell-based model of hemostasis.

  8. Interactions between platelet activating factor and eicosanoids during endotoxic shock in anaesthetized pigs

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    T. Mózes

    1992-01-01

    Full Text Available The effects of platelet activating factor (PAF on eicosanoid release during endotoxic shock was investigated in anaesthetized pigs receiving 5 μg kg−1 Escherichia coli endotoxin (LPS into the superior mesenteric artery over a 60 min period, by measuring plasma levels of a variety of mediators. Fifteen of the 31 animals infused with LPS and not treated with BN 52021, a PAF receptor antagonist, died within 30 min after the commencement of LPS infusion (non-survivors, while the other 16 survived the experimental period of 3 h, though in a state of shock (survivors. No alterations were observed in plasma concentrations of eicosanoids in the non-survivors. A significant, though transient, increase in eicosanoid concentrations occurred only in the survivors. Treatment with BN 52021 (4 mg kg-1, i.v. injected 5 min prior to LPS infusion, failed to exert any effect on the survival rate. However, pretreatment with BN 52021 prevented circulatory collapse in the survivors and reduced the concentration of cyclooxygenase enzyme products, without affecting LTB4 release. Exogenous administration of PAF (0.01 μg kg−1 caused hypotension and increased TXB2 levels although 6-keto PGF1α and LTB4 concentrations were unchanged. The data suggest that prostanoid formation may be secondary to PAF release in circulatory collapse evoked by LPS infusion in survivors, and give further support to the suggestion that PAF prostanoid interaction is important during endotoxic shock. However, their role in early death seems to be negligible, indicating the importance of other mediators.

  9. Determination of platelet-activating factor by reverse phase high-performance liquid chromatography and its application in viral hepatitis

    Institute of Scientific and Technical Information of China (English)

    Hong-Cui Cao; Xiao-Ming Chen; Wei Xu

    2005-01-01

    AIM: To detect the platelet-activating factor (PAF) and the plasma or serum levels of tumor necrosis factor-α (TNF-α) malondialdehyde (MDA), endotoxin (ET) and to discuss their significance in various types of viral hepatitis.METHODS: PAF, TNF-α, MDA, and ET levels in 60 controls, 16 cases of acute viral hepatitis, 71 cases of chronic viral hepatitis, 19 cases of severe viral hepatitis were detected by reverse phase high-performance liquid chromatography (rHPLC), bio-assay, ELISA, thiobarbituric acid (TBA), and limulus lysate test (LLT), respectively.RESULTS: The rHPLC was more sensitive and specific than bio-assay (r = 0.912, P<0.01). The plasma levels of PAF, TNF-α, MDA, and ET in patients with viral hepatitis were higher than those in controls (P<0.01).CONCLUSION: rHPLC is more reliable and accurate for the detection of PAF.

  10. No evidence for a putative involvement of platelet-activating factor in systemic lupus erythematosus without active nephritis

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    Yves Denizot

    2003-01-01

    Full Text Available Background: Platelet-activating factor (PAF seems to be implicated in systemic lupus erythematosus (SLE patients with associated renal diseases.Aims: In this study, we ensured the role of PAF in SLE patients without renal complications.

  11. The Role of Platelet-Activating Factor in Chronic Inflammation, Immune Activation, and Comorbidities Associated with HIV Infection

    Science.gov (United States)

    Kelesidis, Theodoros; Papakonstantinou, Vasiliki; Detopoulou, Paraskevi; Fragopoulou, Elizabeth; Chini, Maria; Lazanas, Marios C.; Antonopoulou, Smaragdi

    2016-01-01

    With the advent of highly effective antiretroviral therapy, cardiovascular disease has become an important cause of morbidity and mortality among people with treated HIV-1, but the pathogenesis is unclear. Platelet-activating factor is a potent lipid mediator of inflammation that has immunomodulatory effects and a pivotal role in the pathogenesis of inflammatory disorders and cardiovascular disease. Limited scientific evidence suggests that the platelet-activating factor pathway may be a mechanistic link between HIV-1 infection, systemic inflammation, and immune activation that contribute to pathogenesis of chronic HIV-related comorbidities, including cardiovascular disease and HIV-associated neurocognitive disorders. In this review, we examine the mechanisms by which the cross-talk between HIV-1, immune dysregulation, inflammation, and perturbations in the platelet-activating factor pathway may directly affect HIV-1 immunopathogenesis. Understanding the role of platelet-activating factor in HIV-1 infection may pave the way for further studies to explore therapeutic interventions, such as diet, that can modify platelet-activating factor activity and use of platelet-activating factor inhibitors that might improve the prognosis of HIV-1 infected patients. PMID:26616844

  12. Role of platelet-activating factor in reproduction:sperm function

    Institute of Scientific and Technical Information of China (English)

    William E. Roudebush

    2001-01-01

    Since its discovery nearly thirty years ago, platelet-activating factor has emerged as one of the more important lipid mediators known. Platelet-activating factor (PAF; 1- O-alkyl-2- O-acetyl-sn-glycero-3-phosphorylcholine) exists en dogenously as a mixture of molecular species with structural variants of the alkyl moiety. PAF is a novel potent signal ing phospholipid that has unique pleiotropic biological properties in addition to platelet activation. PAF also plays a sig nificant role in reproduction. PAF content in squirrel monkey sperm is significantly higher during the breeding season than the non-breeding season. PAF content in human sperm has a positive correlation with seminal parameters and preg nancy outcomes. High-fertility boars have significantly more PAF in their sperm than low-fertility boars. The enzymes (lyso-PAF-acetyltransferase and PAF-acetylhydrolase) necessary for PAF activation and deactivation are present in sperm. PAF-acetylhydrolase may act as a "decapacitation factor". Removal of this enzyme during capacitation may promote PAF synthesis increasing motility and fertilization. PAF also plays a significant role in the fertilization process,enhancing the fertilization rates of oocytes. Enhanced embryo development has also been reported in oocytes fertilized with PAF-treated sperm. PAF antagonists inhibit sperm motility, acrosome reaction, and fertilization, thus suggesting the presence of receptors for PAF. The PAF-receptor is present on sperm, with altered transcript levels and distribution patterns on abnormal cells. Whereas the exact mechanism of PAF in sperm function and reproduction is uncertain, its importance in normal fertility is substantial. The reproductive significance of PAF activity in sperm and fertility plus the role of PAF in the establishment of pregnancy requires further study.

  13. Platelet-activating factor (PAF) receptor-binding antagonist activity of Malaysian medicinal plants.

    Science.gov (United States)

    Jantan, I; Rafi, I A A; Jalil, J

    2005-01-01

    Forty-nine methanol extracts of 37 species of Malaysian medicinal plants were investigated for their inhibitory effects on platelet-activating factor (PAF) binding to rabbit platelets, using 3H-PAF as a ligand. Among them, the extracts of six Zingiberaceae species (Alpinia galanga Swartz., Boesenbergia pandurata Roxb., Curcuma ochorrhiza Val., C. aeruginosa Roxb., Zingiber officinale Rosc. and Z. zerumbet Koenig.), two Cinnamomum species (C. altissimum Kosterm. and C. pubescens Kochummen.), Goniothalamus malayanus Hook. f. Momordica charantia Linn. and Piper aduncum L. are potential sources of new PAF antagonists, as they showed significant inhibitory effects with IC50 values ranging from 1.2 to 18.4 microg ml(-1).

  14. Therapy for acute pancreatitis with platelet-activating factor receptor antagonists

    Institute of Scientific and Technical Information of China (English)

    Chong Chen; Shi-Hai Xia; Hong Chen; Xiao-Hong Li

    2008-01-01

    Acute pancreatitis (AP) causes release of plateletactivating factor (PAF),which induces systemic effects that contribute to circulatory disturbances and multiple organ failure.PAF is a cell surface secretion of bioactive lipid,which could produce physiological and pathological effects by binding to its cell surface receptor called platelet-activating factor receptor (PAF-R).Studies showed that PAF participates in the occurrence and development of AP and administration of platelet-activating factor receptor antagonists (PAF-RAs) could significantly reduce local and systemic events after AP.PAF has also been implicated as a key mediator in the progression of severe AP,which can lead to complications and unacceptably high mortality rates.Several classes of PAF-RA show PAFRAs significant local and systemic effects on reducing inflammatory changes.As a preventive treatment,PAF-RA could block a series of PAF-mediatedinflammatory injury and thus improve the prognosis of AR This review introduces the important role of PAF-RA in the treatment of AP.

  15. Oligomeric state regulated trafficking of human platelet-activating factor acetylhydrolase type-II.

    Science.gov (United States)

    Monillas, Elizabeth S; Caplan, Jeffrey L; Thévenin, Anastasia F; Bahnson, Brian J

    2015-05-01

    The intracellular enzyme platelet-activating factor acetylhydrolase type-II (PAFAH-II) hydrolyzes platelet-activating factor and oxidatively fragmented phospholipids. PAFAH-II in its resting state is mainly cytoplasmic, and it responds to oxidative stress by becoming increasingly bound to endoplasmic reticulum and Golgi membranes. Numerous studies have indicated that this enzyme is essential for protecting cells from oxidative stress induced apoptosis. However, the regulatory mechanism of the oxidative stress response by PAFAH-II has not been fully resolved. Here, changes to the oligomeric state of human PAFAH-II were investigated as a potential regulatory mechanism toward enzyme trafficking. Native PAGE analysis in vitro and photon counting histogram within live cells showed that PAFAH-II is both monomeric and dimeric. A Gly-2-Ala site-directed mutation of PAFAH-II demonstrated that the N-terminal myristoyl group is required for homodimerization. Additionally, the distribution of oligomeric PAFAH-II is distinct within the cell; homodimers of PAFAH-II were localized to the cytoplasm while monomers were associated to the membranes of the endoplasmic reticulum and Golgi. We propose that the oligomeric state of PAFAH-II drives functional protein trafficking. PAFAH-II localization to the membrane is critical for substrate acquisition and effective oxidative stress protection. It is hypothesized that the balance between monomer and dimer serves as a regulatory mechanism of a PAFAH-II oxidative stress response.

  16. Platelet-activating factor induces phospholipid turnover, calcium flux, arachidonic acid liberation, eicosanoid generation, and oncogene expression in a human B cell line

    Energy Technology Data Exchange (ETDEWEB)

    Schulam, P.G.; Kuruvilla, A.; Putcha, G.; Mangus, L.; Franklin-Johnson, J.; Shearer, W.T. (Baylor College of Medicine, Houston, TX (USA))

    1991-03-01

    Platelet-activating factor is a potent mediator of the inflammatory response. Studies of the actions of platelet-activating factor have centered mainly around neutrophils, monocytes, and platelets. In this report we begin to uncover the influence of platelet-activating factor on B lymphocytes. Employing the EBV-transformed human B cell line SKW6.4, we demonstrate that platelet-activating factor significantly alters membrane phospholipid metabolism indicated by the incorporation of 32P into phosphatidylcholine, phosphatidylinositol, and phosphatidic acid but not significantly into phosphatidylethanolamine at concentrations ranging from 10(-9) to 10(-6) M. The inactive precursor, lyso-platelet-activating factor, at a concentration as high as 10(-7) M had no effect on any of the membrane phospholipids. We also show that platelet-activating factor from 10(-12) to 10(-6) M induced rapid and significant elevation in intracellular calcium levels, whereas lyso-platelet-activating factor was again ineffective. We further demonstrate the impact of platelet-activating factor binding to B cells by measuring platelet-activating factor induced arachidonic acid release and 5-hydroxyeicosatetraenoic acid production. Moreover, platelet-activating factor was capable of inducing transcription of the nuclear proto-oncogenes c-fos and c-jun. Finally we explored the possible role of 5-hydroxyeicosatetraenoic acid as a regulator of arachidonic acid liberation demonstrating that endogenous 5-lipoxygenase activity modulates platelet-activating factor induced arachidonic acid release perhaps acting at the level of phospholipase A2. In summary, platelet-activating factor is shown here to have a direct and profound effect on a pure B cell line.

  17. Effects of platelet-activating factor on the interaction of Trypanosoma cruzi with Rhodnius prolixus.

    Science.gov (United States)

    Zimmermann, Luciana T; Folly, Evelize; Gomes, Marta T; Alviano, Daniela S; Alviano, Celuta S; Silva-Filho, Fernando C; Atella, Geórgia C; Lopes, Angela H

    2011-06-01

    We investigated the effects of platelet-activating factor (PAF) on the interaction of Trypanosoma cruzi with Rhodnius prolixus. The parasites (epimastigotes) were treated with PAF and/or WEB 2086 (PAF antagonist) for 1 h prior to the interaction experiments. PAF stimulated both in vivo and ex vivo interactions between T. cruzi and R. prolixus while WEB 2086 abrogated these effects. PAF-treated epimastigotes also showed an increase in surface negativity and in the amount of surface sialic acid. Neither of these effects was observed when the epimastigotes were treated with neuraminidase following PAF treatment. In the ex vivo interaction experiments, the number of epimastigotes bound to the midguts of the insects was reduced when the epimastigotes had been treated with neuraminidase. We conclude that PAF modulates the interaction of T. cruzi with R. prolixus by altering the amount of sialyl residues at the surface of the parasite.

  18. Impact of prostaglandin glaucoma drops on platelet-activating factor action: an in vitro study

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    Moschos MM

    2016-12-01

    Full Text Available Marilita M Moschos,1 Eirini Nitoda,1 Irini P Chatziralli,1 Georgios D Panos,2 Constantinos A Demopoulos3 11st Department of Ophthalmology, Medical School, National and Kapodistrian University of Athens, Athens, Greece; 2Department of Ophthalmology, Geneva University Hospitals (HUG, University of Geneva, Geneva, Switzerland; 3Laboratory of Biochemistry, National and Kapodistrian University of Athens, Athens, Greece Aim: The aim of this study was to investigate the effect of different prostaglandin analogs on platelet-activating factor (PAF levels.Methods: Three prostaglandin analogs were selected: bimatoprost 0.3 mg/mL, latanoprost 50 µg/mL, and tafluprost 15 µg/mL. Each drug sample was tested for its ability to cause platelet aggregation, which was measured as PAF-induced aggregation, before and after the addition of various concentrations of the examined sample, creating a linear curve of percentage inhibition (ranging from 0% to 100% versus different concentrations of the sample. The concentration of the sample that inhibited 50% PAF-induced aggregation was calculated based on this curve, and this value was defined as IC50. In addition, the effect of eye drops on PAF metabolism was examined, through an in vitro analysis on PAF basic metabolic enzymes (PAF-cholinephosphotransferase, PAF-acetyl-CoA:1-O-alkyl-sn-glycero-3-phosphocholine acetyltransferase, and PAF-acetylhydrolase.Results: The IC50 values for Lumigan UD® (bimatoprost 0.3 mg/mL, Monoprost® (latanoprost 50 µg/mL, and Saflutan (tafluprost 15 µg/mL were 8.7, 0.28, and 1.4 µg/mL, respectively.Discussion: All three prostaglandin analogs suspended PAF, but bimatoprost induced the most potent inhibition, compared to tafluprost and to the weak effect of latanoprost. Keywords: glaucoma, platelet-activating factor, prostaglandin analogs, treatment, platelet aggregation

  19. In vitro effects of vitamin supplements on platelet-activating factor and its metabolism in age-related macular degeneration.

    Science.gov (United States)

    Moschos, Marilita M; Chatziralli, Irini P; Stamatakis, George; Papakonstantinou, Vasiliki D; Demopoulos, Constantinos A

    2014-09-01

    The purpose of our study was to investigate for the first time a series of vitamin supplements used for age-related macular degeneration (AMD) as potential inhibitors of platelet-activating factor (PAF). Various vitamin supplements were tested in washed rabbit platelets (WRPs), in order to investigate the interaction between vitamin supplements (InShape, Nutrof, Ocuvite, Vitalux) and inhibition of PAF-induced platelet aggregation. Additionally, we examined their ability to affect PAF-metabolism, through their in vitro effect on PAF basic metabolic enzymes (PAF-CPT, lyso PAF-AT, and PAF-AH). Nutrof exhibited the strongest anti-PAF activity, while Vitalux was the most potent anti-inflammatory factor. This is the first study to bring in surface potent anti-inflammatory and anti-angiogenic activities of some vitamin supplements used against AMD, through their in vitro anti-PAF effects in WRPs and the rabbit plasma and leukocyte PAF metabolism, suggesting a promising role of vitamin supplements and especially resveratrol, concerning its potent anti-angiogenic activity in AMD.

  20. Hydroxyl-platelet-activating factor exists in blood of healthy volunteers and periodontal patients

    Directory of Open Access Journals (Sweden)

    Smaragdi Antonopoulou

    2003-01-01

    Full Text Available Periodontal diseases are localized chronic inflammatory conditions of the gingival and underlying bone and connective tissue. Platelet-activating factor (PAF, a potent inflammatory phospholipid mediator that has been previously detected in elevated levels in inflamed gingival tissues, in gingival crevicular fluid and in saliva, is implicated in periodontal disease. Our results from previous studies showed that the biologically active phospholipid detected in gingival crevicular fluid is a hydroxyl-PAF analogue. In this study, hydroxyl-PAF analogue was detected for the first time in human blood derived from patients with chronic periodontitis as well as from periodontally healthy volunteers. The hydroxyl-PAF analogue was purified by high-performance liquid chromatography, detected by biological assays and identified by electrospray analysis. In addition, the quantitative determination of PAF and hydroxyl-PAF analogue (expressed as PAF-like activity showed a statistically significant increase in the ratio of hydroxyl-PAF analogue levels to PAF levels in periodontal patients, suggesting that this bioactive lipid may play a role in oral inflammation.

  1. Zinc acexamate reduces gastric damage induced by platelet-activating factor.

    Science.gov (United States)

    Escolar, G; Navarro, C; Galmés, J L; Casanovas, L I; Bulbena, O

    1989-10-01

    We have tested the ability of zinc acexamate (ZAC) to prevent platelet-activating-factor (Paf) induced gastric damage in rats. Lesions were characterized by a vascular congestion affecting the entire mucosa, oedema, haemorrhage and frequent necrosis of the more superficial areas. The gastric damage appearing after Paf was accompanied by degranulation of gastric mast cells. Leukocytes were often seen at the submucosal level. Oral pretreatment with ZAC reduced in a dose-dependent manner both gastric damage and mast cell degranulation observed after Paf. ZAC administered orally at a dose of 100 mg kg-1 statistically inhibited (p less than 0.01) gastric damage and mast cell degranulation. ZAC did not affect the hypotension induced by Paf confirming that gastric damage and hypotension appearing in rats after Paf administration are two independent phenomena. The present findings indicate that the inhibitory effect of ZAC upon gastric lesions induced by Paf may be related to the different protective actions exhibited by this zinc compound in a wide variety of experimental models of gastric ulcer.

  2. Endogenous bacterial toxins are required for the injurious action of platelet-activating factor in rats.

    Science.gov (United States)

    Sun, X M; MacKendrick, W; Tien, J; Huang, W; Caplan, M S; Hsueh, W

    1995-07-01

    Platelet-activating factor (PAF), an endogenous mediator for experimental sepsis, has been shown to induce shock and intestinal necrosis in vivo. However, it is unclear whether PAF exerts its injurious effects on the intestinal tissue directly or via synergism with other endogenous products. The aim of this study was to examine the role of endogenous bacterial products, such as endotoxin, in PAF-induced intestinal injury. PAF (3 micrograms/kg) was injected intravenously into normally colonized rats, germfree rats, and normal rats pretreated with a combination of antibiotics, and the systemic response and intestinal injury were assessed. PAF did not cause prolonged shock, leukopenia, hemoconcentration, and bowel necrosis in germfree rats. When germfree rats were primed with a low dose (0.5 mg/kg) of endotoxin, the protection was lost. Combined treatment of the normally colonized rats with neomycin, polymyxin B, and metronidazole for 7 days largely protected the animal from PAF-induced shock and intestinal necrosis. PAF does not directly induce prolonged hypotension, hemoconcentration, persistent leukopenia, and gross intestinal necrosis but causes these changes via a synergism with endogenous bacterial toxins, presumably from the gut flora.

  3. Role of platelet-activating factor in pathogenesis of acute pancreatitis

    Institute of Scientific and Technical Information of China (English)

    Li-Rong Liu; Shi-Hai Xia

    2006-01-01

    Platelet-activating factor (PAF) is a potent proinflammatory phospholipid mediator that belongs to a family of biologically active, structurally related alkyl phosphoglycerides with diverse pathological and physiological effects. This bioactive phospholipid mediates processes as diverse as wound healing,physiological inflammation, angiogenesis, apoptosis,reproduction and long-term potentiation. PAF acts by binding to a specific G protein-coupled receptor to activate multiple intracellular signaling pathways.Since most cells both synthesize and release PAF and express PAF receptors, PAF has potent biological actions in a broad range of cell types and tissues.Inappropriate activation of this signaling pathway is associated with many diseases in which inflammation is thought to be one of the underlying features. Acute pancreatitis (AP) is a common inflammatory disease.The onset of AP is pancreatic autodigestion mediated by abnormal activation of pancreatic enzyme caused by multiple agents, which subsequently induce pancreatic and systemic inflammatory reactions. A number of experimental pancreatitis and clinical trials indicate that PAF does play a critical role in the pathogenesis of AP. Administration of PAF receptor antagonist can significantly reduce local and systemic events that occur in AP. This review focuses on the aspects that are more relevant to the pathogenesis of AP.

  4. Elevated Platelet Activating Factor Level in Ischemia-Related Arrhythmia and Its Electrophysiological Effect on Myocardium

    Institute of Scientific and Technical Information of China (English)

    TAO Yong Kang; ZHAO Shui Ping; YU Pu Lin; SHI Jing; GU Cheng Dong; SUN Hong Tao; ZHANG Guo Qiang

    2013-01-01

    Objective The mechanism through which platelet activating factor (PAF) induces cardiac electrical activity and arrhythmia is not well understood and previous studies have suggested a potential involvement of ion channels in its action. The present study was aimed to clarify the role of PAF in fatal arrhythmias following acute myocardia infarction (AMI) and the underlying mechanism. Methods (1) Blood PAF levels were measured among 72 AMI patients at the time of diagnosis with AMI and 48 h later, and their electrocardiogram (ECG) was recorded continuously. (2) Ischemia simulation and surface electrocardiogram were conducted in 20 pigs and their PAF levels were measured. (3) PAF perfusion and standard microelectrode recording were performed on guinea pig papillary muscles. Results In both humans and pigs, elevated PAF levels were detected in AMI and simulated ischemia, respectively, and even higher PAF levels were found when fatal arrhythmias occurred. In guinea pig myocardium, PAF induced a shortening of action potential duration at 90% level of repolarization (APD90)under non-ischemic conditions and a more pronounced shortening under early simulated ischemic conditions. Conclusion AMI and ischemia are associated with increased PAF levels in humans and pigs, which are further raised when fatal arrhythmia follows. The effects of PAF on the myocardium may be mediated by multiple ion channels.

  5. Stimulation of Leishmania tropica protein kinase CK2 activities by platelet-activating factor (PAF).

    Science.gov (United States)

    Dutra, Patricia M L; Vieira, Danielle P; Meyer-Fernandes, Jose R; Silva-Neto, Mario A C; Lopes, Angela H

    2009-09-01

    Leishmania tropica is one of the causative agents of cutaneous leishmaniasis. Platelet-activating factor (PAF) is a phospholipid mediator in diverse biological and pathophysiological processes. Here we show that PAF promoted a three-fold increase on ecto-protein kinase and a three-fold increase on the secreted kinase activity of L. tropica live promastigotes. When casein was added to the reaction medium, along with PAF, there was a four-fold increase on the ecto-kinase activity. When live L. tropica promastigotes were pre-incubated for 30 min in the presence of PAF-plus casein, a six-fold increase on the secreted kinase activity was observed. Also, a protein released from L. tropica promastigotes reacted with polyclonal antibodies for the mammalian CK2 alpha catalytic subunit. Furthermore, in vitro mouse macrophage infection by L. tropica was doubled when promastigotes were pre-treated for 2 h with PAF. Similar results were obtained when the interaction was performed in the presence of purified CK2 or casein. TBB and DRB, CK2 inhibitors, reversed PAF enhancement of macrophage infection by L. tropica. WEB 2086, a competitive PAF antagonist, reversed all PAF effects here described. This study shows for the first time that PAF promotes the activation of two isoforms of CK2, secreted and membrane-bound, correlating these activities to infection of mouse macrophages.

  6. Platelet activating factor-induced expression of p21 is correlated with histone acetylation

    Science.gov (United States)

    Damiani, Elisabetta; Puebla-Osorio, Nahum; Lege, Bree M.; Liu, Jingwei; Neelapu, Sattva S.; Ullrich, Stephen E.

    2017-01-01

    Ultraviolet (UV)-irradiated keratinocytes secrete the lipid mediator of inflammation, platelet-activating factor (PAF). PAF plays an essential role in UV-induced immune suppression and skin cancer induction. Dermal mast cell migration from the skin to the draining lymph nodes plays a prominent role in activating systemic immune suppression. UV-induced PAF activates mast cell migration by up-regulating mast cell CXCR4 surface expression. Recent findings indicate that PAF up-regulates CXCR4 expression via histone acetylation. UV-induced PAF also activates cell cycle arrest and disrupts DNA repair, in part by increasing p21 expression. Do epigenetic alterations play a role in p21 up-regulation? Here we show that PAF increases Acetyl-CREB-binding protein (CBP/p300) histone acetyltransferase expression in a time and dose-dependent fashion. Partial deletion of the HAT domain in the CBP gene, blocked these effects. Chromatin immunoprecipitation assays indicated that PAF-treatment activated the acetylation of the p21 promoter. PAF-treatment had no effect on other acetylating enzymes (GCN5L2, PCAF) indicating it is not a global activator of histone acetylation. This study provides further evidence that PAF activates epigenetic mechanisms to affect important cellular processes, and we suggest this bioactive lipid can serve as a link between the environment and the epigenome. PMID:28157211

  7. Levels of gingival tissue platelet activating factor after conventional and regenerative periodontal surgery.

    Science.gov (United States)

    Keles, Gonca Cayir; Cetinkaya, Burcu Ozkan; Ayas, Bulent; Isildak, Ibrahim; Diraman, Emine; Koprulu, Hulya; Acikgoz, Gokhan

    2007-12-01

    The hypothesis, a relationship between gingival tissue platelet activating factor (PAF) levels and healing after periodontal surgery, was tested by measuring PAF levels in gingival tissues collected from sites that had undergone flap surgery and guided tissue regeneration (GTR) or flap surgery alone. Using a split-mouth design, 20 intrabony defects were randomly assigned to treatment with flap surgery and GTR (group 1) or with flap surgery alone (group 2). Gingival tissue samples were obtained at surgery (baseline) and at 6-month follow-up evaluation visit. One half of each sample was used for analysis of PAF levels by high-performance liquid chromatography, and the other half of the sample was used for histomorphometric analysis that included measurements of number and diameter of blood vessels. PAF levels and diameter of blood vessels were significantly decreased (p 0.05). Based on the reported results, it is suggested that a decrease in gingival PAF levels might be found after conventional and regenerative periodontal surgery.

  8. Calidad del plasma rico en plaquetas: estudio de la activación plaquetaria Platelet-rich plasma quality: a study on platelet activation

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    C. Sáez-Torres Barroso

    2007-08-01

    Full Text Available Objetivo. El plasma rico en plaquetas (PRP es utilizado de forma cada vez más frecuente en técnicas quirúrgicas de regeneración tisular. No obstante, el procesamiento de la sangre hasta obtener PRP puede desencadenar la activación prematura de las plaquetas y la pérdida de los factores bioactivos. En este trabajo estudiamos la calidad de los concentrados de plaquetas obtenidos siguiendo la técnica de doble centrifugación en tubo. Método. Se someten 50 ml de sangre a una primera centrifugación a 200g 10 minutos, se recoge el sobrenadante y se centrifuga a 700g 15 minutos. Posteriormente, tras eliminar las 2/3 partes del plasma, se resuspenden las plaquetas y se analiza el grado de enriquecimiento, el estado de activación y la reserva funcional de las plaquetas. Resultados. El enriquecimiento en plaquetas del PRP fue de 364±177% (n=45 respecto de los niveles presentes en sangre total. Mediante el estudio de la expresión de CD62 por citometría de flujo se determinó el porcentaje de plaquetas activadas en las muestras de 8 donantes. Mientras que en la sangre no procesada se detectó un 2,7% de plaquetas activadas, tras la preparación del PRP éste era sólo de 3,6%, aumentando hasta el 16% en el concentrado almacenado toda la noche a 22º C. Tras la estimulación con trombina el porcentaje de plaquetas activadas fue de 96,2%. Conclusión. Este protocolo de preparación de PRP no produce una activación significativa de las plaquetas. La respuesta a la estimulación con trombina de los concentrados indica un buen estado de reserva plaquetaria.Objective. Platelet Rich Plasma (PRP is an autologous preparation currently used in oral and maxillofacial reconstructive surgery. Blood collection and preparation of platelet concentrates may lead to platelet activation and the premature loss of their granular load. In this study, we have analyzed the quality of the PRP obtained from a small volume of whole blood through a double centrifugation

  9. Platelet activation indices and apolipoproteins in hypertensive patients.

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    Catalano, M; Belletti, S; Russo, U; Aronica, A; Carzaniga, G; Seregni, R; Libretti, A

    1988-10-01

    We have studied the platelet activation indices beta-thromboglobulin (beta-TG and platelet factor 4(PF4), triglycerides (TG), total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), very-low-density lipoprotein (VLDL) and apolipoprotein (A1, A2, B, C2, C3, E) profiles of 22 untreated essential hypertensive subjects (WHO stages 1 and 2) and 22 controls, to see if there might be some causal relationship between lipoprotein abnormalities and greater platelet activation. The results showed the patients had both greater platelet activation than the controls, as demonstrated by higher plasma beta-TG levels (P less than 0.01) and lower apolipoprotein A2 levels (P less than 0.05). However there were no significant correlations between the platelet activation indices and the plasma levels of apolipoproteins, lipoproteins or lipids in either group.

  10. Lactobacillus acidophilus alleviates platelet-activating factor-induced inflammatory responses in human intestinal epithelial cells.

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    Alip Borthakur

    Full Text Available Probiotics have been used as alternative prevention and therapy modalities in intestinal inflammatory disorders including inflammatory bowel diseases (IBD and necrotizing enterocolitis (NEC. Pathophysiology of IBD and NEC includes the production of diverse lipid mediators, including platelet-activating factor (PAF that mediate inflammatory responses in the disease. PAF is known to activate NF-κB, however, the mechanisms of PAF-induced inflammation are not fully defined. We have recently described a novel PAF-triggered pathway of NF-κB activation and IL-8 production in intestinal epithelial cells (IECs, requiring the pivotal role of the adaptor protein Bcl10 and its interactions with CARMA3 and MALT1. The current studies examined the potential role of the probiotic Lactobacillus acidophilus in reversing the PAF-induced, Bcl10-dependent NF-κB activation and IL-8 production in IECs. PAF treatment (5 µM×24 h of NCM460 and Caco-2 cells significantly increased nuclear p65 NF-κB levels and IL-8 secretion (2-3-fold, P<0.05, compared to control, which were blocked by pretreatment of the cells for 6 h with L. acidophilus (LA or its culture supernatant (CS, followed by continued treatments with PAF for 24 h. LA-CS also attenuated PAF-induced increase in Bcl10 mRNA and protein levels and Bcl10 promoter activity. LA-CS did not alter PAF-induced interaction of Bcl10 with CARMA3, but attenuated Bcl10 interaction with MALT1 and also PAF-induced ubiquitination of IKKγ. Efficacy of bacteria-free CS of LA in counteracting PAF-induced inflammatory cascade suggests that soluble factor(s in the CS of LA mediate these effects. These results define a novel mechanism by which probiotics counteract PAF-induced inflammation in IECs.

  11. Influence of platelet activating factor on expression of adhesion molecules in experimental pancreatitis

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    Hua Zhao; Ji-Wei Chen; Ya-Kui Zhou; Xue-Feng Zhou; Pei-Yun Li

    2003-01-01

    AIM: To determine whether Platelet activating factor (PAF)has a regulation role in the expression of adhesion moleculesand accumulation of neutrophils in a murine model of acutepancreatitis.METHODS: One hundred twenty-eight Kunming mice weredivided into four groups. Group 1 received 0.1 mi saline s.c.every hour for three hours (sham). Group 2 received cerulein(50 μg/kg dose s.c.) every hour for three hours. Group 3received AP and additional challenge of PAF (50 rg/kg inabsolute ethanol) (AP/PAF). Group 4 received AP, plustherapeutic treatment with GAB (25 mg dose i.p.) immediatelyafter the first challenge of cerulein (AP/GAB). Animals weresacrificed at 12 h after the first challenge of saline or cerulein.Adhesion molecules of pancreas were semi-quantified bySP methods. Standard assays were performed for serumamylase and myeloperoxidase activity (MPO) of pancreas.Histology of pancreas was scored in a blind manner. Watercontent of pancreas was also measured at the same time.RESULTS: Control pancreata showed negligible adhesionmolecule expression and neutrophil accumulation. Therewere evident adhesion molecules expression and neutrophilaccumulation in AP and AP/PAF compared with sham (P<0.05).AP/GAB had a lower level of adhesion molecules, neutrophils,and water content versus AP and AP/PAF (P<0.05). Histologyshowed a trend toward improvement in AP/GAB, but didnot reach statistical significance.CONCLUSION: PAF can induce the expression of adhesionmolecules that mediate neutrophil accumulation. The PAFantagonist reduces the expression of adhesion moleculesand the severity of inflammation when given immediatelyafter the induction of mild AP in mice. These results suggestthat PAF antagonism may be useful in the treatment of mildpancreatitis after its clinical onset.

  12. Oxidatively fragmented phosphatidylcholines activate human neutrophils through the receptor for platelet-activating factor.

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    Smiley, P L; Stremler, K E; Prescott, S M; Zimmerman, G A; McIntyre, T M

    1991-06-15

    Platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) activates neutrophils (polymorphonuclear leukocytes, PMN) through a receptor that specifically recognizes short sn-2 residues. We oxidized synthetic [2-arachidonoyl]phosphatidylcholine to fragment and shorten the sn-2 residue, and then examined the phospholipid products for the ability to stimulate PMN. 1-Palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine was fragmented by ozonolysis to 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine. This phospholipid activated human neutrophils at submicromolar concentrations, and is effects were inhibited by specific PAF receptor antagonists WEB2086, L659,989, and CV3988. 1-Palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine next was fragmented by an uncontrolled free radical-catalyzed reaction: it was treated with soybean lipoxygenase to form its sn-2 15-hydroperoxy derivative (which did not activate neutrophils) and then allowed to oxidize under air. The secondary oxidation resulted in the formation of numerous fragmented phospholipids (Stremler, K. E., Stafforini, D. M., Prescott, S. M., and McIntyre, T. M. (1991) J. Biol. Chem. 266, 11095-11103), some of which activated PMN. Hydrolysis of sn-2 residues with phospholipase A2 destroyed biologic activity, as did hydrolysis with PAF acetylhydrolase. PAF acetylhydrolase is specific for short or intermediate length sn-2 residues and does not hydrolyze the starting material (Stremler, K. E., Stafforini, D. M., Prescott, S. M., and McIntyre, T. M. (1991) J. Biol. Chem. 266, 11095-11103). Neutrophil activation was completely blocked by L659,989, a specific PAF receptor antagonist. We conclude that diacylphosphatidylcholines containing an sn-2 polyunsaturated fatty acyl residue can be oxidatively fragmented to species with sn-2 residues short enough to activate the PAF receptor of neutrophils. This suggests a new mechanism for the appearance of biologically active phospholipids, and shows

  13. Endogenous nitric oxide protects against platelet-activating factor-induced bowel injury in the rat.

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    MacKendrick, W; Caplan, M; Hsueh, W

    1993-08-01

    Platelet-activating factor (PAF) causes bowel necrosis in animal models that is histologically identical to that seen in neonatal necrotizing enterocolitis, but little is known about endogenous mechanisms that might protect against PAF-induced bowel injury. We hypothesized that endogenous nitric oxide might represent such a protective mechanism. Adult male Sprague-Dawley rats were pretreated with 2.5 mg/kg NG-nitro-L-arginine methyl ester (L-NAME), a potent nitric oxide synthase inhibitor, and given injections of 1.5 micrograms/kg PAF 15 min later. Animals treated with normal saline placebo, L-NAME alone, and PAF alone were also studied. Superior mesenteric artery blood flow and blood pressure were continuously recorded. At the end of 2 h or upon death of the animal, hematocrit was measured and intestinal samples were taken for histologic examination and determination of myeloperoxidase activity, a measure of intestinal neutrophil content. Compared with animals given PAF alone, animals pretreated with L-NAME followed by PAF developed significantly worse bowel injury (median injury scores: 2.5 versus 0.5, p = 0.005), hemoconcentration (final hematocrit 65.2 +/- 2.0% versus 53.9 +/- 1.0%, p < 0.001), and intestinal myeloperoxidase activity (12.45 +/- 1.94 U/g versus 6.51 +/- 0.57 U/g, p < 0.01). The last two effects were further accentuated when 10 mg/kg L-NAME was given before PAF. Treatment with sodium nitroprusside, a nitric oxide donor, for 10 min before and after PAF administration reversed the effects of L-NAME. Animals pretreated with phenylephrine rather than L-NAME did not develop worse injury than animals treated with PAF alone despite comparable reductions in superior mesenteric blood flow before PAF treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Cholesterol synthesis inhibitors protect against platelet-activating factor-induced neuronal damage

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    Williams Alun

    2007-01-01

    Full Text Available Abstract Background Platelet-activating factor (PAF is implicated in the neuronal damage that accompanies ischemia, prion disease and Alzheimer's disease (AD. Since some epidemiological studies demonstrate that statins, drugs that reduce cholesterol synthesis, have a beneficial effect on mild AD, we examined the effects of two cholesterol synthesis inhibitors on neuronal responses to PAF. Methods Primary cortical neurons were treated with cholesterol synthesis inhibitors (simvastatin or squalestatin prior to incubation with different neurotoxins. The effects of these drugs on neuronal cholesterol levels and neuronal survival were measured. Immunoblots were used to determine the effects of simvastatin or squalestatin on the distribution of the PAF receptor and an enzyme linked immunoassay was used to quantify the amounts of PAF receptor. Results PAF killed primary neurons in a dose-dependent manner. Pre-treatment with simvastatin or squalestatin reduced neuronal cholesterol and increased the survival of PAF-treated neurons. Neuronal survival was increased 50% by 100 nM simvastatin, or 20 nM squalestatin. The addition of mevalonate restored cholesterol levels, and reversed the protective effect of simvastatin. Simvastatin or squalestatin did not affect the amounts of the PAF receptor but did cause it to disperse from within lipid rafts. Conclusion Treatment of neurons with cholesterol synthesis inhibitors including simvastatin and squalestatin protected neurons against PAF. Treatment caused a percentage of the PAF receptors to disperse from cholesterol-sensitive domains. These results raise the possibility that the effects of statins on neurodegenerative disease are, at least in part, due to desensitisation of neurons to PAF.

  15. Platelet-Activating Factor Antagonists Decrease Follicular Dendritic-Cell Stimulation of Human B Lymphocytes

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    Halickman Isaac

    2005-06-01

    Full Text Available Abstract Both B-lymphoblastoid cell lines and tonsillar B lymphocytes express receptors for platelet-activating factor (PAF. In lymph node germinal centres, B lymphocytes interact with follicular dendritic cells (FDCs, which present antigen-containing immune complexes to B lymphocytes. FDCs have phenotypic features that are similar to those of stromal cells and monocytes and may therefore be a source of lipid mediators. In this study, we evaluated the effects of the PAF antagonist WEB 2170 on the activation of tonsillar B lymphocytes by FDCs. FDCs were isolated from tonsils by Bovine Serum Albumin (BSA gradient centrifugation. After being cultured for 6 to 10 days, they were incubated with freshly isolated B cells in the presence or absence of the specific PAF receptor antagonist WEB 2170. B-lymphocyte proliferation was assessed by [3H]-thymidine incorporation, and immunoglobulin (Ig G and IgM secretion was assessed by enzyme-linked immunosorbent assay (ELISA. WEB 2170 (10-6 to 10-8 M inhibited [3H]-thymidine incorporation by up to 35% ± 3%. Moreover, the secretion of IgG and IgM was inhibited by up to 50% by WEB 2170 concentrations ranging from 10-6 to 10-8 M. There was no evidence of toxicity by trypan blue staining, and the addition of WEB 2170 to B cells in the absence of FDCs did not inhibit the spontaneous production of IgG or IgM. The effect of the PAF antagonist is primarily on B lymphocytes, as reverse transcription polymerase chain reaction detected little PAF receptor messenger ribonucleic acid (mRNA from FDCs. These data suggest that endogenous production of PAF may be important in the interaction of B lymphocytes with FDCs.

  16. Low molecular weight heparin alters porcine neutrophil responses to platelet-activating factor.

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    Kruse-Elliott, K T; Chaban, K; Grossman, J E; Tomasko, S; Kamke, C; Darien, B

    1998-09-01

    Because platelet-activating factor (PAF) is an important mediator of inflammation and heparin has anti-inflammatory effects, we hypothesized that low molecular weight heparin (LMWH) would inhibit PAF-induced activation and chemotaxis in porcine neutrophils. Citrated blood was obtained from pentobarbital-anesthetized pigs, and neutrophils were isolated over a 55%/65% Percoll gradient. The effect of LMWH on basal phorbol myristate acetate (PMA)-induced superoxide (SO) release, as well as its effect on PAF priming for PMA-induced SO release, were investigated. Additionally, the effect of LMWH on PAF-induced chemotaxis of neutrophils across transwell membranes was evaluated. Baseline SO release in response to PMA was .351+/-.046 nmol/10(6) cells/min, and this was decreased to .289+/-.034 nmol/10(6) cells/min by pretreatment with 50 U/mL LMWH. PMA-induced SO production was increased by .240+/-.042 nmol/10(6) cells/min when cells were primed with 10 microM PAF. This priming effect of PAF was reduced significantly by pretreatment of neutrophils with LMWH at 10 and 50 U/mL. Chemotaxis of neutrophils in response to 100 microM PAF was significantly decreased to 70.02+/-6.4% (n = 8) of the control response by pretreatment of cells with 50 U/mL LMWH. We conclude that LMWH has anti-inflammatory effects on porcine neutrophils, which includes attenuation of cell activation and chemotaxis in response to the lipid-derived inflammatory mediator, PAF.

  17. Platelet-activating factor in the enteric nervous system of the guinea pig small intestine.

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    Wang, Guo-Du; Wang, Xi-Yu; Hu, Hong-Zhen; Fang, Xiu-Cai; Liu, Sumei; Gao, Na; Xia, Yun

    2006-11-01

    Platelet-activating factor (PAF) is a proinflammatory mediator that may influence neuronal activity in the enteric nervous system (ENS). Electrophysiology, immunofluorescence, Western blot analysis, and RT-PCR were used to study the action of PAF and the expression of PAF receptor (PAFR) in the ENS. PAFR immunoreactivity (IR) was expressed by 6.9% of the neurons in the myenteric plexus and 14.5% of the neurons in the submucosal plexus in all segments of the guinea pig intestinal tract as determined by double staining with anti-human neuronal protein antibody. PAFR IR was found in 6.1% of the neurons with IR for calbindin, 35.8% of the neurons with IR for neuropeptide Y (NPY), 30.6% of the neurons with IR for choline acetyltransferase (ChAT), and 1.96% of the neurons with IR for vasoactive intestinal peptide (VIP) in the submucosal plexus. PAFR IR was also found in 1.5% of the neurons with IR for calbindin, 51.1% of the neurons with IR for NPY, and 32.9% of the neurons with IR for ChAT in the myenteric plexus. In the submucosal plexus, exposure to PAF (200-600 nM) evoked depolarizing responses (8.2 +/- 3.8 mV) in 12.4% of the neurons with S-type electrophysiological behavior and uniaxonal morphology and in 12.5% of the neurons with AH-type electrophysiological behavior and Dogiel II morphology, whereas in the myenteric preparations, depolarizing responses were elicited by a similar concentration of PAF in 9.5% of the neurons with S-type electrophysiological behavior and uniaxonal morphology and in 12.0% of the neurons with AH-type electrophysiological behavior and Dogiel II morphology. The results suggest that subgroups of secreto- and musculomotor neurons in the submucosal and myenteric plexuses express PAFR. Coexpression of PAFR IR with ChAT IR in the myenteric plexus and ChAT IR and VIP IR in the submucosal plexus suggests that PAF, after release in the inflamed bowel, might act to elevate the excitability of submucosal secretomotor and myenteric musculomotor

  18. Airway epithelial platelet-activating factor receptor expression is markedly upregulated in chronic obstructive pulmonary disease

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    Shukla SD

    2014-08-01

    Full Text Available Shakti Dhar Shukla,1,* Sukhwinder Singh Sohal,1,* Malik Quasir Mahmood,1 David Reid,2 Hans Konrad Muller,1 Eugene Haydn Walters1 1NHMRC Centre for Research Excellence for Chronic Respiratory Disease and Lung Ageing, School of Medicine, University of Tasmania, Hobart, Tasmania, Australia; 2Queensland Institute of Medical Research, Iron Metabolism Laboratory, Brisbane, Queensland, Australia *Shakti Dhar Shukla and Sukhwinder Singh Sohal are joint first authors Background: We recently published that platelet-activating factor receptor (PAFr is upregulated on the epithelium of the proximal airways of current smokers and also in bronchial epithelial cells exposed to cigarette smoke extract. These treated cells also showed upregulation of Streptococcus pneumoniae adhesion. Bacterial wall phosphorylcholine specifically binds to PAFr expressed on airway epithelium, thus facilitating adherence and tissue invasion, which may be relevant to chronic obstructive pulmonary disease (COPD. Moreover, the use of inhaled corticosteroids (ICS in COPD patients is associated with an increased risk of invasive respiratory pneumococcal infections. Objective: In this study, we have investigated whether PAFr expression is especially upregulated in airway epithelium in COPD patients and whether this expression may be modulated by ICS therapy. Methods: We cross-sectionally evaluated PAFr expression in bronchial biopsies from 15 COPD patients who were current smokers (COPD-smokers and 12 COPD-ex-smokers, and we compared these to biopsies from 16 smokers with normal lung function. We assessed immunostaining with anti-PAFr monoclonal antibody. We also used material from a previous double-blinded randomized placebo-controlled 6-month ICS intervention study in COPD patients to explore the effect of ICS on PAFr expression. We employed computer-aided image analysis to quantify the percentage of epithelium stained for PAFr. Results: Markedly enhanced expression of PAFr was found

  19. Mechanisms in bradykinin stimulated arachidonate release and synthesis of prostaglandin and platelet activating factor

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    D. Ricupero

    1992-01-01

    Full Text Available Regulatory mechanisms in bradykinin (BK activated release of arachidonate (ARA and synthesis of prostaglandin (PG and platelet activating factor (PAF were studied in bovine pulmonary artery endothelial cells (BPAEC. A role for GTP binding protein (G-protein in the binding of BK to the cells was determined. Guanosine 5-O- (thiotriphosphate, (GTPτS, lowered the binding affinity for BK and increased the Kd for the binding from 0.45 to 1.99 nM. The Bmax remained unaltered at 2.25 × 10-11 mole. Exposure of the cells to aluminium fluoride also reduced the affinity for BK. Bradykinin-induced release of ARA proved pertussis toxin (PTX sensitive, with a maximum sensitivity at 10 ug/ml PTX. GTPτS at 100 μM increased the release of arachidonate. The effect of GTPτS and BK was additive at suboptimal doses of BK up to 0.5 nM but never exceeded the levels of maximal BK stimulation at 50 nM. PTX also inhibited the release of ARA induced by the calcium ionophore, A23187. Phorbol 12-myristate 13-acetate or more commonly known as tetradecanoyl phorbol acetate (TPA itself had little effect on release by the intact cells. However, at 100 nM it augmented the BK activated release. This was downregulated by overnight exposure to TPA and correlated with down-regulation of protein kinase C (PKC activity. The down-regulation only affected the augmentation of ARA release by TPA but not the original BK activated release. TPA displayed a similar, but more potent amplification of PAF synthesis in response to both BK or the calcium ionophore A23187. These results taken together point to the participation of G-protein in the binding of BK to BPAEC and its activation of ARA release. Possibly two types of G-protein are involved, one associated with the receptor, the other activated by Ca2+ and perhaps associated with phospholipase A2 (PLA2. Our results further suggest that a separate route of activation, probably also PLA2 related, takes place through a PKC catalysed

  20. In vitro anti-inflammatory and anti-coagulant effects of antibiotics towards Platelet Activating Factor and thrombin

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    Demopoulos Constantinos A

    2011-07-01

    Full Text Available Abstract Background Sepsis is characterized as a systemic inflammatory response that results from the inability of the immune system to limit bacterial spread during an ongoing infection. In this condition the significant mediator of inflammation Platelet Activating Factor (PAF and the coagulant factor thrombin are implicated. In animal models, treatment with PAF-antagonists or co-administration of antibiotics with recombinant-PAF-Acetylhydrolase (rPAF-AH have exhibited promising results. In order to examine the putative anti-inflammatory and/or antithrombotic interactions between antibiotic treatment used in sepsis with PAF and/or thrombin, we studied the in vitro effects of these compounds towards PAF or/and thrombin related activities and towards PAF basic metabolic enzymes. Methods We assessed the inhibitory effect of these drugs against PAF or thrombin induced aggregation on washed rabbit platelets (WRPs or rabbit Platelet Reach Plasma (rPRP by evaluating their IC50 values. We also studied their effect on Cholinephosphotransferase of PAF (PAF-CPT/Lyso-PAF-Acetyltransferase (Lyso-PAF-AT of rabbit leukocytes (RLs, as well as on rabbit plasma-PAF-AH, the key enzymes of both de novo/remodelling PAF biosynthesis and PAF degradation, respectively. Results Several antibiotics inhibited PAF-induced platelet aggregation of both WRPs and rPRP in a concentration-depended manner, with clarithromycin, azithromycin and amikacin exhibiting the higher inhibitory effect, while when combined they synergistically inhibited PAF. Higher concentrations of all antibiotics tested were needed in order to inhibit PAF induced aggregation of rPRP, but also to inhibit thrombin induced aggregation of WRPs. Concentrations of these drugs similar to their IC50 values against PAF activity in WRPs, inhibited also in vitro PAF-CPT and Lyso-PAF-AT activities of rabbit leukocytes, while only clarithromycin and azithromycin increased rabbit plasma-PAF-AH activity. Conclusions

  1. Platelet activating factors are associated with depressive symptoms in coronary artery disease patients: a hypothesis-generating study

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    Mazereeuw G

    2015-09-01

    Full Text Available Graham Mazereeuw,1,2,4 Nathan Herrmann,1,5 Hongbin Xu,3,4 Alexandre P Blanchard,3,4 Daniel Figeys,3,4 Paul I Oh,6 Steffany AL Bennett,3,4 Krista L Lanctôt1,2,4–61Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, 2Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada; 3Ottawa Institute of Systems Biology and Neural Regeneration Laboratory, Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON, 4CIHR  Training Program in Neurodegenerative Lipidomics, Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON, 5Department of Psychiatry, University of Toronto, Toronto, ON, Canada; 6UHN Toronto Rehabilitation Institute, Toronto, ON, CanadaIntroduction: Depression is a frequent complication of coronary artery disease (CAD with an unknown etiology. Platelet activating factor (PAF lipids, which are associated with CAD, have recently been linked with novel proposed etiopathological mechanisms for depression such as inflammation, oxidative/nitrosative stress, and vascular endothelial dysfunction.Methods and results: This hypothesis-generating study investigated the relationships between various PAF species and depressive symptoms in 26 CAD patients (age: 60.6±9.2 years, 69% male, mean Hamilton Depression Rating Scale [HAM-D] score: 11.8±5.2, HAM-D range: 3–20. Plasma PAF analyses were performed using high performance liquid chromatography electrospray ionization mass spectrometry in precursor ion scan. Significant associations between depressive symptom severity (HAM-D score and a greater plasma abundance of the PAFs phosphocholine (PC PC(O-12:0/2:0 (r=0.49, P=0.01, PC(O-14:1/2:0 (r=0.43, P=0.03, PC(O-17:3/2:0 (r=0.44, P=0.04, and PC(O-18:3/2:0 (r=0.50, P=0.01 were observed. Associations between those PAFs and HAM-D score persisted after adjusting for age and sex.Conclusion: These

  2. Murine monoclonal antibody to platelet factor 4/heparin complexes as a potential reference standard for platelet activation assays in heparin-induced thrombocytopenia.

    Science.gov (United States)

    Asada, Reiko; Wanaka, Keiko; Walenga, Jeanine; Prechel, Margaret; Miyashita, Kumiko; Escalante, Vicki; Kaneko, Chieko; Hoshino, Nobuhiro; Oosawa, Mitsuru; Matsuo, Miyako

    2013-01-01

    Quality control of the platelet activation assays to diagnose heparin-induced thrombocytopenia (HIT), (14)C-serotonin release assay (SRA) and platelet aggregation test (PAT) has yet to be established due to lack of reference standards and the difficulty of obtaining significant amounts of HIT antibodies from patients with HIT. We prepared a murine monoclonal antibody to human platelet factor 4 (hPF4)/heparin complexes (HIT-MoAb) and investigated the platelet activating action of HIT-MoAb by using SRA and PAT. The HIT-MoAb activated human platelets at low heparin concentration and the platelet activations were inhibited at high heparin concentration in both SRA and PAT. The HIT-MoAb produced a concentration-dependent effect. Moreover, the platelet activation at low heparin concentration was inhibited by anti-FcγRIIa antibody. These results indicated that HIT-MoAb has characteristics similar to human HIT antibodies regarding heparin-dependent platelet activation. Therefore, it is suggested that HIT-MoAb has the potential to be a positive control or reference standard in platelet activation assays.

  3. Platelet-activating factor, tumor necrosis factor, hypoxia and necrotizing enterocolitis.

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    Hsueh, W; Caplan, M S; Sun, X; Tan, X; MacKendrick, W; Gonzalez-Crussi, F

    1994-01-01

    The pathogenesis of necrotizing enterocolitis (NEC) is poorly understood. We have established several animal models of NEC by using a combination of various stimuli and stress, including endotoxin, PAF, TNF, and hypoxia. We discuss the mechanism of their actions and the possible roles of these factors in the pathogenesis of human NEC.

  4. Clinical value of serum amylase, serum trypsinogen-2, IL-10 and platelet activating factor detection in diagnosis of post-ERCP pancreatitis

    Institute of Scientific and Technical Information of China (English)

    Di Wang; Xue-Song Li; Peng-Peng Cai

    2016-01-01

    Objective:To explore the clinical value of serum amylase, serum trypsinogen-2, IL-10 and platelet activating factor detection in the diagnosis of post-ERCP pancreatitis.Methods:A total of 256 patients with ERCP were selected in our hospital of the digestive department of internal medicine from January 2015 to December 2015. According to different symptoms, signs, serum amylase and pancreatic CT examination results after ERCP, the subjects were divided into three groups: control group, hyperlipidemia group and PEP group. Serum trypsinogen-2, IL-10, platelet activating factor were detected.Results:There were statistically significant differences in serum trypsinogen-2, IL-10, platelet activating factor among control group, hyperlipidemia group and PEP group patients with serum amylase (Fgroup = 269.578, 139.492, 145.637, 126.891, allP = 0.000), and the value of PEP group was the highest. There were statistically significant differences in serum trypsinogen-2, IL-10, platelet activating factor at different time point (Ftime = 602.506, 494.375, 462.512, 239.564, allP = 0.000), the serum amylase level in the patients with hyperlipidemia group reached the highest value after 4 h, but the 24 h was lower than the normal level after operation, the serum amylase in PEP group increased rapidly after 4 h, and the 24 h was still increased after operation; The serum trypsinogen-2, IL-10, platelet activating factor were all highest 4 h after the operation in the hyperlipidemia group and PEP group, and the 24 h after the operation were all decreased. In PEP group, serum amylase, serum trypsinogen-2, IL-10, platelet activating factor 4 h after the operation and 24 h after the operation were significantly higher than those before operation (Finteractive = 28.492, 22.614, 16.573, 7.819, allP = 0.000). In PEP group, the serum amylase had positive correlations with serum trypsinogen-2, IL-10, platelet activating factor (r=0.591, 0.662, 0.681, allP<0.05).Conclusions: Serum amylase

  5. Expression of a splice variant of the platelet-activating factor receptor transcript 2 in various human cancer cell lines

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    Ibtissam Youlyouz

    2002-01-01

    Full Text Available Platelet-activating factor receptor (PAF-R transcripts were analysed by reverse transcriptase-polymerase chain reaction in five human cancer cell lines derived from the breast (BT20, SKBR3 and T47D cells, the pancreas (Miapaca cells and the bladder (5637 cells in order to confirm the existence of a splice variant of the PAF-R transcript 2. After cloning and sequencing, we confirmed its existence in all cell lines. It consisted of the PAF-R transcript 2 lengthening with 82 nucleotides from the 3' end of exon 1 of the PAF-R gene. The role of this elongated form of the tissue-type PAF-R transcript in cell physiology remains to be elucidated.

  6. Effect of fluticasone propionate aqueous nasal spray treatment on platelet activating factor and eicosanoid production by nasal mucosa in patients with a house dust mite allergy

    NARCIS (Netherlands)

    I.M. Garrelds (Ingrid); T. De Graaf-In 't Veld (T.); A.P.H. Jansen (A. P H); R. Gerth van Wijk (Roy); F.J. Zijlstra (Freek)

    1994-01-01

    textabstractThe relationship between the release of platelet activating factor (PAF), leukotriene C4/D4/EE (LTC4/D4/E4) and prostaglandin D2 (PGD2) from nasal mucosa in vivo was examined in 24 rhinitis patients allergic to the house dust mite (HDM). During a double blind placebo controlled cross-ove

  7. Class A CpG Oligonucleotide Priming Rescues Mice from Septic Shock via Activation of Platelet-Activating Factor Acetylhydrolase

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    Yoshinari Yamamoto

    2017-08-01

    Full Text Available Sepsis is a life-threatening, overwhelming immune response to infection with high morbidity and mortality. Inflammatory response and blood clotting are caused by sepsis, which induces serious organ damage and death from shock. As a mechanism of pathogenesis, platelet-activating factor (PAF induces excessive inflammatory responses and blood clotting. In this study, we demonstrate that a Class A CpG oligodeoxynucleotide (CpG-A1585 strongly induced PAF acetylhydrolase, which generates lyso-PAF. CpG-A1585 rescued mice from acute lethal shock and decreased fibrin deposition, a hallmark of PAF-induced disseminated intravascular coagulation. Furthermore, CpG-A1585 improved endotoxin shock induced by lipopolysaccharide, which comprises the cell wall of Gram-negative bacteria and inhibits inflammatory responses induced by cytokines such as interleukin-6 and tumor necrosis factor-α. These results suggest that CpG-A1585 is a potential therapeutic target to prevent sepsis-related induction of PAF.

  8. Characterization of the De Novo Biosynthetic Enzyme of Platelet Activating Factor, DDT-Insensitive Cholinephosphotransferase, of Human Mesangial Cells

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    Constantinos Alexandros Demopoulos

    2007-06-01

    Full Text Available Platelet activating factor (PAF, a potent inflammatory mediator, is implicated in several proinflammatory/inflammatory diseases such as glomerulonephritis, glomerulosclerosis, atherosclerosis, cancer, allergy, and diabetes. PAF can be produced by several renal cells under appropriate stimuli and it is thought to be implicated in renal diseases. The aim of this study is the characterization of DTT-insensitive cholinephosphotransferase (PAF-CPT of human mesangial cell (HMC, the main regulatory enzyme of PAF de novo biosynthetic pathway. Microsomal fractions of mesangial cells were isolated and enzymatic activity and kinetic parameters were determined by TLC and in vitro biological test in rabbit washed platelets. The effect of bovine serum albumin (BSA, dithiothreitol (DTT, divalent cations (Mg2+ and Ca2+, EDTA, and various chemicals on the activity of PAF-CPT of HMC was also studied. Moreover, preliminary in vitro tests have been performed with several anti-inflammatory factors such as drugs (simvastatin, IFNa, rupatadine, tinzaparin, and salicylic acid and bioactive compounds of Mediterranean diet (resveratrol and lipids of olive oil, olive pomace, sea bass “Dicentrarchus labrax,” and gilthead sea bream “Sparus aurata”. The results indicated that the above compounds can influence PAF-CPT activity of HMC.

  9. Platelet-activating factor induces TLR4 expression in intestinal epithelial cells: implication for the pathogenesis of necrotizing enterocolitis.

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    Antoine Soliman

    Full Text Available Necrotizing enterocolitis (NEC is a leading cause of morbidity and mortality in neonatal intensive care units, however its pathogenesis is not completely understood. We have previously shown that platelet activating factor (PAF, bacteria and TLR4 are all important factors in the development of NEC. Given that Toll-like receptors (TLRs are expressed at low levels in enterocytes of the mature gastrointestinal tract, but were shown to be aberrantly over-expressed in enterocytes in experimental NEC, we examined the regulation of TLR4 expression and signaling by PAF in intestinal epithelial cells using human and mouse in vitro cell lines, and the ex vivo rat intestinal loop model. In intestinal epithelial cell (IEC lines, PAF stimulation yielded upregulation of both TLR4 mRNA and protein expression and led to increased IL-8 secretion following stimulation with LPS (in an otherwise LPS minimally responsive cell line. PAF stimulation resulted in increased human TLR4 promoter activation in a dose dependent manner. Western blotting and immunohistochemical analysis showed PAF induced STAT3 phosphorylation and nuclear translocation in IEC, and PAF-induced TLR4 expression was inhibited by STAT3 and NFκB Inhibitors. Our findings provide evidence for a mechanism by which PAF augments inflammation in the intestinal epithelium through abnormal TLR4 upregulation, thereby contributing to the intestinal injury of NEC.

  10. The role of endogenous nitric oxide and platelet-activating factor in hypoxia-induced intestinal injury in rats.

    Science.gov (United States)

    Caplan, M S; Hedlund, E; Hill, N; MacKendrick, W

    1994-02-01

    Nitric oxide is an endothelium-derived relaxing factor that promotes capillary integrity, inhibits leukocyte adherence and activation, and scavenges oxygen radicals. Because these effects are important in experimental intestinal injury, we studied the role of NO inhibition on hypoxia-induced bowel necrosis in the rat and investigated the interaction between platelet-activating factor (PAF) and NO in this model. Sprague-Dawley rats were treated with either hypoxia, NO synthase inhibition (NG-methyl-L-arginine [LNMA] or NG-nitro-L-arginine methyl ester [L-NAME]), hypoxia+LNMA, hypoxia+LNMA+NO donors, or hypoxia+LNMA+PAF receptor inhibition. Evaluations included blood pressure, superior mesenteric artery blood flow, arterial blood gases, histological intestinal injury, intestinal myeloperoxidase activity, and intestinal PAF activity. We found that hypoxia alone for 90 minutes (10% O2, partial O2 pressure = 45 mm Hg) or LNMA alone had no detrimental effects. However, hypoxia+LNMA together caused hypotension, metabolic acidosis, intestinal injury, increased intestinal myeloperoxidase activity, and elevated intestinal PAF concentrations that were prevented by exogenous L-arginine. Furthermore, the hypotension and intestinal injury was prevented by PAF receptor blockade. We conclude that endogenous NO protects the intestine from hypoxia-induced inflammation and injury, and the balance between local PAF and NO modulates the outcome of hypoxia-stressed intestine.

  11. Effect of platelet-activating factor antagonists (BN-52021, WEB-2170, and BB-882) on bacterial translocation in acute pancreatitis.

    Science.gov (United States)

    de Souza, L J; Sampietre, S N; Assis, R S; Knowles, C H; Leite, K R; Jancar, S; Monteiro Cunha, J E; Machado, M C

    2001-01-01

    Bacterial translocation is an important source of pancreas infection in acute pancreatitis. The effect of platelet-activating factor (PAF) in the pathogenesis of acute pancreatitis has been proved in various studies. The aim of this study was to determine whether potent PAF antagonists influence bacterial translocation in acute pancreatitis. Acute pancreatitis was induced in 62 Wistar rats by injection of 2.5% sodium taurocholate into the biliopancreatic duct. The rats treated with PAF factor antagonists received intravenous injection of WEB-2170 (10 mg/kg), lexipafant (5 mg/kg), and BN-52021 (5 mg/kg) 30 minutes before induction of acute pancreatitis. Six hours after induction of acute pancreatitis, bacteriologic cultures and histologic scoring of tissues were performed. There was a statistically significant reduction in bacterial translocation to the mesenteric lymph nodes and liver but not to the pancreas of the rats treated with PAF antagonists. No significant increase in the intestinal bacterial population of any group was found. There were no statistical differences between the pancreatic histologic scores of the groups. PAF antagonists reduced bacterial translocation to distant sites other than the pancreas, preventing the bacterial dissemination that occurs in the early phase of acute pancreatitis and may have beneficial effects on the evolution of this disease.

  12. Platelet-activating factor increases reactive oxygen species-mediated microbicidal activity of human macrophages infected with Leishmania (Viannia) braziliensis.

    Science.gov (United States)

    Borges, Arissa Felipe; Morato, Camila Imai; Gomes, Rodrigo Saar; Dorta, Miriam Leandro; de Oliveira, Milton Adriano Pelli; Ribeiro-Dias, Fátima

    2017-09-29

    Platelet-activating factor (PAF) is produced by macrophages during inflammation and infections. We evaluated whether PAF is able to modulate the infection of human macrophages by Leishmania braziliensis, the main Leishmania sp. in Brazil. Monocyte-derived macrophages were incubated with promastigote forms in absence or presence of exogenous PAF. We observed that the treatment of macrophages with low concentrations of PAF prior to infection increased the phagocytosis of L. braziliensis. More importantly, exogenous PAF reduced the parasitism when it was added before, during or after infection. In addition, treatment with a PAF antagonist (PCA 4248) resulted in a significant increase of macrophage infection in a concentration-dependent manner, suggesting that endogenous PAF is important to control L. braziliensis infection. Mechanistically, while exogenous PAF increased production of reactive oxygen species (ROS) treatment with PCA 4248 reduced oxidative burst during L. braziliensis infection. The microbicidal effects of exogenous PAF were abolished when macrophages were treated with apocynin, an NADPH oxidase inhibitor. The data show that PAF promotes the production of ROS induced by L. braziliensis, suggesting that this lipid mediator may be relevant to control L. braziliensis infection in human macrophages. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Activation of platelet-activating factor receptor in SZ95 sebocytes results in inflammatory cytokine and prostaglandin E2 production.

    Science.gov (United States)

    Zhang, Qiwei; Seltmann, Holger; Zouboulis, Christos C; Travers, Jeffrey B

    2006-10-01

    Platelet-activating factor (PAF) is a group of phosphocholines with various biological effects mediated by the PAF receptor (PAF-R). Activation of the epidermal PAF-R induces the expression of inflammatory mediators, including cyclooxygenase-2 (COX-2) and prostaglandin E(2) (PGE(2)). The upregulation of COX-2 expression has been shown to be involved in sebocyte proliferation, sebaceous gland inflammation and carcinogenesis. The present study was designed to investigate whether PAF-R activation could induce the expression of COX-2 and production of PGE(2), as well as secretion of the inflammatory cytokine, interleukin-8 (IL-8), in the immortalized sebaceous gland cell line SZ95. Using calcium mobilization studies, we first confirmed that PAF can signal through PAF-R in SZ95 sebocytes. We then found that the production of IL-8 was induced following treatment with PAF-R agonist, however blocked by a specific PAF-R antagonist. Induction of COX-2 expression and increased PGE(2) production were observed in SZ95 sebocytes after PAF-R activation. Finally, it was demonstrated that the production of PGE(2), induced by PAF-R activation and mediated by COX-2 expression, was blocked following PAF-R antagonism in SZ95 sebocytes. These studies suggest that SZ95 sebocytes express functional PAF-Rs and PAF-Rs are involved in regulating the expression of inflammatory mediators, including COX-2, PGE(2) and IL-8.

  14. The novel role of platelet-activating factor in protecting mice against lipopolysaccharide-induced endotoxic shock.

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    Young-Il Jeong

    Full Text Available BACKGROUND: Platelet-activating factor (PAF has been long believed to be associated with many pathophysiological processes during septic shock. Here we present novel activities for PAF in protecting mice against LPS-mediated endotoxic shock. PRINCIPAL FINDINGS: In vivo PAF treatment immediately after LPS challenge markedly improved the survival rate against mortality from endotoxic shock. Administration of PAF prominently attenuated LPS-induced organ injury, including profound hypotension, excessive polymorphonuclear neutrophil infiltration, and severe multiple organ failure. In addition, PAF treatment protects against LPS-induced lymphocytes apoptosis. These protective effects of PAF was correlated with significantly decreases in the production of the inflammatory mediators such as TNF-alpha, IL-1beta, IL-12, and IFN-gamma, while increasing production of the anti-inflammatory cytokine IL-10 in vivo and in vitro. CONCLUSIONS: Taken together, these results suggest that PAF may protect mice against endotoxic shock via a complex mechanism involving modulation of inflammatory and anti-inflammatory mediators.

  15. Lack of Platelet-Activating Factor Receptor Attenuates Experimental Food Allergy but Not Its Metabolic Alterations regarding Adipokine Levels

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    Nathália Vieira Batista

    2016-01-01

    Full Text Available Platelet-activating factor (PAF is known to be an important mediator of anaphylaxis. However, there is a lack of information in the literature about the role of PAF in food allergy. The aim of this work was to elucidate the participation of PAF during food allergy development and the consequent adipose tissue inflammation along with its alterations. Our data demonstrated that, both before oral challenge and after 7 days receiving ovalbumin (OVA diet, OVA-sensitized mice lacking the PAF receptor (PAFR showed a decreased level of anti-OVA IgE associated with attenuated allergic markers in comparison to wild type (WT mice. Moreover, there was less body weight and adipose tissue loss in PAFR-deficient mice. However, some features of inflamed adipose tissue presented by sensitized PAFR-deficient and WT mice after oral challenge were similar, such as a higher rate of rolling leukocytes in this tissue and lower circulating levels of adipokines (resistin and adiponectin in comparison to nonsensitized mice. Therefore, PAF signaling through PAFR is important for the allergic response to OVA but not for the adipokine alterations caused by this inflammatory process. Our work clarifies some effects of PAF during food allergy along with its role on the metabolic consequences of this inflammatory process.

  16. Involvement of leukotriene B4 receptor 1 signaling in platelet-activating factor-mediated neutrophil degranulation and chemotaxis.

    Science.gov (United States)

    Gaudreault, Eric; Stankova, Jana; Rola-Pleszczynski, Marek

    2005-01-01

    Platelet-activating factor (PAF) is a potent lipid mediator of inflammation that can act on human neutrophils. When neutrophils are stimulated with PAF at concentrations greater than 10 nM, a double peak of intracellular calcium mobilization is observed. The second calcium peak observed in PAF-treated neutrophils has already been suggested to come from the production of endogenous leukotriene B4 (LTB4). Here we demonstrate the involvement of endogenous LTB4 production and subsequent activation of the high affinity LTB4 receptor (BLT1) in this second calcium mobilization peak observed after stimulation with PAF. We also show that the second, but not the first peak, could be desensitized by prior exposure to LTB4. Moreover, when neutrophils were pre-treated with pharmacological inhibitors of LTB4 production or with the specific BLT1 antagonist, U75302, PAF-mediated neutrophil degranulation was inhibited by more than 50%. On the other hand, pre-treating neutrophils with the PAF receptor specific antagonist (WEB2086) did not prevent any LTB4-induced degranulation. Also, when human neutrophils were pre-treated with U75302, PAF-mediated chemotaxis was reduced by more than 60%. These data indicate the involvement of BLT1 signaling in PAF-mediated neutrophil activities.

  17. Search for a platelet-activating factor receptor in the Trypanosoma cruzi proteome: a potential target for Chagas disease chemotherapy

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    Daniel Fábio Kawano

    2011-12-01

    Full Text Available Chagas disease (CD causes the highest burden of parasitic diseases in the Western Hemisphere and is therefore a priority for drug research and development. Platelet-activating factor (PAF causes the CD parasite Trypanosoma cruzi to differentiate, which suggests that the parasite may express PAF receptors. Here, we explored the T. cruzi proteome for PAF receptor-like proteins. From a total of 23,000 protein sequences, we identified 29 hypothetical proteins that are predicted to have seven transmembrane domains (TMDs, which is the main characteristic of the G protein-coupled receptors (GPCRs, including the PAF receptor. The TMDs of these sequences were independently aligned with domains from 25 animal PAF receptors and the sequences were analysed for conserved residues. The conservation score mean values for the TMDs of the hypothetical proteins ranged from 31.7-44.1%, which suggests that if the putative T. cruzi PAF receptor is among the sequences identified, the TMDs are not highly conserved. These results suggest that T. cruzi contains several GPCR-like proteins and that one of these GPCRs may be a PAF receptor. Future studies may further validate the PAF receptor as a target for CD chemotherapy.

  18. Homoerydictyl-7-O-β-D-glycosidc—A Receptor Antagonist of Platelet-activating Factor (PAF)

    Institute of Scientific and Technical Information of China (English)

    GuanZengwei; WangYinye; YangXiuwei; CuiYuxin

    2001-01-01

    Homoeriodictyl-7-O-β-D-glycoside, a flavonoid compound isolated from the Chinese medic inalherb, viscum coloratura inhibited platelet aggregation induced by platelet-activating factor(PAF), but it had no inhibitory activity on adenosine diphosphate-induced platelet aggregation. In the present study, we intended to get an insight into the mechanism of its anti-PAF action. Using [3H]PAF receptor binding assay we found that the compound exhibited inhibitory activity. The inhibitory rate was 18.5%, 28.4%, 58.7%, 78% and 78%, respestively, at concentrations of 10-8, 10-7, 10-6, 10-5 and 10-4 mol.L-1, There was a visible dose-effect relationship as well as a correlation between different concentrations and their inhibitory rates (r=0.985, P<0.05) when the dose was equal to or less than 1×10-5 mol.L-1, and its IC50 was 8.0×10-7 mol.L-1. The inhibitory rate didn't increase with increasing concentration of the compound when it went beyond1×10-5 mol.L-1 indicating competitive inhibition of binding of [3H]PAF to PAF receptor reached saturation.

  19. Lack of Platelet-Activating Factor Receptor Attenuates Experimental Food Allergy but Not Its Metabolic Alterations regarding Adipokine Levels

    Science.gov (United States)

    Batista, Nathália Vieira; Fonseca, Roberta Cristelli; Perez, Denise; Pereira, Rafaela Vaz Sousa; de Lima Alves, Juliana; Pinho, Vanessa; Faria, Ana Maria Caetano; Cara, Denise Carmona

    2016-01-01

    Platelet-activating factor (PAF) is known to be an important mediator of anaphylaxis. However, there is a lack of information in the literature about the role of PAF in food allergy. The aim of this work was to elucidate the participation of PAF during food allergy development and the consequent adipose tissue inflammation along with its alterations. Our data demonstrated that, both before oral challenge and after 7 days receiving ovalbumin (OVA) diet, OVA-sensitized mice lacking the PAF receptor (PAFR) showed a decreased level of anti-OVA IgE associated with attenuated allergic markers in comparison to wild type (WT) mice. Moreover, there was less body weight and adipose tissue loss in PAFR-deficient mice. However, some features of inflamed adipose tissue presented by sensitized PAFR-deficient and WT mice after oral challenge were similar, such as a higher rate of rolling leukocytes in this tissue and lower circulating levels of adipokines (resistin and adiponectin) in comparison to nonsensitized mice. Therefore, PAF signaling through PAFR is important for the allergic response to OVA but not for the adipokine alterations caused by this inflammatory process. Our work clarifies some effects of PAF during food allergy along with its role on the metabolic consequences of this inflammatory process. PMID:27314042

  20. Platelet Activating Factor (PAF) biosynthesis is inhibited by phenolic compounds in U-937 cells under inflammatory conditions.

    Science.gov (United States)

    Vlachogianni, Ioanna C; Fragopoulou, Elizabeth; Stamatakis, George M; Kostakis, Ioannis K; Antonopoulou, Smaragdi

    2015-09-01

    Interleukin 1 beta (IL-1β) induced platelet activating factor (PAF) synthesis in U-937 cells through stimulation of acetyl-CoA:lysoPAF-acetyltransferase (lyso PAF-AT) at 3 h and DTT-independentCDP-choline-1-alkyl-2-acetyl-sn-glycerol cholinophosphotransferase (PAF-CPT) at 0.5 h. The aim of this study was to investigate the effect of tyrosol (T), resveratrol (R) and their acetylated derivatives(AcDs) which exhibit enhanced bioavailability, on PAF synthesis in U-937 after IL-1β stimulation. The specific activity of PAF enzymes and intracellular levels were measured in cell homogenates. T and R concentration capable of inducing 50% inhibition in IL-1β effect on lyso PAF-AT was 48 μΜ ± 11 and 157 μΜ ± 77, for PAF-CPT 246 μΜ ± 61 and 294 μΜ ± 102, respectively. The same order of concentration was also observed on inhibiting PAF levels produced by IL-1β. T was more potent inhibitor than R (pactivity, while in the case of R only two AcDs retain the activity. The observed inhibitory effect by T,R and their AcDs, may partly explain their already reported beneficial role.

  1. Clearance of Apoptotic Cells by Macrophages Induces Regulatory Phenotype and Involves Stimulation of CD36 and Platelet-Activating Factor Receptor

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    Matheus Ferracini

    2013-01-01

    Full Text Available Phagocytosis of apoptotic cells (efferocytosis induces macrophage differentiation towards a regulatory phenotype (IL-10high/IL-12p40low. CD36 is involved in the recognition of apoptotic cells (AC, and we have shown that the platelet-activating factor receptor (PAFR is also involved. Here, we investigated the contribution of PAFR and CD36 to efferocytosis and to the establishment of a regulatory macrophage phenotype. Mice bone marrow-derived macrophages were cocultured with apoptotic thymocytes, and the phagocytic index was determined. Blockage of PAFR with antagonists or CD36 with specific antibodies inhibited the phagocytosis of AC (~70–80%. Using immunoprecipitation and confocal microscopy, we showed that efferocytosis increased the CD36 and PAFR colocalisation in the macrophage plasma membrane; PAFR and CD36 coimmunoprecipitated with flotillin-1, a constitutive lipid raft protein, and disruption of these membrane microdomains by methyl-β-cyclodextrin reduced AC phagocytosis. Efferocytosis induced a pattern of cytokine production, IL-10high/IL-12p40low, that is, characteristic of a regulatory phenotype. LPS potentiated the efferocytosis-induced production of IL-10, and this was prevented by blocking PAFR or CD36. It can be concluded that phagocytosis of apoptotic cells engages CD36 and PAFR, possibly in lipid rafts, and this is required for optimal efferocytosis and the establishment of the macrophage regulatory phenotype.

  2. Physiological Roles of Platelet-activating Factor in Mammalian and Human Reproduction

    Institute of Scientific and Technical Information of China (English)

    Jiu-ming ZHU; Joe B. MASSEY; William E. ROUDEBUSH

    2005-01-01

    This review described origination, biosynthesis and functions of platelet-activat-ing factor (PAF) in the reproductive system of mammals and human beings. The articlemainly focused on biological roles of the phospholipid mediator in sperm fertilizationand embryonic implantation. As an autocrine product of sperm and embryos, PAFmarkedly stimulates sperm motility and fertilization and serves as a capacitationfactor in a ligand-receptor manner. After fertilization, embryo-derived PAF improvesits own development, especially from fertilized ova to blastocyst stage and is thoughtto act as an embryo growth factor in the same manner as on sperm. Its mechanism ofaction was also clarified. At the end, it was presented some advances in its clinicalapplication, followed by discussion of some issues possibly concerning in its currentapplication.

  3. Lipoxin A4 and platelet activating factor are involved in E. coli or LPS-induced lung inflammation in CFTR-deficient mice.

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    Haiya Wu

    Full Text Available CFTR (cystic fibrosis transmembrane conductance regulator is expressed by both neutrophils and platelets. Lack of functional CFTR could lead to severe lung infection and inflammation. Here, we found that mutation of CFTR (F508del or inhibition of CFTR in mice led to more severe thrombocytopenia, alveolar neutrocytosis and bacteriosis, and lower lipoxin A4/MIP-2 (macrophage inhibitory protein-2 or lipoxin A4/neutrophil ratios in the BAL (bronchoalveolar lavage during acute E. coli pneumonia. In vitro, inhibition of CFTR promotes MIP-2 production in LPS-stimulated neutrophils; however, lipoxin A4 could dose-dependently suppress this effect. In LPS-induced acute lung inflammation, blockade of PSGL-1 (P-selectin glycoprotein ligand-1 or P-selectin, antagonism of PAF by WEB2086, or correction of mutated CFTR trafficking by KM11060 could significantly increase plasma lipoxin A4 levels in F508del relevant to wildtype mice. Concurrently, F508del mice had higher plasma platelet activating factor (PAF levels and PAF-AH activity compared to wildtype under LPS challenge. Inhibiting hydrolysis of PAF by a specific PAF-AH (PAF-acetylhydrolase inhibitor, MAFP, could worsen LPS-induced lung inflammation in F508del mice compared to vehicle treated F508del group. Particularly, depletion of platelets in F508del mice could significantly decrease plasma lipoxin A4 and PAF-AH activity and deteriorate LPS-induced lung inflammation compared to control F508del mice. Taken together, lipoxin A4 and PAF are involved in E. coli or LPS-induced lung inflammation in CFTR-deficient mice, suggesting that lipoxin A4 and PAF might be therapeutic targets for ameliorating CFTR-deficiency deteriorated lung inflammation.

  4. Effects of Buyang Huanwu decoction and Astragalus mongholicus on platelet activating factor receptor activity in rabbits in vitro

    Institute of Scientific and Technical Information of China (English)

    Hui Yao; Jiping Zhang; Zhixi Chen; Yongjie Wu; Zhiqiang Li

    2006-01-01

    BACKGROUND:The pharmacological action of traditional Chinese medicine compound is the comprehensive effect of the various ingredients,and the interactions of various ingredients are closely correlated with the final effect.In order to reveal the compatibility mechanism of BHD's prescription in treating and preventing ischemic cerebrovascular disease,we needed explore the effect and relation of ingredients in the prescription.OBJECTIVE:To observe the effect of Buyang Huanwu decoction(BHD)and Astragalus mongholicus on the activity of platelet activating factor receptor(PAFR)in the platelet of rabbits in vitro,and investigate the mechanism of Astragalus mongholicus.DESIGN:A decomposed recipes study.SETTING:Guangzhou University of Traditional Chinese Medicine.MATERIALS:Five New Zealand rabbits,weighing 2-3 kg,both sexes,were used.BHD was composed of Sheng Huang Qi 120 g,Dang Gui Wei 6 g,Chi Shao 4.5 g,Chuan Xiong 3 g,Di Long 3 g,Tao Ren 3 g,Hong Hua 3 g.The prescription for activating blood circulation consisted of Dang Gui Wei 6 g,Chi Shao 4.5 g,Chuan Xiong 3 g,Di Long 3 g,Tao Ren 3 g and Hong Hua 3 g.The prescription for invigorating qi consisted of 120 g Sheng Huang Qi.The prepared herbal pieces were purchased from the traditional Chinese medicine Dispensary of Foshan Second People's Hospital,and appraised by Professor Xu from Science of Chinese Materia Medica College,Guangzhou University of Traditional Chinese Medicine.3H-PAF was supplied by Amersham Co.,Ltd.(specific activity:6.475 TBq/mmol;batch number:200402);PAF standard by Biomol Co.,Ltd.(batch number:P1318V).METHODS:The experiments were carried out in the Laboratory of Nuclear Medicine,Guangzhou University of Traditional Chinese Medicine from September to December 2004.①Injections of BHD,prescriptions for activating blood circulation and invigorating qi were prepared by the decoction and alcohol sedimentation technique.Rabbit common carotid artery blood(40 mL)was drawn via intubation to prepare platelet

  5. Effect of Atorvastatin intensive therapy on the serum inflammatory factors, platelet activity and fibrinolytic activity in patients with acute coronary syndrome

    Institute of Scientific and Technical Information of China (English)

    Xiao-Li Zhu; Yun Zhou; Fang Liu

    2016-01-01

    Objective:To observe the effect of Atorvastatin intensive therapy on the serum inflammatory factors, platelet activity and fibrinolytic activity in patients with acute coronary syndrome (ACS).Methods:A total of 92 patients with ACS were randomly divided into observation group (47 cases) and control group (45 cases). The control group was given Atorvastatin (10 mg/d) based on the conventional therapy, while the observation group was given Atorvastatin at an intensive dose (40 mg/d) based on the conventional therapy. Half a month later, the changes of IL-6, IL-8, hs-CRP, TNF-α, TXB2, GMP-140, PAI-1 and t-PA were observed and compared between the two groups.Results:After treatment, the inflammatory factors (IL-6, IL-8, hs-CRP and TNF-α) and the indicators of platelet activity (TXB2, GMP-140 and PAI-1) were obviously decreased, while the indicator of fibrinolytic activity (t-PA) was apparently increased in the two groups. Besides, the amplitudes of change referring to these indicators in the observation group were bigger than those in the control group after treatment, and the differences were statistically significant.Conclusion: The intensive therapy with the administration of Atorvastatin at a dose of 40 mg/d was better than the conventional therapy (Atorvastatin: 10 mg/d) in aspects of reducing inflammatory factors, inhibiting platelet activity and correcting the high coagulation state of fibrinolytic system.

  6. Effect of Follicular Fluid and Platelet-Activating Factor on Lactate Dehydrogenase C Expression in Human Asthenozoospermic Samples

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    Tahereh Esmaeilpour

    2014-01-01

    Full Text Available Background: Application of follicular fluid (FF and platelet-activating factor (PAF in artificial insemination improves sperm motility. Lactate dehydrogenase C (LDH-C is a key enzyme for sperm motility. In this study, the effects of FF and PAF on the sperm motility index and LDH-C expression were investigated. Moreover, LDH-C expression was compared between asthenozoospermic and normozoospermic samples. Methods: The expression of LDH-C was examined by quantitative real-time polymerase chain reaction (q-RT PCR and western blotting after it was treated with optimized concentrations of FF and PAF in twenty asthenozoospermic samples. Also, LDH-C expression was evaluated in five normozoospermic samples. Results: Samples with 75% FF and 100 nM of PAF had an increase in their percentages of progressive and slowly motile sperms and a decrease in their percentages of non-progressive and non-motile sperms. Moreover, LDH-C mRNA transcripts were not changed following PAF and FF treatment, and LDH-C protein was detected in highly progressive motile specimens treated with FF in the asthenozoospermic samples. Furthermore, LDH-C expression was more detectable in the normal sperms. Conclusion: Our results indicated that PAF had more beneficial effects than FF on sperm motility in the asthenozoospermic samples (P=0.0001, although the LDH-C expressions of the sperms were not changed significantly in both groups. We found no association between LDH-C expression and sperm motility after FF and PAF actions. This finding, however, requires further investigation. The fact that LDH-C protein was detected in the normozoospermic, but not asthenozoospermic, samples could be cited as a reason for the infertility in these patients.

  7. Synthesis of platelet-activating factor and its receptor expression in Kupffer cells in rat carbon tetrachloride-induced cirrhosis

    Institute of Scientific and Technical Information of China (English)

    Yin-Ying Lu; Chun-Ping Wang; Lin Zhou; Yan Chen; Shu-Hui Su; Yong-Yi Feng; Yong-Ping Yang

    2008-01-01

    AIM:To determine the platelet-activating factor (PAF)synthesis and its receptor expression in Kupffer cells in rat carbon tetrachloride-induce dcirrhosis.METHODS:Kupffer cells,isolated from the livers of control and CCl4-induced cirrhotic rats,were placed in serum-free medium overnight.PAF saturation binding,ET-1 saturation and competition binding were assayed.ET-1 induced PAF synthesis,mRNA expression of PAF,preproendothelin-1,endothelin A (ETA) and endothelin B (ETB) receptors were also determined.RESULTS:A two-fold increase of PAF synthesis (1.42±0.14 vs 0.66±0.04 pg/μg DNA) and a 1.48-fold increase of membrane-bound PAF (1.02±0.06 vs 0.69±0.07 Pg/μg DNA) were observed in activated Kupffer cells of cirrhotic rats.The application of ET-1 to Kupffer cells induced PAF synthesis in a concentration-dependent manner in both cirrhotic and normal rats via ETB receptor,but PAF synthesis in the activated Kupffer cells was more effective than that in the normal Kupffer cells.In activated Kupffer cells,PAF receptor expression and PAF binding capacity were markedly enhanced.Activated Kupffer cells raised the [125I]-ET-1 binding capacity,but changed neither the affinity of the receptors,nor the expression of ETA receptor.CONCLUSION:Kupffer cells in the course of CCl4-induced cirrhosis are the main source of increased PAF.ET-1 is involved endogenously in stimulating the PAF synthesis in activated Kupffer cells via ETB receptor by paracrine.ETA receptor did not appear in activated Kupffer cells,which may exacerbate the hepatic and extrahepatic complications of cirrhosis.

  8. Quinidine, but Not Eicosanoid Antagonists or Dexamethasone, Protect the Gut from Platelet Activating Factor-Induced Vasoconstriction, Edema and Paralysis

    Science.gov (United States)

    Lautenschläger, Ingmar; Frerichs, Inéz; Dombrowsky, Heike; Sarau, Jürgen; Goldmann, Torsten; Zitta, Karina; Albrecht, Martin; Weiler, Norbert; Uhlig, Stefan

    2015-01-01

    Intestinal circulatory disturbances, atony, edema and swelling are of great clinical relevance, but the related mechanisms and possible therapeutic options are poorly characterized, in part because of the difficulties to comprehensively analyze these conditions. To overcome these limitations we have developed a model of the isolated perfused rat small intestine where all of these symptoms can be studied simultaneously. Here we used this model to study the role of eicosanoids, steroids and quinidine in platelet-activating factor (PAF)-induced intestinal disorders. A vascular bolus of PAF (0.5 nmol) triggered release of thromboxane and peptidoleukotrienes into the vascular bed (peak concentration 35 nM and 0.8 nM) and reproduced all symptoms of intestinal failure: mesenteric vasoconstriction, translocation of fluid and macromolecules from the vasculature to the lumen and lymphatics, intestinal edema formation, loss of intestinal peristalsis and decreased galactose uptake. All effects of PAF were abolished by the PAF-receptor antagonist ABT491 (2.5 μM). The COX and LOX inhibitors ASA and AA861 (500 μM, 10 μM) did not exhibit barrier-protective effects and the eicosanoid antagonists SQ29548 and MK571 (10 μM, each) only moderately attenuated the loss of vascular fluid, the redistribution to the lumen and the transfer of FITC dextran to the lumen. The steroid dexamethasone (10 μM) showed no barrier-protective properties and failed to prevent edema formation. Quinidine (100 μM) inhibited the increase in arterial pressure, stabilized all the intestinal barriers, and reduced lymph production and the transfer of FITC dextran to the lymph. While quinidine by itself reduced peristalsis, it also obviated paralysis, preserved intestinal functions and prevented edema formation. We conclude that quinidine exerts multiple protective effects against vasoconstriction, edema formation and paralysis in the intestine. The therapeutic use of quinidine for intestinal ailments

  9. Evidence for Lipid Packaging in the Crystal Structure of the GM2-Activator Complex with Platelet Activating Factor

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Christine S.; Mi, Li-Zhi; Rastinejad, Fraydoon (Virginia)

    2010-11-16

    GM2-activator protein (GM2-AP) is a lipid transfer protein that has the ability to stimulate the enzymatic processing of gangliosides as well as T-cell activation through lipid presentation. Our previous X-ray crystallographic studies of GM2-AP have revealed a large lipid binding pocket as the central overall feature of the structure with non-protein electron density within this pocket suggesting bound lipid. To extend these studies, we present here the 2 {angstrom} crystal structure of GM2-AP complexed with platelet activating factor (PAF). PAF is a potent phosphoacylglycerol whose toxic patho-physiological effects can be inhibited by GM2-AP. The structure shows an ordered arrangement of two bound lipids and a fatty acid molecule. One PAF molecule binds in an extended conformation within the hydrophobic channel that has an open and closed conformation, and was seen to contain bound phospholipid in the low pH apo structure. The second molecule is submerged inside the pocket in a U-shaped conformation with its head group near the single polar residue S141. It was refined as lyso-PAF as it lacks electron density for the sn-2 acetate group. The alkyl chains of PAF interact through van der Waals contacts, while the head groups bind in different environments with their phosphocholine moieties in contact with aromatic rings (Y137, F80). The structure has revealed further insights into the lipid binding properties of GM2-AP, suggesting an unexpected unique mode of lipid packaging that may explain the efficiency of GM2-AP in inhibiting the detrimental biological effects of PAF.

  10. Quinidine, but not eicosanoid antagonists or dexamethasone, protect the gut from platelet activating factor-induced vasoconstriction, edema and paralysis.

    Science.gov (United States)

    Lautenschläger, Ingmar; Frerichs, Inéz; Dombrowsky, Heike; Sarau, Jürgen; Goldmann, Torsten; Zitta, Karina; Albrecht, Martin; Weiler, Norbert; Uhlig, Stefan

    2015-01-01

    Intestinal circulatory disturbances, atony, edema and swelling are of great clinical relevance, but the related mechanisms and possible therapeutic options are poorly characterized, in part because of the difficulties to comprehensively analyze these conditions. To overcome these limitations we have developed a model of the isolated perfused rat small intestine where all of these symptoms can be studied simultaneously. Here we used this model to study the role of eicosanoids, steroids and quinidine in platelet-activating factor (PAF)-induced intestinal disorders. A vascular bolus of PAF (0.5 nmol) triggered release of thromboxane and peptidoleukotrienes into the vascular bed (peak concentration 35 nM and 0.8 nM) and reproduced all symptoms of intestinal failure: mesenteric vasoconstriction, translocation of fluid and macromolecules from the vasculature to the lumen and lymphatics, intestinal edema formation, loss of intestinal peristalsis and decreased galactose uptake. All effects of PAF were abolished by the PAF-receptor antagonist ABT491 (2.5 μM). The COX and LOX inhibitors ASA and AA861 (500 μM, 10 μM) did not exhibit barrier-protective effects and the eicosanoid antagonists SQ29548 and MK571 (10 μM, each) only moderately attenuated the loss of vascular fluid, the redistribution to the lumen and the transfer of FITC dextran to the lumen. The steroid dexamethasone (10 μM) showed no barrier-protective properties and failed to prevent edema formation. Quinidine (100 μM) inhibited the increase in arterial pressure, stabilized all the intestinal barriers, and reduced lymph production and the transfer of FITC dextran to the lymph. While quinidine by itself reduced peristalsis, it also obviated paralysis, preserved intestinal functions and prevented edema formation. We conclude that quinidine exerts multiple protective effects against vasoconstriction, edema formation and paralysis in the intestine. The therapeutic use of quinidine for intestinal ailments

  11. Neutrophils accentuate renal cold ischemia-reperfusion injury. Dose-dependent protective effect of a platelet-activating factor receptor antagonist.

    Science.gov (United States)

    Riera, M; Torras, J; Herrero, I; Valles, J; Paubert-Braquet, M; Cruzado, J M; Alsina, J; Grinyo, J M

    1997-02-01

    This study was undertaken to evaluate whether the renal damage induced by cold ischemia-reperfusion was worsened by neutrophils (PMN), and if blockade of platelet-activating factor (PAF) could effectively decrease this injury. After flushing with EuroCollins, 85 kidneys from Sprague-Dawley rats underwent either no cold ischemia or a 4-h cold ischemia, and then were reperfused for 75 min at 37 degrees C and 100 mm Hg in an isolated perfusion circuit. Reperfusion was performed with a Krebs-Henseleit solution containing 4.5% albumin, with and without human PMN (7.5 x 10(5) cells/ml) and with and without addition of a PAF receptor antagonist (BN 52021). Hemodynamic and functional parameters were continuously assessed during reperfusion. At end of the study, PAF production was evaluated. Presence of PMN during reperfusion of nonischemic kidneys produced no alteration of functional parameters or PAF production. After 4-h cold ischemia, the presence of PMN during reperfusion produced a significant worsening of plasma flow rate, glomerular filtration rate and sodium reabsorption in comparison with kidneys reperfused without PMN. Also, higher production of PAF was observed in the kidneys reperfused with PMN than in the kidneys reperfused without PMN. After 4-h cold ischemia, addition of BN 52021 during reperfusion in the presence of PMN significantly increased the plasma flow rate, glomerular filtration rate and sodium reabsorption in comparison with kidneys reperfused without this PAF antagonist. This effect was dose dependent. After 4-h cold ischemia, addition of BN 52021 during reperfusion in the absence of PMN produced no significant effect on functional parameters in comparison with kidneys reperfused without this PAF antagonist. These results indicate that PMN contribute to renal cold ischemia-reperfusion injury evaluated in the isolated perfused kidney. Treatment with a PAF receptor antagonist attenuated this injury in a dose-dependent manner, which suggests that it

  12. Effect of exercise on platelet activation during aspirin or clopidogrel intake in healthy men

    DEFF Research Database (Denmark)

    Hjorth Madsen, Esben; Christiansen, Morten Krogh; Schmidt, Erik Berg;

    2009-01-01

    aggregometry. A significant increase in plasma von Willebrand Factor was also found in response to exercise. In conclusion, platelet activation occurs during exercise in healthy individuals. This activation is not prevented by use of aspirin or clopidogrel, and may partly be explained by an increase in plasma...

  13. Platelet-activating factor receptor (PAF-R-dependent pathways control tumour growth and tumour response to chemotherapy

    Directory of Open Access Journals (Sweden)

    Rohde Ciro BS

    2010-05-01

    Full Text Available Abstract Background Phagocytosis of apoptotic cells by macrophages induces a suppressor phenotype. Previous data from our group suggested that this occurs via Platelet-activating factor receptor (PAF-R-mediated pathways. In the present study, we investigated the impact of apoptotic cell inoculation or induction by a chemotherapeutic agent (dacarbazine, DTIC on tumour growth, microenvironmental parameters and survival, and the effect of treatment with a PAF-R antagonist (WEB2170. These studies were performed in murine tumours: Ehrlich Ascitis Tumour (EAT and B16F10 melanoma. Methods Tumour growth was assessed by direct counting of EAT cells in the ascitis or by measuring the volume of the solid tumour. Parameters of the tumour microenvironment, such as the frequency of cells expressing cyclo-oxygenase-2 (COX-2, caspase-3 and galectin-3, and microvascular density, were determined by immunohistochemistry. Levels of vascular endothelium growth factor (VEGF and prostaglandin E2 (PGE2 were determined by ELISA, and levels of nitric oxide (NO by Griess reaction. PAF-R expression was analysed by immunohistochemistry and flow cytometry. Results Inoculation of apoptotic cells before EAT implantation stimulated tumour growth. This effect was reversed by in vivo pre-treatment with WEB2170. This treatment also reduced tumour growth and modified the microenvironment by reducing PGE2, VEGF and NO production. In B16F10 melanoma, WEB2170 alone or in association with DTIC significantly reduced tumour volume. Survival of the tumour-bearing mice was not affected by WEB2170 treatment but was significantly improved by the combination of DTIC with WEB2170. Tumour microenvironment elements were among the targets of the combination therapy since the relative frequency of COX-2 and galectin-3 positive cells and the microvascular density within the tumour mass were significantly reduced by treatment with WEB2170 or DTIC alone or in combination. Antibodies to PAF-R stained

  14. Evidence of platelet activation in multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Alexander J Steven

    2008-06-01

    Full Text Available Abstract Objective A fatality in one multiple sclerosis (MS patient due to acute idiopathic thrombocytopenic purpura (ITP and a near fatality in another stimulated our interest in platelet function abnormalities in MS. Previously, we presented evidence of platelet activation in a small cohort of treatment-naive MS patients. Methods In this report, 92 normal controls and 33 stable, untreated MS patients were studied. Platelet counts, measures of platelet activation [plasma platelet microparticles (PMP, P-selectin expression (CD62p, circulating platelet microaggragtes (PAg], as well as platelet-associated IgG/IgM, were carried out. In addition, plasma protein S activity was measured. Results Compared to controls, PMP were significantly elevated in MS (p Conclusion Platelets are significantly activated in MS patients. The mechanisms underlying this activation and its significance to MS are unknown. Additional study of platelet activation and function in MS patients is warranted.

  15. Antiplatelet activity of L-sulforaphane by regulation of platelet activation factors, glycoprotein IIb/IIIa and thromboxane A2.

    Science.gov (United States)

    Oh, Chung-Hun; Shin, Jang-In; Mo, Sang Joon; Yun, Sung-Jo; Kim, Sung-Hoon; Rhee, Yun-Hee

    2013-07-01

    L-sulforaphane was identified as an anticarcinogen that could produce quinine reductase and a phase II detoxification enzyme. In recent decades, multi-effects of L-sulforaphane may have been investigated, but, to the authors' knowledge, the antiplatelet activation of L-sulforaphane has not been studied yet.In this study, 2 μg/ml of collagen, 50 μg/ml of ADP and 5 μg/ml of thrombin were used for platelet aggregations with or without L-sulforaphane. L-sulforaphane inhibited the platelet aggregation dose-dependently. Among these platelet activators, collagen was most inhibited by L-sulforaphane, which markedly decreased collagen-induced glycoprotein IIb/IIIa activation and thromboxane A2 (TxA2) formation in vitro. L-sulforaphane also reduced the collagen and epinephrine-induced pulmonary embolism, but did not affect prothrombin time (PT) in vivo. This finding demonstrated that L-sulforaphane inhibited the platelet activation through an intrinsic pathway.L-sulforaphane had a beneficial effect on various pathophysiological pathways of the collagen-induced platelet aggregation and thrombus formation as a selective inhibition of cyclooxygenase and glycoprotein IIb/IIIa antagonist. Thus, we recommend L-sulforaphane as a potential antithrombotic drug.

  16. Vascular endothelial (VEGF) and epithelial growth factor (EGF) as well as platelet-activating factor (PAF) and receptors are expressed in the early pregnant canine uterus.

    Science.gov (United States)

    Schäfer-Somi, S; Sabitzer, S; Klein, D; Reinbacher, E; Kanca, H; Beceriklisoy, H B; Aksoy, O A; Kucukaslan, I; Macun, H C; Aslan, S

    2013-02-01

    The aim of this study was to investigate the course of expression of platelet-activating factor (PAF), PAF-receptor (PAF-R), epidermal growth factor (EGF), EGF-R, vascular endothelial growth factor (VEGF), VEGF-R1 and VEGF-R2 in uterine tissue during canine pregnancy. For this purpose, 20 bitches were ovariohysterectomized at days 10-12 (n = 10), 18-25 (n = 5) and 28-45 (n = 5) days after mating, respectively. The pre-implantation group was proven pregnant by embryo flushing of the uterus after the operation, the others by sonography. Five embryo negative, that is, non-pregnant, bitches in diestrus (day 10-12) served as controls. Tissue samples from the uterus (placentation sites and horn width, respectively) were excised and snap-frozen in liquid nitrogen after embedding in Tissue Tec(®). Extraction of mRNA for RT-PCR was performed with Tri-Reagent. In the embryos, mRNA from all factors except VEGF was detected. In the course of pregnancy, significantly higher expression of PAF and PAFR as well as VEGF and VEGFR2 during the pre-implantation stage than in all other stages and a strong upregulation of EGF during implantation were characteristic. The course of EGF was in diametrical opposition to the course of the receptor. These results point towards an increased demand for VEGF, EGF and PAF during the earliest stages of canine pregnancy.

  17. Crosstalk between Protease-activated Receptor 1 and Platelet-activating Factor Receptor Regulates Melanoma Cell Adhesion Molecule (MCAM/MUC18) Expression and Melanoma Metastasis*

    Science.gov (United States)

    Melnikova, Vladislava O.; Balasubramanian, Krishnakumar; Villares, Gabriel J.; Dobroff, Andrey S.; Zigler, Maya; Wang, Hua; Petersson, Frederik; Price, Janet E.; Schroit, Alan; Prieto, Victor G.; Hung, Mien-Chie; Bar-Eli, Menashe

    2009-01-01

    The cellular and molecular pathways that regulate platelet activation, blood coagulation, and inflammation are emerging as critical players in cancer progression and metastasis. Here, we demonstrate a novel signaling mechanism whereby protease-activated receptor 1 (PAR1) mediates expression of melanoma cell adhesion molecule MCAM/MUC18 (MUC18), a critical marker of melanoma metastasis, via activation of platelet-activating factor receptor (PAFR) and cAMP-responsive element-binding protein (CREB). We found that PAR1 silencing with small hairpin RNA inhibits MUC18 expression in metastatic melanoma cells by inhibiting CREB phosphorylation, activity, and binding to the MUC18 promoter. We further demonstrate that the PAF/PAFR pathway mediates MUC18 expression downstream of PAR1. Indeed, PAR1 silencing down-regulates PAFR expression and PAF production, PAFR silencing blocks MUC18 expression, and re-expression of PAFR in PAR1-silenced cells rescues MUC18 expression. We further demonstrate that the PAR1-PAFR-MUC18 pathway mediates melanoma cell adhesion to microvascular endothelial cells, transendothelial migration, and metastatic retention in the lungs. Rescuing PAFR expression in PAR1-silenced cells fully restores metastatic phenotype of melanoma, indicating that PAFR plays critical role in the molecular mechanism of PAR1 action. Our results link the two pro-inflammatory G-protein-coupled receptors, PAR1 and PAFR, with the metastatic dissemination of melanoma and suggest that PAR1, PAFR, and MUC18 are attractive therapeutic targets for preventing melanoma metastasis. PMID:19703903

  18. Platelet-Activating Factor (PAF Antagonistic Activity of a New Biflavonoid from Garcinia nervosa var. pubescens King

    Directory of Open Access Journals (Sweden)

    Azura Abdul Ghani

    2012-09-01

    Full Text Available The methanol extract of the leaves of Garcinia nervosa var. pubescens King, which showed strong inhibitory effects on platelet-activating factor (PAF receptor binding, was subjected to bioassay-guided isolation to obtain a new biflavonoid, II-3,I-5, II-5,II-7,I-4',II-4'-hexahydroxy-(I-3,II-8-flavonylflavanonol together with two known flavonoids, 6-methyl-4'-methoxyflavone and acacetin. The structures of the compounds were elucidated by spectroscopic methods. The compounds were evaluated for their ability to inhibit PAF receptor binding to rabbit platelets using 3H-PAF as a ligand. The biflavonoid and acacetin showed strong inhibition with IC50 values of 28.0 and 20.4 µM, respectively. The results suggest that these compounds could be responsible for the strong PAF antagonistic activity of the plant.

  19. Inhibition of platelet-activating factor- and zymosan-activated serum-induced chemotaxis of human neutrophils by nedocromil sodium, BN 52021 and sodium cromoglycate.

    Science.gov (United States)

    Bruijnzeel, P. L.; Warringa, R. A.; Kok, P. T.

    1989-01-01

    1. Inflammatory cells such as eosinophils and neutrophils are thought to contribute actively to the pathogenesis of asthma since they infiltrate into the lung tissue. These cells are mobilized by lipid-like and protein-like chemotactic factors. As illustrative examples of both groups, platelet-activating-factor (Paf) and zymosan-activated-serum (ZAS) were used in this study. The inhibitory effects of nedocromil sodium, the Paf antagonist BN 52021 and sodium cromoglycate on Paf- and ZAS-induced neutrophil chemotaxis were evaluated. 2. All tested drugs inhibited Paf-induced neutrophil chemotaxis with approximately the same potency (IC50 approximately 1 nM). 3. Nedocromil sodium and sodium cromoglycate were equally potent in inhibiting ZAS-induced neutrophil chemotaxis (IC50 = 0.1-1 microM), whereas BN 52021 was considerably less potent (IC30 = 10 microM). 4. To find out whether the drugs tested could inhibit early events in cell activation, their capacity to inhibit Paf- and ZAS-induced cytosolic free Ca2+-mobilization was investigated. BN 52021, at a concentration of 100 microM, completely inhibited Paf-induced Ca2+-mobilization and inhibited ZAS-induced Ca2+-mobilization by about 50%. Nedocromil sodium and sodium cromoglycate were ineffective. PMID:2551444

  20. BN 52021 (a platelet activating factor-receptor antagonist decreases alveolar macrophage-mediated lung injury in experimental extrinsic allergic alveolitis

    Directory of Open Access Journals (Sweden)

    J-L. Pérez-Arellano

    1998-01-01

    Full Text Available Several lines of research indirectly suggest that platelet activating factor (PAF may intervene in the pathogenesis of extrinsic allergic alveolitis (EAA. The specific aim of our study was to evaluate the participation of PAF on macrophage activation during the acute phase of EAA in an experimental model of this disease developed in guinea pigs. Initially we measured the concentration of PAF in bronchoalvedar lavage fluid, blood and lung tissue. In a second phase we evaluate the participation of PAF on alveolar macrophage activation and parenchymal lung injury. The effect of PAF on parenchymal lung injury was evaluated by m easuring several lung parenchymatous lesion indices (lung index, bronchoalvedar lavage fluid (BALF lactic hydrogenase activity and BALF alkaline phosphatase activity and parameters of systemic response to the challenge (acute phase reagents. We observed that induction of the experimental EAA gave rise to an increase in the concentration of PAF in blood and in lung tissue. The use of the PAF-receptor antagonist BN52021 decreases the release of lysosomal enzymes (β-glucuronidase and tartrate-sensitive acid phosphatase to the extracellular environment both in vivo and in vitro. Furthermore, antagonism of the PAF receptors notably decreases pulmonary parenchymatous lesion. These data suggest that lung lesions from acute EAA are partly mediated by local production of PAF.

  1. Polyunsaturated fatty acids block platelet-activating factor-induced phosphatidylinositol 3 kinase/Akt-mediated apoptosis in intestinal epithelial cells.

    Science.gov (United States)

    Lu, Jing; Caplan, Michael S; Li, Dan; Jilling, Tamas

    2008-05-01

    We have shown earlier that platelet-activating factor (PAF) causes apoptosis in enterocytes via a mechanism that involves Bax translocation to mitochondria, followed by caspase activation and DNA fragmentation. Herein we report that, in rat small intestinal epithelial cells (IEC-6), these downstream apoptotic effects are mediated by a PAF-induced inhibition of the phosphatidylinositol 3-kinase (PI 3-kinase)/protein kinase B (Akt) signaling pathway. Treatment with PAF results in rapid dephosphorylation of Akt, phosphoinositide-dependent kinase-1, and the YXXM p85 binding motif of several proteins and redistribution of Akt-pleckstrin homology domain-green fluorescent protein, i.e., an in vivo phosphatidylinositol (3,4,5)-trisphosphate sensor, from membrane to cytosol. The proapoptotic effects of PAF were inhibited by both n-3 and n-6 polyunsaturated fatty acids but not by a saturated fatty acid palmitate. Indomethacin, an inhibitor of prostaglandin biosynthesis, did not influence the baseline or PAF-induced apoptosis, but 2-bromopalmitate, an inhibitor of protein palmitoylation, inhibited all of the proapoptotic effects of PAF. Our data strongly suggest that an inhibition of the PI 3-kinase/Akt signaling pathway is the main mechanism of PAF-induced apoptosis in enterocytes and that polyunsaturated fatty acids block this mechanism very early in the signaling cascade independently of any effect on prostaglandin synthesis, and probably directly via an effect on protein palmitoylation.

  2. Effects of nitric oxide (NO) on platelet-activating factor (PAF)- and. alpha. -adrenergic-stimulated vasoconstriction and glycogenolysis in the perfused rat liver

    Energy Technology Data Exchange (ETDEWEB)

    Moy, J.A.; Bates, J.N.; Fisher, R.A. (Univ. of Iowa, Iowa City (United States))

    1991-03-11

    Effects of NO on hemodynamic and glycogenolytic responses to platelet-activating factor (PAF) and phenylephrine were investigated in perfused livers derived from fed rats. Infusion of NO into perfused livers inhibited PAF-induced increases in hepatic glucose output and portal pressure approximately 90% and 85%, respectively, and abolished effects of PAF on hepatic oxygen consumption. NO attenuated PAF-stimulated increases in glucose output and portal pressure, the latter indicative of hepatic vasoconstriction, with a similar dose-dependence with an IC{sub 50} of approximately 8 {mu}M. In contrast to its effects on PAF-induced responses in the perfused liver, NO inhibited increases in hepatic portal pressure in response to phenylephrine approximately 75% without altering phenylephrine-stimulated glucose output and oxygen consumption. Similarly, infusion of NO into perfused livers inhibited significantly increases in hepatic portal pressure but not increases in glucose output in response to a submaximal concentration of phenylephrine. Like NO, sodium nitroprusside significantly inhibited hemodynamic but not glycogenolytic responses to phenylephrine in perfused livers. However, PAF-stimulated alterations in hepatic portal pressure, glucose output and oxygen consumption were unaffected by infusion of sodium nitroprusside into perfused livers. These results provide the first evidence for regulatory effects of NO in the perfused liver and support the contention that PAF, unlike phenylephrine, stimulates glycogenolysis by mechanisms secondary to hepatic vasoconstriction. These observations raise the intriguing possibility that NO may act in liver to regulate hemodynamic responses to vasoactive mediators.

  3. Pharmacological inhibition of eicosanoids and platelet-activating factor signaling impairs zymosan-induced release of IL-23 by dendritic cells.

    Science.gov (United States)

    Rodríguez, Mario; Márquez, Saioa; Montero, Olimpio; Alonso, Sara; Frade, Javier García; Crespo, Mariano Sánchez; Fernández, Nieves

    2016-02-15

    The engagement of the receptors for fungal patterns induces the expression of cytokines, the release of arachidonic acid, and the production of PGE2 in human dendritic cells (DC), but few data are available about other lipid mediators that may modulate DC function. The combined antagonism of leukotriene (LT) B4, cysteinyl-LT, and platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) inhibited IL23A mRNA expression in response to the fungal surrogate zymosan and to a lower extent TNFA (tumor necrosis factor-α) and CSF2 (granulocyte macrophage colony-stimulating factor) mRNA. The combination of lipid mediators and the lipid extract of zymosan-conditioned medium increased the induction of IL23A by LPS (bacterial lipopolysaccharide), thus suggesting that unlike LPS, zymosan elicits the production of mediators at a concentration enough for optimal response. Zymosan induced the release of LTB4, LTE4, 12-hydroxyeicosatetraenoic acid (12-HETE), and PAF C16:0. DC showed a high expression and detectable Ser663 phosphorylation of 5-lipoxygenase in response to zymosan, and a high expression and activity of LPCAT1/2 (lysophosphatidylcholine acyltransferase 1 and 2), the enzymes that incorporate acetate from acetyl-CoA into choline-containing lysophospholipids to produce PAF. Pharmacological modulation of the arachidonic acid cascade and the PAF receptor inhibited the binding of P-71Thr-ATF2 (activating transcription factor 2) to the IL23A promoter, thus mirroring their effects on the expression of IL23A mRNA and IL-23 protein. These results indicate that LTB4, cysteinyl-LT, and PAF, acting through their cognate G protein-coupled receptors, contribute to the phosphorylation of ATF2 and play a central role in IL23A promoter trans-activation and the cytokine signature induced by fungal patterns.

  4. Quantitative, functional and biochemical alterations in the peritoneal cells of mice exposed to whole-body gamma-irradiation. 1. Changes in cellular protein, adherence properties and enzymatic activities associated with platelet-activating factor formation and inactivation

    Energy Technology Data Exchange (ETDEWEB)

    Steel, L.K.; Hughes, H.N.; Walden, T.L. Jr.

    1988-06-01

    Changes in total number, differentials, cell protein, adherence properties, acetyl-CoA transferase and acetylhydrolase activities, prostaglandin E/sub 2/ and leukotriene C/sub 4/ production, as well as Ca/sup 2+/ ionophore A23187 stimulation were examined in resident peritoneal cells isolated from mice 2 h to 10 days postexposure to a single dose (7, 10 or 12 Gy) of gamma-radiation. Radiation dose-related reductions in macrophage and lymphocyte numbers and increases in cellular protein and capacity to adhere to plastic surfaces were evident. In vivo irradiation also elevated the activities of acetyltransferase and acetyl-CoA hydrolase (catalysing platelet-activating factor biosynthesis and inactivation, respectively) in adherent and nonadherent peritoneal cells, particularly 3-4 days postexposure. Blood plasma from irradiated animals did not reflect the increased cellular acetyl-hydrolase activity. Prostaglandin E/sub 2/ and leukotriene C/sub 4/ synthesis were elevated postexposure, suggesting increased substrate (arachidonate) availability and increased cyclooxygenase and lipoxygenase activities. Ionophore stimulation of enzyme activities and eicosanoid release also differed in irradiated peritoneal cells.

  5. The poly-γ-d-glutamic acid capsule surrogate of the Bacillus anthracis capsule induces nitric oxide production via the platelet activating factor receptor signaling pathway.

    Science.gov (United States)

    Lee, Hae-Ri; Jeon, Jun Ho; Park, Ok-Kyu; Chun, Jeong-Hoon; Park, Jungchan; Rhie, Gi-Eun

    2015-12-01

    The poly-γ-d-glutamic acid (PGA) capsule, a major virulence factor of Bacillus anthracis, confers protection of the bacillus from phagocytosis and allows its unimpeded growth in the host. PGA capsules released from B. anthracis are associated with lethal toxin in the blood of experimentally infected animals and enhance the cytotoxic effect of lethal toxin on macrophages. In addition, PGA capsule itself activates macrophages and dendritic cells to produce proinflammatory cytokine such as IL-1β, indicating multiple roles of PGA capsule in anthrax pathogenesis. Here we report that PGA capsule of Bacillus licheniformis, a surrogate of B. anthracis capsule, induces production of nitric oxide (NO) in RAW264.7 cells and bone marrow-derived macrophages. NO production was induced by PGA in a dose-dependent manner and was markedly reduced by inhibitors of inducible NO synthase (iNOS), suggesting iNOS-dependent production of NO. Induction of NO production by PGA was not observed in macrophages from TLR2-deficient mice and was also substantially inhibited in RAW264.7 cells by pretreatment of TLR2 blocking antibody. Subsequently, the downstream signaling events such as ERK, JNK and p38 of MAPK pathways as well as NF-κB activation were required for PGA-induced NO production. In addition, the induced NO production was significantly suppressed by treatment with antagonists of platelet activating factor receptor (PAFR) or PAFR siRNA, and mediated through PAFR/Jak2/STAT-1 signaling pathway. These findings suggest that PGA capsule induces NO production in macrophages by triggering both TLR2 and PAFR signaling pathways which lead to activation of NF-kB and STAT-1, respectively.

  6. Different contributions of platelet-activating factor and nitric oxide in long-term potentiation of the rat medial vestibular nuclei.

    Science.gov (United States)

    Pettorossi, V E; Grassi, S

    2001-01-01

    In rat brainstem slices, we investigated the differential role of nitric oxide (NO) and platelet-activating factor (PAF) in long-term potentiation (LTP) induced in the ventral portion of the medial vestibular nuclei (MVN) by high-frequency stimulation (HFS) of the primary vestibular afferents. The NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO) and the PAF receptor antagonist ginkgolide B (BN-52021) were administered before and after induction of potentiation. The effect of carboxy-PTIO was to completely prevent LTP. By contrast, BN-52021 only reduced the amplitude of HFS potentiation, which could develop fully at the drug washout or decline to zero, becoming a short-term phenomenon, in the case of long-lasting PAF receptor block. Both drugs, when given after HFS, had no effect on the already established potentiation, but whilst BN-52021 showed an influence within 5 min of the LTP induction, carboxy-PTIO did not affect the response once HFS was delivered. Moreover, we showed that the NO donor, sodium nitroprusside, and methylcarbamyl PAF (mc-PAF) induced LTP which was associated with an increase in glutamate release as shown by reduction in the paired-pulse facilitation ratio. The mc-PAF LTP was prevented by the NO scavenger, while NO LTP was only reduced by BN-52021. We suggest that NO and PAF are implicated as retrograde messengers in two different phases of vestibular LTP: NO in the induction phase; and PAF in the full expression phase.

  7. Topical application of a platelet activating factor receptor agonist suppresses phorbol ester-induced acute and chronic inflammation and has cancer chemopreventive activity in mouse skin.

    Science.gov (United States)

    Sahu, Ravi P; Rezania, Samin; Ocana, Jesus A; DaSilva-Arnold, Sonia C; Bradish, Joshua R; Richey, Justin D; Warren, Simon J; Rashid, Badri; Travers, Jeffrey B; Konger, Raymond L

    2014-01-01

    Platelet activating factor (PAF) has long been associated with acute edema and inflammatory responses. PAF acts by binding to a specific G-protein coupled receptor (PAF-R, Ptafr). However, the role of chronic PAF-R activation on sustained inflammatory responses has been largely ignored. We recently demonstrated that mice lacking the PAF-R (Ptafr-/- mice) exhibit increased cutaneous tumorigenesis in response to a two-stage chemical carcinogenesis protocol. Ptafr-/- mice also exhibited increased chronic inflammation in response to phorbol ester application. In this present study, we demonstrate that topical application of the non-hydrolysable PAF mimetic (carbamoyl-PAF (CPAF)), exerts a potent, dose-dependent, and short-lived edema response in WT mice, but not Ptafr -/- mice or mice deficient in c-Kit (c-KitW-sh/W-sh mice). Using an ear inflammation model, co-administration of topical CPAF treatment resulted in a paradoxical decrease in both acute ear thickness changes associated with a single PMA application, as well as the sustained inflammation associated with chronic repetitive PMA applications. Moreover, mice treated topically with CPAF also exhibited a significant reduction in chemical carcinogenesis. The ability of CPAF to suppress acute and chronic inflammatory changes in response to PMA application(s) was PAF-R dependent, as CPAF had no effect on basal or PMA-induced inflammation in Ptafr-/- mice. Moreover, c-Kit appears to be necessary for the anti-inflammatory effects of CPAF, as CPAF had no observable effect in c-KitW-sh/W-sh mice. These data provide additional evidence that PAF-R activation exerts complex immunomodulatory effects in a model of chronic inflammation that is relevant to neoplastic development.

  8. BIRM 270: a novel inhibitor of arachidonate release that blocks leukotriene B4 and platelet-activating factor biosynthesis in human neutrophils.

    Science.gov (United States)

    Farina, P R; Graham, A G; Hoffman, A F; Watrous, J M; Borgeat, P; Nadeau, M; Hansen, G; Dinallo, R M; Adams, J; Miao, C K

    1994-12-01

    (S)-N-[2-Cyclohexyl-1-(2-pyridinyl)ethyl]-5-methyl-2-benzoxazolamine+ ++ (BIRM 270) was identified as a potent and enantiomerically selective inhibitor of calcium ionophore A23187-stimulated leukotriene B4 biosynthesis in human neutrophils. The (S)- and (R)-enantiomers exhibited IC50 values of 1 nM and 40 nM, respectively. BIRM 270 did not inhibit 5-lipoxygenase activity in a cell-free assay. In addition, the compound did not interfere with the conversion of exogenous 5-lipoxygenase substrate (15S)-hydroperoxyeicosatetraenoic acid to (5S, 15S)-dihydroxyeicosatetraenoic acid in intact, ionophore-stimulated neutrophils. Under the same experimental conditions, BIRM 270 inhibited the production of 5-lipoxygenase products from endogenous substrate, suggesting that the compound affected arachidonate availability rather than metabolism. Consistent with this concept, the inhibition of leukotriene B4 biosynthesis by BIRM 270 was overcome by the addition of exogenous arachidonic acid to the leukocyte preparation. Direct measurement of free arachidonate by gas chromatography-mass spectrometry confirmed that BIRM 270 inhibited arachidonate release from ionophore-stimulated neutrophils. The compound did not affect arachidonate reacylation. The blockage of arachidonate release coincided with inhibition of leukotriene B4 biosynthesis in these cells. BIRM 270 also inhibited ionophore-stimulated platelet-activating factor biosynthesis by human neutrophils. Although these results suggest that BIRM 270 inhibited phospholipase A2-mediated deacylation of membrane phospholipids, the compound did not directly inhibit the high molecular weight, cytosolic phospholipase A2 derived from human neutrophils or U937 cells. Thus, suppression of arachidonate mobilization by BIRM 270 may be due to indirect inhibition of intracellular phospholipase A2 or to inhibition of another acylhydrolase activity.

  9. The GPIIb/IIIa antagonist eptifibatide markedly potentiates platelet-leukocyte interaction and tissue factor expression following platelet activation in whole blood in vitro.

    Science.gov (United States)

    Scholz, Thomas; Zhao, Lian; Temmler, Uta; Bath, Philip; Heptinstall, Stan; Lösche, Wolfgang

    2002-11-01

    Tissue factor (TF) is the most important initiator of intravascular coagulation. Activated platelets are able to adhere to leukocytes and this heterotypic cell-cell interaction results in a CD62P-dependent TF expression on monocytes. GPIIb/IIIa antagonists are inhibitors of the common pathway of platelet aggregation and they are widely used in patients with acute coronary syndromes undergoing coronary interventions. As GPIIb/IIIa antagonists do not prevent platelet activation we investigated the effect a GPIIb/IIIa antagonist, eptifibatide, on the formation of platelet-leukocyte conjugates and leukocyte TF expression. Flow cytometry was used to detect conjugates and TF. When platelets in citrated human blood were stimulated for 30 min with collagen there was a increase in the number of both neutrophils and monocytes with the platelet-specific antigen CD42a, indicating the formation of platelet-neutrophil (P/N) and platelet-monocyte (P/M) conjugates. P/M formation was associated with about a 2.5-fold increase in TF expression on monocytes, whereas P/N formation changed TF expression neutrophils only by about 10%. Eptifibatide enhanced dose-dependently (0.0625-1.5 microg/ml) both collagen-induced P/M formation and monocyte TF expression. Maximum enhancement by about 60 and 120%, respectively, was observed at 0.5 microg/ml eptifibatide. In contrast, eptifibatide had only a minor effect on P/N formation and no effect on neutrophil TF expression. The augmented P/M formation and monocyte TF expression in the presence of a GPIIb/IIIa antagonist may be relevant to the poor antithrombotic efficiency of oral GPIIb/IIIa antagonists as shown in recent large clinical trials.

  10. Activation of platelet-activating factor receptor and pleiotropic effects on tyrosine phospho-EGFR/Src/FAK/paxillin in ovarian cancer.

    Science.gov (United States)

    Aponte, Margarita; Jiang, Wei; Lakkis, Montaha; Li, Ming-Jiang; Edwards, Dale; Albitar, Lina; Vitonis, Allison; Mok, Samuel C; Cramer, Daniel W; Ye, Bin

    2008-07-15

    Among the proinflammatory mediators, platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphorylcholine) is a major primary and secondary messenger involved in intracellular and extracellular communication. Evidence suggests that PAF plays a significant role in oncogenic transformation, tumor growth, angiogenesis, and metastasis. However, PAF, with its receptor (PAFR) and their downstream signaling targets, has not been thoroughly studied in cancer. Here, we characterized the PAFR expression pattern in 4 normal human ovarian surface epithelial (HOSE) cell lines, 13 ovarian cancer cell lines, paraffin blocks (n = 84), and tissue microarrays (n = 230) from patients with ovarian cancer. Overexpression of PAFR was found in most nonmucinous types of ovarian cancer but not in HOSE and mucinous cancer cells. Correspondingly, PAF significantly induced cell proliferation and invasion only in PAFR-positive cells (i.e., OVCA429 and OVCA432), but not in PAFR-negative ovarian cells (HOSE and mucinous RMUG-L). The dependency of cell proliferation and invasion on PAFR was further confirmed using PAFR-specific small interfering RNA gene silencing probes, antibodies against PAFR and PAFR antagonist, ginkgolide B. Using quantitative multiplex phospho-antibody array technology, we found that tyrosine phosphorylation of EGFR/Src/FAK/paxillin was coordinately activated by PAF treatment, which was correlated with the activation of phosphatidylinositol 3-kinase and cyclin D1 as markers for cell proliferation, as well as matrix metalloproteinase 2 and 9 for invasion. Specific tyrosine Src inhibitor (PP2) reversibly blocked PAF-activated cancer cell proliferation and invasion. We suggest that PAFR is an essential upstream target of Src and other signal pathways to control the PAF-mediated cancer progression.

  11. Effects of the platelet-activating factor receptor antagonist BN 52021 on hematologic variables and blood loss during and after cardiopulmonary bypass.

    Science.gov (United States)

    Nathan, N; Mercury, P; Denizot, Y; Cornu, E; Laskar, M; Arnoux, B; Feiss, P

    1994-08-01

    Cardiopulmonary bypass (CPB)-induced thrombocytopenia and leukopenia is augmented after heparin reversal of protamine. Platelet-activating factor (PAF) might be implicated in these disorders. To evaluate the effects of PAF on the hematologic disorders and blood loss during and after CPB, patients were pretreated with BN 52021, a PAF receptor antagonist, or a placebo. BN 52021 (120 mg) (n = 13) or placebo (n = 15) were infused intravenously before vascular cannulation and before cross-clamp release. Platelet and leukocyte counts were assessed in venous blood before and after the first dose of BN 52021 or placebo, 2 min after the beginning of CPB (at the entry of the oxygenator), at the end of CPB, 1, 15, and 30 min after protamine infusion, and 6 and 24 h after CPB. The decrease in platelet and leukocyte counts were the same between groups during and after CPB and after protamine infusion. Bleeding times were not modified by the pretreatment of patients with BN 52021. During surgery, blood loss reached 1660 +/- 297 mL in the BN 52021 group and 1599 +/- 283 mL in the placebo group (P > 0.05). Forty-eight hours postoperatively, the chest tube outputs were not different between groups (1460 +/- 418 mL vs 1640 +/- 362 mL in the BN 52021 and placebo groups, respectively). This study shows that BN 52021 infusion did not change the hematologic variables studied. Moreover, a PAF antagonist pretreatment did not protect the patients against CPB- or protamine-induced hematologic changes.

  12. Platelet activation determines the severity of thrombocytopenia in dengue infection

    Science.gov (United States)

    Ojha, Amrita; Nandi, Dipika; Batra, Harish; Singhal, Rashi; Annarapu, Gowtham K.; Bhattacharyya, Sankar; Seth, Tulika; Dar, Lalit; Medigeshi, Guruprasad R.; Vrati, Sudhanshu; Vikram, Naval K.; Guchhait, Prasenjit

    2017-01-01

    Thrombocytopenia is common in patients with dengue virus (DENV) infections. With a focus on understanding the possible mechanism of thrombocytopenia in DENV infections we described a direct correlation between activation and depletion of platelets in patients. Our data showed a sharp decrease in platelet counts at day 4 of fever in patients. The high DENV genome copies in platelets correlated directly with the elevated platelet activation along with increased binding of complement factor C3 and IgG on their surface at day 4. Recovery in platelet count was observed on day 10 through day 6 and 8 with simultaneous decrease in platelet activation markers. Further, our in vitro data supported the above observations describing a concentration-dependent increase in platelet activation by DENV serotype-2. The high copy number of DENV2 genome in the platelet pellet correlated directly with platelet activation, microparticle generation and clot formation. Furthermore the DENV2-activated platelets were phagocytosed in large numbers by the monocytes. The DENV2-mediated lysis and clearance of platelets were abrogated in presence of platelet activation inhibitor, prostacyclin. These observations collectively suggest that platelet activation status is an important determinant of thrombocytopenia in dengue infections. A careful strategy of inactivation of platelets may rescue them from rapid destruction during DENV infections. PMID:28139770

  13. Prostanoid production in the presence of platelet activation in hypoxic cocaine-treated rats.

    Science.gov (United States)

    Togna, G; Graziani, M; Sorrentino, C; Caprino, L

    1996-01-01

    To extend our previous in vitro data, we investigated the effects of cocaine on thromboxane A2 (TXA2) and prostacyclin (PGI2) production in vivo in the rat. To obtain the slight platelet activation that our in vitro experiments showed useful to highlight the effect of cocaine, we infused cocaine in rats in the presence of platelet-activating factors (circulation of blood through a perspex vascular device or by infusion of sodium arachidonate) and in various respiratory conditions. Experiments were conducted in rats breathing atmospheric air (normoxic conditions) and in rats breathing an oxygen-poor mixture (hypoxic conditions). In rats under hypoxic conditions cocaine invariably increased TXA2 plasma levels, whereas in normoxic conditions it increased TXA2 only in the presence of platelet-activating factors. Cocaine significantly increased PGI2 plasma levels in arachidonate-treated rats in hypoxic respiratory conditions; in normoxic conditions cocaine left PGI2 levels unchanged. These results support the hypothesis that in cocaine users who have concomitant pathological conditions able to activate platelets, such as atherosclerosis, coronary vasospasm or ischaemia, or both, cocaine may contribute to the onset of thrombotic phenomena by interfering with the prostaglandin system.

  14. Lipoprotein lipase and hydrofluoric acid deactivate both bacterial lipoproteins and lipoteichoic acids, but platelet-activating factor-acetylhydrolase degrades only lipoteichoic acids.

    Science.gov (United States)

    Seo, Ho Seong; Nahm, Moon H

    2009-08-01

    To identify the Toll-like receptor 2 ligand critically involved in infections with gram-positive bacteria, lipoprotein lipase (LPL) or hydrogen peroxide (H(2)O(2)) is often used to selectively inactivate lipoproteins, and hydrofluoric acid (HF) or platelet-activating factor-acetylhydrolase (PAF-AH) is used to selectively inactivate lipoteichoic acid (LTA). However, the specificities of these chemical reactions are unknown. We investigated the reaction specificities by using two synthetic lipoproteins (Pam(3)CSK(4) and FSL-1) and LTAs from pneumococci and staphylococci. Changes in the structures of the two synthetic proteins and the LTAs were monitored by mass spectrometry, and biological activity changes were evaluated by measuring tumor necrosis factor alpha production by mouse macrophage cells (RAW 264.7) following stimulation. PAF-AH inactivated LTA without reducing the biological activities of Pam(3)CSK(4) and FSL-1. Mass spectroscopy confirmed that PAF-AH monodeacylated pneumococcal LTA but did not alter the structure of either Pam(3)CSK(4) or FSL-1. As expected, HF treatment reduced the biological activity of LTA by more than 80% and degraded LTA. HF treatment not only deacylated Pam(3)CSK(4) and FSL-1 but also reduced the activities of the lipoproteins by more than 60%. Treatment with LPL decreased the biological activities by more than 80%. LPL also removed an acyl chain from the LTA and reduced its activity. Our results indicate that treatment with 1% H(2)O(2) for 6 h at 37 degrees C inactivates Pam(3)CSK(4), FSL-1, and LTA by more than 80%. Although HF, LPL, and H(2)O(2) treatments degrade and inactivate both lipopeptides and LTA, PAF-AH selectively inactivated LTA with no effect on the biological and structural properties of the two lipopeptides. Also, the ability of PAF-AH to reduce the inflammatory activities of cell wall extracts from gram-positive bacteria suggests LTA to be essential in inflammatory responses to gram-positive bacteria.

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

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    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 (PGF2α)? In our study Giant Panda post-thawed sperm was incubated in Ham's F-10 medium with different concentration of PF,PAF and PGF2α,under 37℃.The effects of PF,PAF and PGF2α,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 PGF2α 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-1PGF2α,had no significant effect on Giant Panda postthawed sperm,but when the PGFzα 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.

  16. Relationship between Platelet Activation Related Factors and Polymorphism of Related Genes in Patients with Coronary Heart Disease of Blood-stasis Syndrome

    Institute of Scientific and Technical Information of China (English)

    XUE Mei; CHEN Ke-ji; YIN Hui-jun

    2008-01-01

    Objective: To comparatively study the expressive conditions of platelet activation related factors (GP Ⅰ b, GP Ⅱ b-Ⅲ a and GMP-140) in healthy subjects and patients with coronary heart disease (CHD) of blood-stasis (BS) or non-blood-stasis (non-BS) syndrome, and to analyze the relationship between the activities of various glycoproteins and the polymorphism of genes. Methods: With case control design adopted, patients with the CHD (40 of BS, 37 of non-BS) and 39 healthy subjects for control, all fitting to the inclusion criteria, were selected in this study. The number of affected coronary branches was recorded by the contrast examination. The mean fluorescence intensity (MFI) of GP Ⅰ b, GP Ⅱ b-Ⅲ a, and GMP-140 (CD42b, CD61, CD62p) in patients and healthy persons was measured with flow cytometry, the polymorphism of HPA-3 gene was detected by Taqman probe technique and that of HPA-2 gene was determined by gene sequencing. Results: MFI of CD61 and CD62p was higher in the CHD patients than in the healthy control, which was also higher in patients of BS syndrome than in patients of non-BS syndrome (P0.05); at the same time, no significant difference of all the above-mentioned three MFI could be found in patients with various numbers of affected coronary branches, neither in patients with different genotypes at GP Ⅱ b HPA-3 and GP Ⅰ b HPA-2 polymorphism loci (P>0.05). Conclusion: (1) The activities of GP Ⅱ b-Ⅲ a and GMP-140 were obviously increased in the genesis and developing process of CHD and CHD of BS syndrome, and so they could be taken as one of the objective indexes for microscopic diagnosis of BS syndrome. (2) The level of GP Ⅰ b was lower in CHD patients than in healthy persons, but it was not a sensitive indicator for BS syndrome of CHD. (3) Levels of GP Ⅱ b-Ⅲ a, GP Ⅰ b and GMP-140 were not related with the number of affected coronary branches in CHD patients. (4) The changes in amino-acids expression induced by the two loci

  17. Lipoprotein-associated phospholipase A2 (Lp-PLA2 activity, platelet-activating factor acetylhydrolase (PAF-AH in leukocytes and body composition in healthy adults

    Directory of Open Access Journals (Sweden)

    Pitsavos Christos

    2009-06-01

    Full Text Available Abstract Background Lipoprotein-associated phospholipase A2 (Lp-PLA2 also known as serum platelet activating factor acetylhydrolase (PAF-AH activity constitutes a novel risk marker for cardiovascular disease. Leukocytes constitute one main cellular source of circulating Lp-PLA2. The aim of the present study was to evaluate the association of both serum and leukocyte PAF-AH activities with fat distribution and lean tissue. One hundred healthy volunteers without cardiovascular disease history participated in this study (n = 52 men, 44 ± 13 years and n = 48 women, 43 ± 13 years. Body composition was assessed with dual-energy X-ray absorptiometry, while anthropometrical indices were also measured. The activity of Lp-PLA2 and levels of lipid and glycemic parameters were determined in fasting samples. Results Mean Lp-PLA2 activity was 24.8 ± 4.5 and 19.6 ± 5.0 nmol/min/mL in men and women, respectively (P 2 activity in men after adjusting for LDL-cholesterol, age, smoking, hs-CRP and physical activity, whereas no associations were found with PAF-AH leukocyte homogenates activity. Hierarchical analysis revealed that the variables with the highest explanatory ability of Lp-PLA2 activity in men, were DXA deriving L1–L4 region of interest and arms fat (increase in R2 = 0.136, P = 0.005 and increase in R2 = 0.118, P = 0.009, respectively, followed by trunk fat and total fat. In women, no association of body composition variables with Lp-PLA2 nor PAF-AH leukocyte homogenates activity was found. Conclusion Lp-PLA2 activity is differentiated across levels of adiposity and topology of adipose tissue, whereas no association was found regarding PAF-AH leukocyte homogenates activity. Our findings suggest that Lp-PLA2 may compensate for the adiposity-associated increases in inflammatory and oxidative burden, in men.

  18. 粉防己碱对兔血小板聚集和血小板活化因子生成的影响%Effects of tetrandrine on rabbit platelet aggregation and platelet activating factor generation

    Institute of Scientific and Technical Information of China (English)

    张敏; 张乐之; 吕金胜

    1995-01-01

    目的:探讨粉防己碱(Tet)对兔血小板聚集和PAF生成的影响.方法:卡西霉素(Cal)和PAF诱导血小板聚集的聚集率和Tet对血小板聚集的抑制率被测定;给予或未给予Tet处理之血小板用Cal刺激释放PAF的量也被测定.结果:在4-64 μmol·L-1浓度范围,Tet明显抑制Cal和PAF诱导的血小板聚集.IC50值分别为8.6μmol·L-1和14.0μmol·L-1.Tet 也浓度依赖性的抑制Cal诱导血小板释放PAF,IC50值为21.0 μmol·L-1.结论:Tet抑制血小板聚集作用与抑制内源性PAF生成有关.%AIM: To study the effects of tetrandrine (Tet) on platelet aggregation and platelet activating factor (PAF) generation in rabbit platelet-rich plasma (PRP). METHODS:The aggregation rate of platelets induced by calcimycin (Cal) and PAF and the inhibition rate of Tet on platelet aggregation were measured. The amount of PAF in PRP stimulated with Cal and treated with Tet was also meaaggregation. At the final concentrations of 4PRP aggregation by Cal, there was a marked increase in PAF content. Tet dependented the release of PAF from platelets by Cal in a concentration-dependent manner, with IC50 of 21hibition effect of Tet on platelet aggregation might be concerned with the reduction of endogenous PAF generation.

  19. Quantitative, functional, and biochemical alterations in the peritoneal cells of mice exposed to whole-body gamma irradiation. 1. Changes in cellular protein, adherence properties, and enzymatic activities associated with platelet-activating factor formation and inactivation, and arachidonate metabolism. Scientific report

    Energy Technology Data Exchange (ETDEWEB)

    Steel, L.K.; Hughes, H.N.; Walden, T.L.

    1988-01-01

    Changes in total number, differentials, cell protein, adherence properties, acetyltransferase and acetylhydrolase activities, prostaglandin E2 and leukotriene C4 production, as well as calcium (2+) ionophore A23187 stimulation were examined in resident peritoneal cells isolated from mice 2h to 10 days postexposure to a single dose (7,10 or 12 Gy) of gamma radiation. Radiation dose-related reductions in macrophage and lymphocyte numbers and increases in cellular protein and capacity to adhere to plastic surfaces were evident. In-vitro irradiation also elevated the activities of acetyltransferase and acetylhydrolase (catalyzing platelet-activating factor biosynthesis and inactivation, respectively) in adherent and nonadherent peritoneal cells, particularly 3-4 days postexposure. Blood plasma from irradiated animals did not reflect the increased cellular acetylhydrolase activity. Prostaglandin E2 and leukotriene C4 synthesis were elevated postexposure, suggesting increased substrate (arachidonate) availability and increased cyclooxygenase and lipoxygenase activities. Ionospheric stimulation of enzyme activities and eicosanoid release also differed in irradiated peritoneal cells. While the properties of adherence, platelet-activating factor synthesis/inactivation-associated enzyme activities, and eicosanoid production are generally characterized as those of macrophages, lymphocytes or their products may influence or contribute to the observed radiation-induced changes.

  20. In vitro effects of buyang huanwu decoction and its ingredients on inhibiting the specific binding of 3H-platelet activating factor to its receptor in rabbits

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    BACKGROUND: Pharmacologic action of traditional Chinese medicine compound is the comprehensive effect of various ingredients, and the interactions of various ingredients are closely correlated with the final effect. In order to reveal the compatibility mechanism of buyang huanwu decoction (BHD)'s prescription in treating and preventing ischemic cerebrovascular disease, we need to explore the effect and relation of ingredients in prescription except for considering the effect of each ingredient on the whole prescription.OBJECTIVE: To study the effect of BHD and its ingredients in the prescription on the specific binding of 3H-platelet activating factor (PAF) to its receptor (PAFR)in rabbits in vitro, and to analyze the action of each ingredient in the prescription.DESIGN: A decomposed recipe study based on orthogonal test.SETTING: Guangzhou University of Traditional Chinese Medicine.MATERIALS: Five healthy adult New Zealand rabbits of either gender were provided by the Experimental Animal Center of Guangzhou University of Traditional Chinese medicine. The prescription herbal pieces were purchased from Foshan Kangpu Pharmaceuticals Company and Jianmin Pharmaceuticals Company, and were appraised by Professor Yanchen Xu from College of Traditional Chinese Medicine, Guangzhou University of Traditional Chinese Medicine. 3H-PAF was supplied by Amersham Co.,Ltd.(Specific activity:6.475 TBq/mmol;batch number:200402); PAF standard by Biomol Co., Ltd.(batch number: P1318V).METHODS: This experiment was carried out in the Laboratory of Nuclear Medicine, Guangzhou University of Traditional Chinese Medicine between September and December 2004. ① The seven influencing factors were selected: such as Shenghuangqi , Dangguiwei, Chishao, Dilong, Taoren, Honghua, Chuanxiong. Each factor was divided into two levels, selected or not selected. The tests were arranged according to L8 (27) orthogonal test table. ②The specific binding of 3H-PAF to its receptors in rabbits was measured by

  1. Platelet activation in the postoperative period after lung transplantation

    Science.gov (United States)

    Sternberg, David I.; Shimbo, Daichi; Kawut, Steven M.; Sarkar, Joydeep; Hurlitz, Georg; D’Ovidio, Frank; Lederer, David J.; Wilt, Jessie S.; Arcasoy, Selim M.; Pinsky, David J.; D’Armiento, Jeanine M.; Sonett, Joshua R.

    2010-01-01

    Objective During lung transplantation, cells in the pulmonary parenchyma are subjected to ischemia, hypothermic storage, and reperfusion injury. Platelets, whose granular contents include adhesion receptors, chemokines, and coactivating substances that activate inflammatory and coagulant cascades, likely play a critical role in the lung allograft response to ischemia and reperfusion. The platelet response to the pulmonary allograft, however, has never been studied. Here we report significant platelet activation immediately after lung transplantation. Methods We performed a prospective cohort study comparing markers of platelet activation in patients undergoing lung transplantation and patients undergoing nontransplant thoracotomy. Plasma levels of soluble P-selectin, soluble CD40 ligand, and platelet–leukocyte conjugates were measured before surgery, after skin closure, and at 6 postoperative hours. Results Both soluble P-selectin and soluble CD40 ligand levels increased significantly after lung transplantation but not after thoracotomy. Additionally, platelet–monocyte conjugate fluorescence was significantly higher after lung transplantation than after thoracotomy alone. Conclusion These findings suggest that platelet activation is significantly increased after lung transplantation beyond that expected from the postoperative state. The increase in circulating platelet–monocyte conjugates suggests an important interaction between platelets and inflammatory cells. Further research should examine whether platelet activation affects early graft function after lung transplantation. PMID:18329493

  2. Platelet activation during exercise induced asthma: effect of prophylaxis with cromoglycate and salbutamol.

    Science.gov (United States)

    Johnson, C E; Belfield, P W; Davis, S; Cooke, N J; Spencer, A; Davies, J A

    1986-01-01

    Peak expiratory flow (PEF) and plasma concentrations of platelet factor 4 and beta thromboglobulin were measured before and after exercise in nine asthmatic patients and 12 non-asthmatic volunteers. Exercise was preceded by administration in random order of either placebo, salbutamol 200 micrograms, or sodium cromoglycate 2 mg from a pressurised inhaler. In control subjects there were minimal changes in PEF and plasma concentrations of platelet factor 4 and beta thromboglobulin. In the asthmatic patients the typical changes in PEF were seen on exercise; plasma concentrations of platelet factor 4 and beta thromboglobulin rose significantly in parallel, the rise preceding the fall in PEF. The changes in peak flow and platelet activation induced by exercise were attenuated by prior administration of salbutamol or cromoglycate. These results indicate that exercise induced asthma is associated with a rise in platelet release products similar to that observed in antigen induced asthma. PMID:2943049

  3. Significance of platelet activating factor receptor expression in pancreatic tissues of rats with severe acute pancreatitis and effects of BN52021

    Institute of Scientific and Technical Information of China (English)

    Shi-Hai Xia; Chun-Xiu Hu; Zhi-Ling Zhao; Guo-Dong Xia; Yao Di

    2007-01-01

    AIM: To investigate the dynamic changes and significance of platelet activating factor receptor (PAF-R)mRNA and protein in pancreatic tissues of rats with severe acute pancreatitis (SAP) and effects of BN52021(Ginkgolide B).METHODS: Wistar male rats were randomly assigned to the negative control group (NC group), SAP model group (SAP group), and BN52051-remedy group (BN group), and each of the groups was divided into 6 subgroups at different time points after operation (1 h,2 h, 3 h, 6 h, 12 h, and 24 h) (n = 10 in each). PT-PCR and Western blot methods were used to detect PAFRmRNA and protein expression in pancreatic tissues of rats respectively. Pathological examination of pancreatic tissues was performed and the serum amylase change was detected.RESULTS: Serum amylase and pathological results showed the that SAP model was successfully prepared,BN52021 was able to decrease serum amylase, and the pathological ratings in BN group at 3 h, 6 h, and 12 h significantly decreased compared with those in the SAP group (8.85 ± 0.39 vs 5.95 ± 0.19, 9.15 ± 0.55 vs 5.55 ± 0.36, 10.10 ± 0.65 vs 6.72 ± 0.30, P < 0.05). The result of PAF-mRNA showed dynamic changes in SAP and BN groups, which increased gradually in early stage,reached a peak at 3 h (0.71 ± 0.14 vs 0.54 ± 0.14,0.69 ± 0.13 vs 0.59 ± 0.04, P < 0.05), and decreased gradually later. There were significant differences at each time point except 1 h and 2 h, when compared with those in the NC group (0.71 ± 0.14 or 0.69 ± 0.13 vs 0.47 ± 0.10, 0.38 ± 0.08 or 0.59 ± 0.04 vs 0.47 ± 0.09, 0.25 ± 0.07 or 0.29 ± 0.05 vs 0.46 ± 0.10, 0.20 ± 0.06 or 0.20 ± 0.04 vs 0.43 ± 0.09, P < 0.05), whereas there was no significant difference between BN and SAP groups at each time point. The result of PAF-R protein showed that the change of PAF-R protein in the SAP group and the BN group was consistent with that of PAF-R mRNA.There were significant differences at each time point except 1 h, when compared with

  4. Atividade da enzima acetil-hidrolase do fator ativador de plaquetas (PAF-AH em pacientes com diabete melito tipo 1 Platelet-activating factor acetylhydrolase (PAF-AH activity in patients with type 1 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Simone Henriques de Castro

    2007-02-01

    Full Text Available OBJETIVO: Avaliar a atividade da acetil-hidrolase do fator ativador de plaquetas (PAF-AH e sua relação com variáveis clinicodemográficas, com o controle metabólico, os níveis de apolipoproteínas A e B e a suscetibilidade da lipoproteína de baixa densidade (LDL à oxidação in vitro em pacientes com DM tipo 1 (DM 1. MÉTODOS: Foram avaliados 42 pacientes com DM1 (27 mulheres e 48 não-diabéticos (16 mulheres, pareados por sexo, idade e índice de massa corporal (IMC. Os exames realizados foram: glicemia de jejum (GJ e pós-prandial (GPP, lipidograma, ácido úrico (AU, hemoglobina glicosilada (HbA1c e coeficiente de oxidação da lipoproteína de baixa densidade (LDL por espectrofotometria. A análise da atividade da PAF-AH foi realizada por espectrofotometria (Cayman Chemical. RESULTADOS: A análise da atividade da PAF-AH mostrou haver maior atividade enzimática nos pacientes com DM 1 do que nos não-diabéticos (0,0150 ± 0,0051 versus 0,0116 ± 0,0041; p OBJECTIVE: To evaluate platelet-activating factor acetylhydrolase (PAF-AH activity and its relationship with clinical and demographic variables, metabolic control, apolipoprotein A and B levels and the susceptibility of low-density lipoprotein (LDL to in vitro oxidation in patients with type 1 diabetes mellitus (DM 1. METHODS: Forty two patients with DM 1 (27 females and 48 control subjects (16 females matched for gender, age and body mass index (BMI were evaluated. The following tests were performed: fast plasma glucose (FG and postprandial plasma glucose (PPG, lipid profile, uric acid (UA, glycosylated hemoglobin (HbA1c, and low-density lipoprotein (LDL oxidation rate using colorimetric assay. The PAF-AH activity was analyzed using colorimetric assay (Cayman Chemical. RESULTS: The analysis of PAF-AH activity showed a higher enzyme activity in patients with DM 1 than in control subjects (0.0150 ± 0.0051 vs. 0.0116 ± 0.0041; p < 0.001. In patients with DM 1, a direct correlation

  5. 血小板活化因子在药源性严重过敏反应中的研究现状%Advance of platelet activating factor in drug-induced anaphylaxis

    Institute of Scientific and Technical Information of China (English)

    马翔; 李潇潇; 刘维; 翟所迪

    2015-01-01

    药源性严重过敏反应有难以预测、发作突然和致命性等特点,从而成为困扰临床药物使用的重要安全性因素。由于目前尚无严格的随机对照试验支持抢救药物的推荐,医生常根据临床经验用肾上腺素、抗组胺药和/或糖皮质激素应对突发的药源性严重过敏反应。血小板活化因子( PAF)信号通路可为研究药源性严重过敏反应提供崭新的视角。本文将就药源性严重过敏反应的临床和流行病学特点、PAF通路、抗PAF通路的药物等进行概述。%The acute unpredictably life -threatening characteristic of drug-induced anaphylaxis hinders the safe use of clinical medication.In the absence of rigid randomized controlled trials supporting the recommen-dations for the treatment of immediate onset, doctors often treat drug-induced anaphylaxis with epinephrine, antihistamines and/or glucocorticoids.The researches in platelet activating factor signaling path-way could provide a novel perspective for drug-induced anaphylaxis.This review will briefly introduce the clinical and epidemiological characteristics of drug-induced anaphylaxis, platelet activating factor pathway and drugs targeting at this pathway.

  6. Platelet Activation in Human Immunodeficiency Virus Type-1 Patients Is Not Altered with Cocaine Abuse.

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    Michelle Kiebala

    Full Text Available Recent work has indicated that platelets, which are anucleate blood cells, significantly contribute to inflammatory disorders. Importantly, platelets also likely contribute to various inflammatory secondary disorders that are increasingly associated with Human Immunodeficiency Virus Type-1 (HIV infection including neurological impairments and cardiovascular complications. Indeed, HIV infection is often associated with increased levels of platelet activators. Additionally, cocaine, a drug commonly abused by HIV-infected individuals, leads to increased platelet activation in humans. Considering that orchestrated signaling mechanisms are essential for platelet activation, and that nuclear factor-kappa B (NF-κB inhibitors can alter platelet function, the role of NF-κB signaling in platelet activation during HIV infection warrants further investigation. Here we tested the hypothesis that inhibitory kappa B kinase complex (IKK activation would be central for platelet activation induced by HIV and cocaine. Whole blood from HIV-positive and HIV-negative individuals, with or without cocaine abuse was used to assess platelet activation via flow cytometry whereas IKK activation was analyzed by performing immunoblotting and in vitro kinase assays. We demonstrate that increased platelet activation in HIV patients, as measured by CD62P expression, is not altered with reported cocaine use. Furthermore, cocaine and HIV do not activate platelets in whole blood when treated ex vivo. Finally, HIV-induced platelet activation does not involve the NF-κB signaling intermediate, IKKβ. Platelet activation in HIV patients is not altered with cocaine abuse. These results support the notion that non-IKK targeting approaches will be better suited for the treatment of HIV-associated inflammatory disorders.

  7. An antagonist of the platelet-activating factor receptor inhibits adherence of both nontypeable Haemophilus influenzae and Streptococcus pneumoniae to cultured human bronchial epithelial cells exposed to cigarette smoke

    Directory of Open Access Journals (Sweden)

    Shukla SD

    2016-07-01

    Full Text Available Shakti D Shukla,1,* Rory L Fairbairn,1,* David A Gell,1 Roger D Latham,1 Sukhwinder S Sohal,1,2 Eugene H Walters,1 Ronan F O’Toole11Breathe Well Centre, School of Medicine, Faculty of Health, University of Tasmania, Hobart, TAS, Australia; 2School of Health Sciences, Faculty of Health, University of Tasmania, Launceston, TAS, Australia*These authors contributed equally to this workBackground: COPD is emerging as the third largest cause of human mortality worldwide after heart disease and stroke. Tobacco smoking, the primary risk factor for the development of COPD, induces increased expression of platelet-activating factor receptor (PAFr in the lung epithelium. Nontypeable Haemophilus influenzae (NTHi and Streptococcus pneumoniae adhere to PAFr on the luminal surface of human respiratory tract epithelial cells.Objective: To investigate PAFr as a potential drug target for the prevention of infections caused by the main bacterial drivers of acute exacerbations in COPD patients, NTHi and S. pneumoniae.Methods: Human bronchial epithelial BEAS-2B cells were exposed to cigarette smoke extract (CSE. PAFr expression levels were determined using immunocytochemistry and quantitative polymerase chain reaction. The epithelial cells were challenged with either NTHi or S. pneumoniae labeled with fluorescein isothiocyanate, and bacterial adhesion was measured using immunofluorescence. The effect of a well-evaluated antagonist of PAFr, WEB-2086, on binding of the bacterial pathogens to BEAS-2B cells was then assessed. In silico studies of the tertiary structure of PAFr and the binding pocket for PAF and its antagonist WEB-2086 were undertaken.Results: PAFr expression by bronchial epithelial cells was upregulated by CSE, and significantly associated with increased bacterial adhesion. WEB-2086 reduced the epithelial adhesion by both NTHi and S. pneumoniae to levels observed for non-CSE-exposed cells. Furthermore, it was nontoxic toward the bronchial epithelial

  8. The impact of vitamin C on the relationship among inflammation, lipid peroxidation, and platelet activation during analgesic nephropathy in rats.

    Science.gov (United States)

    Hadzi-Petrushev, Nikola; Mitrov, Dine; Kostovski, Vladimir; Mladenov, Mitko

    2017-08-03

    Oxidative stress and inflammation are involved in the pathogenesis of paracetamol-induced renal damage. This study examines the relationship between 8-iso-prostaglandin F2α (8-iso-PGF2α) and platelet activation as well as the relative contribution of the pro-inflammatory markers interleukin (IL)-1β and tumor necrosis factor-α (TNF-α) in enhanced 8-iso-PGF2α biosynthesis, as a complementary onset during analgesic nephropathy induced by chronic treatment with paracetamol. The protective effects of vitamin C on the aforementioned settings are also investigated. Analgesic nephropathy was induced in Wistar rats. Renal function markers and the activity of antioxidant enzymes were determined spectrophotometrically. Immunoassays were used to measure the pro-inflammatory markers and the markers of lipid peroxidation and platelet activation. The chronic treatment with paracetamol led to renal dysfunction, represented by the elevation of plasma urea and creatinine and the decline in the enzymatic antioxidant status, but did not cause a significant increase in TNF-α and IL-1β. The paracetamol-induced lipid peroxidation and enhanced production of 8-iso-PGF2α was not sufficient to cause changes in platelet activation represented by the level of 11-dehydro thromboxane B2. Our results suggest that oxidative stress cannot circumvent the need of stimulation by circulatory cytokines in order to induce inflammatory response and changes in platelet activation during analgesic nephropathy. Vitamin C proved to be beneficial in restoring the renal function markers to normal, increasing the renal enzymatic antioxidant potential, inhibiting lipid peroxidation, and lowering cytokine production and 11-dehydro thromboxane B2 excretion. The observed effects of vitamin C offer support for its potential use as protective treatment in cases of chronic paracetamol overdose.

  9. Lipoteichoic acid from Lactobacillus plantarum inhibits the expression of platelet-activating factor receptor induced by Staphylococcus aureus lipoteichoic acid or Escherichia coli lipopolysaccharide in human monocyte-like cells.

    Science.gov (United States)

    Kim, Hangeun; Jung, Bong Jun; Jeong, Jihye; Chun, Honam; Chung, Dae Kyun

    2014-08-01

    Platelet-activating factor receptor (PAFR) plays an important role in bacterial infection and inflammation. We examined the effect of the bacterial cell wall components lipopolysaccharide (LPS) and lipoteichoic acid (LTA) from Lactobacillus plantarum (pLTA) and Staphylococcus aureus (aLTA) on PAFR expression in THP-1, a monocyte-like cell line. LPS and aLTA, but not pLTA, significantly increased PAFR expression, whereas priming with pLTA inhibited LPSmediated or aLTA-mediated PAFR expression. Expression of Toll-like receptor (TLR) 2 and 4, and CD14 increased with LPS and aLTA treatments, but was inhibited by pLTA pretreatment. Neutralizing antibodies against TLR2, TLR4, and CD14 showed that these receptors were important in LPS-mediated or aLTA-mediated PAFR expression. PAFR expression is mainly regulated by the nuclear factor kappa B signaling pathway. Blocking PAF binding to PAFR using a PAFR inhibitor indicated that LPS-mediated or aLTA-mediated PAF expression affected TNF-α production. In the mouse small intestine, pLTA inhibited PAFR, TLR2, and TLR4 expression that was induced by heat-labile toxin. Our data suggested that pLTA has an anti-inflammatory effect by inhibiting the expression of PAFR that was induced by pathogenic ligands.

  10. Effect of Volatile Oil of Amomum on Expressions of Platelet Activating Factor and Mastocarcinoma-related Peptide in the Gastric Membrane of Chronic Gastritis Patients with Helicobacter-pylori Infection

    Institute of Scientific and Technical Information of China (English)

    HUANG Guo-dong; HUANG Yuan-hua; XIAO Mei-zhen; HUANG Dao-fu; LIU Juan; LI Jia-bang

    2008-01-01

    Objective: To observe the effect of volatile oil of amomum (VOA) on the expressions of mastocarcinoma-related peptide (PS2) and platelet activating factor (PAF) in helicobacter pylori-associated gastritis (HPG) and to analyze its potential mechanism. Methods: Eighty patients with HPG were randomly assigned to two groups, 42 patients in the treated group treated with 0.5 mL VOA, thrice per day; and the 38 patients in the control group receiving Western tertiary medicinal treatment. Gastroscopic picture and helicobacter pylori (HP) infection (by quick urease and Warthin-Starry stain) of the gastro-membrane, expressions of PS2 and PAF (by immunohistochemical assay and Western blotting) as well as the contents of aminohexose and phospholipid (by Neuhaus method) in the gastric membrane of all patients were detected before treatment and 4 weeks after treatment. The clinical efficacy in the two groups was compared. Results: The total effective rate in the treated group was 88.1%, which was significantly higher than that in the control group (78.9%, P 0.05). Conclusion: The mechanism of VOA for anti-gastritis might be related with its action in increasing the expression of PS2 and decreasing the expression of PAF, and thus regulating the hydrophobicity of the gastric membrane.

  11. Reactivation of Gαi-coupled formyl peptide receptors is inhibited by Gαq-selective inhibitors when induced by signals generated by the platelet-activating factor receptor.

    Science.gov (United States)

    Holdfeldt, André; Dahlstrand Rudin, Agnes; Gabl, Michael; Rajabkhani, Zahra; König, Gabriele M; Kostenis, Evi; Dahlgren, Claes; Forsman, Huamei

    2017-09-01

    Formyl peptide receptor (FPR)-desensitized neutrophils display increased production/release of superoxide (O2(-)) when activated by platelet-activating factor (PAF), a priming of the response achieved through a unique receptor crosstalk mechanism. The aim of this study was to determine the effect of an inhibitor selective for small, heterotrimeric G proteins belonging to the Gαq subclass on that receptor crosstalk. We show that signals generated by FPRs and the PAF receptor (PAFR) induce activation of the neutrophil O2(-), producing NADPH-oxidase, and that response was sensitive to Gαq inhibition in cells activated by PAF, but no inhibition was obtained in cells activated by FPR agonists. Signaling in naive neutrophils is terminated fairly rapidly, and the receptors become homologously desensitized. The downstream sensitivity to Gαq inhibition in desensitized cells displaying increased production/release of O2(-) through the PAFR receptor crosstalk mechanism also comprised the reactivation of the FPRs, and the activation signals were redirected from the PAFR to the desensitized/reactivated FPRs. The Gαq-dependent activation signals generated by the PAFRs activate the Gαi-coupled FPRs, a receptor crosstalk that represents a novel pathway by which G protein-coupled receptors can be regulated and signaling can be turned on and off. © Society for Leukocyte Biology.

  12. The Correlation Analysis of Primary Nephrotic Syndrome with Platelet Activating Factor Acetylhydrolase%原发性肾病综合征与血小板活化因子水解酶的相关性分析

    Institute of Scientific and Technical Information of China (English)

    田鲁; 胡亚琳; 操轩

    2015-01-01

    Objective:To observe the correlation of primary nephrotic syndrome ( primary nephritic syn-drome,PNS) with platelet activating factor acetylhydrolase (platelet activating factor cetylhydrolase ,PAF-AH).Method:48 patients with primary nephrotic syndrome treated in the hospital from Jan .2013 to Jun. 2013 were selected as the research object , all were initial treatment patients .They were divided into simple nephrotic syndrome group (STNS group with 31 cases) and nephritic type nephrotic syndrome group (NTNS group with 17 cases);and according to the difference in effects of hormone treatment all patients were divided sensitive nephrotic syndrome ( steroid-sensitive nephritic syndrome , SSNS ) group ( 19 cases ) , steroid re-sistant nephrotic syndrome (steroid-resistent nephritic syndrome, SRNS) group (15 cases), steroid depend-ent nephrotic syndrome group ( steroid-dependent nephritic syndrome , SDNS ) group ( 14 cases ) , then se-lected healthy persons with 30 cases as control group , 78 cases were determined the activity of PAF-AH, then compared differences between two groups .Result:PAF-AH activity in STNS group was(51.9 ±8.3)μmoL· min-1 · L-1 and was higher than those in NTNS group and healthy control group , all P<0.05; and NTNS activity in PAF-AH group were higher than that in healthy control group , all P<0.05.The activity of PAF-AH in SSNS group were higher than those in SRNS group , SDNS group and the control group , P<0.05 group, SDNS group, SRNS and PAF-AH activity were higher than the control group , all P<0.05.By the a-nalysis of perason , PAF-AH activity and primary nephrotic syndrome had obvious correlation analysis ,rSTNS=0.618;rNTNS=0.524; rSSNS=0.717; rSRNS=0.567.; rSDNS=0.327, P<0.05.Conclusion: Platelet activating factor acetylhydrolase activity of patients with nephrotic syndrome is significantly higher than the normal population, and the different types of PNS patients ’ PAF-AH activity are different.%目的:观察

  13. Effect of BN 52021, a specific antagonist of platelet activating factor (PAF-acether), on calcium movements and phosphatidic acid production induced by PAF-acether in human platelets

    Energy Technology Data Exchange (ETDEWEB)

    Simon, M.F.; Chap, H.; Braquet, P.; Douste-Blazy, L.

    1987-02-15

    /sup 32/P-labelled human platelets loaded with quin 2 and pretreated with aspirin were stimulated with 1-100 nM platelet activating factor (PAF-acether or 1-0-alkyl-2-acetyl-sn-glycero-3-phosphocholine) in a medium containing the ADP-scavenging system creatine phosphate/creatine phosphokinase. Under these conditions, PAF-acether evoked a characteristic fluorescence change allowing to quantify elevations in cytoplasmic free Ca/sup 2 +/ from internal stores (Ca/sup 2 +/ mobilization) or from external medium (Ca/sup 2 +/ influx), as well as an increased production of phosphatidic acid, reflecting phospholipase C activation. These effects, which can be attributed to PAF-acether only and not to released products such as ADP or thromboxane A2, were strongly inhibited in a dose-dependent manner by BN 52021, a specific antagonist of PAF-acether isolated from Ginkgo biloba. As the drug remained inactive against the same effects elicited by thrombin, it is concluded that BN 52021 does not interfere directly with the mechanism of transmembrane signalling involving inositol-phospholipids or (and) some putative receptor-operated channels, but rather acts on the binding of PAF-acether to its presumed membrane receptor.

  14. Platelet-Activating Factor Blockade Inhibits the T-Helper Type 17 Cell Pathway and Suppresses Psoriasis-Like Skin Disease in K5.hTGF-β1 Transgenic Mice

    Science.gov (United States)

    Singh, Tej Pratap; Huettner, Barbara; Koefeler, Harald; Mayer, Gerlinde; Bambach, Isabella; Wallbrecht, Katrin; Schön, Michael P.; Wolf, Peter

    2011-01-01

    Platelet-activating factor (PAF), a potent biolipid mediator, is involved in a variety of cellular transduction pathways and plays a prominent role in inducing inflammation in different organs. We used K5.hTGF-β1 transgenic mice, which exhibit an inflammatory skin disorder and molecular and cytokine abnormalities with strong similarities to human psoriasis, to study the pathogenic role of PAF. We found that injecting PAF into the skin of transgenic mice led to inflammation and accelerated manifestation of the psoriatic phenotype by a local effect. In contrast, injecting mice with PAF receptor antagonist PCA-4248 lowered the PAF level (most likely by depressing an autocrine loop) and neutrophil, CD68+ cell (monocyte/macrophage), and CD3+ T-cell accumulation in the skin and blocked progression of the psoriasis-like phenotype. This effect of PAF blockade was specific and similar to that of psoralen–UV-A and was paralleled by a decrease in abnormally elevated mRNA and/or protein levels of T-helper type 17 cell–related cytokines IL-17A, IL-17F, IL-23, IL-12A, and IL-6 and its transcription factor signal transducer and activator of transcription 3. In contrast, PCA-4248 treatment up-regulated mRNA levels of cyclooxygenase-2 and IL-10 in dorsal skin and release of IL-10 in serum and skin. Interfering with PAF may offer the opportunity to develop novel therapeutic strategies for inflammatory psoriasis and associated comorbidities, including metabolic syndrome and atherosclerosis, in which the IL-17 axis may be involved. PMID:21281802

  15. Treatment with a histone deacetylase inhibitor, valproic acid, is associated with increased platelet activation in a large animal model of traumatic brain injury and hemorrhagic shock

    DEFF Research Database (Denmark)

    Dekker, Simone E; Sillesen, Martin; Bambakidis, Ted

    2014-01-01

    BACKGROUND: We have previously shown that resuscitation with fresh frozen plasma (FFP) in a large animal model of traumatic brain injury (TBI) and hemorrhagic shock (HS) decreases the size of the brain lesion, and that addition of a histone deacetylase inhibitor, valproic acid (VPA), provides...... synergistic benefits. In this study, we hypothesized that VPA administration would be associated with a conservation of platelet function as measured by increased platelet activation after resuscitation. MATERIALS AND METHODS: Ten swine (42-50 kg) were subjected to TBI and HS (40% blood loss). Animals were...... left in shock for 2 h before resuscitation with either FFP or FFP + VPA (300 mg/kg). Serum levels of platelet activation markers transforming growth factor beta, CD40 L, P-selectin, and platelet endothelial cell adhesion molecule (PECAM) 1 were measured at baseline, postresuscitation, and after a 6-h...

  16. A study on single nucleotide polymorphism of exon 7 T/C (locus 593 of platelet-activating factor acetylhydrolase gene in healthy Han population in the Shanghai region

    Directory of Open Access Journals (Sweden)

    Tian-bao XIA

    2012-08-01

    Full Text Available Objective To investigate the distribution of single nucleotide polymorphism (SNP in platelet-activating factor acetylhydrolase (PAF-AH gene exon 7 T/C (locus 593 in healthy Han population in Shanghai region and the features different from other races. Methods The SNP in PAF-AH gene exon 7 T/C (locus 593 was detected and analyzed by PCR and sequencing in 110 healthy Han people from Shanghai areas. The genotype and allele frequency were then calculated and compared with that in other races in combination with review of relevant literature. Results The amplified product of the SNP in PAF-AH gene exon 7 T/C (locus 593 was 240 bp in 110 healthy Han people, of whom 97 were with TT genotype and 13 with TC genotype, but no CC genotype was found. As to the allele frequency distribution, T type allele took the highest position, and C type followed. The genotype frequency of TT and TC was 88.2% and 11.8%, respectively, and they were markedly different from that in German population (0.95%, while not statistically significant different from that in British population (7.67%. Conclusions There exists SNP in PAF-AH gene exon 7 T/C (position 593 in healthy Han people in Shanghai region, with a higher frequency of T→C mutation. The mutational genotype frequency is found to be located at the locus 593 is 11.81%, and it is markedly different from that in German population, but not significantly different from that in British population.

  17. Unfractionated and low-molecular-weight heparin and the phosphodiesterase inhibitors, IBMX and cilostazol, block ex vivo Equid Herpesvirus type-1-induced platelet activation

    Directory of Open Access Journals (Sweden)

    Tracy Stokol

    2016-11-01

    Full Text Available Equid herpes virus type-1 (EHV-1 is a major pathogen of horses, causing abortion storms and outbreaks of herpes virus myeloencephalopathy. These clinical syndromes are partly attributed to ischemic injury from thrombosis in placental and spinal vessels. The mechanism of thrombosis in affected horses is unknown. We have previously shown that EHV-1 activates platelets through virus-associated tissue factor-initiated thrombin generation. Activated platelets participate in thrombus formation by providing a surface to localize coagulation factor complexes that amplify and propagate thrombin generation. We hypothesized that coagulation inhibitors that suppress thrombin generation (heparins or platelet inhibitors that impede post-receptor thrombin signaling (phosphodiesterase [PDE] antagonists would inhibit EHV-1-induced platelet activation ex vivo. We exposed platelet-rich plasma collected from healthy horses to the RacL11 abortigenic and Ab4 neuropathogenic strains of EHV-1 at 1 plaque forming unit/cell in the presence or absence of unfractionated heparin (UFH, low-molecular-weight (LMWH heparin or the PDE inhibitors, 3-isobutyl-1methylxanthine (IBMX and cilostazol. We assessed platelet activation status in flow cytometric assays by measuring P-selectin expression. We found that all of the inhibitors blocked EHV-1- and thrombin-induced platelet activation in a dose-dependent manner. Platelet activation in PRP was maximally inhibited at concentrations of 0.05 U/mL UFH and 2.5 μg/mL LMWH. These concentrations represented 0.1 to 0.2 U/mL anti-Factor Xa activity measured in chromogenic assays. Both IBMX and cilostazol showed maximal inhibition of platelet activation at the highest tested concentration of 50 μM but inhibition was lower than that seen with UFH and LMWH. Our results indicate that heparin anticoagulants and strong non-selective (IBMX or isoenzyme-3 selective (cilostazol PDE antagonists inhibit ex vivo EHV-1-induced platelet activation

  18. Echicetin coated polystyrene beads: a novel tool to investigate GPIb-specific platelet activation and aggregation.

    Science.gov (United States)

    Navdaev, Alexey; Subramanian, Hariharan; Petunin, Alexey; Clemetson, Kenneth J; Gambaryan, Stepan; Walter, Ulrich

    2014-01-01

    von Willebrand factor/ristocetin (vWF/R) induces GPIb-dependent platelet agglutination and activation of αIIbβ3 integrin, which also binds vWF. These conditions make it difficult to investigate GPIb-specific signaling pathways in washed platelets. Here, we investigated the specific mechanisms of GPIb signaling using echicetin-coated polystyrene beads, which specifically activate GPIb. We compared platelet activation induced by echicetin beads to vWF/R. Human platelets were stimulated with polystyrene beads coated with increasing amounts of echicetin and platelet activation by echicetin beads was then investigated to reveal GPIb specific signaling. Echicetin beads induced αIIbβ3-dependent aggregation of washed platelets, while under the same conditions vWF/R treatment led only to αIIbβ3-independent platelet agglutination. The average distance between the echicetin molecules on the polystyrene beads must be less than 7 nm for full platelet activation, while the total amount of echicetin used for activation is not critical. Echicetin beads induced strong phosphorylation of several proteins including p38, ERK and PKB. Synergistic signaling via P2Y12 and thromboxane receptor through secreted ADP and TxA2, respectively, were important for echicetin bead triggered platelet activation. Activation of PKG by the NO/sGC/cGMP pathway inhibited echicetin bead-induced platelet aggregation. Echicetin-coated beads are powerful and reliable tools to study signaling in human platelets activated solely via GPIb and GPIb-triggered pathways.

  19. Kaempferol inhibits thrombosis and platelet activation.

    Science.gov (United States)

    Choi, Jun-Hui; Park, Se-Eun; Kim, Sung-Jun; Kim, Seung

    2015-08-01

    The objectives of the present study were to investigate whether kaempferol affects pro-coagulant proteinase activity, fibrin clot formation, blood clot and thrombin (or collagen/epinephrine)-stimulated platelet activation, thrombosis, and coagulation in ICR (Imprinting Control Region) mice and SD (Sprague-Dawley) rats. Kaempferol significantly inhibited the enzymatic activities of thrombin and FXa by 68 ± 1.6% and 52 ± 2.4%, respectively. Kaempferol also inhibited fibrin polymer formation in turbidity. Microscopic analysis was performed using a fluorescent conjugate. Kaempferol completely attenuated phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, p38, c-Jun N-terminal kinase (JNK) 1/2, and phosphoinositide 3-kinase (PI3K)/PKB (AKT) in thrombin-stimulated platelets and delayed aggregation time (clotting) by 34.6% in an assay of collagen/epinephrine-stimulated platelet activation. Moreover, kaempferol protected against thrombosis development in 3 animal models, including collagen/epinephrine- and thrombin-induced acute thromboembolism models and an FeCl3-induced carotid arterial thrombus model. The ex vivo anticoagulant effect of kaempferol was further confirmed in ICR mice. This study demonstrated that kaempferol may be clinically useful due to its ability to reduce or prevent thrombotic challenge.

  20. 强化他汀对大鼠心肌梗死后血小板活化及炎症的影响%Effect of intensive statin on platelet activity and inflammation factors in rat with myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    唐显军; 钟艺华; 南映瑜

    2015-01-01

    目的:探讨强化他汀对大鼠心肌梗死后24 h血小板活化及炎症因子的影响。方法70只SD大鼠分为SHAM 组、心肌梗死对照组、常规剂量组、强化他汀组、混合剂量组,每组14只。予以手术开胸结扎大鼠心脏左冠状动脉前降支制备心肌梗死动物模型(SHAM组只穿线不结扎)。术前常规剂量组、混合剂量组分别予以小剂量阿托伐他汀(10 mg · kg -1· d-1)灌胃2周;强化他汀组、混合剂量组术前12 h给予单剂阿托伐他汀50 mg/kg 灌胃;各组大鼠于术后24 h采血检测肿瘤坏死因子‐α(TNF‐α)、超敏C‐反应蛋白(hs‐CRP)、血小板活化因子‐1(PAC‐1)、CD62p。结果术后24 h急性炎症因子 TNF‐α、hs‐CRP水平心肌梗死对照组显著高于SHAM 组,血小板活化表面标志物PAC‐1、CD62p亦显著性高于SHAM 组(P<0.05);强化他汀组炎症因子水平,血小板活化标志物显著低于心肌梗死对照组(P<0.05);强化他汀组与混合剂量组比较,在炎症因子,血小板活化标志物水平差异无统计学意义(P>0.05);常规剂量他汀组在心肌梗死大鼠术后短期与心肌梗死对照组比较炎症因子,血小板活化标志物水平差异无统计学意义(P>0.05)。结论术前使用强化阿托伐他汀能显著降低心肌梗死大鼠术后急性炎性反应,抑制血小板活化。%Objective To explore the effect of intensive statin on platelet activity and inflammation factors 24 h after rat myocar‐dial infarction .Methods Seventy Sprague‐Dawley rats were randomly divided into five groups (n= 14):Sham‐operated group (SHAM group);AMI group(control group) ,general group;intensive statin therapy group ;general and intensive statin therapy group;established AMI rat model by ligation of left anterior descending branch of coronary artery .The general group ,general and intensive statin therapy group was fed

  1. Platelet activation biomarkers in Berkeley sickle cell mice and the response to prasugrel.

    Science.gov (United States)

    Ohno, Kousaku; Tanaka, Hisako; Samata, Naozumi; Jakubowski, Joseph A; Tomizawa, Atsuyuki; Mizuno, Makoto; Sugidachi, Atsuhiro

    2014-10-01

    Vaso-occlusive crisis (VOC) is a common complication that occurs in sickle cell disease (SCD) patients. Although underlying mechanisms of VOC remain unclear, platelet activation has been associated with VOC. In the present study, plasma adenine nucleotide measurements using LC-ESI-MS/MS showed that plasma ADP in the Berkeley murine model of SCD was significantly higher (applox. 2.7-fold increase) compared with control mice. Assessment of platelet activation markers using flow cytometry indicated that in SCD mice at steady state (8 weeks old), circulating platelets were partially activated and this tended to increase with age (15 weeks old). The administration of prasugrel, a thienopiridyl P2Y12 antagonist, did not affect the activation state of circulating platelets suggesting P2Y12 independent mechanism of activation. In this murine SCD model, ex vivo addition of ADP or PAR4 TRAP resulted in further platelet activation as assessed by expression of activated GPIIb/IIIa and P-selectin both at 8 and 15 weeks. In 15 weeks old SCD mice, agonist-induced increases in activation markers were enhanced compared to control mice. Oral administration of prasugrel effectively inhibited ex vivo platelet activation consistent with clinical data in patients with SCD. In conclusion, in the Berkeley murine model of SCD, we found evidence of basal and agonist-stimulated platelet activation which could in part be attenuated by prasugrel. These data are consistent with observations made in patients with SCD and suggest possible utility of this murine model and prasugrel therapy in exploring treatment options for patients with SCD.

  2. 血小板活化因子乙酰水解酶与子痫前期的相关性研究%A study on the association between preeclampsia and platelet-activating factor acetylhydrolase

    Institute of Scientific and Technical Information of China (English)

    姜晶; 张华伟; 唐萍

    2014-01-01

    目的 通过测定子痫前期患者母血及新生儿脐血中血小板活化因子乙酰水解酶(platelet-activating factor-acetylhydrolase,PAF-AH)水平,探讨其在子痫前期中的作用.方法 选取妊娠晚期子痫前期患者46例作为子痫前期组(其中轻度子痫前期21例,重度子痫前期25例),30例正常晚期孕妇作为对照组;采用酶联免疫法测定两组母血及脐血中PAF-AH活性,分析其对子痫前期发病的影响.结果 ①子痫前期组PAF-AH活性[(10.52±3.11) μmol·min-1·L-1]与对照组[(11.40±2.88) μmol· min-1·L-1]比较,差异无统计学意义(P>0.05);但重度子痫前期组PAF-AH活性[(8.23±1.41) μmol·min1·L-1]与对照组比较,差异有统计学意义(P<0.05),重度子痫前期组PAF-AH活性与轻度组[(12.81±2.60) μmol·min-1·L-1]比较,差异有统计学意义(P<0.001);②子痫前期组脐血PAF-AH活性[(6.09±2.10) μmol·min-1·L-1]与对照组[(5.75±1.96) μmol·min-1·L-1]比较,差异无统计学意义(P>0.05);轻度子痫前期组脐血PAF-AH活性[(6.58±2.68) μmol·min-1·L-1]与重度组[(5.69±1.50) μmol·min-1·L-1]和对照组比较,差异均无统计学意义(P>0.05);③PAF-AH活性与子痫前期程度呈负相关(r=-0.405,P<0.05).结论 重度子痫前期患者中PAF-AH活性降低,其活性与子痫前期病情程度呈负相关,可能在子痫前期病情的发生发展中起着重要作用.

  3. Platelet activation by extracellular matrix proteins in haemostasis and thrombosis.

    Science.gov (United States)

    Watson, Steve P

    2009-01-01

    The prevention of excessive blood loss to avoid fatal haemorrhage is a pivotal process for all organisms possessing a circulatory system. Increased circulating blood volume and pressure, as required in larger animals, make this process all the more important and challenging. It is essential to have a powerful and rapid system to detect damage and generate an effective seal, and which is also exquisitely regulated to prevent unwanted, excessive or systemic activation so as to avoid blockage of vessels. Thus, a highly specialised and efficient haemostatic system has evolved that consists of cellular (platelets) and protein (coagulation factors) components. Importantly, this is able to support haemostasis in both the low shear environment of the venous system and the high shear environment of the arterial system. Endothelial cells, lining the entire circulation system, play a crucial role in the delicate balance between activation and inhibition of the haemostatic system. An intact and healthy endothelium supports blood flow by preventing attachment of cells and proteins which is required for initiation of coagulation and platelet activation. Endothelial cells produce and release the two powerful soluble inhibitors of platelet activation, nitric oxide and prostacyclin, and express high levels of CD39 which rapidly metabolises the major platelet feedback agonist, ADP. This antithrombotic environment however can rapidly change following activation or removal of endothelial cells through injury or rupture of atherosclerotic plaques. Loss of endothelial cells exposes the subendothelial extracellular matrix which creates strong signals for activation of the haemostatic system including powerful platelet adhesion and activation. Quantitative and qualitative changes in the composition of the subendothelial extracellular matrix influence these prothrombotic characteristics with life threatening thrombotic and bleeding complications, as illustrated by formation of

  4. Echicetin coated polystyrene beads: a novel tool to investigate GPIb-specific platelet activation and aggregation.

    Directory of Open Access Journals (Sweden)

    Alexey Navdaev

    Full Text Available von Willebrand factor/ristocetin (vWF/R induces GPIb-dependent platelet agglutination and activation of αIIbβ3 integrin, which also binds vWF. These conditions make it difficult to investigate GPIb-specific signaling pathways in washed platelets. Here, we investigated the specific mechanisms of GPIb signaling using echicetin-coated polystyrene beads, which specifically activate GPIb. We compared platelet activation induced by echicetin beads to vWF/R. Human platelets were stimulated with polystyrene beads coated with increasing amounts of echicetin and platelet activation by echicetin beads was then investigated to reveal GPIb specific signaling. Echicetin beads induced αIIbβ3-dependent aggregation of washed platelets, while under the same conditions vWF/R treatment led only to αIIbβ3-independent platelet agglutination. The average distance between the echicetin molecules on the polystyrene beads must be less than 7 nm for full platelet activation, while the total amount of echicetin used for activation is not critical. Echicetin beads induced strong phosphorylation of several proteins including p38, ERK and PKB. Synergistic signaling via P2Y12 and thromboxane receptor through secreted ADP and TxA2, respectively, were important for echicetin bead triggered platelet activation. Activation of PKG by the NO/sGC/cGMP pathway inhibited echicetin bead-induced platelet aggregation. Echicetin-coated beads are powerful and reliable tools to study signaling in human platelets activated solely via GPIb and GPIb-triggered pathways.

  5. Echicetin Coated Polystyrene Beads: A Novel Tool to Investigate GPIb-Specific Platelet Activation and Aggregation

    Science.gov (United States)

    Petunin, Alexey; Clemetson, Kenneth J.; Gambaryan, Stepan; Walter, Ulrich

    2014-01-01

    von Willebrand factor/ristocetin (vWF/R) induces GPIb-dependent platelet agglutination and activation of αIIbβ3 integrin, which also binds vWF. These conditions make it difficult to investigate GPIb-specific signaling pathways in washed platelets. Here, we investigated the specific mechanisms of GPIb signaling using echicetin-coated polystyrene beads, which specifically activate GPIb. We compared platelet activation induced by echicetin beads to vWF/R. Human platelets were stimulated with polystyrene beads coated with increasing amounts of echicetin and platelet activation by echicetin beads was then investigated to reveal GPIb specific signaling. Echicetin beads induced αIIbβ3-dependent aggregation of washed platelets, while under the same conditions vWF/R treatment led only to αIIbβ3-independent platelet agglutination. The average distance between the echicetin molecules on the polystyrene beads must be less than 7 nm for full platelet activation, while the total amount of echicetin used for activation is not critical. Echicetin beads induced strong phosphorylation of several proteins including p38, ERK and PKB. Synergistic signaling via P2Y12 and thromboxane receptor through secreted ADP and TxA2, respectively, were important for echicetin bead triggered platelet activation. Activation of PKG by the NO/sGC/cGMP pathway inhibited echicetin bead-induced platelet aggregation. Echicetin-coated beads are powerful and reliable tools to study signaling in human platelets activated solely via GPIb and GPIb-triggered pathways. PMID:24705415

  6. Reduction of CTRP9, a novel anti-platelet adipokine, contributes to abnormal platelet activity in diabetic animals.

    Science.gov (United States)

    Wang, Wenqing; Lau, Wayne Bond; Wang, Yajing; Ma, Xinliang; Li, Rong

    2016-01-11

    Platelet hyper-reactivity is a crucial cause of accelerated atherosclerosis increasing risk of thrombotic vascular events in diabetic patients. The mechanisms leading to abnormal platelet activity during diabetes are complex and not fully defined. The current study attempted to clarify the role of CTRP9, a novel adiponectin paralog, in enhanced platelet activity and determined whether CTRP9 may inhibit platelet activity. Adult male C57BL/6 J mice were randomized to receive high-fat diet (HFD) or normal diet (ND). 8 weeks after HFD, animals were sacrificed, and both plasma CTRP9 and platelet aggregation were determined. HFD-fed animals increased weight gain significantly, and became hyperglycemic and hyperinsulinemic 8 weeks post-HFD. Compared to ND animals, HFD animals exhibited significantly decreased plasma CTRP9 concentration and increased platelet response to ADP, evidenced by augmented aggregation amplitude, steeper aggregation slope, larger area under the curve, and shorter lag time (P animals. Taken together, our results suggest reduced plasma CTRP9 concentration during diabetes plays a causative role in platelet hyper-activity, contributing to platelet-induced cardiovascular damage during this pathologic condition. Enhancing CTRP9 production and/or exogenous supplementation of CTRP9 may protect against diabetic cardiovascular injury via inhibition of abnormal platelet activity.

  7. LDL oxidation by platelets propagates platelet activation via an oxidative stress-mediated mechanism.

    Science.gov (United States)

    Carnevale, Roberto; Bartimoccia, Simona; Nocella, Cristina; Di Santo, Serena; Loffredo, Lorenzo; Illuminati, Giulio; Lombardi, Elisabetta; Boz, Valentina; Del Ben, Maria; De Marco, Luigi; Pignatelli, Pasquale; Violi, Francesco

    2014-11-01

    Platelets generate oxidized LDL (ox-LDL) via NOX2-derived oxidative stress. We investigated if once generated by activated platelets ox-LDL can propagate platelet activation. Experiments were performed in platelets from healthy subjects (HS), hyper-cholesterolemic patients and patients with NOX2 hereditary deficiency. Agonist-stimulated platelets from HS added with LDL were associated with a dose-dependent increase of reactive oxidant species and ox-LDL. Agonist-stimulated platelets from HS added with a fixed dose of LDL (57.14 μmol/L) or added with homogenized human atherosclerotic plaque showed enhanced ox-LDL formation (approximately +50% and +30% respectively), which was lowered by a NOX2 inhibitor (approximately -35% and -25% respectively). Compared to HS, ox-LDL production was more pronounced in agonist-stimulated platelet rich plasma (PRP) from hyper-cholesterolemic patients but was almost absent in PRP from NOX2-deficient patients. Platelet aggregation and 8-iso-PGF2α-ΙΙΙ formation increased in LDL-treated washed platelets (+42% and +53% respectively) and PRP (+31% and +53% respectively). Also, LDL enhanced platelet-dependent thrombosis at arterial shear rate (+33%) but did not affect platelet activation in NOX2-deficient patients. Platelet activation by LDL was significantly inhibited by CD36 or LOX1 blocking peptides, two ox-LDL receptor antagonists, or by a NOX2 inhibitor. LDL-added platelets showed increased p38MAPK (+59%) and PKC (+51%) phosphorylation, p47(phox) translocation to platelet membrane (+34%) and NOX2 activation (+30%), which were inhibited by ox-LDL receptor antagonists. Platelets oxidize LDL, which in turn amplify platelet activation via specific ox-LDL receptors; both effects are mediated by NOX2 activation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  8. Platelet activation through a Bi-leaflet mechanical heart valve

    Science.gov (United States)

    Hedayat, Mohammadali; Borazjani, Iman

    2016-11-01

    Platelet activation is one of the major drawbacks of the Mechanical Heart Valves (MHVs) which can increase the risk of thrombus formation in patients. The platelet activation in MHVs can be due to the abnormal shear stress during the systole, the backward leakage flow during the diastole, and the flow through the hinge region. We investigate the contribution of each of the above mechanism to the activation of platelets in MHVs by performing simulations of the flow through the MHV and in the hinge region. The large scale heart valve simulations are performed in a straight aorta using a sharp interface curvilinear immersed boundary method along with a strong-coupling algorithm under physiological flow conditions. In addition, in order to perform the simulation of hinge region the flow field boundary conditions are obtained from the largescale simulations during a whole cardiac cycle. In order to investigate the role of hinge flow on platelet activation in MHVs, a 23mm St. Jude Medical Regent valve hinge with three different gap sizes is tested along with different platelet activation models to ensure the consistency of our results with different activation models. We compare the platelet activation of the hinge region against the bulk of the flow during one cardiac cycle. This work is supported by the American Heart Association Grant 13SDG17220022, and the computational resources were partly provided by Center for Computational Research (CCR) at University at Buffalo.

  9. The effect of centrifugation speed and time on pre-analytical platelet activation

    DEFF Research Database (Denmark)

    Söderström, Anna Cecilia; Nybo, Mads; Nielsen, Christian

    2016-01-01

    . METHODS: Citrate- and EDTA-anticoagulated blood from healthy volunteers were centrifuged at 80-10,000 g for 5-15 min to prepare plasma and platelet-rich plasma. Pre-analytical platelet activation was assessed by flow cytometric measurement of platelet P-selectin (CD62p) expression. Blood cell counts, mean...... platelet volume (MPV), immature platelet fraction (IPF), and platelet distribution width (PDW) were measured. Platelet aggregation in platelet-rich plasma induced by arachidonic acid (AA), ADP or thrombin receptor activator peptide-6 (TRAP) was tested by 96-well aggregometry. RESULTS: The median percentage...... of platelets expressing P-selectin in citrate- and EDTA-plasma centrifuged at 2000 g for 10 min were 43% [interquartile range (IQR), 38%-53%] and 56% (IQR, 31%-78%), respectively (p=0.82). Platelet-rich plasma prepared at 100-250 g for 10 min had significantly lower platelet P-selectin expression (11%-15%), p...

  10. Oxidative damage and platelet activation as new predictors of mobility disability and mortality in elders.

    Science.gov (United States)

    Cesari, Matteo; Kritchevsky, Stephen B; Leeuwenburgh, Christiaan; Pahor, Marco

    2006-01-01

    Mobility disability is an early phase of the disablement process in older adults, and represents a major risk factor for physical disability and mortality. Pathophysiological mechanisms responsible for the onset of mobility limitation are still largely unknown. Oxidative damage, responsible for the disruption of the equilibrium of biological systems by damaging major constituent molecules, might play an important role in the pathway leading to major health-related events. It has been suggested the existence of a vicious cycle involving oxidative damage, platelet activation, and inflammation as promoter of pathophysiological changes occurring with aging. This hypothesis is based on the following observations: (a) oxidative damage is associated with diseases and clinical conditions potentially leading to disability and mortality; (b) oxidative damage is associated with platelet activation, and a vicious cycle involving oxidative damage, platelet activation, and inflammation has been demonstrated in several metabolic disorders potentially leading to mobility disability; (c) the age-related physical decline may be associated to the oxidative damage due to the excess of free radicals; (d) antioxidant defense and behavioral factors (e.g., physical activity, dietary restriction, smoking cessation) play an important role in the reduction of oxidative damage levels and are associated with improved physical performance and muscle strength.

  11. Platelet Activating Factor: A Growth Factor for Breast Cancer

    Science.gov (United States)

    2006-09-01

    families are obtained only from the diet. The omega 3 family is enriched in fish and grains and the omega 6 family is enriched in the meats and oils... omega 3 and omega 6 fatty acids influences the synthesis of PAF. This idea came from the fact that these fatty acids must be removed from the precursor

  12. Phage-Derived Protein Induces Increased Platelet Activation and Is Associated with Mortality in Patients with Invasive Pneumococcal Disease

    Directory of Open Access Journals (Sweden)

    Rahajeng N. Tunjungputri

    2017-01-01

    Full Text Available To improve our understanding about the severity of invasive pneumococcal disease (IPD, we investigated the association between the genotype of Streptococcus pneumoniae and disease outcomes for 349 bacteremic patients. A pneumococcal genome-wide association study (GWAS demonstrated a strong correlation between 30-day mortality and the presence of the phage-derived gene pblB, encoding a platelet-binding protein whose effects on platelet activation were previously unknown. Platelets are increasingly recognized as key players of the innate immune system, and in sepsis, excessive platelet activation contributes to microvascular obstruction, tissue hypoperfusion, and finally multiorgan failure, leading to mortality. Our in vitro studies revealed that pblB expression was induced by fluoroquinolones but not by the beta-lactam antibiotic penicillin G. Subsequently, we determined pblB induction and platelet activation by incubating whole blood with the wild type or a pblB knockout mutant in the presence or absence of antibiotics commonly administered to our patient cohort. pblB-dependent enhancement of platelet activation, as measured by increased expression of the α-granule protein P-selectin, the binding of fibrinogen to the activated αIIbβ3 receptor, and the formation of platelet-monocyte complex occurred irrespective of antibiotic exposure. In conclusion, the presence of pblB on the pneumococcal chromosome potentially leads to increased mortality in patients with an invasive S. pneumoniae infection, which may be explained by enhanced platelet activation. This study highlights the clinical utility of a bacterial GWAS, followed by functional characterization, to identify bacterial factors involved in disease severity.

  13. Phage-Derived Protein Induces Increased Platelet Activation and Is Associated with Mortality in Patients with Invasive Pneumococcal Disease

    Science.gov (United States)

    Cremers, Amelieke J.; van der Gaast-de Jongh, Christa E.; Ferwerda, Gerben; Meis, Jacques F.; Roeleveld, Nel; Bentley, Stephen D.; Pastura, Alexander S.; van Hijum, Sacha A. F. T.; van der Ven, Andre J.; de Mast, Quirijn; Zomer, Aldert

    2017-01-01

    ABSTRACT To improve our understanding about the severity of invasive pneumococcal disease (IPD), we investigated the association between the genotype of Streptococcus pneumoniae and disease outcomes for 349 bacteremic patients. A pneumococcal genome-wide association study (GWAS) demonstrated a strong correlation between 30-day mortality and the presence of the phage-derived gene pblB, encoding a platelet-binding protein whose effects on platelet activation were previously unknown. Platelets are increasingly recognized as key players of the innate immune system, and in sepsis, excessive platelet activation contributes to microvascular obstruction, tissue hypoperfusion, and finally multiorgan failure, leading to mortality. Our in vitro studies revealed that pblB expression was induced by fluoroquinolones but not by the beta-lactam antibiotic penicillin G. Subsequently, we determined pblB induction and platelet activation by incubating whole blood with the wild type or a pblB knockout mutant in the presence or absence of antibiotics commonly administered to our patient cohort. pblB-dependent enhancement of platelet activation, as measured by increased expression of the α-granule protein P-selectin, the binding of fibrinogen to the activated αIIbβ3 receptor, and the formation of platelet-monocyte complex occurred irrespective of antibiotic exposure. In conclusion, the presence of pblB on the pneumococcal chromosome potentially leads to increased mortality in patients with an invasive S. pneumoniae infection, which may be explained by enhanced platelet activation. This study highlights the clinical utility of a bacterial GWAS, followed by functional characterization, to identify bacterial factors involved in disease severity. PMID:28096486

  14. Effect of simvastatin combined amlodipine besylate on blood rheology and platelet activation in elderly patients with hypertension complicated with hyperlipemia

    Institute of Scientific and Technical Information of China (English)

    Ming-Zheng Jiang; Li Qiong; Hui Liu

    2016-01-01

    Objective:To investigate the effect of simvastatin combined amlodipine besylate on blood rheology and platelet activation in elderly patients with hypertension complicated with hyperlipemia.Methods: A total of 200 elderly patients with hypertension complicated with hyperlipemia were divided into hypertension group (n=64), hyperlipemia group (n=71) and combined (hypertension complicated with hyperlipemia) group (n=65). And alternate period health check-up 100 cases were selected as control group. The hypertension group was treated with amlodipine besylate monotherapy, hyperlipidemia group with simvastatin monotherapy, combined group received simvastatin combined with amlodipine besylate treatment, patients of three groups were treated for 12 weeks. Blood rheology and platelet activation before and after treatment were compared.Results: After treatment, blood pressure was significantly lower than that before treatment in hypertension and combined group (P<0.05), and the combined group reduced more significantly (P<0.05), blood fat was significantly lower than that before treatment in hyperlipemia and combined group (P<0.05), and combined group reduced more significantly (P<0.05); Before treatment, indexes of blood rheology (high shear whole blood viscosity, low shear whole blood viscosity, plasma viscosity, fibrinogen and platelet activation index (CD62p and CD63) of three groups were significantly higher than those in control group (P<0.05), and the combined group was increased more significantly than hypertension and hyperlipidemia group (P<0.05); After treatment, blood rheology (high shear whole blood viscosity, low shear whole blood viscosity, plasma viscosity, fibrinogen) and platelet activation index (CD62p and CD63) of hyperlipidemia group and combined group were significantly lower than before treatment (P<0.05), and the reduction combined group were more significant in amplitude (P<0.05).Conclusions: Simvastatin combined amlodipine besylate therapy can

  15. Plasma factor XIII and platelet factor XIII in hyperlipaemia.

    Science.gov (United States)

    Cucuianu, M P; Miloszewski, K; Porutiu, D; Losowsky, M S

    1976-12-31

    Plasma factor XIII activity measured by a quantitative assay was found to be significantly higher in hypertriglyceridaemic patients (type IV and combined hyperlipoproteinaemia), as compared to normolipaemic controls. No such elevation in plasma factor XIII activity was found in patients with type Ha hyperlipaemia. Plasma pseudocholinesterase was found to parallel the elevated factor XIII activity in hypertriglyceridaemic subjects. In contrast, platelet factor XIII activity was not raised in hyperlipaemic subjects, and plasma factor XIII was found to be normal in a normolipaemic subjects with thrombocythaemia. It was concluded that there is no significant contribution from platelets to plasma factor XIII activity, and that the observed increase in plasma factor XIII in hypertriglyceridaemia results from enhanced hepatic synthesis of the enzyme.

  16. DMSO inhibits human platelet activation through cyclooxygenase-1 inhibition. A novel agent for drug eluting stents?

    Energy Technology Data Exchange (ETDEWEB)

    Asmis, Lars [Institute for Clinical Hematology, University Hospital Zuerich, Zuerich (Switzerland); Tanner, Felix C. [Cardiovascular Research, Physiology Institute, University of Zuerich, Zuerich (Switzerland); Center for Integrative Human Physiology, University of Zuerich, Zuerich (Switzerland); Cardiology, Cardiovascular Center, University Hospital Zuerich, Zuerich (Switzerland); Sudano, Isabella [Cardiology, Cardiovascular Center, University Hospital Zuerich, Zuerich (Switzerland); Luescher, Thomas F. [Cardiovascular Research, Physiology Institute, University of Zuerich, Zuerich (Switzerland); Center for Integrative Human Physiology, University of Zuerich, Zuerich (Switzerland); Cardiology, Cardiovascular Center, University Hospital Zuerich, Zuerich (Switzerland); Camici, Giovanni G., E-mail: giovannic@access.uzh.ch [Cardiovascular Research, Physiology Institute, University of Zuerich, Zuerich (Switzerland); Center for Integrative Human Physiology, University of Zuerich, Zuerich (Switzerland)

    2010-01-22

    Background: DMSO is routinely infused together with hematopoietic cells in patients undergoing myeloablative therapy and was recently found to inhibit smooth muscle cells proliferation and arterial thrombus formation in the mouse by preventing tissue factor (TF), a key activator of the coagulation cascade. This study was designed to investigate whether DMSO prevents platelet activation and thus, whether it may represent an interesting agent to be used on drug eluting stents. Methods and results: Human venous blood from healthy volunteers was collected in citrated tubes and platelet activation was studied by cone and platelet analyzer (CPA) and rapid-platelet-function-assay (RPFA). CPA analysis showed that DMSO-treated platelets exhibit a lower adherence in response to shear stress (-15.54 {+-} 0.9427%, n = 5, P < 0.0001 versus control). Additionally, aggregometry studies revealed that DMSO-treated, arachidonate-stimulated platelets had an increased lag phase (18.0% {+-} 4.031, n = 9, P = 0.0004 versus control) as well as a decreased maximal aggregation (-6.388 {+-} 2.212%, n = 6, P = 0.0162 versus control). Inhibitory action of DMSO could be rescued by exogenous thromboxane A2 and was mediated, at least in part, by COX-1 inhibition. Conclusions: Clinically relevant concentrations of DMSO impair platelet activation by a thromboxane A2-dependent, COX-1-mediated effect. This finding may be crucial for the previously reported anti-thrombotic property displayed by DMSO. Our findings support a role for DMSO as a novel drug to prevent not only proliferation, but also thrombotic complications of drug eluting stents.

  17. Calcium-dependent synergistic interaction of platelet activating factor and epinephrine in human platelet aggregation%血小板活化因子和肾上腺素对人血小板凝集的钙依赖性协同作用

    Institute of Scientific and Technical Information of China (English)

    Sheikh Arshad SAEED; Huma RASHEED

    2003-01-01

    AIM: To investigate the mechanism (s) involved in the synergistic interaction of platelet activating factor (PAF) and epinephrine. METHODS: Blood was obtained from healthy human subjects reported to be free of medications for at least two weeks before sampling. Aggregation was monitored at 37 ℃ using Dual-channel Lumi-aggregometer.The resulting aggregation was recorded for 5 min by the measurement of light transmission as a function of time.RESULTS: Platelet aggregation mediated by subthreshold concentrations of PAF (5-8 nmol/L) plus epinephrine (0.5-2 μmol/L) was inhibited by α2-receptor blocker, yohimbine, and PAF receptor antagonist WEB 2086. This synergism was inhibited by calcium channel blockers, verapamil and diltiazem. In addition, platelet aggregation by co-addition of PAF and epinephrine was also inhibited by very low concentrations of phospholipase C (PLC)inhibitor (U73122; IC50=0.2 μmol/L), the MAP kinase inhibitor, PD 98059 (IC50=3 μmol/L), and cyclooxygenase (COX-1) inhibitors including indomethacin (IC50=0.25 μmol/L), flurbiprofen (IC50=0.7 μmol/L), and piroxicam (IC50=7 μmol/L). However, COX-2 inhibitors, nimesulide (IC50=26 μmol/L), NS-398 (IC50=7 μmol/L), and etodolac (IC50=15 μmol/L) were also effective in inhibiting the aggregation. The inhibitors of protein kinase C (chelerythrine)and tyrosine kinase (genistien), and phosphatidylinositol 3-kinase inhibitor (wortmannin) had no significant effect on platelet aggregation induced by PAF and epinephrine. CONCLUSION: The synergistic effect of PAF and epinephrine on human platelet aggregation is receptor-mediated and involves the activation of PLC/Ca2+, COX and MAP kinase signalling pathways.

  18. Valsartan Decreases Platelet Activity and Arterial Thrombotic Events in Elderly Patients with Hypertension

    Institute of Scientific and Technical Information of China (English)

    Fang Wu; Hong-Yan Wang; Fan Cai; Ling-Jie Wang; Feng-Ru Zhang; Xiao-Nan Chen; Qian Yang

    2015-01-01

    Background:Angiotensin type 1 receptor (AT1R) antagonists are extensively used for blood pressure control in elderly patients with hypertension.This study aimed to investigate the inhibitory effects of AT1R antagonist valsartan on platelet aggregation and the occurrence of cardio-cerebral thrombotic events in elderly patients with hypertension.Methods:Two-hundred and ten patients with hypertension and aged > 60 years were randomized to valsartan (n =140) or amlodipine (n =70) on admission.The primary endpoint was platelet aggregation rate (PAR) induced by arachidonic acid at discharge,and the secondary endpoint was the rate of thrombotic events including brain infarction and myocardial infarction during follow-up.Human aortic endothelial cells (HAECs) were stimulated by angiotensin Ⅱ (Ang Ⅱ,100 nmol/L) with or without pretreatment of valsartan (100 nmol/L),and relative expression of cyclooxygenase-2 (COX-2) and thromboxane B2 (TXB2) and both p38 mitogen-activated protein kinase (p38MAPK) and nuclear factor-kB (NF-kB) activities were assessed.Statistical analyses were performed by GraphPad Prism 5.0 software (GraphPad Software,Inc.,California,USA).Results:PAR was lower after treatment with valsartan (1 1.49 ± 0.69% vs.18.71 ± 2.47%,P < 0.001),associated with more reduced plasmalevels of COX-2 (76.94 ± 7.07 U/L vs.116.4 ± 15.89 U/L,P < 0.001) and TXB2 (1667 ± 56.50 pg/ml vs.2207 ± 180.20 pg/ml) (all P < 0.001).Plasma COX-2 and TXB2 levels correlated significantly with PAR in overall patients (r =0.109,P < 0.001).During follow-up (median,18 months),there was a significantly lower thrombotic event rate in patients treated with valsartan (14.3% vs.32.8%,P =0.002).Relative expression of COX-2 and secretion of TXB2 with concordant phosphorylation ofp38MAPK and NF-kB were increased in HAECs when stimulated by Ang Ⅱ (100 nmol/L) but were significantly decreased by valsartan pretreatment (100 nmol/L).Conclusions:AT1R antagonist valsartan

  19. Salivary Platelet Activating Factor Levels in Periodontal Disease

    Science.gov (United States)

    1991-05-01

    Genco , et al, 1974). Several studies suggest that periodontal tissue damage may occur due to inflammatory cells and mediators. Taichman et al (1966...Listgarten, et al. 1968. Electron microscopic features of chronically inflammed human gingiva. J. Periodont. Res., 3:313. Genco , R.J., P.A. Mashimo

  20. Correlation between Platelet Gelsolin and Platelet Activation Level in Acute Myocardial Infarction Rats and Intervention Effect of Effective Components of Chuanxiong Rhizome and Red Peony Root

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    Yue Liu

    2013-01-01

    Full Text Available The biological role of platelet gelsolin in platelet activation of acute myocardial infarction is not defined. In order to provide a potential new antiplatelet target for Chinese medicine and to elucidate the contribution of Xiongshao capsule, the effective components of Chuanxiong rhizome and red peony root, in this study, we randomly allocated Sprague Dawley rats to left anterior descending coronary artery ligation or sham surgery and different drug prophylaxis as control. We found that gelsolin is highly expressed in platelet rich plasma and lowly expressed in platelet poor plasma, accompanied by the high platelet activation level in model rats; plasma actin filaments and mean fluorescence intensity (MFI of platelet calcium ion increased and plasma vitamin D binding protein decreased in model rats. Xiongshao capsule could inhibit the gelsolin expression in platelet rich plasma and ischemic heart tissue simultaneously and reduce the level of plasma F-actin and MFI of platelet calcium ion. Our study concludes that platelet gelsolin is an important contributor to platelet activation, and platelet gelsolin inhibition may form a novel target for antiplatelet therapy. Xiongshao capsule may be a promising Chinese medicine drug for antiplatelet and aspirin-like cardioprotection effect.

  1. The human endogenous circadian system causes greatest platelet activation during the biological morning independent of behaviors.

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    Frank A J L Scheer

    Full Text Available BACKGROUND: Platelets are involved in the thromboses that are central to myocardial infarctions and ischemic strokes. Such adverse cardiovascular events have day/night patterns with peaks in the morning (~9 AM, potentially related to endogenous circadian clock control of platelet activation. The objective was to test if the human endogenous circadian system influences (1 platelet function and (2 platelet response to standardized behavioral stressors. We also aimed to compare the magnitude of any effects on platelet function caused by the circadian system with that caused by varied standardized behavioral stressors, including mental arithmetic, passive postural tilt and mild cycling exercise. METHODOLOGY/PRINCIPAL FINDINGS: We studied 12 healthy adults (6 female who lived in individual laboratory suites in dim light for 240 h, with all behaviors scheduled on a 20-h recurring cycle to permit assessment of endogenous circadian function independent from environmental and behavioral effects including the sleep/wake cycle. Circadian phase was assessed from core body temperature. There were highly significant endogenous circadian rhythms in platelet surface activated glycoprotein (GP IIb-IIIa, GPIb and P-selectin (6-17% peak-trough amplitudes; p ≤ 0.01. These circadian peaks occurred at a circadian phase corresponding to 8-9 AM. Platelet count, ATP release, aggregability, and plasma epinephrine also had significant circadian rhythms but with later peaks (corresponding to 3-8 PM. The circadian effects on the platelet activation markers were always larger than that of any of the three behavioral stressors. CONCLUSIONS/SIGNIFICANCE: These data demonstrate robust effects of the endogenous circadian system on platelet activation in humans--independent of the sleep/wake cycle, other behavioral influences and the environment. The 9 AM timing of the circadian peaks of the three platelet surface markers, including platelet surface activated GPIIb-IIIa, the

  2. Sulfatides partition disabled-2 in response to platelet activation.

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    Karen E Drahos

    Full Text Available BACKGROUND: Platelets contact each other at the site of vascular injury to stop bleeding. One negative regulator of platelet aggregation is Disabled-2 (Dab2, which is released to the extracellular surface upon platelet activation. Dab2 inhibits platelet aggregation through its phosphotyrosine-binding (PTB domain by competing with fibrinogen for alphaIIbbeta3 integrin receptor binding by an unknown mechanism. METHODOLOGY/PRINCIPAL FINDINGS: Using protein-lipid overlay and liposome-binding assays, we identified that the N-terminal region of Dab2, including its PTB domain (N-PTB, specifically interacts with sulfatides. Moreover, we determined that such interaction is mediated by two conserved basic motifs with a dissociation constant (K(d of 0.6 microM as estimated by surface plasmon resonance (SPR analysis. In addition, liposome-binding assays combined with mass spectroscopy studies revealed that thrombin, a strong platelet agonist, cleaved N-PTB at a site located between the basic motifs, a region that becomes protected from thrombin cleavage when bound to sulfatides. Sulfatides on the platelet surface interact with coagulation proteins, playing a major role in haemostasis. Our results show that sulfatides recruit N-PTB to the platelet surface, sequestering it from integrin receptor binding during platelet activation. This is a transient recruitment that follows N-PTB internalization by an actin-dependent process. CONCLUSIONS/SIGNIFICANCE: Our experimental data support a model where two pools of Dab2 co-exist at the platelet surface, in both sulfatide- and integrin receptor-bound states, and their balance controls the extent of the clotting response.

  3. Platelet activation attracts a subpopulation of effector monocytes to sites of Leishmania major infection.

    Science.gov (United States)

    Goncalves, Ricardo; Zhang, Xia; Cohen, Heather; Debrabant, Alain; Mosser, David M

    2011-06-01

    Leishmania species trigger a brisk inflammatory response and efficiently induce cell-mediated immunity. We examined the mechanisms whereby leukocytes were recruited into lesions after Leishmania major infection of mice. We found that a subpopulation of effector monocytes expressing the granulocyte marker GR1 (Ly6C) is rapidly recruited into lesions, and these monocytes efficiently kill L. major parasites. The recruitment of this subpopulation of monocytes depends on the chemokine receptor CCR2 and the activation of platelets. Activated platelets secrete platelet-derived growth factor, which induces the rapid release of CCL2 from leukocytes and mesenchymal cells. This work points to a new role for platelets in host defense involving the selective recruitment of a subpopulation of effector monocytes from the blood to efficiently kill this intracellular parasite.

  4. A novel role of sesamol in inhibiting NF-κB-mediated signaling in platelet activation

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    Chang Chao-Chien

    2011-12-01

    Full Text Available Abstract Background Platelet activation is relevant to a variety of coronary heart diseases. Our previous studies revealed that sesamol possesses potent antiplatelet activity through increasing cyclic AMP formation. Although platelets are anucleated cells, they also express the transcription factor, NF-κB, that may exert non-genomic functions in platelet activation. Therefore, we further investigated the inhibitory roles of sesamol in NF-κB-mediated platelet function. Methods Platelet aggregation, Fura 2-AM fluorescence, and immunoblotting analysis were used in this study. Results NF-κB signaling events, including IKKβ phosphorylation, IκBα degradation, and p65 phosphorylation, were markedly activated by collagen (1 μg/ml in washed human platelets, and these signaling events were attenuated by sesamol (2.5~25 μM. Furthermore, SQ22536 and ODQ, inhibitors of adenylate cyclase and guanylate cyclase, respectively, strongly reversed the sesamol (25 μM-mediated inhibitory effects of IKKβ phosphorylation, IκBα degradation, and p65 phosphorylation stimulated by collagen. The protein kinase A (PKA inhibitor, H89, also reversed sesamol-mediated inhibition of IκBα degradation. Moreover, BAY11-7082, an NF-κB inhibitor, abolished IκBα degradation, phospholipase C (PLCγ2 phosphorylation, protein kinase C (PKC activation, [Ca2+]i mobilization, and platelet aggregation stimulated by collagen. Preincubation of platelets with the inhibitors, SQ22536 and H89, both strongly reversed sesamol-mediated inhibition of platelet aggregation and [Ca2+]i mobilization. Conclusions Sesamol activates cAMP-PKA signaling, followed by inhibition of the NF-κB-PLC-PKC cascade, thereby leading to inhibition of [Ca2+]i mobilization and platelet aggregation. Because platelet activation is not only linked to hemostasis, but also has a relevant role in inflammation and metastasis, our data demonstrating that inhibition of NF-κB interferes with platelet function may

  5. 冠心病伴牙周炎患者非刺激性唾液及龈沟液中血小板活化因子的检测及意义%Detection of platelet-activating factor in unstimulated mixed saliva and gingival crevicular fluid of periodontitis patients with coronary heart disease

    Institute of Scientific and Technical Information of China (English)

    冯伟; 吴婷; 孙钦峰; 杨丕山; 刘晓玲

    2010-01-01

    目的:检测冠心病伴中重度牙周炎、单纯冠心病、单纯中重度牙周炎及健康对照组的非刺激性全唾液(unstimulated mixed saliva)及龈沟液(gingival crevicular fluid,GCF)中血小板活化因子(platelet-activating factor,PAF)水平,探讨牙周炎与心血管疾病之间的关系.方法:选取经冠状动脉造影确诊为冠心病且伴有中重度牙周炎患者24例(C+P组),单纯冠心病患者36例(C组),单纯中重度牙周炎患者32例(P组)及健康人(H组)28例.对所有受检者进行口腔检查,记录其探诊出血指数、牙石指数、探诊深度、附着丧失等相关临床牙周指标,并收集非刺激性全唾液和龈沟液,采用ELISA检测其中PAF水平.各组间PAF水平差异应用SPSS13.0软件包进行统计学分析.结果:C+P组和P组患者唾液和龈沟液中PAF水平显著高于C组和H组患者(P<0.05),相关分析显示,龈沟液中PAF水平与牙周探诊深度、附着丧失水平呈正相关(P<0.05).结论:冠心病伴牙周炎患者的唾液及龈沟液中PAF水平明显升高,提示PAF的升高可能是牙周炎影响心血管疾病发生、发展的又一重要因素.

  6. Effect of Bexarotene on Platelet Activation and Apoptosis

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    Hang Cao

    2017-06-01

    Full Text Available Background/Aims: The retinoid X receptor (RXRs stimulator Bexarotene ((4-[1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydro-2-naphthylethynyl] benzoic acid is used for the treatment of several malignancies. Bexarotene is at least in part effective by stimulation of apoptosis of tumor cells. Moreover, Bexarotene triggers eryptosis, the suicidal death of erythrocytes. Similar to erythrocytes, blood platelets lack nuclei but are nevertheless able to enter an apoptosis-like phenotype, characterized by caspase activation, cell shrinkage and cell membrane scrambling with phospha-tidylserine translocation to the cell surface. Platelet apoptosis is triggered by increase of cytosolic Ca2+-activity ([Ca2+]i, which further leads to degranulation and integrin activation. Platelet activation and apoptosis could be elicited by thrombin or collagen related peptide (CRP. The present study explored whether treatment of platelets with bexarotene modifies platelet activation and apoptosis following exposure to thrombin or CRP. Methods: Platelets isolated from wild-type mice were exposed for 30 minutes to bexarotene (6 µg/ml without or with an additional treatment with thrombin (0.01 U/ml or CRP (2 µg/ml or 5 µg/ml. Flow cytometry was employed to estimate cytosolic Ca2+-activity ([Ca2+]i from Fluo-3 fluorescence, platelet degranulation from P-selectin abundance, integrin activation from αIIbβ3 integrin abundance, caspase activity utilizing an Active Caspase-3 Staining kit, phosphatidylserine abundance from annexin-V-binding, and relative platelet volume from forward scatter. Results: In the absence of thrombin or CRP, the administration of bexarotene slightly but significantly increased [Ca2+]i, but did not significantly modify P-selectin abundance, activated αIIbβ3 integrin, annexin-V-binding, cell volume, or caspase activity. Exposure of platelets to thrombin or CRP was followed by significant increase of [Ca2+]i, P-selectin abundance, active αIIbβ3 integrin

  7. Intracellular matrix metalloproteinase-2 (MMP-2) regulates human platelet activation via hydrolysis of talin.

    Science.gov (United States)

    Soslau, Gerald; Mason, Christopher; Lynch, Stephen; Benjamin, James; Ashak, Dani; Prakash, Jamunabai M; Moore, Andrew; Bagsiyao, Pamela; Albert, Trevine; Mathew, Lynn M; Jost, Monika

    2014-01-01

    Matrix metalloproteinase (MMP) activity is generally associated with normal or pathological extracellular processes such as tissue remodelling in growth and development or in tumor metastasis and angiogenesis. Platelets contain at least three MMPs, 1, 2 and 9 that have been reported to stimulate or inhibit agonist-induced platelet aggregation via extracellular signals. The non-selective Zn+2 chelating MMP inhibitor, 1,10-phenanthroline, and the serine protease inhibitor, AEBSF, were found to inhibit all tested agonist-induced platelet aggregation reactions. In vitro analysis demonstrated that 1,10-phenanthroline completely inhibited MMP-1,2,and 9 but had little to no effect on calpain activity while the converse was true with AEBSF. We now demonstrate that MMP-2 functions intracellularly to regulate agonist-induced platelet aggregations via the hydrolytic activation of talin, the presumed final activating factor of glycoprotein (GP)IIb/IIIa integrin (the inside-out signal). Once activated GPIIb/IIIa binds the dimeric fibrinogen molecule required for platelet aggregation. The active intracellular MMP-2 molecule is complexed with JAK 2/STAT 3, as demonstrated by the fact that all three proteins are co-immunoprecipitated with either anti-JAK 2, or anti-STAT 3 antibodies and by immunofluorescence studies. The MMP-2 platelet activation pathway can be synergistically inhibited with the non-selective MMP inhibitor, 1,10-phenanthroline, plus a JAK 2 inhibitor. This activation pathway is distinct from the previously reported calpain-talin activating pathway. The identification of a new central pathway for platelet aggregation presents new potential targets for drug regulation and furthers our understanding of the complexity of platelet activation mechanisms.

  8. Influence of red algal sulfated polysaccharides on blood coagulation and platelets activation in vitro.

    Science.gov (United States)

    Sokolova, Ekaterina V; Byankina, Anna O; Kalitnik, Alexandra A; Kim, Yong H; Bogdanovich, Larisa N; Solov'eva, Tamara F; Yermak, Irina M

    2014-05-01

    The influence of sulfated polysaccharides (λ-, κ-, and κ/β-carrageenan and porphyran) - on platelet activation was studied. Carrageenans were much weaker inhibitors of a coagulation process than heparin, while porphyran had not that effect. Results of the aPTT and PT assays suppose that carrageenans affected mostly intrinsic pathway of coagulation, while their effect on the extrinsic pathway is extremely low (λ and κ/β) or absent (κ, LMW derivative of κ-carrageenan). λ-Carrageenan was the most potent anticoagulant agent in TT, aPTT, PT, and anti-factor Xa activity. This sample was also the strongest inhibitor of collagen-induced platelet aggregation in PRP. Generally, the correlation of anticoagulant and antithrombotic action in PRP is preserved for carrageenans but not for heparin. Carrageenans and porphyran affected platelet adhesion to collagen by influencing glycoprotein VI. Low molecular weight κ-carrageenan had a similar effect on platelet adhesion mediated with both major collagen receptors: integrin α2 β1 and glycoprotein VI as native polysaccharide had. Carrageenans resulted in activation of platelets under platelet adhesion mediated by integrin αIIb β3 with less degree than heparin. The least sulfated κ/β-carrageenan that possessed an inhibiting effect on thrombin- and collagen-induced aggregation of washed platelets and on the PT test but it had no significant effect on TT was the weakest promoter of integrin αIIb β3 mediated platelet activation. In summary, our study showed that the polysaccharide action was complex, since it depended on its molecular mass, sulfation degree, and monosaccharide contents (3,6-anhydrogalactose).

  9. Novel Bioactivity of Ellagic Acid in Inhibiting Human Platelet Activation

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    Yi Chang

    2013-01-01

    Full Text Available Pomegranates are widely consumed either as fresh fruit or in beverage form as juice and wine. Ellagic acid possesses potent antioxidative properties; it is known to be an effective phytotherapeutic agent with antimutagenic and anticarcinogenic qualities. Ellagic acid (20 to 80 μM exhibited a potent activity in inhibiting platelet aggregation stimulated by collagen; however, it did not inhibit platelet aggregation stimulated by thrombin, arachidonic acid, or U46619. Treatment with ellagic acid (50 and 80 μM significantly inhibited platelet activation stimulated by collagen; this alteration was accompanied by the inhibition of relative [Ca2+]i mobilization, and the phosphorylation of phospholipase C (PLCγ2, protein kinase C (PKC, mitogen-activated protein kinases (MAPKs, and Akt, as well as hydroxyl radical (OH● formation. In addition, ellagic acid also inhibited p38 MAPK and Akt phosphorylation stimulated by hydrogen peroxide. By contrast, ellagic acid did not significantly affect PKC activation and platelet aggregation stimulated by PDBu. This study is the first to show that, in addition to being considered a possible agent for preventing tumor growth, ellagic acid possesses potent antiplatelet properties. It appears to initially inhibit the PLCγ2-PKC cascade and/or hydroxyl radical formation, followed by decreased phosphorylation of MAPKs and Akt, ultimately inhibiting platelet aggregation.

  10. NF-κB信号通路在鞘内注射血小板活化因子诱发大鼠痛敏中的作用%Role of NF-κB pathway in the development of intrathecal platelet- activating factor- induced hyperalgesia in rats

    Institute of Scientific and Technical Information of China (English)

    杨京利; 刘菊英; 马国平; 熊良志

    2010-01-01

    Objective To investigate the role of NF-κB pathway in the development of intrathecal(IT)platelet-activating factor (PAF)-induced hyperalgesia in rats. Methods Sixty-four male SD rats (200-250 g) in which intrathecal catheters were successfully implanted without complications were randomly divided into 6 groups:group Ⅰ received artificial cerebro-spinal fluid (ACSF) 10 μl IT (n = 16); group Ⅱ received PAF 10 μg in ACSF 10 μl IT; group Ⅲ received 0.1% DMSO 2 ml intraperitoneally (IP) (n = 8); group Ⅳ, Ⅴ, Ⅵ received IP SC-514 (a selective IKK-β inhibitor) 10, 50, 100 mg/kg in 0.1% DMSO 2 ml respectively at 2 h before IT PAF. Paw withdrawal threshold to mechanical stimulation (PWMT) and paw withdrawal latency to thermal stimuli (PWTL) were measured before (baseline) and at 5, 15, 30, 45, 60 min and then every 30 min for another 4 h after IT administration. The animals were killed after the last pain threshold measurement at 5 h after IT PAF. The lumbar segment (L4-6) of the spinal cord was removed for determination of TNF-α and IL-lβ content (by ELISA).Results lntrathecal PAF induced tactile allodynia and thermal hyperalgesia rapidly, increased the expression of TNF-α and IL-lβ in lumbar spinal cord. Pretreatment with SC-514 attenuated PAF-induced hyperalgesia and inhibited the increase in TNF-α and IL-1β expression in the spinal cord. Conclusion NF-κB is involved in intrathecal PAF-induced hyperalgesia.%目的 评价NF-κB信号通路在鞘内注射血小板活化因子(PAF)诱发大鼠痛敏中的作用.方法 鞘内置管成功的雄性SD大鼠64只,体重200~250 g,随机分为6组:人工脑脊液(ACSF)对照组(AC组,n=16)鞘内注射ACSF 10μl;PAF诱发大鼠痛敏组(PAF组,n=16)鞘内注射PAF 10μg(溶于10μl ACSF);二甲基亚砜(DMSO)对照组(DC组,n=8)和低、中和高剂量SC-514组(S1-3组,n=8)分别于鞘内注射PAF前2 h腹腔注射0.1%DMSO溶液2 ml、SC-514(溶于2 ml 0.1%DMSO溶液)10、50、100 mg/kg.分别

  11. 脊髓神经元凋亡在鞘内注射血小板活化因子诱发大鼠痛敏中的作用%Effects of platelet-activating factor administered intrathecally on the expression of neuronal apoptosis in spi-nal cord of rats

    Institute of Scientific and Technical Information of China (English)

    杨京利; 段宏伟; 马国平

    2014-01-01

    Objective To investigate the roles of neuronal apoptosis in development of tactile allodynia and thermal hyperalgesia induced by platelet-activating factor administered intrathecally.Methods 60 Sprague-Dawley rats with intrathecal PE-10 catheters were randomly divided into two groups:control(artificial cerebral spinal fluid,10 μl)group,PAF (10 μg,dissolved in 10 μl ACSF)group.Paw withdrawal mechanical threshold and thermal latency were measured at-1 ,1 ,3,5,7 and 14 days after surgery .Changes of apoptosis of spinal neuron were observed by TUNEL.Results Intrathecally administered PAF induced development of tactile all-odynia and thermal hyperalgesia rapidly,The expression of spinal neuronal apoptotic index in control group were significantly lower than those in the PAF group(P <0.01).Conclusions Intrathecally administered PAF may induce development of tactile allodynia and thermal hyperalgesia in rats,and this process might be associ-ated with neuronal apoptosis in spinal cord.%目的:探讨脊髓神经元凋亡在鞘内注射血小板活化因子(PAF)诱发大鼠痛敏中的作用。方法鞘内置管成功的雄性 Sprague-Dawley 大鼠60只,随机分为2组:对照组,30只,鞘内注射人工脑脊液(arti-ficial cerebral spinal fluid,ACSF)10μl;PAF 组,30只,鞘内注射 PAF 10μg,溶解于10μl 人工脑脊液;分别于鞘内给药前1 d、给药后1、3、5、7、14 d 分别测定机械痛阈(PWMT)和热痛阈(PWTL)。取 L4-6脊髓,采用TUNEL 法观察脊髓神经元凋亡。结果鞘内注射血小板活化因子(PAF)可诱发出大鼠机械性触诱发痛和热痛觉过敏。PAF 组术后1 d 脊髓中开始有少量凋亡神经元出现,凋亡指数于术后3 d 开始迅速增加,术后5 d 达峰值,与对照组比较,有显著性差异(P <0.01)。结论鞘内注射 PAF 诱发大鼠触觉异常痛敏和热痛敏,脊髓神经元凋亡可能参与了鞘内注射 PAF 大鼠痛敏的形成。

  12. Expression and clinical significance of platelet activating factor (PAC-1), CD629P and thrombus precursor protein (TpP) in severe sepsis%血小板活化相关因子和血栓前体蛋白在严重脓毒症中的表达

    Institute of Scientific and Technical Information of China (English)

    耿平; 马爱闻; 张劲松; 夏仲芳; 顾健; 徐敏; 徐继扬; 谈定玉; 解松刚; 沈连军

    2008-01-01

    Objective To investigate the expression and clinical significance of platelet activating factor [PAC]-1, CD62P and TPP hi severe sepsis. Method Patients with severe sepsis who were admitted into the EICU of Subei People's Hospital from April 2007 to March 2008 were included. Patients with severe sepsis (Group Ⅲ)were treated according to the treatment guidelines for severe sepsis, and were divided, according to their clinical records, into those who survived and those who died within 28 days of admission. Patients admitted during the same period with symptoms of infection but without severe sepsis were included as the General Infected Group (Group Ⅱ). A Control Group (Group Ⅰ) comprised patients who visited the hospital over the same period for physical examination or the healthy volunteers. The group members were all included randomly, and the gender and sex of patients in all three groups were similar. Patients with acute brain infarction, acute coronary syndrome,serious diabetes, hyperlipidemia, malignant tumor, leukemia, primary liver, renal and hematopoietic system dis-eases,long-term bedridden patients, pregnant women, and patients taking hormone treatment or hranunosuppres-sants were excluded from the study. Morning venous blood was collected and ELISA and Flow Cytometry performed on the fwst day of admission for Groups Ⅰ- and Ⅱ, and on the first, third and fifth day after admission for Group Ⅲ, to determine the TpP,PAC-1 and CD62P respectively; and the Marshall score was determined. Data were ana-lyzed by SPSS 12.0 software. For continuous variables, comparisons among groups were analyzed by ANOVA.Levene's and LSD test were applied to assess homogeneity. Bivariate test is applied to Correlation Analysis. P0.05); however, Group Ⅲ was significantly different compared with both Group Ⅰ and Group Ⅱ (both:P0.05); on the third day,however, a significant difference appeared with values of (2.89±1.48) % vs. (5.04±2.57) % (P0.05),但Ⅰ组与Ⅲ

  13. 川崎病心型脂肪酸结合蛋白及血小板活化因子的变化及临床意义%Serum heart-type fatty acid-binding protein and platelet activating factor levels in Kawasaki disease and their clinical significance

    Institute of Scientific and Technical Information of China (English)

    洪泽; 孙兴珍

    2011-01-01

    46例川崎病患儿(观察组)根据超声心动图结果分为冠状动脉损伤(CAL)组19例和非冠状动脉损伤(NCAL)组27例,另选择正常健康者50例为对照组.检测所有对象的心型脂肪酸结合蛋白(h-FABP)、血小板活化因子(PAF)、肌钙蛋白Ⅰ及肌酸磷酸激酶同工酶等.结果显示,观察组h-FABP、肌钙蛋白Ⅰ水平和阳性率均显著高于对照组(P<0.05),两组间肌酸磷酸激酶同工酶水平和阳性率比较差异无统计学意义(P>0.05),观察组h-FABP阳性率显著高于肌钙蛋白Ⅰ和肌酸磷酸激酶同工酶阳性率(P<0.05),PAF水平及血小板、中性粒细胞计数显著高于对照组(P<0.05);CAL组h-FABP、PAF水平显著高于NCAL组(P<0.05).提示,h-FABP和PAF对预测川崎病患儿冠状动脉病变有重要的临床价值.%Forty six children with Kawasaki disease (observer group) were classified as coronary artery lesions (CAL) subgroup (19 cases) and non-coronary artery lesions (NCAL) subgroup (27 cases)according to echocardiography; 50 healthy children served as control group.Serum heart-type fatty acidbinding protein (h-FABP), platelet activating factor (PAF), cardiac tropnin Ⅰ (cTnI) and creatine kinase isoenzyme MB (CK-MB) levels of all subjects were detected.The results showed that the h-FABP and cTnI levels and positive rate in observer group were higher those in control group (P < 0.05 ), while there were no differences in CK-MB level and positive rate between two groups ( P > 0.05 ).The h-FABP positive rate in observation group was higher than the positive rates of cTnI and CK-MB (P <0.05).The PAF level, PLT and polymorphonuclear neutrophil count in observer group were higher than those in control group ( P <0.05).The h-FABP and PAF levels in CAL subgroup were higher than those in NCAL subgroup (P <0.05).The results suggest that serum h-FABP and PAF can be used as diagnostic indicators for Kawasaki disease complicated with coronary artery lesions.

  14. Pro-thrombotic effect of exercise in a polluted environment: a P-selectin- and CD63-related platelet activation effect.

    Science.gov (United States)

    Wauters, Aurélien; Esmaeilzadeh, Fatemeh; Bladt, Sandrine; Beukinga, Ingrid; Wijns, Walter; van de Borne, Philippe; Pradier, Olivier; Argacha, Jean-François

    2015-01-01

    Exposure to diesel exhaust is an important cardiovascular risk factor and may promote atherothrombotic events. Some data suggest that polluted air exposure could affect haemostasis through platelet activation. The aim of the study was to investigate the effects of acute exposure to diesel exhaust on platelet activation and platelet function. We tested the hypothesis in a randomised, crossover study in 25 healthy men exposed to ambient and polluted air; 11 of the subjects also performed exercise during exposure sessions. Platelet activation was evaluated by surface expression of CD62P (P-selectin) and CD63 (dense granule glycoprotein) using flow cytometry of labelled platelets. Platelet function was measured using the PFA-100 platelet function analyser and by Multiplate whole blood impedance platelet aggregometry. Acute diesel exhaust exposure had no effect on platelet activation at rest, but exercise in polluted air increased the collagen-induced expression of CD62P and CD63 (both p< 0.05). The increase in the expression of CD62P and CD63 was related to the total amount of PM2.5 inhaled during the exercise sessions (r=+0.58 and +0.60, respectively, both p< 0.05). Platelet aggregation was not impaired after polluted air exposure at rest or during exercise. In conclusion, in healthy subjects, diesel exhaust exposure induces platelet activation as illustrated by a dose-response increase in the release of CD62P and CD63. This platelet priming effect could be a contributor to the triggering of atherothrombotic events related to air pollution exposure.

  15. VAMP-7 links granule exocytosis to actin reorganization during platelet activation.

    Science.gov (United States)

    Koseoglu, Secil; Peters, Christian G; Fitch-Tewfik, Jennifer L; Aisiku, Omozuanvbo; Danglot, Lydia; Galli, Thierry; Flaumenhaft, Robert

    2015-07-30

    Platelet activation results in profound morphologic changes accompanied by release of granule contents. Recent evidence indicates that fusion of granules with the plasma membrane during activation provides auxiliary membrane to cover growing actin structures. Yet little is known about how membrane fusion is coupled with actin reorganization. Vesicle-associated membrane protein (VAMP)-7 is found on platelet vesicles and possesses an N-terminal longin domain capable of linking exocytosis to cytoskeletal remodeling. We have evaluated platelets from VAMP-7(-/-) mice to determine whether this VAMP isoform contributes to granule release and platelet spreading. VAMP-7(-/-) platelets demonstrated a partial defect in dense granule exocytosis and impaired aggregation. α Granule exocytosis from VAMP-7(-/-) platelets was diminished both in vitro and in vivo during thrombus formation. Consistent with a role of VAMP-7 in cytoskeletal remodeling, spreading on matrices was decreased in VAMP-7(-/-) platelets compared to wild-type controls. Immunoprecipitation of VAMP-7 revealed an association with VPS9-domain ankyrin repeat protein (VARP), an adaptor protein that interacts with both membrane-bound and cytoskeleton proteins and with Arp2/3. VAMP-7, VARP, and Arp2/3 localized to the platelet periphery during spreading. These studies demonstrate that VAMP-7 participates in both platelet granule secretion and spreading and suggest a mechanism whereby VAMP-7 links granule exocytosis with actin reorganization.

  16. Detection value of Th17 related indexes and platelet activation indexes in patients with liver cancer

    Institute of Scientific and Technical Information of China (English)

    Pai-Qiang Chen; Qiao-Li Jiang; Jun Li; Jing Zhang

    2017-01-01

    Objective:To study the detection value of Th17 related indexes and platelet activation indexes in the patients with liver cancer.Methods: A total of 59 patients with liver cancer in our hospital from July 2015 to June 2016 were selected as the observation group, 59 healthy persons of the same ages with physical examination were selected as the control group, then the serum Th17 related indexes and platelet activation indexes levels of two groups were detected and compared, then the serum Th17 related indexes and platelet activation indexes levels of observation group with different stages and types of liver cancer were compared too. Results:The serum Th17 related indexes and platelet activation indexes levels of observation group were all higher than those of control group, the serum Th17 related indexes and platelet activation indexes levels of observation group with different stages and types of liver cancer had obvious differences (allP<0.05).Conclusions: The Th17 related indexes and platelet activation indexes of patients with liver cancer show higher expression state, and the expression levels of patients with different stages and types of liver cancer have obvious differences too, so the clinical detection value of those indexes in the patients with liver cancer are higher.

  17. Platelet activation, function, and reactivity in atherosclerotic carotid artery stenosis: a systematic review of the literature.

    LENUS (Irish Health Repository)

    Kinsella, J A

    2012-09-27

    An important proportion of transient ischemic attack or ischemic stroke is attributable to moderate or severe (50-99%) atherosclerotic carotid stenosis or occlusion. Platelet biomarkers have the potential to improve our understanding of the pathogenesis of vascular events in this patient population. A detailed systematic review was performed to collate all available data on ex vivo platelet activation and platelet function\\/reactivity in patients with carotid stenosis. Two hundred thirteen potentially relevant articles were initially identified; 26 manuscripts met criteria for inclusion in this systematic review. There was no consistent evidence of clinically informative data from urinary or soluble blood markers of platelet activation in patients with symptomatic moderate or severe carotid stenosis who might be considered suitable for carotid intervention. Data from flow cytometry studies revealed evidence of excessive platelet activation in patients in the early, sub-acute, or late phases after transient ischemic attack or stroke in association with moderate or severe carotid stenosis and in asymptomatic moderate or severe carotid stenosis compared with controls. Furthermore, pilot data suggest that platelet activation may be increased in recently symptomatic than in asymptomatic severe carotid stenosis. Excessive platelet activation and platelet hyperreactivity may play a role in the pathogenesis of first or subsequent transient ischemic attack or stroke in patients with moderate or severe carotid stenosis. Larger longitudinal studies assessing platelet activation status with flow cytometry and platelet function\\/reactivity in symptomatic vs. asymptomatic carotid stenosis are warranted to improve our understanding of the mechanisms responsible for transient ischemic attack or stroke.

  18. Effects of Antimalarial Tafenoquine on Blood Platelet Activity and Survival

    Directory of Open Access Journals (Sweden)

    Hang Cao

    2017-01-01

    significantly increased ROS and annexin-V-binding, significantly augmented the effect of thrombin on caspase 3 activity and platelet volume and significantly enhanced platelet aggregation. Conclusions: Tafenoquine counteracts thrombin and CRP induced increase of cytosolic Ca2+ activity and platelet activation, but enhances platelet apoptosis and platelet aggregation.

  19. Cyclic nucleotides and mitogen-activated protein kinases: regulation of simvastatin in platelet activation

    Directory of Open Access Journals (Sweden)

    Hou Ssu-Yu

    2010-06-01

    Full Text Available Abstract Background 3-Hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA reductase inhibitors (statins have been widely used to reduce cardiovascular risk. These statins (i.e., simvastatin may exert other effects besides from their cholesterol-lowering actions, including inhibition of platelet activation. Platelet activation is relevant to a variety of coronary heart diseases. Although the inhibitory effect of simvastatin in platelet activation has been studied; the detailed signal transductions by which simvastatin inhibit platelet activation has not yet been completely resolved. Methods The aim of this study was to systematically examine the detailed mechanisms of simvastatin in preventing platelet activation. Platelet aggregation, flow cytometric analysis, immunoblotting, and electron spin resonance studies were used to assess the antiplatelet activity of simvastatin. Results Simvastatin (20-50 μM exhibited more-potent activity of inhibiting platelet aggregation stimulated by collagen than other agonists (i.e., thrombin. Simvastatin inhibited collagen-stimulated platelet activation accompanied by [Ca2+]i mobilization, thromboxane A2 (TxA2 formation, and phospholipase C (PLCγ2, protein kinase C (PKC, and mitogen-activated protein kinases (i.e., p38 MAPK, JNKs phosphorylation in washed platelets. Simvastatin obviously increased both cyclic AMP and cyclic GMP levels. Simvastatin markedly increased NO release, vasodilator-stimulated phosphoprotein (VASP phosphorylation, and endothelial nitric oxide synthase (eNOS expression. SQ22536, an inhibitor of adenylate cyclase, markedly reversed the simvastatin-mediated inhibitory effects on platelet aggregation, PLCγ2 and p38 MAPK phosphorylation, and simvastatin-mediated stimulatory effects on VASP and eNOS phosphorylation. Conclusion The most important findings of this study demonstrate for the first time that inhibitory effect of simvastatin in platelet activation may involve activation of the cyclic AMP

  20. Preanalytical requirements for flow cytometric evaluation of platelet activation: choice of anticoagulant.

    Science.gov (United States)

    Mody, M; Lazarus, A H; Semple, J W; Freedman, J

    1999-06-01

    Accurate assessment of in vivo or in vitro platelet activation requires optimal preanalytical conditions to prevent artefactual in vitro activation of the platelets. The choice of anticoagulant is one of the critical preanalytical conditions as anticoagulants exert different effects on the activation of platelets ex vivo. We tested the effectiveness of Diatube-H (also known as CTAD; sodium citrate, theophylline, adenosine and dipyridamole) and citrate vacutainer tubes in preventing artefactual activation of platelets and preserving functional reserve. Platelet surface expression of the CD62P (reflecting alpha granule release), CD63 (reflecting lysosomal release) and modulation of normal platelet membrane glycoproteins CD41a and CD42b, were measured in whole blood and in isolated platelets immediately after collection and at 6, 24 and 48 h after venipuncture. Samples taken into Diatube-H showed less spontaneous platelet activation than did those taken into citrate. To measure in vitro platelet functional reserve, thrombin was added as agonist to blood stored for varying periods up to 48 h. Although Diatube-H suppressed in vitro platelet activation for up to 4 h, in samples kept for 6-24 h before thrombin addition, the inhibitory effect was lost and platelets responded fully to agonist activation. Hence, Diatube-H preserved platelets and allowed for measurement of in vivo platelet activation as well as thrombin-induced in vitro platelet activation after 6-24 h, in both whole blood and isolated platelets.

  1. Lymphocyte-mediated regulation of platelet activation during desensitization in patients with hymenoptera venom hypersensitivity.

    Science.gov (United States)

    Ledru, E; Pestel, J; Tsicopoulos, A; Joseph, M; Wallaert, B; Tonnel, A B; Capron, A

    1988-01-01

    T cells from peripheral blood of hymenoptera sensitive patients were studied before and after venom desensitization. Before treatment, T cells showed a variable but higher proliferative response to allergen than T cells of treated patients or controls. While before desensitization, T cell products, specifically released after in vitro allergen stimulation, were able to amplify the IgE-dependent platelet activity, we showed that after treatment of the same patients, T cell products strongly reduced platelet activation. Considering the modifications in platelet activation previously observed in patients treated by specific immunotherapy, the present results suggest that, through a modification of T cell reactivity to allergen, T cell functions are modulated by desensitization, and emphasize the involvement of T cell products in the desensitization mechanisms. PMID:3263227

  2. New organic nitrate-containing benzyloxy isonipecotanilide derivatives with vasodilatory and anti-platelet activity.

    Science.gov (United States)

    de Candia, Modesto; Marini, Elisabetta; Zaetta, Giorgia; Cellamare, Saverio; Di Stilo, Antonella; Altomare, Cosimo D

    2015-05-25

    A number of new nitric oxide (NO)-precursors were synthesized by grafting nitrate-containing moieties on the structures of the benzyloxy isonipecotanilide derivatives 1 and 2 already reported as moderately potent antiplatelet agents. Various nitrooxy (ONO2)-alkyl side chains were covalently linked to the piperidine nitrogen of the parent compounds through carbamate and amide linkage, and the synthesis of a benzyl nitrate analog (15) of compound 1 was also achieved. The in vitro vasodilatory activities, as well as platelet anti-aggregatory effects, of the newly synthesized organic nitrates were assessed. The (ONO2)methyl carbamate-based derivative 5a and the benzyl nitrate analog 15, which on the other hand retain activity as inhibitors of ADP-induced platelet aggregation, exhibited strong NO-mediated vasodilatory effects on pre-contracted rat aorta strips, with EC50 values in the low nanomolar range (13 and 29 nM, respectively). Experiments carried out with the selectively inhibited soluble guanylate cyclase (sGC), which is the key enzyme of the NO-mediated pathway leading to vascular smooth muscle relaxation, confirmed the involvement of NO in the observed vasodilation. The nitrate derivatives proved to be stable in acidic aqueous solution and at pH 7.4. In human serum, unlike 5a, which showed not to undergo enzyme-catalyzed decomposition, the other tested (ONO2)-alkyl carbamate-based compounds (5b and 5e) and benzyl nitrate 15 underwent a faster degradation. However, their decomposition rates in serum were quite slow (t½>2.6 h), which suggests that nitrate moiety is poorly metabolized in blood plasma and that much of the in vitro anti-platelet activity has to be attributed to the intact (ONO2)-containing molecules.

  3. Plasma rich in growth factors in dentistry

    Directory of Open Access Journals (Sweden)

    Ana Glavina

    2017-06-01

    Full Text Available Background Plasma rich in growth factors (PRGF has wider use in many fields of dentistry due to its endogenous biocompatible regenerative potential i.e., their potential to stimulate and accelerate tissue healing and bone regeneration. Aims This review shows the increasing use of PRGF technology in various fields of dentistry. Methods In the last nine years PubMed has been searched in order to find out published articles upon PRGF in dentistry and 36 papers have been included. Results PRGF technology has many advantages with positive clinical and biological outcomes in tissue healing and bone regeneration. Conclusion In order to determine the most effective therapeutic value for patients, further research is required.

  4. Platelet function alterations in dengue are associated with plasma leakage

    NARCIS (Netherlands)

    Michels, M.; Alisjahbana, B.; Groot, P.G. de; Indrati, A.R.; Fijnheer, R.; Puspita, M.; Dewi, I.M.; Wijer, L. van de; Boer, E.M. de; Roest, M.; Ven, A.J. van der; Mast, Q. de

    2014-01-01

    Severe dengue is characterised by thrombocytopenia, plasma leakage and bleeding. Platelets are important for preservation of endothelial integrity. We hypothesised that platelet activation with secondary platelet dysfunction contribute to plasma leakage. In adult Indonesian patients with acute dengu

  5. Iron deficiency generates secondary thrombocytosis and platelet activation in IBD: the randomized, controlled thromboVIT trial.

    Science.gov (United States)

    Kulnigg-Dabsch, Stefanie; Schmid, Werner; Howaldt, Stefanie; Stein, Jürgen; Mickisch, Oliver; Waldhör, Thomas; Evstatiev, Rayko; Kamali, Houman; Volf, Ivo; Gasche, Christoph

    2013-07-01

    Secondary thrombocytosis is a common clinical feature. In patients with cancer, it is a risk factor for venous thromboembolic events. In inflammatory bowel disease (IBD), thrombocytosis is so far considered a marker of active disease and may contribute to the increased thromboembolic risk in this population. Observed effects of iron therapy on normalization of platelet counts led us to hypothesize that iron itself may regulate megakaryopoiesis. Here, we want to test the effect of iron replacement on platelet count and activity in IBD-associated thrombocytosis. We performed a randomized, single-blinded placebo-controlled trial testing the effect of ferric carboxymaltose (FCM) in patients with IBD with secondary thrombocytosis (platelets > 450 G/L). Changes in platelet counts, hemoglobin, iron parameters, disease activity, megakaryopoietic growth factors, erythropoietin, and platelet activity were assessed. Patients received placebo or up to 1500 mg iron as FCM. Endpoints were evaluated at week 6. A total of 26 patients were included in the study, 15 patients were available for the per protocol analysis. A drop in platelets >25% (primary endpoint) was observed in 4 of 8 (50%, iron group) and 1 of 7 patients (14%, placebo group, P = 0.143). Mean platelet counts dropped on FCM but not on placebo (536 G/L to 411 G/L versus 580 G/L to 559 G/L; P = 0.002). Disease activity and megakaryopoietic growth factors remained unchanged and hemoglobin and iron parameters increased on FCM. The normalization of platelet counts was associated with a decrease in platelet aggregation and P-selectin expression. FCM lowers platelet counts and platelet activation in patients with IBD-associated secondary thrombocytosis.

  6. Study on the relationship between serum interleukins, platelet activation indexes and cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    Bo Wu

    2015-01-01

    Objective:To study and investigate the relationship between serum interleukins, platelet activation indexes and cerebral infarction.Methods:58 patients with cerebral infarction in our hospital from March 2013 to September 2014 were selected as observation group; meanwhile, 58 healthy persons at the same period were selected as control group, then the serum interleukins and platelet activation indexes of two groups were detected and compared, then the detection results of observation group with different stages and severity of cerebral infarction were compared too, and the relationship between those blood detection indexes and cerebral infarction were analyzed by the Logistic analysis.Results:The serum interleukins and platelet activation indexes of observation group were obviously higher than those of control group, and the detection levels of observation group with cerebral infarction at early and severe stage were obviously higher than those of patients at other stages and light, moderate, and those blood indexes all had close relationship to the cerebral infarction by the Logistic analysis,P<0.05. Conclusion:The serum interleukins and platelet activation indexes all have close relationship to cerebral infarction, and they can be as the important monitoring indexes of the disease.

  7. Three-dimentional simulation of flow-induced platelet activation in artificial heart valves

    Science.gov (United States)

    Hedayat, Mohammadali; Asgharzadeh, Hafez; Borazjani, Iman

    2015-11-01

    Since the advent of heart valve, several valve types such as mechanical and bio-prosthetic valves have been designed. Mechanical Heart Valves (MHV) are durable but suffer from thromboembolic complications that caused by shear-induced platelet activation near the valve region. Bio-prosthetic Heart Valves (BHV) are known for better hemodynamics. However, they usually have a short average life time. Realistic simulations of heart valves in combination with platelet activation models can lead to a better understanding of the potential risk of thrombus formation in such devices. In this study, an Eulerian approach is developed to calculate the platelet activation in three-dimensional simulations of flow through MHV and BHV using a parallel overset-curvilinear immersed boundary technique. A curvilinear body-fitted grid is used for the flow simulation through the anatomic aorta, while the sharp-interface immersed boundary method is used for simulation of the Left Ventricle (LV) with prescribed motion. In addition, dynamics of valves were calculated numerically using under-relaxed strong-coupling algorithm. Finally, the platelet activation results for BMV and MHV are compared with each other.

  8. Platelet activation and lipid peroxidation in patients with acute ischemic stroke

    NARCIS (Netherlands)

    F. van Kooten (Fop); G. Ciabattoni; C. Patrono; D.W.J. Dippel (Diederik); P.J. Koudstaal (Peter Jan)

    1997-01-01

    textabstractBACKGROUND AND PURPOSE: Both platelet activation and lipid peroxidation are potential sources of vasoactive eicosanoids that can be produced via the cyclooxygenase pathway, ie, thromboxane (TX) A2, or by free radical-catalyzed peroxidation of arachidonic acid, ie, isoprostanes. We invest

  9. All-trans-Retinoic Acid Ameliorated High Fat Diet-Induced Atherosclerosis in Rabbits by Inhibiting Platelet Activation and Inflammation

    Directory of Open Access Journals (Sweden)

    Birong Zhou

    2012-01-01

    Full Text Available Background. All-trans-retinoic acid (atRA is effective for many proliferative diseases. We investigated the protective effects of atRA against atherosclerosis. Methods. Rabbits were randomly allocated to receive basal diet or an HFD for 4 weeks. HFD group then received rosuvastatin (3 mg/day, atRA (5 mg/kg/day, or the same volume of vehicle, respectively, for next 8 weeks. Results. HFD group showed increases in plasma lipids and aortic plaque formation. P-selectin expression and fibrinogen binding on platelets or deposition on the intima of the aorta also increased significantly as did the levels of TNF-α, IL-6, and fibrinogen in plasma. After 8 weeks of treatment with atRA, there was a significant decrease in plasma lipids and improvement in aortic lesions. AtRA also inhibited the expression of P-selectin and fibrinogen binding on platelets and deposition on the intima of the aorta. Conclusion. AtRA can ameliorate HFD-induced AS in rabbits by inhibiting platelet activation and inflammation.

  10. Early local intracoronary platelet activation after drug-eluting stent placement

    Institute of Scientific and Technical Information of China (English)

    Ailiman Mahemuti; Nicolas Meneveau; Marie-France Seronde; Francois Schiele; Mariette Mercier; Evelyne Racadot; Jean-Pierre Bassand

    2007-01-01

    Background Early local platelet activation after coronary intervention identifies patients at increased risk of acute stent thrombosis (AST). However, early changes in platelet activation in coronary circulation following drug-eluting stent (DES) implantation have never been reported.Methods In a prospective study of 26 consecutive elective stable angina patients, platelet activation was analyzed by measuring soluble glycoprotein V (sGPV) and P-selectin (CD62P) before and after implantation of either DES or bare metal stent (BMS). All patients were pretreated with clopidogrel (300 mg loading dose) and aspirin (75 mg orally) the day before the procedure. Blood samples were drawn from the coronary ostium and 10 - 20 mm distal to the lesion site.Results Consistent with the lower baseline clinical risk, the levels of CD62P and sGPV were within normal reference range, both in the coronary ostium and distal to the lesion before percutaneous coronary intervention (PCl) procedure.The levels of CD62P and sGPV did not change significantly (CD62P: (31.1 ± 9.86) ng/ml vs (29.5 ± 9.02) ng/ml, P=0.319and sGPV: (52.4 ± 13.5) ng/ml vs (51.8 ± 11.7) ng/ml, P=0.674, respectively) after stent implantation when compared with baseline. Changes in these platelet activation markers did not differ between stent types.Conclusions Intracoronary local platelet activation does not occur in stable angina patients before and immediately following DES implantation when dual anti-platelet is administered.

  11. Platelet activation and thrombus formation relates to the presence of myocardial inflammation in patients with cardiomyopathy.

    Science.gov (United States)

    Bobbert, Peter; Weikert, Ulf; Schmidt-Lucke, Caroline; Skurk, Carsten; Meyer, Alexander; Steffens, Daniel; Schultheiss, Heinz Peter; Rauch, Ursula

    2014-05-01

    Patients with cardiomyopathy show a significantly increased risk for thromboembolic events due to a hypercoagulable state and platelet dysfunction. The pathophysiologic mechanism underlying the increasing platelet activity in patients with cardiomyopathy remains unclear. We performed a clinical study to elucidate the link between myocardial tissue alterations and platelet activation in patients with cardiomyopathy. A total of 30 patients with suspected cardiomyopathy and 10 healthy control patients were included in our study. Hemodynamic parameters were measured by catheterization and echocardiography. Endomyocardial biopsies were taken to determine myocardial inflammation. Flow cytometry was performed to examine the platelet activation by quantification of p-selectin and thrombospondin expression on platelets. The p-selectin (8.46 ± 3.67 AU) and thrombospondin (26.56 ± 23.21 AU) expression was significantly correlated with the amount of CD3+ T cells (p-selectin: r=0.573, p<0.05; thrombospondin: r=0.488, p<0.05) and the endothelial/interstitial activation (p-selectin: r=0.521, p<0.05; thrombospondin: r=0.39, p<0.05). This was found to be independent of hemodynamic parameters, age, and gender. The platelet activation of patients (n=3) with echocardiographically documented ventricular thrombi was significantly increased (p-selectin: 12.57 ± 5.5 AU vs. 8.1 ± 3.2 AU, p<0.05) and this was associated with elevated myocardial inflammation scores. Myocardial inflammation is associated with a significant increase in platelet activation and ventricular thrombus formation independently of the hemodynamic conditions. Copyright © 2013 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  12. Potential Participation of calpain in platelet activation studied by use of a cell penetrating calpain inhibitor (Calpeptin)

    Energy Technology Data Exchange (ETDEWEB)

    Tsujinaka, Toshimasa; Ariyoshi, Hideo; Uemura, Yoshio; Sakon, Masato; Kambayashi, Junichi; Mori, Takesada (Osaka Univ. Medical School, Fukushima (Japan))

    1990-01-01

    Employing a cell penetrating calpain inhibitor (calpeptin), the role of calpain in platelet activation was examined. In washed platelets (WPs) both thrombin and collagen-induced platelet aggregation were dose-dependently inhibited by calpeptin. The addition of plasma to WPs interfered with the action of calpeptin, however more than 3 min preincubation of calpeptin with WPs completely abolished the influence of plasma. In thrombin-activated WPs with calcium, the increase of intracellular calcium concentration, (Ca{sup 2+})i, and the production of inositol triphosphate (IP{sub 3}) were dose-dependently inhibited by calpeptin. The generation of thromboxane B{sub 2} (TxB{sub 2}) was inhibited by calpeptin in collagen and thrombin-activated WPs. In ({sub 3}H)-arachidonic acid (AA)-labelled platelets, calpeptin increased the amount of ({sup 3}H)-AA liberated by inhibiting ({sup 3}H)-AA degradation after collagen or thrombin stimulation. When ({sup 14}C)-AA degradation by the platelet suspension was observed, calpeptin inhibited TxB{sub 2} and hydroxyheptadecatrienoic acid (HHT) generation but increased prostaglandin (PG) E{sub 1}, E{sub 2}, 12-hydroxyeicosatetraenoic acid (12HETE) and AA. Based on these findings, calpain may be involved in the activation phospholipase C and thromboxane synthetase.

  13. Amarogentin, a Secoiridoid Glycoside, Abrogates Platelet Activation through PLCγ2-PKC and MAPK Pathways

    Directory of Open Access Journals (Sweden)

    Ting-Lin Yen

    2014-01-01

    Full Text Available Amarogentin, an active principle of Gentiana lutea, possess antitumorigenic, antidiabetic, and antioxidative properties. Activation of platelets is associated with intravascular thrombosis and cardiovascular diseases. The present study examined the effects of amarogentin on platelet activation. Amarogentin treatment (15~60 μM inhibited platelet aggregation induced by collagen, but not thrombin, arachidonic acid, and U46619. Amarogentin inhibited collagen-induced phosphorylation of phospholipase C (PLCγ2, protein kinase C (PKC, and mitogen-activated protein kinases (MAPKs. It also inhibits in vivo thrombus formation in mice. In addition, neither the guanylate cyclase inhibitor ODQ nor the adenylate cyclase inhibitor SQ22536 affected the amarogentin-mediated inhibition of platelet aggregation, which suggests that amarogentin does not regulate the levels of cyclic AMP and cyclic GMP. In conclusion, amarogentin prevents platelet activation through the inhibition of PLCγ2-PKC cascade and MAPK pathway. Our findings suggest that amarogentin may offer therapeutic potential for preventing or treating thromboembolic disorders.

  14. PLATELET ACTIVATION AND ENDOTHELIAL CELL IMPAIRMENT ON ADRENOGLUCOCORTISONE-INDUCED OSTEONECROSIS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective To investigate the effects of the platelet activation and the endothelial cell impairment on the osteonecrosis. Methods The contents of TXB2,6-keto-PGF1a, GMP-140 and TM in different periods of animal models of adrenoglucocortisone-induced osteonerosis were measured by the radio-immunity method. Results The contents in group B increased dramatically from 24h after the injection of adrenoglucocortisone, and the contents of GMP-140 and TM from 3d after injection increased with significant difference from group A. Conclusion The results suggest that the early emergence of the platelet activation and endothelial cell impairment models induced by horse serum and adrenoglucocortisone plays a role in the formation of the osteonecrosis.

  15. Xanthohumol, a Prenylated Flavonoid from Hops (Humulus lupulus), Prevents Platelet Activation in Human Platelets

    OpenAIRE

    Ye-Ming Lee; Kuo-Hsien Hsieh; Wan-Jung Lu; Hsiu-Chu Chou; Duen-Suey Chou; Li-Ming Lien; Joen-Rong Sheu; Kuan-Hung Lin

    2012-01-01

    Xanthohumol is the principal prenylated flavonoid in the hop plant (Humulus lupulus L.). Xanthohumol was found to be a very potent cancer chemopreventive agent through regulation of diverse mechanisms. However, no data are available concerning the effects of xanthohumol on platelet activation. The aim of this paper was to examine the antiplatelet effect of xanthohumol in washed human platelets. In the present paper, xanthohumol exhibited more-potent activity in inhibiting platelet aggregation...

  16. The influence of statin therapy on platelet activity markers in hyperlipidemic patients after ischemic stroke

    Science.gov (United States)

    Chmielewski, Henryk; Kaczorowska, Beata; Przybyła, Monika; Baj, Zbigniew

    2015-01-01

    Introduction Low-density lipoprotein cholesterol (LDL-C) has been reported to increase platelet activation. Reducing the level of LDL-C with statins induces important pleiotropic effects such as platelet inhibition. This association between platelet activity and statin therapy may be clinically important in reducing the risk of ischemic stroke. We investigated the effect of simvastatin therapy on platelet activation markers (platelet CD62P, sP-selectin, and platelet-derived microparticles (PDMPs)) in hyperlipidemic patients after ischemic stroke. Material and methods The study group consisted of 21 hyperlipidemic patients after ischemic stroke confirmed by CT, and 20 healthy subjects served as controls. We assessed the CD62P expression on resting and thrombin-activated blood platelets. CD62P and PDMPs were analyzed by the use of monoclonal antibodies anti-CD61 and anti-CD62 on a flow cytometer. The level of sP-selectin in serum was measured by the ELISA (enzyme-linked immunosorbent assay) method. All markers were re-analyzed after 6 months of treatment with simvastatin (20 mg/day). Results Hyperlipidemic patients presented a significantly higher percentage of CD62+ platelets and higher reactivity to thrombin compared to control subjects. After simvastatin therapy hyperlipidemic patients showed a reduction of the percentage of resting CD62P(+) platelets (p = 0.005) and a reduction of expression and percentage of CD62P(+) platelets after activation by thrombin (median p < 0.05; percentage: p = 0.001). A decrease of sP-selectin levels (p = 0.001) and percentage of PDMPs (p < 0.05) in this group was also observed. Conclusions HMG-CoA reductase inhibitor therapy in stroke patients with hyperlipidemia may be useful not only due to the lipid-lowering effect but also because of a significant role in reduction of platelet activation and reactivity. PMID:25861297

  17. Glaucocalyxin A inhibits platelet activation and thrombus formation preferentially via GPVI signaling pathway.

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    Wei Li

    Full Text Available Platelets play a pivotal role in atherothrombosis and the antiplatelet agents have been proved to be useful in preventing onset of acute clinical events including myocardial infarction and stroke. Increasing number of natural compounds has been identified to be potential antiplatelet agents. Here we report the antiplatelet effect of glaucocalyxin A (GLA, an ent-diterpenoid that we isolated and purified from the aerial parts of Rabdosia japonica (Burm. f. var. glaucocalyx (Maxim. Hara, and investigate the molecular mechanisms by which GLA inhibits platelet activation and thrombus formation. The effect of GLA on platelet activation was measured using platelets freshly isolated from peripheral blood of healthy donors. Results showed that pretreatment of human platelets with lower concentrations of GLA (0.01 μg/ml, 0.1 μg/ml significantly inhibited platelet aggregation induced by collagen (P<0.001 and CRP (P<0.01, a synthetic GPVI ligand, but not by ADP and U46619. Accordingly, GLA inhibited collagen-stimulated tyrosine phosphorylation of Syk, LAT, and phospholipase Cγ2, the signaling events in collagen receptor GPⅥ pathway. GLA also inhibited platelet p-selectin secretion and integrin activation by convulxin, a GPVI selective ligand. Additionally, GLA was found to inhibit low-dose thrombin-induced platelet activation. Using a flow chamber device, GLA was found to attenuate platelet adhesion on collagen surfaces in high shear condition. In vivo studies showed that GLA administration increased the time for complete occlusion upon vascular injury in mice, but did not extend tail-bleeding time when mice were administered with relatively lower doses of GLA. Therefore, the present results provide the molecular basis for the inhibition effect of GLA on platelet activation and its in vivo effect on thrombus formation, suggesting that GLA could potentially be developed as an antiplatelet and antithrombotic agent.

  18. Cigarette smoking inhibits the anti-platelet activity of aspirin in patients with coronary heart disease

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    LI Wei-ju; ZHANG Hong-yin; MIAO Cheng-long; TANG Ri-bo; DU Xin; SHI Ji-hui; MA Chang-sheng

    2011-01-01

    Objective Tobacco smoking results in increased platelet aggregability, which suggests that low-dose aspirin used in common clinical practice may not effectively inhibit platelet activity in smokers with coronary heart disease (CHD). This review was performed to assess the effect of aspirin on platelet aggregation in patients with CHD.Data sources We performed an electronic literature search of MEDLINE (starting from the beginning to March 15, 2009)using the term "smoking" or "tobacco" paired with the following: "platelet", "aspirin" or "coronary heart disease".Study selection We looked for review articles regarding the effect of tobacco smoking on platelet activity and on the anti-platelet efficacy of aspirin in healthy people and patients with CHD. The search was limited in "core clinical journal".In total, 1321 relevant articles were retrieved, and 36 articles were ultimately cited.Results Tobacco smoking results in increased platelet aggregability, which can be inhibited by low-dose aspirin in the healthy population. However, in patients with CHD, the increased platelet aggregability can not be effectively inhibited by the same low-dose of aspirin. A recent study indicated that clopidogrel or an increased dose of aspirin can effectively inhibit the increased platelet aggregability induced by tobacco smoking in patients with CHD.Conclusions It is important for patients with CHD to quit smoking. For the current smoker, it may be necessary to take larger doses of aspirin than normal or take an adenosine diphosphate receptor inhibitor along with aspirin to effectively inhibit the increased platelet activity.

  19. Effects of hormone replacement therapy on platelet activation in postmenopausal women

    Institute of Scientific and Technical Information of China (English)

    古健; 杨冬梓; 王良岸; 尹松梅; 邝健全

    2003-01-01

    Objective To assess the effects of hormone replacement therapy (HRT) on platelet activation in postmenopausal women compared with premenopausal women. Methods The expressions of CD41 and CD62P in fifteen postmenopausal women before and after HRT were detected using flow cytometry (FCM), with fifteen premenopausal women with a mean age of 47 years as controls.Results The expressions of CD41 and CD62P in postmenopausal women were higher than those in the control group. CD62P(%), CD62P(I) and CD41 were reduced from 36.40±5.9, 37.75±5.8, and 470.11±74.0 to 27.97±5.6, 26.64±4.9, and 303.23±72.8 after six months of HRT (P<0.05). Conclusions Platelet activation in postmenopausal women was higher than in premenopausal women and was reduced significantly after six months of HRT. HRT may have a favorable effect on reduction of platelet activity.

  20. Plasma Viscosity : A Risk Factor In Hypertension

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    Puniyani R. R

    1989-01-01

    Full Text Available Haemorrheological study on hypertension was done at Indian Institute of Technology Hospital, Bombay. Male population in the age groups of 35 to 60 years was screened for hypertension from February 1986 to February 1987. Out of 340 subjects examined, 44 hypertensive cases were found, who were investigated for blood viscosity profile and were compared with 45 controls. The parameters studied were plasma viscosity, whole blood viscosity, red cell aggregation, red cell deformability and haematocrit W.H.O. criteria of hypertension (HT was strictly adhered to (B.P. above 160/95 mm of Hg. When compared to control group, plasma viscosity and whole blood viscosity were elevated in freshly detected and uncontrolled hypertensives. Red cell aggregation and deformability were significantly altered in chronic hypertensives than in normal, but haematocrit was not affected in any group.

  1. The Effect of PEI and PVP-Stabilized Gold Nanoparticles on Equine Platelets Activation: Potential Application in Equine Regenerative Medicine

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    Mateusz Hecold

    2017-01-01

    Full Text Available The aim of this work was to assess the effect of different stabilizing agents, for example, polyethylenimine (PEI and polyvinylpyrrolidone (PVP, on gold nanoparticles (AuNPs and their influence on equine platelet activation and release of particular growth factors. The gold nanoparticles were produced by chemical reduction of chloroauric acid. UV-Vis spectroscopy confirmed the presence of gold nanoparticles in investigated solutions. The AuNPs were incubated with whole blood at various concentrations. The morphology of platelets in PRP prepared from the blood incubated with AuNPs was characterized by scanning transmission electron microscopy, whereas the concentrations of growth factors and cytokines were evaluated by ELISA assays. The most promising results were obtained with equine platelets incubated with 5% AuNPs stabilized by PEI, which lead to secretion of bone morphogenetic protein 2 (BMP-2, vascular endothelial growth factor (VEGF, and fibroblast growth factor 1 (FGF-1 and simultaneously cause decrease in concentration of interleukin-1 alpha (IL-1α. The qRT-PCR confirmed ELISA test results. The incubation with 5% AuNPs stabilized by PEI leads to upregulation of BMP-2 and VEGF transcripts of mRNA level and to downregulating expression of interleukin-6 (IL-6. Obtained data shed a promising light on gold nanoparticle application for future regenerative medicine application.

  2. Isolation and characterization of bovine plasma prekallikrein (Fletcher factor).

    Science.gov (United States)

    Heimark, R L; Davie, E W

    1979-12-11

    Prekallikrein (Fletcher factor) has been purified from bovine plasma approximately 25 000-fold with an overall yield of 14%. Purification steps included ammonium sulfate fractionation and column chromatography on heparin-agarose, DEAE-Sephadex, CM-Sephadex, benzamidine-agarose, and arginine methyl ester-agarose. The purified protein was homogeneous as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and amino-terminal sequence analysis. Bovine plasma prekallikrein is a glycoprotein with a molecular weight of 82 000 as determined by sedimentation equilibrium centrifugation. It contains 12.9% carbohydrate, including 6.2% hexose, 4.5% N-acetylglucosamine, and 2.2% N-acetylneuraminic acid. Prekallikrein is a single polypeptide chain with an amino-terminal sequence of Gly-Cys-Leu-Thr-Gln-Leu-Tyr-His-Asn-Ile-Phe-Phe-Arg-Gly-Gly. This sequence is homologous to the amino-terminal sequence of human factor XI (plasma thromboplastin antecedent). Both prekallikrein and kallikrein require kaolin to correct Fletcher factor deficient plasma. Kallikrein, however, has a specific activity 3.5 times greater than prekallikrein. Prekallikrein does not correct plasma deficient in factor XII (Hageman factor), factor XI, or high molecular weight kininogen (Fitzgerald factor).

  3. ExoU-induced vascular hyperpermeability and platelet activation in the course of experimental Pseudomonas aeruginosa pneumosepsis.

    Science.gov (United States)

    Machado, Gloria-Beatriz S; de Assis, Maria-Cristina; Leão, Robson; Saliba, Alessandra M; Silva, Mauricio C A; Suassuna, Jose H; de Oliveira, Albanita V; Plotkowski, Maria-Cristina

    2010-03-01

    To address the question whether ExoU, a Pseudomonas aeruginosa cytotoxin with phospholipase A2 activity, can induce hemostatic abnormalities during the course of pneumosepsis, mice were instilled i.t. with the ExoU-producing PA103 P. aeruginosa or with a mutant obtained by deletion of the exoU gene. Control animals were instilled with sterile vehicle. To assess the role of ExoU in animal survival, mice were evaluated for 72 h. In all the other experiments, animals were studied at 24 h after infection. PA103-infected mice showed significantly higher mortality rate, lower blood leukocyte concentration, and higher platelet concentration and hematocrit than animals infected with the bacterial mutant, as well as evidences of increased vascular permeability and plasma leakage, which were confirmed by our finding of higher protein concentration in bronchoalveolar lavage fluids and by the Evans blue dye assay. Platelets from PA103-infected mice demonstrated features of activation, assessed by the flow cytometric detection of higher percentage of P-selectin expression and of platelet-derived microparticles as well as by the enzyme immunoassay detection of increased thromboxane A2 concentration in animal plasma. Histopathology of lung and kidney sections from PA103-infected mice exhibited evidences of thrombus formation that were not detected in sections of animals from the other groups. Our results demonstrate the ability of ExoU to induce vascular hyperpermeability, platelet activation, and thrombus formation during P. aeruginosa pneumosepsis, and we speculate that this ability may contribute to the reported poor outcome of patients with severe infection by ExoU-producing P. aeruginosa.

  4. Effect of red blood cells on platelet activation and thrombus formation in tortuous arterioles

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    Jennifer K. W. Chesnutt

    2013-12-01

    Full Text Available Thrombosis is a major contributor to cardiovascular disease, which can lead to myocardial infarction and stroke. Thrombosis may form in tortuous microvessels, which are often seen throughout the human body, but the microscale mechanisms and processes are not well understood. In straight vessels, the presence of red blood cells (RBCs is known to push platelets toward walls, which may affect platelet aggregation and thrombus formation. However in tortuous vessels, the effects of RBC interactions with platelets in thrombosis are largely unknown. Accordingly, the objective of this work was to determine the physical effects of RBCs, platelet size, and vessel tortuosity on platelet activation and thrombus formation in tortuous arterioles. A discrete element computational model was used to simulate the transport, collision, adhesion, aggregation, and shear-induced platelet activation of hundreds of individual platelets and RBCs in thrombus formation in tortuous arterioles. Results showed that high shear stress near the inner sides of curved arteriole walls activated platelets to initiate thrombosis. RBCs initially promoted platelet activation, but then collisions of RBCs with mural thrombi reduced the amount of mural thrombus and the size of emboli. In the absence of RBCs, mural thrombus mass was smaller in a highly tortuous arteriole compared to a less tortuous arteriole. In the presence of RBCs however, mural thrombus mass was larger in the highly tortuous arteriole compared to the less tortuous arteriole. As well, smaller platelet size yielded less mural thrombus mass and smaller emboli, either with or without RBCs. This study shed light on microscopic interactions of RBCs and platelets in tortuous microvessels, which have implications in various pathologies associated with thrombosis and bleeding.

  5. The nitric oxide donor pentaerythritol tetranitrate reduces platelet activation in congestive heart failure.

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    Ulrike Flierl

    Full Text Available Platelet activation associated with endothelial dysfunction and impaired endogenous platelet inhibition is part of the cardiovascular phenotype of congestive heart failure (CHF and contributes to the increased risk for thromboembolic complications. Pentaerythritol tetranitrate (PETN has been shown to release nitric oxide without development of nitrate tolerance. We investigated the effect of chronic PETN treatment on platelet activation and aggregation in an experimental CHF model.Chronic ischemic heart failure was induced in male Wistar rats by coronary artery ligation. Starting 7 days thereafter, rats were randomised to placebo or PETN (80 mg/kg twice daily. After 9 weeks, activation of circulating platelets was determined measuring platelet bound fibrinogen, which requires activated glycoprotein IIb/IIIa on the platelet surface. Binding was quantified by flow-cytometry using a FITC-labelled anti-fibrinogen antibody. Platelet-bound fibrinogen was significantly increased in CHF-Placebo (mean fluorescence intensity: Sham 88±4, CHF-Placebo 104±6, p<0.05 and reduced following treatment with PETN (89±7, p<0.05 vs. CHF-Placebo. Maximal and final ADP-induced aggregation was significantly enhanced in CHF-Placebo vs. Sham-operated animals and normalized / decreased following chronic PETN treatment. Moreover, platelet adhesion was significantly reduced (number of adherent platelets: control: 85.6±5.5, PETN: 40±3.3; p<0.001 and VASP phosphorylation significantly enhanced following in vitro PETN treatment.Chronic NO supplementation using PETN reduces platelet activation in CHF rats. Thus, PETN may constitute a useful approach to prevent thromboembolic complications in CHF.

  6. Effect of Red Blood Cells on Platelet Activation and Thrombus Formation in Tortuous Arterioles.

    Science.gov (United States)

    Chesnutt, Jennifer K W; Han, Hai-Chao

    2013-01-01

    Thrombosis is a major contributor to cardiovascular disease, which can lead to myocardial infarction and stroke. Thrombosis may form in tortuous microvessels, which are often seen throughout the human body, but the microscale mechanisms and processes are not well understood. In straight vessels, the presence of red blood cells (RBCs) is known to push platelets toward walls, which may affect platelet aggregation and thrombus formation. However in tortuous vessels, the effects of RBC interactions with platelets in thrombosis are largely unknown. Accordingly, the objective of this work was to determine the physical effects of RBCs, platelet size, and vessel tortuosity on platelet activation and thrombus formation in tortuous arterioles. A discrete element computational model was used to simulate the transport, collision, adhesion, aggregation, and shear-induced platelet activation of hundreds of individual platelets and RBCs in thrombus formation in tortuous arterioles. Results showed that high shear stress near the inner sides of curved arteriole walls activated platelets to initiate thrombosis. RBCs initially promoted platelet activation, but then collisions of RBCs with mural thrombi reduced the amount of mural thrombus and the size of emboli. In the absence of RBCs, mural thrombus mass was smaller in a highly tortuous arteriole compared to a less tortuous arteriole. In the presence of RBCs however, mural thrombus mass was larger in the highly tortuous arteriole compared to the less tortuous arteriole. As well, smaller platelet size yielded less mural thrombus mass and smaller emboli, either with or without RBCs. This study shed light on microscopic interactions of RBCs and platelets in tortuous microvessels, which have implications in various pathologies associated with thrombosis and bleeding.

  7. Release kinetics of platelet-derived and plasma-derived growth factors from autologous plasma rich in growth factors.

    Science.gov (United States)

    Anitua, Eduardo; Zalduendo, Mari Mar; Alkhraisat, Mohammad Hamdan; Orive, Gorka

    2013-10-01

    Many studies have evaluated the biological effects of platelet rich plasma reporting the final outcomes on cell and tissues. However, few studies have dealt with the kinetics of growth factor delivery by plasma rich in growth factors. Venous blood was obtained from three healthy volunteers and processed with PRGF-Endoret technology to prepare autologous plasma rich in growth factors. The gel-like fibrin scaffolds were then incubated in triplicate, in a cell culture medium to monitor the release of PDGF-AB, VEGF, HGF and IGF-I during 8 days of incubation. A leukocyte-platelet rich plasma was prepared employing the same technology and the concentrations of growth factors and interleukin-1β were determined after 24h of incubation. After each period, the medium was collected, fibrin clot was destroyed and the supernatants were stored at -80°C until analysis. The growth factor delivery is diffusion controlled with a rapid initial release by 30% of the bioactive content after 1h of incubation and a steady state release when almost 70% of the growth factor content has been delivered. Autologous fibrin matrix retained almost 30% of the amount of the growth factors after 8 days of incubation. The addition of leukocytes to the formula of platelet rich plasma did not increase the concentration of the growth factors, while it drastically increased the presence of pro-inflammatory IL-1β. Further studies employing an in vitro inflammatory model would be interesting to study the difference in growth factors and pro-inflammatory cytokines between leukocyte-free and leukocyte-rich platelet rich plasma.

  8. Plasma levels of factor XII, prekallikrein and high molecular weight kininogen in normal blood donors and patients having suffered venous thrombosis.

    Science.gov (United States)

    Gallimore, Michael J; Harris, Simon L; Jones, David W; Winter, Mark

    2004-01-01

    The contact system proteins factor XII (FXII), prekallikrein (PK) and high molecular weight kininogen (HK) have roles in coagulation, fibrinolysis, thrombin-induced platelet activation, cell adhesion and angeogenisis. It has been suggested that inherited or acquired deficiencies of these proteins may be risk factors for thrombosis. Studies on the levels of FXII in plasma from normal and thrombotic patient populations have been reported, to our knowledge however, no systematic study on plasma levels of PK and HK in large populations of normal blood donors and patients having had venous thrombotic events has been performed. Chromogenic substrate assays were used to measure plasma levels of FXII, PK and HK in 300 normal blood donors (ND) and 300 patients attending our anticoagulant clinic who had a history of venous thrombosis (deep vein thrombosis or pulmonary embolism [VT]). All subjects were Caucasian, antiphospholipid antibody negative and had normal liver function. Mean values +/- SD were: FXII: ND 99.4 +/- 26.7%: VT 91.0 +/- 27.2%: PKK: ND 99.7 +/- 19.8%: VT 99.1 +/- 21.2%: HK: ND 101.0 +/- 20.5%: VT 110.7 +/- 32.3%. Statistical analysis of the data revealed significantly lower (pPKK: 66.8%, HK: 63.4%. The prevalence of values below the lower limit of normal were FXII-ND 2.3%: FXII-VT 8.0%, PKK-ND 3.0%: PKK-VT 4.7%, HK-ND 2.3%: HK-VT 5.0%. No homozygous deficiency patients were found for any parameter. One VT patient had combined FXII and HK deficiency and one ND and two VT patients had combined PK and HK deficiency. FXII levels were lower and HK levels and the prevalence of FXII, PK and HK deficiency higher in a population of patients with a history of VT than in a population of healthy blood donors.

  9. Ativação plaquetária na esclerose sistêmica e alternativas metodológicas para sua avaliação Platelet activation in systemic sclerosis and methodological options to its assessment

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    Paulo Sergio Massabki

    2004-02-01

    immunologic abnormalities. The microangiopathic aspect is responsible for the most severe and life-threatening features of the disease. The interaction between endothelium and platelets plays an important role in the pathophysiology of SSc. Evidence of platelet activation in SSc includes high plasma levels of platelet-derived substances (Von Willenbrand factor, platelet factor 4, thromboxane A2, and ß-thromboglobulin, circulating platelet aggregates, ultra structural abnormalities in platelets, and the presence of platelets adhered to the endothelium. This review addresses the principles and possible pitfalls of the main methods for evaluation of platelet activation and function. The assessment of the ability of platelet aggregation is performed with and without the addition of agonists (adenosine diphosphate, collagen, adrenaline. Platelet activation may be assessed by two ways: by measurement of plasma concentration of substances that are released as the platelets are activated (e.g., thromboxane, platelet factor 4 and by the measurement of membrane expression of molecules that are transported to the platelet membrane during the activation process (e.g., GMP-140, glycoprotein IIb/IIIa. A recent contribution to this field was the demonstration that neuron-specific enolase (NSE is released from the platelets into the blood in patients with active SSc. NSE, which is readily available in clinical laboratories with emphasis in tumor markers, may become a useful platelet activation marker in a series of clinical conditions.

  10. Secondary failure of plasma therapy in factor H deficiency.

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    Nathanson, Sylvie; Ulinski, Tim; Frémeaux-Bacchi, Véronique; Deschênes, Georges

    2006-11-01

    We report a patient with homozygous factor H deficiency leading to permanent alternate complement activation and early onset of the hemolytic uremic syndrome. He was successfully treated with weekly infusions of fresh frozen plasma over 4 years, displaying normal blood pressure while only treated with an angiotensin converting enzyme (ACE) inhibitor, a steady level of haptoglobin, low-range proteinuria and normal creatinine clearance. By the end of the fourth year of treatment, he dramatically developed a relapse of hemolytic and uremic syndrome, displaying undetectable haptoglobin, nephrotic range proteinuria and progressive renal failure. Despite a ten-fold increase in the dosage of plasma infusion through daily plasma exchange, haptoglobin remained undetectable while circulating antigenic factor H levels reached 22-24% (normal values 65-140%). Three months following the biological onset of the relapse, a bilateral nephrectomy was performed owing to uncontrolled hypertension and rapidly progressive renal failure. The molecular mechanism of plasma resistance remained unclear while antifactor H antibodies were not detected in the plasma. We suggest that protracted administration of exogenous factor H might not be a long-term strategy in homozygous factor H deficiency.

  11. Fish-Free Diet in Patients with Phenylketonuria Is Not Associated with Early Atherosclerotic Changes and Enhanced Platelet Activation.

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    Patrik Htun

    Full Text Available Since patients with phenylketonuria (PKU have to follow a lifelong restriction of natural protein to lower phenylalanine-intake, they never eat fish. This diet may lead to a chronic deficit of omega-3 and omega-6 fatty acids with the risk of early atherosclerotic changes. The aim of the study was to analyse the fatty acid profile of PKU patients and to correlate the results with surrogate markers of early atherosclerotic changes [enhanced carotid intima media thickness (CIMT and ß-stiffness index] and platelet activation.In 43 PKU patients and in 58 healthy controls we prospectively examined the fatty acid profile, CIMT, ß-stiffness index and platelet activation (flow cytometric determination of markers of platelet activation. CIMT was measured bilaterally by ultrasound. CIMTmean was defined as the mean value of the sum of CIMTleft and CIMTright.Despite of lower HDL-cholesterol and higher triglyceride concentrations in the PKU group, there was no significant difference in the omega-6 or omega-3 fatty acid profile, CIMT, ß-stiffness index between both groups. Platelet activation was not enhanced in the PKU group.Fish-free diet does not induce early atherosclerotic changes or enhanced platelet activation in PKU patients.

  12. Xanthohumol, a Prenylated Flavonoid from Hops (Humulus lupulus), Prevents Platelet Activation in Human Platelets.

    Science.gov (United States)

    Lee, Ye-Ming; Hsieh, Kuo-Hsien; Lu, Wan-Jung; Chou, Hsiu-Chu; Chou, Duen-Suey; Lien, Li-Ming; Sheu, Joen-Rong; Lin, Kuan-Hung

    2012-01-01

    Xanthohumol is the principal prenylated flavonoid in the hop plant (Humulus lupulus L.). Xanthohumol was found to be a very potent cancer chemopreventive agent through regulation of diverse mechanisms. However, no data are available concerning the effects of xanthohumol on platelet activation. The aim of this paper was to examine the antiplatelet effect of xanthohumol in washed human platelets. In the present paper, xanthohumol exhibited more-potent activity in inhibiting platelet aggregation stimulated by collagen. Xanthohumol inhibited platelet activation accompanied by relative [Ca(2+)](i) mobilization, thromboxane A(2) formation, hydroxyl radical (OH(●)) formation, and phospholipase C (PLC)γ2, protein kinase C (PKC), mitogen-activated protein kinase (MAPK), and Akt phosphorylation. Neither SQ22536, an inhibitor of adenylate cyclase, nor ODQ, an inhibitor of guanylate cyclase, reversed the xanthohumol-mediated inhibitory effect on platelet aggregation. Furthermore, xanthohumol did not significantly increase nitrate formation in platelets. This study demonstrates for the first time that xanthohumol possesses potent antiplatelet activity which may initially inhibit the PI3-kinase/Akt, p38 MAPK, and PLCγ2-PKC cascades, followed by inhibition of the thromboxane A(2) formation, thereby leading to inhibition of [Ca(2+)](i) and finally inhibition of platelet aggregation. Therefore, this novel role of xanthohumol may represent a high therapeutic potential for treatment or prevention of cardiovascular diseases.

  13. Xanthohumol, a Prenylated Flavonoid from Hops (Humulus lupulus, Prevents Platelet Activation in Human Platelets

    Directory of Open Access Journals (Sweden)

    Ye-Ming Lee

    2012-01-01

    Full Text Available Xanthohumol is the principal prenylated flavonoid in the hop plant (Humulus lupulus L.. Xanthohumol was found to be a very potent cancer chemopreventive agent through regulation of diverse mechanisms. However, no data are available concerning the effects of xanthohumol on platelet activation. The aim of this paper was to examine the antiplatelet effect of xanthohumol in washed human platelets. In the present paper, xanthohumol exhibited more-potent activity in inhibiting platelet aggregation stimulated by collagen. Xanthohumol inhibited platelet activation accompanied by relative [Ca2+]i mobilization, thromboxane A2 formation, hydroxyl radical (OH● formation, and phospholipase C (PLCγ2, protein kinase C (PKC, mitogen-activated protein kinase (MAPK, and Akt phosphorylation. Neither SQ22536, an inhibitor of adenylate cyclase, nor ODQ, an inhibitor of guanylate cyclase, reversed the xanthohumol-mediated inhibitory effect on platelet aggregation. Furthermore, xanthohumol did not significantly increase nitrate formation in platelets. This study demonstrates for the first time that xanthohumol possesses potent antiplatelet activity which may initially inhibit the PI3-kinase/Akt, p38 MAPK, and PLCγ2-PKC cascades, followed by inhibition of the thromboxane A2 formation, thereby leading to inhibition of [Ca2+]i and finally inhibition of platelet aggregation. Therefore, this novel role of xanthohumol may represent a high therapeutic potential for treatment or prevention of cardiovascular diseases.

  14. Effects of simvastatin on lipid levels and platelet activation in elderly patients with hypercholesterolemia

    Institute of Scientific and Technical Information of China (English)

    Zhe Chen; Yuanping Hou; Miaobin Liu

    2007-01-01

    Background and Objective To investigate the effects of simvastatin on lipid lowering therapy and platelet activation in elderly patients with hypercholesterolemia. Methods Fasting serum lipids, CD63, CD41a, serum glucose, hepatic and renal function, routine urine analysis (UA) were measured in 50 healthy subjects, and in 50 elderly patients with hypercholesterolemia before and after 4 weeks treatment with simvastatin (20mg daily for 4 weeks). Results 1. After simvastatin treatment for 4 weeks, the fasting serum level of lipids in elderly patients with hypercholesterolemia was significantly lower than before treatment (P<0.01). 2. CD63 and CD41a were decreased after treatment compared with before, respectively (1.36 0.34) vs (4.26 1.06), (P<0.01) and (123.54 19.73) vs (253.78 16.75), (P<0.01).3. Changes in serum lipid level tended to be positively correlated with the declines in CD63 and CD41a, but there was no statistical significance (P>0.05). Conclusions The results suggested that lipid lowering therapy with simvastatin inhibit platelet activity.

  15. Mechanism study of endothelial protection and inhibits platelet activation of low molecular weight fucoidan from Laminaria japonica

    Science.gov (United States)

    Chen, Anjin; Zhang, Fang; Shi, Jie; Zhao, Xue; Yan, Meixing

    2016-10-01

    Several studies have indicated that fucoidan fractions with low molecular weight and different sulfate content from Laminaria japonica could inhibit the activation of platelets directly by reducing the platelet aggregation. To explore the direct effect of LMW fucoidan on the platelet system furthermore and examine the possible mechanism, the endothelial protection and inhibits platelet activation effects of two LMW fucoidan were investigated. In the present study, Endothelial injury model of rats was made by injection of adrenaline (0.4 mg kg-1) and human umbilical vein endothelial cells were cultured. vWF level was be investigated in vivo and in vitro as an important index of endothelial injury. LMW fucoidan could significantly reduce vWF level in vascular endothelial injury rats and also significantly reduce vWF level in vitro. The number of EMPs was be detected as another important index of endothelial injury. The results showed that LMW fucoidan reduced EMPs stimulated by tumor necrosis factor. In this study, it was found that by inhibiting platelet adhesion, LMW fucoidan played a role in anti-thrombosis and the specific mechanism of action is to inhibit the flow of extracellular Ca2+. All in a word, LMW fucoidan could inhibit the activation of platelets indirectly by reducing the concentration of EMPs and vWF, at the same time; LMW fucoidan inhibited the activation of platelets directly by inhibiting the flow of extracellular Ca2+.

  16. Effects of Anti-CD59 on Complement- induced Platelet Activation in Adult Males with Coronary Heart Disease

    Institute of Scientific and Technical Information of China (English)

    王礼春; 马虹; 黄守坚; 麦炜颐; 董吁钢; 曾武涛; 廖新学; 何建桂; 徐冬

    2003-01-01

    Objectives To study the reactions of platelet to active complement and the ef-fects of anti- CD59 on platelet activation induced bycomplement in coronary heart disease (CHD) adultmales. Methods By applying cobra venom factor(CVF) to activate complement, observed the plateletaggregation and release reactions induced by activecomplement with or without applying anti- CD59 toblock the complement modulation protein CD59.Results CVF could induce platelet of CHD individ-uals release ATP and cause significant and lastingmetamorphosis, but failed to induce platelet aggregate.The platelet maximum shape change showed positivelinear correlation with lg concentration of CVF. Theregressive equation was Y=28.7171gx - 19. 798 ( r =0. 956, P <0.01, n = 36). Anti - CD59 could enhanceCVF- induced platelet shape change and ATP releasewith a dose-dependent manner. ConclusionsComplement activated by CVF can induce significantand lasting platelet metamorphosis and release reac-tion, but can't induce platelet aggregation in CHD adultmales. Anti -CD59 can promote the platelet reactionsinduced by active complement.

  17. 前列腺素E2(PG-E2)、白三烯B4(LT-B4)、血小板活化因子(PAF)及血管内皮生长因子(VEGF)在溃疡性结肠炎中的意义%Prostaglandin E2 (PG - E2), leukotriene B4 (LT - B4), platelet activating factor (PAF) and vascular endothelial growth factor (VEGF) in ulcerative colitis

    Institute of Scientific and Technical Information of China (English)

    何山; 刘梅; 赵亚玲; 熊晶晶; 丁臻博; 黄永坤

    2014-01-01

    the pathogenesis of ulcerative colitis is not clear so far, the diagnosis and treatment of ulcerative colitis, both at home and abroad ,are mainly concentrated in the immune, environmental, genetic, infection and so on many aspects, especially in immune factors, is a research focus.But because in the process of the pathogenesis of ulcerative colitis, inflammatory factors involved in more, so what inflammatory factor plays a key role, there is still no conclusion.According to a series of studies about Ulcerative colitis(Uc) at home and abroad in recent years, selecting high expressed in Uc which closely associated with Uc pathogenesis and disease severity, but the research still is not perfected of four kinds of inflammatory mediators: prostaglandin e2 (PG - e2), leukotriene B4 (lt - B4), platelet activating factor (Paf) and vascular endothelial growth factor (VeGf) were summarized.%溃疡性结肠炎的发病机理,迄今为止尚不清楚,国内外目前对溃疡性结肠炎的诊治,主要集中在免疫、环境、遗传、感染等诸多方面,尤其在免疫因素方面。然而由于在溃疡性结肠炎的发病过程中,参与的炎性因子较多,故究竟哪些炎性因子起到较为关键的作用,目前仍没有定论。本文主要针对近年来,溃疡性结肠炎的国内外研究,选取在Uc 中表达较高,与 Uc 发病及病情严重程度密切相关,但研究尚不完善的四种炎性介质:前列腺素 e2(PG-e2)、白三烯 B4(lt-B4)、血小板活化因子(Paf)及血管内皮生长因子(VeGf)进行综述。

  18. Sepsis prediction in critically ill patients by platelet activation markers on ICU admission: a prospective pilot study.

    Science.gov (United States)

    Layios, Nathalie; Delierneux, Céline; Hego, Alexandre; Huart, Justine; Gosset, Christian; Lecut, Christelle; Maes, Nathalie; Geurts, Pierre; Joly, Arnaud; Lancellotti, Patrizio; Albert, Adelin; Damas, Pierre; Gothot, André; Oury, Cécile

    2017-12-01

    Platelets have been involved in both immune surveillance and host defense against severe infection. To date, whether platelet phenotype or other hemostasis components could be associated with predisposition to sepsis in critical illness remains unknown. The aim of this work was to identify platelet markers that could predict sepsis occurrence in critically ill injured patients. This single-center, prospective, observational, 7-month study was based on a cohort of 99 non-infected adult patients admitted to ICUs for elective cardiac surgery, trauma, acute brain injury, and post-operative prolonged ventilation and followed up during ICU stay. Clinical characteristics and severity score (SOFA) were recorded on admission. Platelet activation markers, including fibrinogen binding to platelets, platelet membrane P-selectin expression, plasma soluble CD40L, and platelet-leukocytes aggregates were assayed by flow cytometry at admission and 48 h later, and then at the time of sepsis diagnosis (Sepsis-3 criteria) and 7 days later for sepsis patients. Hospitalization data and outcomes were also recorded. Of the 99 patients, 19 developed sepsis after a median time of 5 days. These patients had a higher SOFA score at admission; levels of fibrinogen binding to platelets (platelet-Fg) and of D-dimers were also significantly increased compared to the other patients. Levels 48 h after ICU admission no longer differed between the two patient groups. Platelet-Fg % was an independent predictor of sepsis (P = 0.0031). By ROC curve analysis, cutoff point for Platelet-Fg (AUC = 0.75) was 50%. In patients with a SOFA cutoff of 8, the risk of sepsis reached 87% when Platelet-Fg levels were above 50%. Patients with sepsis had longer ICU and hospital stays and higher death rate. Platelet-bound fibrinogen levels assayed by flow cytometry within 24 h of ICU admission help identifying critically ill patients at risk of developing sepsis.

  19. Can mean platelet component be used as an index of platelet activity in stable coronary artery disease?

    LENUS (Irish Health Repository)

    Cooke, John

    2012-01-31

    Acute coronary syndrome is associated with intracoronary thrombosis secondary to platelet activation. Previous groups have investigated platelet activation in both stable and unstable vascular disease. Most measures of platelet activation are not routinely available or easily adaptable to large scale clinical use. Recently, measurement of the mean platelet component (MPC) has become part of the routine data provided by an automated full blood count analyser, the Advia 120. MPC measures platelet density which changes on platelet activation. Our objectives were to determine if platelet activation, as measured by MPC, is increased in patients with stable coronary artery disease (CAD) and to determine if MPC could be useful in differentiating people with stable CAD from controls on an everyday clinical basis. Three hundred and forty-five consecutive patients attending for elective coronary angiography had full blood count analysis and MPC measurement performed using an ADVIA-120 analyser. Three hundred and twenty-four were analysed in our final dataset. Two hundred and fifty-three (78%) had CAD. Patients with CAD were significantly (p<0.001) older than those without (63.8 versus 56.0 years). Results failed to demonstrate a difference (p=0.467) in MPC between patients with CAD and those with normal coronary arteries (25.8 versus 26.0). Likewise, there was no correlation between MPC and the severity of CAD (Kendall\\'s tau b=-0.086, p=0.04). MPC is not a useful index of platelet activity in stable CAD when used in everyday clinical practice.

  20. Can mean platelet component be used as an index of platelet activity in stable coronary artery disease?

    LENUS (Irish Health Repository)

    Cooke, John

    2009-04-01

    Acute coronary syndrome is associated with intracoronary thrombosis secondary to platelet activation. Previous groups have investigated platelet activation in both stable and unstable vascular disease. Most measures of platelet activation are not routinely available or easily adaptable to large scale clinical use. Recently, measurement of the mean platelet component (MPC) has become part of the routine data provided by an automated full blood count analyser, the Advia 120. MPC measures platelet density which changes on platelet activation. Our objectives were to determine if platelet activation, as measured by MPC, is increased in patients with stable coronary artery disease (CAD) and to determine if MPC could be useful in differentiating people with stable CAD from controls on an everyday clinical basis. Three hundred and forty-five consecutive patients attending for elective coronary angiography had full blood count analysis and MPC measurement performed using an ADVIA-120 analyser. Three hundred and twenty-four were analysed in our final dataset. Two hundred and fifty-three (78%) had CAD. Patients with CAD were significantly (p<0.001) older than those without (63.8 versus 56.0 years). Results failed to demonstrate a difference (p=0.467) in MPC between patients with CAD and those with normal coronary arteries (25.8 versus 26.0). Likewise, there was no correlation between MPC and the severity of CAD (Kendall\\'s tau b=-0.086, p=0.04). MPC is not a useful index of platelet activity in stable CAD when used in everyday clinical practice.

  1. Diurnal variation of von Willebrand factor in plasma

    DEFF Research Database (Denmark)

    Timm, Annette; Fahrenkrug, Jan; Jørgensen, Henrik L;

    2014-01-01

    BACKGROUND: Quantitation of von Willebrand factor (VWF) in plasma is a central element in assessing von Willebrand disease (VWD). VWF activity is known to vary, which has partly been ascribed to biological and preanalytical variation. However, a possible diurnal expression of VWF has not been tho...

  2. Decreased plasma brain-derived neurotrophic factor and vascular endothelial growth factor concentrations during military training.

    Directory of Open Access Journals (Sweden)

    Go Suzuki

    Full Text Available Decreased concentrations of plasma brain-derived neurotrophic factor (BDNF and serum BDNF have been proposed to be a state marker of depression and a biological indicator of loaded psychosocial stress. Stress evaluations of participants in military mission are critically important and appropriate objective biological parameters that evaluate stress are needed. In military circumstances, there are several problems to adopt plasma BDNF concentration as a stress biomarker. First, in addition to psychosocial stress, military missions inevitably involve physical exercise that increases plasma BDNF concentrations. Second, most participants in the mission do not have adequate quality or quantity of sleep, and sleep deprivation has also been reported to increase plasma BDNF concentration. We evaluated plasma BDNF concentrations in 52 participants on a 9-week military mission. The present study revealed that plasma BDNF concentration significantly decreased despite elevated serum enzymes that escaped from muscle and decreased quantity and quality of sleep, as detected by a wearable watch-type sensor. In addition, we observed a significant decrease in plasma vascular endothelial growth factor (VEGF during the mission. VEGF is also neurotrophic and its expression in the brain has been reported to be up-regulated by antidepressive treatments and down-regulated by stress. This is the first report of decreased plasma VEGF concentrations by stress. We conclude that decreased plasma concentrations of neurotrophins can be candidates for mental stress indicators in actual stressful environments that include physical exercise and limited sleep.

  3. In vitro effect of anti-β2 glycoprotein I antibodies on P-selectin expression, a marker of platelet activation

    Directory of Open Access Journals (Sweden)

    A. Hoxha

    2012-03-01

    Full Text Available Antiphospholipid antibodies (aPL associated with thromboembolic events and/or pregnancy morbidity characterize the so-called antiphospholipid syndrome (APS. Beta2glycoprotein I (β2GPI is the main target antigen for aPL, but the pathogenic role of anti-β2GPI antibodies (aβ2GPI is still unclear. Some authors assume they play a role in activating platelets. We evaluated the effects of aβ2GPI antibodies on platelet P-selectin expression. Aβ2GPI antibodies in the plasma of a pregnant APS patient were isolated by affinity chromatography at two different stages (catastrophic and quiescent of the disease. Gel filtered platelets (100 x 109/L from healthy volunteers were incubated with β2-GPI (20 µg/mL and with different concentrations (5. 25 and 50 µg/mL of aβ2GPI antibodies. P-selectin surface expression on platelets was assessed by flow cytometry using a specific fluorescent antibody directed against P-selectin. Aβ2GPI antibodies induced platelet activation only in the presence of thrombin receptor activator for peptide 6 (TRAP-6, a platelet agonist, at a subthreshold concentration. Aβ2GPI antibody enhancement on platelet surface P-selectin expression was stronger in the catastrophic than in the quiescent phase of the disease (47 vs 15%. TRAP-6 dependent platelet activation by aβ2GPI antibodies is consistent with the “two hit” pathogenetic hypothesis for thrombosis. Aβ2GPI antibodies induce higher platelet P-selectin expression during the active rather than the acute phases.

  4. Effects of Xuezhikang Capsule(血脂康胶囊) on Blood Lipids,Platelet Activation and Coagulation-Fibrinolysis Activity in Patients with Hyperlipidemia

    Institute of Scientific and Technical Information of China (English)

    刘志高; 余细勇

    2004-01-01

    Objective: To investigate the effects of Xuezhikang capsule (XZK, 血脂康胶囊) on blood lipids level, platelet activation and coagulation-fibrinolysis activity in patients with hyerlipidemia. Methods:Seventy-six patients of hyperlipidemia were randomly divided into two groups, the XZK group (n = 38) treated with XZK 600mg, taken two times per day and the Simvastatin (SIM) group (n = 38) treated with SIM 20mg per day, with the treatment lasting 8 weeks for both groups. Levels of fasting serum lipids, including total cholesterol (TC), triglyceride (TG), high and low density l ipoprotein cholesterol (HDL-C and LDL-C),plasma GMP-140, fibrinogen (FIB), tissue plasminogen activator (t-PA), plasminogen activator inhibitor type-1 (PAl-) and prothrombin time (PT) were all measured before and 8 weeks after treatment. Data were compared before and after treatment and also compared with those measured in 20 healthy subjects of control. Results: Before treantment the levels of TC, TG and LDL-C were obviously higher and HDL-C level was significantly lower in hyperlipidemia patients than those in healthy subjects ( P<0.05 or P<0.01). After 4-8 weeks of XZK treatment, the levels of TC, TG, LDL-C and FIB and activities of GMP-140 and PAl-1 were obviously lowered (P<0.05 or P<0.01). But in the SIM group there was no obvious change in FIB (P>0.05), instead it showed obvious increase of HDL-C and decrease of TC and LDL-C after treatment ( P<0.05 or P<0.01). Conclusion: XZK could inhibit platelet activity and improve coagulation-fibrinolysis function, besides its lipids lowering effect.

  5. Hypocoagulant and lipid-lowering effects of dietary n-3 polyunsaturated fatty acids with unchanged platelet activation in rats

    NARCIS (Netherlands)

    Nieuwenhuys, C.M.A.; Béguin, S.; Offermans, R.F.G.; Emeis, J.J.; Hornstra, G.; Heemskerk, J.W.M.

    1998-01-01

    We investigated the effects of dietary polyunsaturated fatty acids (PUFAs) on blood lipids and processes that determine hemostatic potential: platelet activation, coagulation, and fibrinolysis. For 8 to 10 weeks, Wistar rats were fed a high-fat diet containing various amounts (2% to 16%) of n-3 PUFA

  6. Effect of combined anti-platelets drugs on platelet activation in the elderly patients with acute coronary syndrome

    Institute of Scientific and Technical Information of China (English)

    黄大海

    2012-01-01

    Objective To investigate the effect of combined anti-platelets drugs on platelet activation in the elderly patients with acute coronary syndrome(ACS).Methods Totally 72 elderly patients with ACS were divided randomly into two groups according to age ≤80 years and>80 years.

  7. Hypocoagulant and lipid-lowering effects of dietary n-3 polyunsaturated fatty acids with unchanged platelet activation in rats

    NARCIS (Netherlands)

    Nieuwenhuys, C.M.A.; Béguin, S.; Offermans, R.F.G.; Emeis, J.J.; Hornstra, G.; Heemskerk, J.W.M.

    1998-01-01

    We investigated the effects of dietary polyunsaturated fatty acids (PUFAs) on blood lipids and processes that determine hemostatic potential: platelet activation, coagulation, and fibrinolysis. For 8 to 10 weeks, Wistar rats were fed a high-fat diet containing various amounts (2% to 16%) of n-3

  8. Effect of Antrodia camphorata on Inflammatory Arterial Thrombosis-Mediated Platelet Activation: The Pivotal Role of Protein Kinase C

    Directory of Open Access Journals (Sweden)

    Wan-Jung Lu

    2014-01-01

    Full Text Available Antrodia camphorata is a rare Taiwanese medicinal mushroom. Antrodia camphorata extract has been reported to exhibit antioxidant, anti-inflammation, antimetastasis, and anticancer activities and plays a role in liver fibrosis, vasorelaxation, and immunomodulation. Critical vascular inflammation leads to vascular dysfunction and cardiovascular diseases, including abdominal aortic aneurysms, hypertension, and atherosclerosis. Platelet activation plays a crucial role in intravascular thrombosis, which is involved in a wide variety of cardiovascular diseases. However, the effect of Antrodia camphorata on platelet activation remains unclear. We examined the effects of Antrodia camphorata on platelet activation. In the present study, Antrodia camphorata treatment (56–224 μg/mL inhibited platelet aggregation induced by collagen, but not U46619, an analogue of thromboxane A2, thrombin, and arachidonic acid. Antrodia camphorata inhibited collagen-induced calcium (Ca2+ mobilization and phosphorylation of protein kinase C (PKC and Akt. In addition, Antrodia camphorata significantly reduced the aggregation and phosphorylation of PKC in phorbol-12, 13-dibutyrate (PDBu activated platelets. In conclusion, Antrodia camphorata may inhibit platelet activation by inhibiting of Ca2+ and PKC cascade and the Akt pathway. Our study suggests that Antrodia camphorata may be a potential therapeutic agent for preventing or treating thromboembolic disorders.

  9. A class of 3S-2-aminoacyltetrahydro-beta-carboline-3-carboxylic acids: their facile synthesis, inhibition for platelet activation, and high in vivo anti-thrombotic potency.

    Science.gov (United States)

    Liu, Jiawang; Jiang, Xueyun; Zhao, Ming; Zhang, Xiaoyi; Zheng, Meiqing; Peng, Li; Peng, Shiqi

    2010-04-22

    3S-Tetrahydro-beta-carboline-3-carboxylic acid (TCCA) effectively inhibits ADP-induced platelet activation. This paper used TCCA as a lead, modified its 2-position with amino acids, and provided 20 novel 3S-2-aminoacyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acids (5a-t). With the in vitro assay, it was demonstrated that this modification diminished the IC(50) values from 701 nM of TCCA to 10 nM of 5a-t. With the in vivo assay, it was demonstrated that this modification reduced the efficacious dose from 5.0 micromol/kg of TCCA to 0.1 micromol/kg of 5a-t. Comparing the Cerius based conformation of them with that of their analogues, the 3-position modified TCCA, it was suggested that the comparatively unfolded conformation was one of the important factors of enhancing the in vivo antithrombotic potency.

  10. Systemic platelet dysfunction is the result of local dysregulated coagulation and platelet activation in the brain in a rat model of isolated traumatic brain injury.

    Science.gov (United States)

    Ploplis, Victoria A; Donahue, Deborah L; Sandoval-Cooper, Mayra J; MorenoCaffaro, Maria; Sheets, Patrick; Thomas, Scott G; Walsh, Mark; Castellino, Francis J

    2014-10-01

    Coagulopathy after severe traumatic brain injury (TBI) has been extensively reported. Clinical studies have identified a strong relationship between diminished platelet-rich thrombus formation, responsiveness to adenosine diphosphate agonism, and severity of TBI. The mechanisms that lead to platelet dysfunction in the acute response to TBI are poorly understood. The development of a rodent model of TBI that mimics the coagulopathy observed clinically has recently been reported. Using immunohistochemical techniques and thromboelastography platelet mapping, the current study demonstrated that the expression of coagulation (tissue factor and fibrin) and platelet activation (P-selectin) markers in the injured brain paralleled the alteration in systemic platelet responsiveness to the agonists, adenosine diphosphate and arachodonic acid. Results of this study demonstrate that local procoagulant changes in the injured brain have profound effects on systemic platelet function.

  11. Platelet-mediated cytotoxicity and its enhancement by platelet activating factor.

    Science.gov (United States)

    Bykovskaya, S N; Bolvacheva, A V; Kiselevsky, M V; Khaylenko, V A; Bykovsky, A F

    1991-01-01

    Platelet cytotoxicity was assessed in 70 cancer patients with various tumor localizations and in 30 normal donors. The data presented reveal that the ACL cell line displays the highest sensitivity to platelet cytotoxicity. Using the ACL cells, we discovered that platelets from oncological patients and normal donors display comparable cytotoxicity. The level of platelet lytic activity is irrelevant to tumor localisation; however, it appears to be dependent on the stage of tumor growth. Incubation of platelets, both from donors and patients, with PAF (concentration range 10 pM to 10 nM) results in a significant rise of the killing activity of platelets. PAF induces greater cytotoxicity enhancement for platelets with lower initial activity, this pattern appearing to be the specific feature of the PAF mediated effect. Hence, platelets can be considered as effector cells relevant to antitumor immunity; PAF-mediated enhancement of platelet cytotoxicity can appear to be useful in the search for new immunotherapeutic drugs.

  12. Is platelet activating factor (PAF an important mediator in bronchial asthma?

    Directory of Open Access Journals (Sweden)

    R. H. Gundel

    1992-01-01

    Full Text Available The development of selective PAF receptor antagonists may provide a novel approach to the treatment of human bronchial asthma. In preclinical animal models of human asthma, PAF receptor antagonists have been found to be efficacious in blocking antigen-induced changes in lung function. However, the majority of these models involve acute inflammatory events and transient changes in lung function and, therefore, their relevance to human asthma is questionable. In a recent study with a primate model of chronic airway inflammation and hyperresponsiveness, we have shown that treatment with a PAF receptor antagonist had no effect on reducing chronic inflammation and hyperresponsiveness. Similarly, recent studies in human asthmatics with PAF receptor antagonists have failed to show efficacy in blocking allergen-induced airway responses or to have any steroid sparing effects in patients with ongoing asthma. Thus, it seems that PAF may not be a key mediator which can be blocked and thereby provide therapy for bronchial asthma.

  13. Decreased levels of serum platelet-activating factor acetylhydrolase in patients with rheumatic diseases

    Directory of Open Access Journals (Sweden)

    P. Vergne

    1997-01-01

    Full Text Available PAF is a potent inflammatory compound known to stimulate the release of various cytokines involved in rheumatic diseases. Elevated blood PAF levels are reported in these patients. We report that serum PAF acetylhydrolase activity (AHA levels are decreased in patients with rheumatoid arthritis or osteoarthritis as compared to healthy controls. Serum and synovial fluid AHA levels were correlated in these patients. The present study suggests the potential role of AHA in controling systemic and/or local PAF levels in patients with rheumatic diseases.

  14. Temporal reliability of cytokines and growth factors in EDTA plasma

    Directory of Open Access Journals (Sweden)

    Marrangoni Adele M

    2010-11-01

    Full Text Available Abstract Background Cytokines are involved in the development of chronic diseases, including cancer. It is important to evaluate the temporal reproducibility of cytokines in plasma prior to conducting epidemiologic studies utilizing these markers. Findings We assessed the temporal reliability of CRP, 22 cytokines and their soluble receptors (IL-1α, IL-1β, IL-1RA, IL-2, sIL-2R, IL-4, IL-5, IL-6, sIL-6R, IL-7, IL-8, IL-10, IL-12p40, IL-12p70, IL-13, IL-15, IL-17, TNFα, sTNF-R1, sTNF-R2, IFNα, IFNγ and eight growth factors (GM-CSF, EGF, bFGF, G-CSF, HGF, VEGF, EGFR, ErbB2 in repeated EDTA plasma samples collected an average of two years apart from 18 healthy women (age range: 42-62 enrolled in a prospective cohort study. We also estimated the correlation between serum and plasma biomarker levels using 18 paired clinical samples from postmenopausal women (age range: 75-86. Twenty-six assays were able to detect their analytes in at least 70% of samples. Of those 26 assays, we observed moderate to high intra-class correlation coefficients (ICCs(ranging from 0.53-0.89 for 22 assays, and low ICCs (0-0.47 for four assays. Serum and plasma levels were highly correlated (r > 0.6 for most markers, except for seven assays (r Conclusions For 22 of the 31 biomarkers, a single plasma measurement is a reliable estimate of a woman's average level over a two-year period.

  15. Factors affecting plasma aluminum concentrations in nonexposed workers

    Energy Technology Data Exchange (ETDEWEB)

    House, R.A. (Department of Occupational and Environmental Health, St Michael' s Hospital, University of Toronto, Ontario (Canada))

    1992-10-01

    In this study, the distribution and determinants of plasma aluminum concentrations were examined in 71 office employees not occupationally exposed to aluminum. The samples were analyzed by Zeeman graphite furnace atomic absorption spectroscopy and were found to be log normally distributed. After using the International Federation of Clinical Chemistry (IFCC) recommended procedure for removal of likely aberrant values, the 95th percentile value was 198 nmol/L (90% CI:165-238); when those using antacids were also excluded, the 95th percentile value fell to 175 nmol/L (90% CI:147-208). Multiple regression analysis indicated that the factors most predictive of log plasma aluminum were the batch in which the sample was analyzed and the use of antacids containing aluminum. The statistical significance of the batch variable likely indicates the well-recognized problem of contamination in sampling and analyzing aluminum.35 references.

  16. 高脂血症与血小板活化关系的研究进展%The Advances of the Relationship between Hyperlipidemia and Platelet Activation

    Institute of Scientific and Technical Information of China (English)

    陈乐闻(综述); 李剑; 罗心平(审校)

    2015-01-01

    高脂血症是导致动脉粥样硬化形成的主要因素。高脂血症通过作用于血小板,影响其活化、聚集等作用,进而影响动脉血栓形成。而采用他汀干预高脂血症后可改善血小板的活化功能,提示高脂血症与血小板活化密切相关。低密度脂蛋白胆固醇及高密度脂蛋白胆固醇可通过作用于血小板活化通路而影响血小板的活化聚集。该文就近年来高脂血症与血小板活化关系的研究进展予以综述。%Hyperlipidemia is the main factor of the formation of atherosclerosis.Moreover, hyperlipidemia effects on platelet,influences the function of activation and aggregation,therefore influences the formation of atherosclerosis.By administration of statin to hyperlipidemia,it improves the platelet function,which indicates that hyperlipidemia is highly associated with platelet activation .Low-density lipoprotein cholesterol and high-density lipoprotein cholesterol influence platelet function through the impact of platelet signaling pathways . Here is to make review of the research progress of correlation between hyperlipidemia and platelet activation in recent years.

  17. Dialyzer membranes: effect of surface area and chemical modification of cellulose on complement and platelet activation.

    Science.gov (United States)

    Mahiout, A; Meinhold, H; Kessel, M; Schulze, H; Baurmeister, U

    1987-04-01

    Using an ex vivo model, the effects of membrane composition and surface area on both the complement system (as reflected by plasma C3a levels) and platelets [as indicated by plasma concentrations of thromboxane B2 (TXB2) and platelet factor 4 (PF4)] were studied. In this model, polyacrylonitrile (PAN) was associated with less complement activation than cuprammonium cellulose (CC). A new "modified cellulose" (MC) membrane, in which a small number of the free hydroxyl groups on cellulose are substituted with a tertiary amino compound, was also associated with a low degree of complement activation, similar to that with PAN. However, the extent of hydroxyl group substitution in four MC membrane subtypes did not correlate with the reduction in complement activation. In studies using CC, the amount of generated C3a correlated with the membrane surface area, although the relationship was curvilinear. Plasma concentrations at the "dialyzer" outlet of TXB2 and PF4 were similar with CC, PAN, and MC. In studies with the MC subtypes, increasing the extent of hydroxyl group substitution paradoxically increased, albeit slightly, the amount of TXB2 generation. In studies with CC, a linear relationship between membrane surface area and TXB2 generation was found. The results suggest a dissociation between platelet and complement effects among different dialyzer membranes, and underline the importance of membrane surface area.

  18. Effects of calcium-modified titanium implant surfaces on platelet activation, clot formation, and osseointegration.

    Science.gov (United States)

    Anitua, Eduardo; Prado, Roberto; Orive, Gorka; Tejero, Ricardo

    2015-03-01

    The clinical success of load bearing dental and orthopedic implants relies on adequate osseointegration. Because of its favorable properties, titanium is generally considered as the material of choice. Following implant placement, titanium surfaces establish an ionic equilibrium with the surrounding tissues in which calcium plays major roles. Calcium is a cofactor of the coagulation cascade that mediates plasma protein adsorption and intervenes in a number of other intra and extracellular processes relevant for bone regeneration. In this study, titanium surfaces were modified with calcium ions (Ca(2+) surfaces) and their responses to in vitro and in vivo models were analyzed. Unlike unmodified surfaces, Ca(2+) surfaces were superhydrophilic and induced surface clot formation, platelet adsorption and activation when exposed to blood plasma. Interestingly, in vivo osseointegration using a peri-implant gap model in rabbit demonstrated that Ca(2+) surfaces significantly improved peri-implant bone volume and density at 2 weeks and bone implant contact at 8 weeks as compared to the unmodified controls. The combination of Ca(2+) surfaces with plasma rich in growth factors produced significantly more bone contact already at 2 weeks of implantation. These findings suggest the importance of the provisional matrix formation on tissue integration and highlight the clinical potential of Ca(2+) titanium surfaces as efficient stimulators of implant osseointegration.

  19. The tyrosine phosphatase CD148 is an essential positive regulator of platelet activation and thrombosis.

    Science.gov (United States)

    Senis, Yotis A; Tomlinson, Michael G; Ellison, Stuart; Mazharian, Alexandra; Lim, Jenson; Zhao, Yan; Kornerup, Kristin N; Auger, Jocelyn M; Thomas, Steve G; Dhanjal, Tarvinder; Kalia, Neena; Zhu, Jing W; Weiss, Arthur; Watson, Steve P

    2009-05-14

    Platelets play a fundamental role in hemostasis and thrombosis. They are also involved in pathologic conditions resulting from blocked blood vessels, including myocardial infarction and ischemic stroke. Platelet adhesion, activation, and aggregation at sites of vascular injury are regulated by a diverse repertoire of tyrosine kinase-linked and G protein-coupled receptors. Src family kinases (SFKs) play a central role in initiating and propagating signaling from several platelet surface receptors; however, the underlying mechanism of how SFK activity is regulated in platelets remains unclear. CD148 is the only receptor-like protein tyrosine phosphatase identified in platelets to date. In the present study, we show that mutant mice lacking CD148 exhibited a bleeding tendency and defective arterial thrombosis. Basal SFK activity was found to be markedly reduced in CD148-deficient platelets, resulting in a global hyporesponsiveness to agonists that signal through SFKs, including collagen and fibrinogen. G protein-coupled receptor responses to thrombin and other agonists were also marginally reduced. These results highlight CD148 as a global regulator of platelet activation and a novel antithrombotic drug target.

  20. Micro-structuring of polycarbonate-urethane surfaces in order to reduce platelet activation and adhesion.

    Science.gov (United States)

    Clauser, Johanna; Gester, Kathrin; Roggenkamp, Jan; Mager, Ilona; Maas, Judith; Jansen, Sebastian V; Steinseifer, Ulrich

    2014-01-01

    In the development of new hemocompatible biomaterials, surface modification appears to be a suitable method in order to reduce the thrombogenetic potential of such materials. In this study, polycarbonate-urethane (PCU) tubes with different surface microstructures to be used for aortic heart valve models were investigated with regard to the thrombogenicity. The surface structures were produced by using a centrifugal casting process for manufacturing PCU tubes with defined casting mold surfaces which are conferred to the PCU surface during the process. Tubes with different structures defined by altering groove widths were cut into films and investigated under dynamic flow conditions in contact with porcine blood. The analysis was carried out by laser scanning microscopy which allowed for counting various morphological types of platelets with regard to the grade of activation. The comparison between plain and shaped PCU samples showed that the surface topography led to a decline of the activation of the coagulation cascade and thus to the reduction of the fibrin synthesis. Comparing different types of structures revealed that smooth structures with a small groove width (d ~ 3 μm) showed less platelet activation as well as less adhesion in contrast to a distinct wave structure (d ~ 90 μm). These results prove surface modification of polymer biomaterials to be a suitable method for reducing thrombogenicity and hence give reason for further alterations and improvements.

  1. MALT1-ubiquitination triggers non-genomic NF-κB/IKK signaling upon platelet activation.

    Science.gov (United States)

    Karim, Zubair A; Vemana, Hari Priya; Khasawneh, Fadi T

    2015-01-01

    We have recently shown that IKK complex plays an important non-genomic role in platelet function, i.e., regulates SNARE machinery-dependent membrane fusion. In this connection, it is well known that MALT1, whose activity is modulated by proteasome, plays an important role in the regulation of IKK complex. Therefore, the present studies investigated the mechanism by which IKK signaling is regulated in the context of the platelet proteasome. It was found that platelets express a functional proteasome, and form CARMA/MALT1/Bcl10 (CBM) complex when activated. Using a pharmacological inhibitor, the proteasome was found to regulate platelet function (aggregation, integrin activation, secretion, phosphatidylserine exposure and changes in intracellular calcium). It was also found to regulate thrombogenesis and physiologic hemostasis. We also observed, upon platelet activation, that MALT1 is ubiquitinated, and this coincides with the activation of the IKK/NF-κB-signaling pathway. Finally, we observed that the proteasome inhibitor blocks CBM complex formation and the interaction of IKKγ and MALT1; abrogates SNARE formation, and the association of MALT1 with TAK1 and TAB2, which are upstream of the CBM complex. Thus, our data demonstrate that MALT1 ubiquitination is critical for the engagement of CBM and IKK complexes, thereby directing platelet signals to the NF-κB pathway.

  2. MALT1-ubiquitination triggers non-genomic NF-κB/IKK signaling upon platelet activation.

    Directory of Open Access Journals (Sweden)

    Zubair A Karim

    Full Text Available We have recently shown that IKK complex plays an important non-genomic role in platelet function, i.e., regulates SNARE machinery-dependent membrane fusion. In this connection, it is well known that MALT1, whose activity is modulated by proteasome, plays an important role in the regulation of IKK complex. Therefore, the present studies investigated the mechanism by which IKK signaling is regulated in the context of the platelet proteasome. It was found that platelets express a functional proteasome, and form CARMA/MALT1/Bcl10 (CBM complex when activated. Using a pharmacological inhibitor, the proteasome was found to regulate platelet function (aggregation, integrin activation, secretion, phosphatidylserine exposure and changes in intracellular calcium. It was also found to regulate thrombogenesis and physiologic hemostasis. We also observed, upon platelet activation, that MALT1 is ubiquitinated, and this coincides with the activation of the IKK/NF-κB-signaling pathway. Finally, we observed that the proteasome inhibitor blocks CBM complex formation and the interaction of IKKγ and MALT1; abrogates SNARE formation, and the association of MALT1 with TAK1 and TAB2, which are upstream of the CBM complex. Thus, our data demonstrate that MALT1 ubiquitination is critical for the engagement of CBM and IKK complexes, thereby directing platelet signals to the NF-κB pathway.

  3. Metabolic syndrome, platelet activation and the development of transient ischemic attack or thromboembolic stroke.

    Science.gov (United States)

    van Rooy, Mia-Jeanne; Pretorius, Etheresia

    2015-03-01

    Stroke is the second most common cause of mortality in the world today, where transient ischemic attack (TIA) is a period of focal ischemia, the symptoms of which resemble a thromboembolic stroke. Contrary to stroke, TIA symptoms typically last less than one hour and necrosis is absent. Stroke is often preceded by TIA, making it an important predictor of future ischemic events. The causal role of atherosclerosis in the development of TIA is well established, however, research indicates that the atherosclerotic process begins years earlier with the development of metabolic syndrome, which affects approximately 45% of the adult population worldwide. Metabolic syndrome is present if three or more of the following is present: increased waist circumference, increased triglycerides, decreased HDL, increased fasting glucose and hypertension. This syndrome causes systemic inflammation that activates the coagulation system and may cause the formation of pathological thrombi. The role of platelets in stroke has been studied and platelet activation pathways identified. ADP and thromboxane A(2) are the most common activators of platelets in normal physiology. Several pharmacological treatments have been employed to prevent the activation of platelets, the most common of which include aspirin and P2Y(12)-inhibitors. Although treatment is administered strokes and subsequent TIAs are very common in individuals that suffered an initial event. This indicates that research needs to be done in order to elucidate new therapeutic targets, but also to better treat ischemic events to not only decrease the amount of recurring events but also decrease stroke mortality worldwide.

  4. Marine Benthic Diatoms Contain Compounds Able to Induce Leukemia Cell Death and Modulate Blood Platelet Activity

    Science.gov (United States)

    Prestegard, Siv Kristin; Oftedal, Linn; Coyne, Rosie Theresa; Nygaard, Gyrid; Skjærven, Kaja Helvik; Knutsen, Gjert; Døskeland, Stein Ove; Herfindal, Lars

    2009-01-01

    In spite of the high abundance and species diversity of diatoms, only a few bioactive compounds from them have been described. The present study reveals a high number of mammalian cell death inducing substances in biofilm-associated diatoms sampled from the intertidal zone. Extracts from the genera Melosira, Amphora, Phaeodactylum and Nitzschia were all found to induce leukemia cell death, with either classical apoptotic or autophagic features. Several extracts also contained inhibitors of thrombin-induced blood platelet activation. Some of this activity was caused by a high content of adenosine in the diatoms, ranging from 0.07 to 0.31 μg/mg dry weight. However, most of the bioactivity was adenosine deaminase-resistant. An adenosine deaminase-resistant active fraction from one of the extracts was partially purified and shown to induce apoptosis with a distinct phenotype. The results show that benthic diatoms typically found in the intertidal zone may represent a richer source of interesting bioactive compounds than hitherto recognized. PMID:20098602

  5. Secretory phospholipase A2 modified HDL rapidly and potently suppresses platelet activation.

    Science.gov (United States)

    Curcic, Sanja; Holzer, Michael; Pasterk, Lisa; Knuplez, Eva; Eichmann, Thomas O; Frank, Saša; Zimmermann, Robert; Schicho, Rudolf; Heinemann, Akos; Marsche, Gunther

    2017-08-14

    Levels of secretory phospholipases A2 (sPLA2) highly increase under acute and chronic inflammatory conditions. sPLA2 is mainly associated with high-density lipoproteins (HDL) and generates bioactive lysophospholipids implicated in acute and chronic inflammatory processes. Unexpectedly, pharmacological inhibition of sPLA2 in patients with acute coronary syndrome was associated with an increased risk of myocardial infarction and stroke. Given that platelets are key players in thrombosis and inflammation, we hypothesized that sPLA2-induced hydrolysis of HDL-associated phospholipids (sPLA2-HDL) generates modified HDL particles that affect platelet function. We observed that sPLA2-HDL potently and rapidly inhibited platelet aggregation induced by several agonists, P-selectin expression, GPIIb/IIIa activation and superoxide production, whereas native HDL showed little effects. sPLA2-HDL suppressed the agonist-induced rise of intracellular Ca(2+) levels and phosphorylation of Akt and ERK1/2, which trigger key steps in promoting platelet activation. Importantly, sPLA2 in the absence of HDL showed no effects, whereas enrichment of HDL with lysophosphatidylcholines containing saturated fatty acids (the main sPLA2 products) mimicked sPLA2-HDL activities. Our findings suggest that sPLA2 generates lysophosphatidylcholine-enriched HDL particles that modulate platelet function under inflammatory conditions.

  6. Marine Benthic Diatoms Contain Compounds Able to Induce Leukemia Cell Death and Modulate Blood Platelet Activity

    Directory of Open Access Journals (Sweden)

    Lars Herfindal

    2009-11-01

    Full Text Available In spite of the high abundance and species diversity of diatoms, only a few bioactive compounds from them have been described. The present study reveals a high number of mammalian cell death inducing substances in biofilm-associated diatoms sampled from the intertidal zone. Extracts from the genera Melosira, Amphora, Phaeodactylum and Nitzschia were all found to induce leukemia cell death, with either classical apoptotic or autophagic features. Several extracts also contained inhibitors of thrombin-induced blood platelet activation. Some of this activity was caused by a high content of adenosine in the diatoms, ranging from 0.07 to 0.31 μg/mg dry weight. However, most of the bioactivity was adenosine deaminase-resistant. An adenosine deaminase-resistant active fraction from one of the extracts was partially purified and shown to induce apoptosis with a distinct phenotype. The results show that benthic diatoms typically found in the intertidal zone may represent a richer source of interesting bioactive compounds than hitherto recognized.

  7. A whole blood flow cytometric determination of platelet activation by unfractionated and low molecular weight heparin in vitro.

    Science.gov (United States)

    Klein, Bernd; Faridi, Andreé; von Tempelhoff, G F; Heilmann, Lothar; Mittermayer, Christian; Rath, Werner

    2002-12-15

    The influence of unfractionated (Heparin-Natrium) and low-molecular heparin (Fragmin(R)) on platelet activation in whole blood was investigated by FACS analysis in vitro using antibodies against glycoprotein (gp) IIb/IIIa (CD 41), GMP 140 (CD 62P), gp 53 (CD 63) and fibrinogen. Samples were also labeled with anti-gp Ib (CD 42b). Neither unfractionated heparin (UFH) nor low molecular weight heparin (LMWH) led to significant (i.e., p<0.05) changes in fluorescence intensities of platelets labeled with anti-gp IIb/IIIa or anti-gp 53. Significant platelet activation due to unfractionated heparin could be observed by labeling with anti-GMP 140 (UFH: p=0.009; LMWH: p=0.16). The proportion of platelets with surface-bound fibrinogen was significantly increased (UFH: p=0.00006; LMWH: p=0.008). After incubation with heparins, activation ability of platelets by adenosine diphosphate (ADP) was significantly increased. The potentiating action of unfractionated heparin was larger. Therefore, flow cytometric results of platelet activation in patients receiving heparin should be interpreted carefully.

  8. Modifications produced by selective inhibitors of cyclooxygenase and ultra low dose aspirin on platelet activity in portal hypertension

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To study the mechanism involved in the potentially beneficial effect of ultra low dose aspirin (ULDA) in prehepatic portal hypertension, rats were pretreated with selective COX 1 or 2 inhibitors (SC-560 or NS-398 respectively), and subsequently injected with ULDA or placebo.METHODS: Portal hypertension was induced by portal vein ligation. Platelet activity was investigated with an in-vivo model of laser induced thrombus production in mesenteric circulation and induced hemorrhagic time (IHT). Platelet aggregation induced by ADP and dosing of prostanoid products 6-keto-PGF1α, TXB2, PGE2 and LTB4 were also performed.RESULTS: The portal hypertensive group receiving a placebo showed a decreased in vivo platelet activity with prolonged IHT, an effect that was normalized by ULDA. SC-560 induced a mild antithrombotic effect in the normal rats, and an unmodified effect of ULDA. NS-398 had a mild prothrombotic action in portal hypertensive rats, similar to ULDA, but inhibited a further effect when ULDA was added. An increased 6-keto-PGF1α was observed in portal hypertensive group that was normalised after ULDA administration. TXA2 level after ULDA, remained unchanged.CONCLUSION: These results suggest that the effect of ULDA on platelet activity in portal hypertensive rats,could act through a COX 2 pathway more than the COX 1,predominant for aspirin at higher doses.

  9. In vitro platelet activation, aggregation and platelet-granulocyte complex formation induced by surface modified single-walled carbon nanotubes.

    Science.gov (United States)

    Fent, János; Bihari, Péter; Vippola, Minnamari; Sarlin, Essi; Lakatos, Susan

    2015-08-01

    Surface modification of single-walled carbon nanotubes (SWCNTs) such as carboxylation, amidation, hydroxylation and pegylation is used to reduce the nanotube toxicity and render them more suitable for biomedical applications than their pristine counterparts. Toxicity can be manifested in platelet activation as it has been shown for SWCNTs. However, the effect of various surface modifications on the platelet activating potential of SWCNTs has not been tested yet. In vitro platelet activation (CD62P) as well as the platelet-granulocyte complex formation (CD15/CD41 double positivity) in human whole blood were measured by flow cytometry in the presence of 0.1mg/ml of pristine or various surface modified SWCNTs. The effect of various SWCNTs was tested by whole blood impedance aggregometry, too. All tested SWCNTs but the hydroxylated ones activate platelets and promote platelet-granulocyte complex formation in vitro. Carboxylated, pegylated and pristine SWCNTs induce whole blood aggregation as well. Although pegylation is preferred from biomedical point of view, among the samples tested by us pegylated SWCNTs induced far the most prominent activation and a well detectable aggregation of platelets in whole blood.

  10. Sequential plasma angiogenic factors levels in women with suspected preeclampsia.

    Science.gov (United States)

    Baltajian, Kedak; Bajracharya, Surichhya; Salahuddin, Saira; Berg, Anders H; Geahchan, Carl; Wenger, Julia B; Thadhani, Ravi; Karumanchi, S Ananth; Rana, Sarosh

    2016-07-01

    Alterations in circulating angiogenic factors are associated with the diagnosis of preeclampsia and correlate with adverse perinatal outcomes during the third trimester. Analysis of the sequential levels of plasma angiogenic factors among patients admitted for evaluation of preeclampsia. We performed an observational study among women with singleton pregnancies admitted to Beth Israel Deaconess Medical Center, Boston, Massachusetts, for evaluation of preeclampsia at less than 37 weeks of gestation. Plasma samples were collected on admission and daily for the first 3 days and then weekly until delivery. Doppler ultrasound was performed on admission (within 48 hours) and then weekly (within 24 hours of blood collection) to evaluate uteroplacental and umbilical blood flows. Maternal demographics, hospital course, mode of delivery, diagnosis of hypertensive disorder, adverse maternal outcomes (elevated liver function enzymes, low platelet count, pulmonary edema, cerebral hemorrhage, convulsion, acute renal insufficiency, or maternal death), and adverse fetal/neonatal outcomes (small for gestational age, abnormal umbilical artery Doppler, fetal death, and neonatal death) were recorded. Circulating angiogenic factors (soluble fms-like tyrosine kinase and placental growth factor were measured on automated platform in a single batch after delivery and in a blinded fashion. Data are presented as median (25th to 75th centile), mean, or proportions as appropriate. During the study period, data from 100 women were analyzed for the study, and 43 had adverse outcomes. Women with adverse outcomes had lower gestational age of delivery, higher systolic and diastolic blood pressures during hospitalization, and lower birthweight and placental weight (all P preeclampsia, women at risk for adverse pregnancy outcomes have higher soluble fms-like tyrosine kinase/placental growth factor ratio on admission, which continued to rise until delivery. Women with high soluble fms-like tyrosine

  11. Technetium 99m-labeled annexin v scintigraphy of platelet activation in vegetations of experimental endocarditis

    Energy Technology Data Exchange (ETDEWEB)

    Rouzet, F.; Sarda-Mantel, L.; Le Guludec, D. [Nucl Med Serv, Grp Hosp Bichat Claude Bernard, AP-HP, Paris (France); Rouzet, F.; Sarda-Mantel, L.; LeGuludec, D. [Univ Denis Diderot Paris 7, UMR S773, Paris (France); Rouzet, F.; Sarda-Mantel, L.; Le Guludec, D. [INSERM, U773, Paris (France); Hernandez, M.D.; Louedec, L.; Michel, J.B. [Univ Paris 07, CHU Xavier Bichat, INSERM, U698, Paris (France); Hervatin, F. [CEA, DSV, DRM, SHFJ, Orsay (France); Lefort, A.; Fantin, B. [Univ Denis Diderot Paris 7, EA 3964, Paris (France); Duval, X. [Univ Denis Diderot Paris 7, INSERM, CIC 007, Paris (France); Duval, X. [Univ Denis Diderot Paris 7, AP-HP, Grp Hosp Bichat Claude Bernard, Ctr Invest Clin, Paris (France); Hernandez, M.D. [Univ Guadalajara, DeptPathol, Guadalajara 44430, Jalisco (Mexico)

    2008-07-01

    Background: The pathophysiology of infective endocarditis involves a pathogen/host tissue interaction, leading to formation of infected thrombotic vegetations. Annexin V is a ligand of phosphatidyl-serines exposed by activated platelets and apoptotic cells. Because vegetations are platelet-fibrin clots in which platelet pro-aggregant activity is enhanced by bacterial colonization, we investigated the ability of annexin V labeled with technetium {sup 99m}Tc ({sup 99m}Tc-ANX) to provide functional imaging of these vegetations in experimental models of infective endocarditis. This ability was assessed in rabbits and rats because of the different interest of these 2 species in preclinical analysis. Methods and Results: Non-bacterial thrombotic endocarditis was induced with the use of a catheter left indwelling through the aortic or tricuspid valve, and animals were injected with either a bacterial inoculum or saline. Scintigraphic investigations were performed 5 days later and showed a higher {sup 99m}Tc-ANX uptake by vegetations in infected versus non-infected animals (ratio,1.3 for in vivo acquisitions and 2 for autoradiography; P {<=} 0.0001 for all), whereas no significant uptake was present in controls. Right-sided endocarditis was associated with pulmonary uptake foci corresponding to emboli. Histological analysis of vegetations showed a specific uptake of {sup 99m}Tc-ANX at the interface between circulating blood and vegetation. In parallel, underlying myocardial tissue showed myocyte apoptosis and mucoid degeneration, without extracellular matrix degradation at this stage. Conclusions: {sup 99m}Tc-ANX is suitable for functional imaging of platelet-fibrin vegetations in endocarditis, as well as embolic events. {sup 99m}Tc-ANX uptake reflects mainly platelet activation in the luminal layer of vegetations. This uptake is enhanced by bacterial colonization. (authors)

  12. High duty factor plasma generator for CERN's Superconducting Proton Linac.

    Science.gov (United States)

    Lettry, J; Kronberger, M; Scrivens, R; Chaudet, E; Faircloth, D; Favre, G; Geisser, J-M; Küchler, D; Mathot, S; Midttun, O; Paoluzzi, M; Schmitzer, C; Steyaert, D

    2010-02-01

    CERN's Linac4 is a 160 MeV linear accelerator currently under construction. It will inject negatively charged hydrogen ions into CERN's PS-Booster. Its ion source is a noncesiated rf driven H(-) volume source directly inspired from the one of DESY and is aimed to deliver pulses of 80 mA of H(-) during 0.4 ms at a 2 Hz repetition rate. The Superconducting Proton Linac (SPL) project is part of the luminosity upgrade of the Large Hadron Collider. It consists of an extension of Linac4 up to 5 GeV and is foreseen to deliver protons to a future 50 GeV synchrotron (PS2). For the SPL high power option (HP-SPL), the ion source would deliver pulses of 80 mA of H(-) during 1.2 ms and operate at a 50 Hz repetition rate. This significant upgrade motivates the design of the new water cooled plasma generator presented in this paper. Its engineering is based on the results of a finite element thermal study of the Linac4 H(-) plasma generator that identified critical components and thermal barriers. A cooling system is proposed which achieves the required heat dissipation and maintains the original functionality. Materials with higher thermal conductivity are selected and, wherever possible, thermal barriers resulting from low pressure contacts are removed by brazing metals on insulators. The AlN plasma chamber cooling circuit is inspired from the approach chosen for the cesiated high duty factor rf H(-) source operating at SNS.

  13. High levels of LDL-C combined with low levels of HDL-C further increase platelet activation in hypercholesterolemic patients.

    Science.gov (United States)

    Chan, L W; Luo, X P; Ni, H C; Shi, H M; Liu, L; Wen, Z C; Gu, X Y; Qiao, J; Li, J

    2015-02-01

    High levels of low-density lipoprotein cholesterol (LDL-C) enhance platelet activation, whereas high levels of high-density lipoprotein cholesterol (HDL-C) exert a cardioprotective effect. However, the effects on platelet activation of high levels of LDL-C combined with low levels of HDL-C (HLC) have not yet been reported. We aimed to evaluate the platelet activation marker of HLC patients and investigate the antiplatelet effect of atorvastatin on this population. Forty-eight patients with high levels of LDL-C were enrolled. Among these, 23 had HLC and the other 25 had high levels of LDL-C combined with normal levels of HDL-C (HNC). A total of 35 normocholesterolemic (NOMC) volunteers were included as controls. Whole blood flow cytometry and platelet aggregation measurements were performed on all participants to detect the following platelet activation markers: CD62p (P-selectin), PAC-1 (GPIIb/IIIa), and maximal platelet aggregation (MPAG). A daily dose of 20 mg atorvastatin was administered to patients with high levels of LDL-C, and the above assessments were obtained at baseline and after 1 and 2 months of treatment. The expression of platelets CD62p and PAC-1 was increased in HNC patients compared to NOMC volunteers (PHDL-C further increased platelet activation in patients with high levels of LDL-C. Platelet activation remained higher among HLC patients regardless of atorvastatin treatment.

  14. No evidence for increased platelet activation in patients with hepatitis B- or C-related cirrhosis and hepatocellular carcinoma

    NARCIS (Netherlands)

    Alkozai, Edris M.; Porte, Robert J.; Adelmeijer, Jelle; Zanetto, Alberto; Simioni, Paolo; Senzolo, Marco; Lisman, Ton

    2015-01-01

    Introduction: Cancer is a major risk factor for developing venous thromboembolism (VTE). Plasma hypercoagulability is an established risk factor for cancer-related VTE. In addition, thrombocytosis and hyperreactive platelets have been implicated in VTE and cancer progression. Cirrhosis is associated

  15. ADAMTS13 content in plasma-derived factor VIII/von Willebrand factor concentrates.

    Science.gov (United States)

    Peyvandi, Flora; Mannucci, Pier M; Valsecchi, Carla; Pontiggia, Silvia; Farina, Claudio; Retzios, Anastassios D

    2013-10-01

    Thrombotic thrombocytopenic purpura (TTP) is a microangiopathy syndrome caused by a congenital or acquired deficiency of ADAMTS13, a plasma metalloprotease that cleaves von Willebrand factor (VWF) and thus prevents the formation of platelet-rich thrombi in the microcirculation. TTP can be fatal if not appropriately and timely treated with the infusion of fresh frozen plasma (FFP) or exchange plasmapheresis, that reverse the process of microangiopathy by removing anti-ADAMTS13 autoantibodies and replacing functional ADAMTS13. The treatment of TTP with FFP is not free from risks and must be administered in hospitals or clinics, owing to the substantial amount of plasma volume infused or exchanged and the frequent need of catheter application. Moreover, most FFPs are not subjected to treatments to remove or inactivate blood-borne infectious agents. A number of recent reports indicate that certain plasma-derived VWF-factor VIII (FVIII) concentrates are clinically effective in the treatment of congenital TTP. In this study, we measured ADAMTS13 levels in various plasma-derived VWF-FVIII concentrates, showing that Koate(®) -DVI (Grifols), contained relatively high amounts of ADAMTS13 and that Alphanate(®) (Grifols) was the closest other product in terms of protease content. Koate(®) -DVI contains, on average (five lots tested), 0.091 ± 0.007 Units of ADAMTS13 activity per IU of FVIII. On the basis of this analysis and other reports of VWF-FVIII concentrate utilization in congenital TTP, potential dosing, and future clinical developments are discussed.

  16. Kaempferol suppresses collagen-induced platelet activation by inhibiting NADPH oxidase and protecting SHP-2 from oxidative inactivation.

    Science.gov (United States)

    Wang, Su Bin; Jang, Ji Yong; Chae, Yun Hee; Min, Ji Hyun; Baek, Jin Young; Kim, Myunghee; Park, Yunjeong; Hwang, Gwi Seo; Ryu, Jae-Sang; Chang, Tong-Shin

    2015-06-01

    Reactive oxygen species (ROS) generated upon collagen stimulation act as second messengers to propagate various platelet-activating events. Among the ROS-generating enzymes, NADPH oxidase (NOX) plays a prominent role in platelet activation. Thus, NOX has been suggested as a novel target for anti-platelet drug development. Although kaempferol has been identified as a NOX inhibitor, the influence of kaempferol on the activation of platelets and the underlying mechanism have never been investigated. Here, we studied the effects of kaempferol on NOX activation, ROS-dependent signaling pathways, and functional responses in collagen-stimulated platelets. Superoxide anion generation stimulated by collagen was significantly inhibited by kaempferol in a concentration-dependent manner. More importantly, kaempferol directly bound p47(phox), a major regulatory subunit of NOX, and significantly inhibited collagen-induced phosphorylation of p47(phox) and NOX activation. In accordance with the inhibition of NOX, ROS-dependent inactivation of SH2 domain-containing protein tyrosine phosphatase-2 (SHP-2) was potently protected by kaempferol. Subsequently, the specific tyrosine phosphorylation of key components (Syk, Vav1, Btk, and PLCγ2) of collagen receptor signaling pathways was suppressed by kaempferol. Kaempferol also attenuated downstream responses, including cytosolic calcium elevation, P-selectin surface exposure, and integrin-αIIbβ3 activation. Ultimately, kaempferol inhibited platelet aggregation and adhesion in response to collagen in vitro and prolonged in vivo thrombotic response in carotid arteries of mice. This study shows that kaempferol impairs collagen-induced platelet activation through inhibition of NOX-derived ROS production and subsequent oxidative inactivation of SHP-2. This effect suggests that kaempferol has therapeutic potential for the prevention and treatment of thrombovascular diseases.

  17. Vascular endothelial growth factor in the circulation in cancer patients may not be a relevant biomarker.

    Directory of Open Access Journals (Sweden)

    Tatjana M H Niers

    Full Text Available BACKGROUND: Levels of circulating vascular endothelial growth factor (VEGF have widely been used as biomarker for angiogenic activity in cancer. For this purpose, non-standardized measurements in plasma and serum were used, without correction for artificial VEGF release by platelets activated ex vivo. We hypothesize that "true" circulating (cVEGF levels in most cancer patients are low and unrelated to cancer load or tumour angiogenesis. METHODOLOGY: We determined VEGF levels in PECT, a medium that contains platelet activation inhibitors, in citrate plasma, and in isolated platelets in 16 healthy subjects, 18 patients with metastatic non-renal cancer (non-RCC and 12 patients with renal cell carcinoma (RCC. In non-RCC patients, circulating plasma VEGF levels were low and similar to VEGF levels in controls if platelet activation was minimized during the harvest procedure by PECT medium. In citrate plasma, VEGF levels were elevated in non-RCC patients, but this could be explained by a combination of increased platelet activation during blood harvesting, and by a two-fold increase in VEGF content of individual platelets (controls: 3.4 IU/10(6, non-RCC: 6.2 IU/10(6 platelets, p = 0.001. In contrast, cVEGF levels in RCC patients were elevated (PECT plasma: 64 pg/ml vs. 21 pg/ml, RCC vs. non-RCC, p<0.0001, and not related to platelet VEGF concentration. CONCLUSIONS: Our findings suggest that "true" freely cVEGF levels are not elevated in the majority of cancer patients. Previously reported elevated plasma VEGF levels in cancer appear to be due to artificial release from activated platelets, which in cancer have an increased VEGF content, during the blood harvest procedure. Only in patients with RCC, which is characterized by excessive VEGF production due to a specific genetic defect, were cVEGF levels elevated. This observation may be related to limited and selective success of anti-VEGF agents, such as bevacizumab and sorafenib, as monotherapy in

  18. Cystamine immobilization on TiO 2 film surfaces and the influence on inhibition of collagen-induced platelet activation

    Science.gov (United States)

    Zhou, Yujuan; Weng, Yajun; Zhang, Liping; Jing, Fengjuan; Huang, Nan; Chen, Junying

    2011-12-01

    Poor haemocompatibility is a main issue of artificial cardiovascular materials in clinical application. Nitric oxide (NO), produced by vascular endothelial cells, is a well known inhibitor of platelet adhesion and activation. Thus, NO-releasing biomaterials are beneficial for improving haemocompatibility of blood-contacting biomedical devices. In this paper, a novel method was developed for enhancement of haemocompatibility by exploiting endogenous NO donors. TiO 2 films were firstly synthesized on Si (1 0 0) wafers via unbalanced magnetron sputtering technology, and then polydopamine was grafted on TiO 2 films and used as a linker for further immobilization of cystamine. The obtained surfaces were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis. NO generation is evaluated by saville-griess reagents, and it shows that cystamine immobilized samples are able to catalytically generate NO by decomposing endogenous S-nitrosothiols (RSNO). In vitro platelet adhesion results reveal that cystamine modified surfaces can inhibit collagen-induced platelet activation. ELISA analysis reveals that cGMP in platelets obviously increases on cystamine immobilized surface, which suggests the reducing of platelet activation is through NO/cGMP signal channel. It can be concluded that cystamine immobilized surface shows better blood compatibility by catalyzing NO release from the endogenous NO donor. It may be a promising method for improvement of haemocompatibility of blood-contacting implants.

  19. Inflammation, oxidative stress and platelet activation in aspirin-treated critical limb ischaemia: beneficial effects of iloprost.

    Science.gov (United States)

    Lessiani, Gianfranco; Vazzana, Natale; Cuccurullo, Chiara; Di Michele, Dario; Laurora, Giuseppe; Sgrò, Giuseppe; Di Ruscio, Paolo; Simeone, Emilio; Di Iorio, Pierangelo; Lattanzio, Stefano; Liani, Rossella; Ferrante, Elisabetta; Davì, Giovanni

    2011-02-01

    Platelets critically contribute to atherothrombosis and worsening ischaemia in patients with peripheral arterial disease (PAD), eventually leading to critical limb ischaemia (CLI). Furthermore, persistent platelet activation despite antiplatelet therapy has been reported in this setting. The prostacyclin analogue iloprost is currently recommended in CLI patients for its effects in relieving symptoms by promoting local perfusion. In this study, we investigated the effects of iloprost infusion on urinary 11-dehydro-TXB₂ and 8-iso-PGF(₂α) excretion rate, as in vivo indexes of thromboxane-dependent platelet activation and lipid peroxidation, respectively, and on platelet-derived proinflammatory sCD40L and nitric oxide bioavailability in 44 patients with CLI while on chronic treatment with low-dose aspirin. Daily iloprost infusion for one-week significantly decreased urinary 11-dehydro-TXB₂ [499 (277-807) vs. 380 (189-560) pg/mg creatinine, p iloprost treatment (Rho = 0.695, p iloprost is able to significantly reduce residual thromboxane biosynthesis, oxidative stress, endothelial dysfunction and platelet-derived inflammation in low-dose aspirin treated patients with CLI.

  20. Minimizing Platelet Activation-Induced Clogging in Deterministic Lateral Displacement Arrays for High-Throughput Capture of Circulating Tumor Cells

    Science.gov (United States)

    D'Silva, Joseph; Loutherback, Kevin; Austin, Robert; Sturm, James

    2013-03-01

    Deterministic lateral displacement arrays have been used to separate circulating tumor cells (CTCs) from diluted whole blood at flow rates up to 10 mL/min (K. Loutherback et al., AIP Advances, 2012). However, the throughput is limited to 2 mL equivalent volume of undiluted whole blood due to clogging of the array. Since the concentration of CTCs can be as low as 1-10 cells/mL in clinical samples, processing larger volumes of blood is necessary for diagnostic and analytical applications. We have identified platelet activation by the micro-post array as the primary cause of this clogging. In this talk, we (i) show that clogging occurs at the beginning of the micro-post array and not in the injector channels because both acceleration and deceleration in fluid velocity are required for clogging to occur, and (ii) demonstrate how reduction in platelet concentration and decrease in platelet contact time within the device can be used in combination to achieve a 10x increase in the equivalent volume of undiluted whole blood processed. Finally, we discuss experimental efforts to separate the relative contributions of contact activated coagulation and shear-induced platelet activation to clogging and approaches to minimize these, such as surface treatment and post geometry design.

  1. Hematopoietic lineage cell specific protein 1 (HS1) is a functionally important signaling molecule in platelet activation.

    Science.gov (United States)

    Kahner, Bryan N; Dorsam, Robert T; Mada, Sripal R; Kim, Soochong; Stalker, Timothy J; Brass, Lawrence F; Daniel, James L; Kitamura, Daisuke; Kunapuli, Satya P

    2007-10-01

    Collagen activates platelets through an intracellular signaling cascade downstream of glycoprotein VI (GPVI). We have investigated the contribution of hematopoietic lineage cell-specific protein 1 (HS1) downstream of GPVI in platelet activation. Stimulation of GPVI leads to tyrosine phosphorylation of HS1, which is blocked by Src-family kinase inhibitors. Coimmunoprecipitation experiments revealed that HS1 associates with Syk and phosphatidylinositol 3-kinases. HS1-null mice displayed increased bleeding times and increased time to occlusion in the FeCl(3) in vivo thrombosis model compared with their wild-type littermates. In addition, aggregation and secretion responses were diminished in HS1-null mouse platelets after stimulation of GPVI and protease-activated receptor 4 (PAR-4) agonists compared with wild-type littermate mouse platelets. Finally, Akt phosphorylation was diminished after GPVI or PAR-4 stimulation in platelets from HS1-null mice compared with their wild-type littermates. These results demonstrate that phosphorylation of the HS1 protein occurs downstream of GPVI stimulation and that HS1 plays a significant functional role in platelet activation downstream of GPVI and PARs.

  2. Effect of in-water oxygen prebreathing at different depths on decompression-induced bubble formation and platelet activation.

    Science.gov (United States)

    Bosco, Gerardo; Yang, Zhong-jin; Di Tano, Guglielmo; Camporesi, Enrico M; Faralli, Fabio; Savini, Fabio; Landolfi, Angelo; Doria, Christian; Fanò, Giorgio

    2010-05-01

    Effect of in-water oxygen prebreathing at different depths on decompression-induced bubble formation and platelet activation in scuba divers was evaluated. Six volunteers participated in four diving protocols, with 2 wk of recovery between dives. On dive 1, before diving, all divers breathed normally for 20 min at the surface of the sea (Air). On dive 2, before diving, all divers breathed 100% oxygen for 20 min at the surface of the sea [normobaric oxygenation (NBO)]. On dive 3, before diving, all divers breathed 100% O2 for 20 min at 6 m of seawater [msw; hyperbaric oxygenation (HBO) 1.6 atmospheres absolute (ATA)]. On dive 4, before diving, all divers breathed 100% O2 for 20 min at 12 msw (HBO 2.2 ATA). Then they dove to 30 msw (4 ATA) for 20 min breathing air from scuba. After each dive, blood samples were collected as soon as the divers surfaced. Bubbles were measured at 20 and 50 min after decompression and converted to bubble count estimate (BCE) and numeric bubble grade (NBG). BCE and NBG were significantly lower in NBO than in Air [0.142+/-0.034 vs. 0.191+/-0.066 (Pbubbles and platelet activation and, therefore, may be beneficial in reducing the development of decompression sickness.

  3. Enhanced P-selectin expression on platelet-a marker of platelet activation, in young patients with angiographically proven coronary artery disease.

    Science.gov (United States)

    George, Reema; Bhatt, Anugya; Narayani, Jayakumari; Thulaseedharan, Jissa Vinoda; Sivadasanpillai, Harikrishnan; Tharakan, Jaganmohan A

    2016-08-01

    P-selectin (CD62p) exposure is an established marker for platelet activation. P-selectin exposure can trigger variety of thrombotic and inflammatory reactions. In patients with coronary artery disease (CAD), platelets are activated, and hence, there is increased P-selectin exposure. The role of P-selectin exposure in patients on treatment with statins and anti-platelets is conflicting. A case-control study was performed to determine P-selectin exposure in consecutively recruited 142 patients (age ≤ 55 years) with angiographically proven CAD on treatment and 92 asymptomatic controls. P-selectin exposure was determined by flow cytometry. Data on conventional risk factors were obtained along with estimation of levels of thrombotic [fibrinogen, lipoprotein (a), tissue plasminogen activator, plasminogen activator inhibitor-1, homocysteine and von Willebrand factor] and anti-thrombotic factors (antithrombin III). The P-selectin exposure was compared among patient groups who had different modes of presentation of CAD and categories of CAD disease severity. The patients were followed up for a period of 26 months. The results indicate that P-selectin exposure was significantly elevated in patients (mean ± SD 9.24 ± 11.81) compared to controls (mean ± SD 1.48 ± 2.85) with p P-selectin exposure showed significant negative correlation with antithrombin III levels. P-selectin exposure was higher in patients who presented with acute coronary syndromes than those who presented with effort angina. Cardiovascular event rate was 6 % on follow-up. The study establishes that thrombotic-inflammatory pathways enhancing P-selectin exposure unrelated to treatment might be activated in patients, while the event rate remained lowered, and hence, treatment strategies should be inclusive to control these factors.

  4. Relationship and significance between anti-β2-glycoprotein I antibodies and platelet activation state in patients with ulcerative colitis

    Institute of Scientific and Technical Information of China (English)

    Yan-Hang Gao; Pu-Jun Gao; Chun-Guang Wang; Xiao-Cong Wang; Yun-Feng Piao

    2008-01-01

    AIM:To study the relationship between anti-β2-glycoproteinⅠ(aβ2GPⅠ) antibodies and platelet activation state in patients with ulcerative colitis (UC)and its significance.METHODS:Peripheral blood samples were collected from 56 UC patients (34 males and 22 females,aged 43.5 years,range 21-66 years),including 36 at active stage and 20 at remission stage,and 25 sex-and age-matched controls.The level of aβ2GPⅠwas measured by ELISA.The platelet activation markers,platelet activation complex-I (PAC- I) and P-selectin (CD62P) were detected by flow cytometry.RESULTS:The A value for IgG aβzGPⅠin the active UC group was 0.61±0.13,significantly higher than that in the remittent UC and control groups (0.50±0.13 and 0.22±0.14,P<0.01).There was a significant difference between the two groups (P<0.01).The A value for IgM aβ2GPⅠin the active and remittent UC groups was 0.43±0.13 and 0.38±0.12,significantly higher than that in the control group (0.20±0.12,P<0.01).However,there was no significant difference between the two groups (P>0.05).The PAC-I positive rate for the active and remittent UC groups was 30.6%±7.6% and 19.6%±7.8% respectively,significantly higher than that for the control group (6.3%±1.7%,P<0.01).There was a significant difference between the two groups (P<0.01).The CD62P positive rate for the active and remittent UC groups was 45.0%±8.8% and 31.9%±7.8% respectively,significantly higher than that for the control group (9.2%±2.7%,P<0.01).There was a significant difference between the two groups (P<0.01).In the active UC group,the more severe the state of illness was,the higher the A value for IgG aβ2GPⅠwas,and the positive rate for PAC-I and CD62P was positively correlated with the state of illness (Faβ2GPⅠ= 3.679,P<0.05;FPAC-I (%) = 5.346,P<0.01;and FCD62P (%) = 5.418,P<0.01).Meanwhile,in the same state of illness,the A value for IgG aβ2GPⅠwas positively correlated to the positive rates for PAC-I and CD62P

  5. Duration of exposure to high fluid shear stress is critical in shear-induced platelet activation-aggregation.

    Science.gov (United States)

    Zhang, Jian-ning; Bergeron, Angela L; Yu, Qinghua; Sun, Carol; McBride, Latresha; Bray, Paul F; Dong, Jing-fei

    2003-10-01

    Platelet functions are increasingly measured under flow conditions to account for blood hydrodynamic effects. Typically, these studies involve exposing platelets to high shear stress for periods significantly longer than would occur in vivo. In the current study, we demonstrate that the platelet response to high shear depends on the duration of shear exposure. In response to a 100 dyn/cm2 shear stress for periods less than 10-20 sec, platelets in PRP or washed platelets were aggregated, but minimally activated as demonstrated by P-selectin expression and binding of the activation-dependent alphaIIbbeta3 antibody PAC-1 to sheared platelets. Furthermore, platelet aggregation under such short pulses of high shear was subjected to rapid disaggregation. The disaggregated platelets could be re-aggregated by ADP in a pattern similar to unsheared platelets. In comparison, platelets that are exposed to high shear for longer than 20 sec are activated and aggregated irreversibly. In contrast, platelet activation and aggregation were significantly greater in whole blood with significantly less disaggregation. The enhancement is likely via increased collision frequency of platelet-platelet interaction and duration of platelet-platelet association due to high cell density. It may also be attributed to the ADP release from other cells such as red blood cells because increased platelet aggregation in whole blood was partially inhibited by ADP blockage. These studies demonstrate that platelets have a higher threshold for shear stress than previously believed. In a pathologically relevant timeframe, high shear alone is likely to be insufficient in inducing platelet activation and aggregation, but acts synergistically with other stimuli.

  6. Statin and Aspirin Pretreatment Are Associated with Lower Neurological Deterioration and Platelet Activity in Patients with Acute Ischemic Stroke.

    Science.gov (United States)

    Yi, Xingyang; Han, Zhao; Wang, Chun; Zhou, Qiang; Lin, Jing

    2017-02-01

    Aspirin and statin are recommended for the treatment of acute ischemic stroke. However, whether aspirin and statin pretreatment is associated with clinical outcomes has not been well addressed. This study aimed to evaluate the effect of pre-existing statin and aspirin use on platelet activation and clinical outcome in acute ischemic stroke patients. We conducted a prospective, multicenter observational study in patients with acute ischemic stroke. Platelet aggregation and platelet-leukocyte aggregates were measured on admission and during 7-10 days after admission. The primary outcome of the study was neurological deterioration (ND) within 10 days after admission. The secondary outcome was a composite of recurrent ischemic stroke, myocardial infarction, and death during the first 3 months after admission. Physical disability was evaluated using the modified Rankin Scale score at 3 months after admission. Among 1124 enrolled patients, 270 (24%) experienced ND. Higher platelet aggregation and platelet-leukocyte aggregates on admission and during 7-10 days were associated with ND. Platelet aggregation and platelet-leukocyte aggregates on admission were significantly lower in the patients with pre-existing statin or aspirin use than those without treatment. Patients with prestroke concomitant statin and aspirin treatment had significantly lower incidence of ND than those without treatment. Diabetes mellitus, fasting glucose, platelet-leukocyte aggregates, and prestroke concomitant statin and aspirin use were independently associated with ND. Prestroke concomitant statin and aspirin use is associated with lower neurological deterioration and platelet activity in patients with acute ischemic stroke. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  7. Whole blood coagulation and platelet activation in the athlete: A comparison of marathon, triathlon and long distance cycling

    Directory of Open Access Journals (Sweden)

    Hanke AA

    2010-02-01

    Full Text Available Abstract Introduction Serious thrombembolic events occur in otherwise healthy marathon athletes during competition. We tested the hypothesis that during heavy endurance sports coagulation and platelets are activated depending on the type of endurance sport with respect to its running fraction. Materials and Methods 68 healthy athletes participating in marathon (MAR, running 42 km, n = 24, triathlon (TRI, swimming 2.5 km + cycling 90 km + running 21 km, n = 22, and long distance cycling (CYC, 151 km, n = 22 were included in the study. Blood samples were taken before and immediately after completion of competition to perform rotational thrombelastometry. We assessed coagulation time (CT, maximum clot firmness (MCF after intrinsically activation and fibrin polymerization (FIBTEM. Furthermore, platelet aggregation was tested after activation with ADP and thrombin activating peptide 6 (TRAP by using multiple platelet function analyzer. Results Complete data sets were obtained in 58 athletes (MAR: n = 20, TRI: n = 19, CYC: n = 19. CT significantly decreased in all groups (MAR -9.9%, TRI -8.3%, CYC -7.4% without differences between groups. In parallel, MCF (MAR +7.4%, TRI +6.1%, CYC +8.3% and fibrin polymerization (MAR +14.7%, TRI +6.1%, CYC +8.3% were significantly increased in all groups. However, platelets were only activated during MAR and TRI as indicated by increased AUC during TRAP-activation (MAR +15.8% and increased AUC during ADP-activation in MAR (+50.3% and TRI (+57.5%. Discussion While coagulation is activated during physical activity irrespective of type we observed significant platelet activation only during marathon and to a lesser extent during triathlon. We speculate that prolonged running may increase platelet activity, possibly, due to mechanical alteration. Thus, particularly prolonged running may increase the risk of thrombembolic incidents in running athletes.

  8. Ingestion of onion soup high in quercetin inhibits platelet aggregation and essential components of the collagen-stimulated platelet activation pathway in man: a pilot study

    NARCIS (Netherlands)

    Hubbard, G.; Wolffram, S.; Vos, de C.H.; Bovy, A.G.; Gibbins, J.; Lovegrove, J.

    2006-01-01

    Epidemiological data suggest that those who consume a diet rich in quercetin-containing foods may have a reduced risk of CVD. Furthermore, in vitro and ex vivo studies have observed the inhibition of collagen-induced platelet activation by quercetin. The aim of the present study was to investigate t

  9. Time-dependent release of growth factors from implant surfaces treated with plasma rich in growth factors.

    Science.gov (United States)

    Sánchez-Ilárduya, María Belén; Trouche, Elodie; Tejero, Ricardo; Orive, Gorka; Reviakine, Ilya; Anitua, Eduardo

    2013-05-01

    Plasma rich in growth factors (PRGFs) technology is an autologous platelet-rich plasma approach that provides a pool of growth factors and cytokines that have been shown to increase tissue regeneration and accelerate dental implant osseointegration. In this framework, the spatiotemporal release of growth factors and the establishment of a provisional fibrin matrix are likely to be key aspects governing the stimulation of the early phases of tissue regeneration around implants. We investigated the kinetics of growth factor release at implant surfaces functionalized either with PRGFs or platelet-poor plasma and correlated the results obtained with the morphology of the resulting interfaces. Our main finding is that activation and clot formation favors longer residence times of the growth factors at the interfaces studied, probably due to their retention in the adsorbed fibrin matrix. The concentration of the platelet-derived growth factors above the interfaces becomes negligible after 2-4 days and is significantly higher in the case of activated interfaces than in the case of nonactivated ones, whereas that of the plasmatic hepatocyte growth factor is independent of platelet concentration and activation, and remains significant for up to 9 days. Platelet-rich plasma preparations should be activated to permit growth factor release and thereby facilitate implant surface osseointegration.

  10. Pathogen inactivation in fresh frozen plasma using riboflavin and ultraviolet light: Effects on plasma proteins and coagulation factor VIII

    Directory of Open Access Journals (Sweden)

    Stanojković Zoran

    2011-01-01

    Full Text Available Background/Aim. Riboflavin (vitamin B2 activated by ultraviolet (UV light, produces active oxygen which damages cell membrane and prevents replication of the carrier of diseases (viruses, bacteria, protozoa in all blood products. The aim of this study was to establish the influence of the process of photo inactivation in pathogens using riboflavin and UV rays on the concentration of coagulation factor VIII:C (FVIII:C and proteins in plasma that were treated before freezing. Methods. The examination included 20 units of plasma, separated from whole blood donated by voluntary blood donors around 6 hours from the moment of collection. The units were pooled and separated in to two groups: one consisted of 10 control units and the other of 10 experimental units. Experimental units of the plasma were treated by riboflavin (35 mL and UV rays (6.24 J/mL, 265-370 nm on Mirasol aparature (Caridian BCT Biotechnologies, USA in approximate duration of 6 minutes. Furthermore, 35 mL of saline solution was added to the control plasma. One sample for examining was taken from the control plasma (KG and two residual were taken from experimental plasma after the addition of riboflavin either before (EG1 or post illumination (EG2. Results. Comparing the mean values of FVIII:C (% we noticed statistically significantly higher level in the EG1 group than in the EG2 group (65.00 ± 4.52 vs 63.20 ± 4.73; t = 4.323, p = 0.002, while between the KG and experimental groups (EG1 and EG2 there was no statistically significant difference in the concentration of FVIII:C. There was a statistically significant decrease of albumin concentration (g/L in the EG2 group comparing to the KG (33.35 ± 0.94 vs 31.94 ± 0.84; t = 3.534, p = 0.002, but there was no mentioned difference in albumin concentration between the KG and the EG1, so as between the EG1 and the EG2. Conclusion. Plasma inactivated by riboflavin and UV rays (Mirasol PRT sistem, Caridian BCT, USA keeps all the

  11. Fibulin-1 purification from human plasma using affinity chromatography on Factor H-Sepharose.

    Science.gov (United States)

    DiScipio, Richard G; Liddington, Robert C; Schraufstatter, Ingrid U

    2016-05-01

    A method is reported to purify Fibulin-1 from human plasma resulting in a 36% recovery. The steps involve removal of the cryoglobulin and the vitamin K dependent proteins followed by polyethylene glycol and ammonium sulfate precipitations, DEAE-Sephadex column chromatography and finally Factor H-Sepharose affinity purification. The procedure is designed to be integrated into an overall scheme for the isolation of over 30 plasma proteins from a single batch of human plasma. Results from mass spectroscopy, SDS-PAGE, and Western blotting indicate that human plasma Fibulin-1 is a single chain of the largest isotype. Functional binding assays demonstrated calcium ion dependent interaction of Fibulin-1 for fibrinogen, fibronectin, and Factor H. The procedure described is the first to our knowledge that enables a large scale purification of Fibulin-1 from human plasma.

  12. In vitro Evaluation of the Function of Sheet Biomaterials in Platelet Activation%片状材料对血小板激活作用的体外评价

    Institute of Scientific and Technical Information of China (English)

    许建霞; 王志杰; 王春仁; 奚廷斐

    2013-01-01

    In China, the evaluation of hemocompatibility of biomaterials is limited to hemolysis, coagulation time,and the number and morphology of platelets adhered on biomaterials. The present research,however, is aimed to establish a method for evaluating the function of sheet biomaterials in platelet activation. Platelet activation caused by glass, polyvinyl chloride or polymethylvinylsiloxane sheets was evaluated by measuringcrgranule membrane protein (GMP-140) in platelet poor plasma, using a reasonable blood-material contact model vibrating at different speed. The result showed that the difference in platelet activation was not significantly different among the three above-mentioned materials at 140r/m or 200r/m. However, when it comes to 230r/m, significant difference was observed a-mong these three groups, with glass> polyvinyl chloride> polymethylvinylsiloxane. But the order was reversed at 270r/m, which may be due to the different interfacial tension of different materials. Therefore, the method is suitable to evaluate platelet activation caused by sheet biomaterials, but an appropriate vibrating speed should be chosen. The interfacial tension plays an important role in the model and should be considered for results assessment.%对生物材料血液相容性的评价,通常局限于溶血、凝血时间、血小板黏附等实验.本研究旨在建立一种评价片状材料对血小板激活作用的方法.本研究采用一种合理的血液与片状材料接触模型,以血浆血小板α-颗粒膜蛋白(GMP-140)为检测指标,对玻璃、聚氯乙烯、聚甲基乙烯基硅氧烷3种基础材料片在不同震荡速率下对血小板的激活作用进行了比较.结果显示:在140 r/m和200 r/m的震荡速率下,3种材料对血小板激活作用的差异不能完全区分开;而在230 r/m的震荡速率下,3种材料对血小板的激活作用的差异具有统计学意义,玻璃组>聚氯乙烯组>硅橡胶组.但在270 r/m的震荡速率下,顺序

  13. Platelet-rich plasma, plasma rich in growth factors and simvastatin in the regeneration and repair of alveolar bone.

    Science.gov (United States)

    Rivera, César; Monsalve, Francisco; Salas, Juan; Morán, Andrea; Suazo, Iván

    2013-12-01

    Platelet preparations promote bone regeneration by inducing cell migration, proliferation and differentiation in the area of the injury, which are essential processes for regeneration. In addition, several studies have indicated that simvastatin (SIMV), widely used for the treatment of hypercholesterolemia, stimulates osteogenesis. The objective of this study was to evaluate the effects of treatment with either platelet-rich plasma (PRP) or plasma rich in growth factors (PRGF) in combination with SIMV in the regeneration and repair of alveolar bone. The jaws of Sprague Dawley rats (n=18) were subjected to rotary instrument-induced bone damage (BD). Animals were divided into six groups: BD/H2O (n=3), distilled water without the drug and alveolar bone damage; BD/H2O/PRP (n=3), BD and PRP; BD/H2O/PRGF (n=3), BD and PRGF; BD/SIMV (n=3), BD and water with SIMV; BD/SIMV/PRP (n=3), BD, PRP and SIMV; and BD/SIMV/PRGF (n=3), BD, PRGF and SIMV. Conventional histological analysis (hematoxylin and eosin staining) revealed that the BD/SIMV group showed indicators for mature bone tissue, while the BD/SIMV/PRP and BD/SIMV/PRGF groups showed the coexistence of indicators for mature and immature bone tissue, with no statistical differences between the platelet preparations. Simvastatin did not improve the effect of platelet-rich plasma and plasma rich in growth factors. It was not possible to determine which platelet preparation produced superior effects.

  14. Multi-omics Analysis of Serum Samples Demonstrates Reprogramming of Organ Functions Via Systemic Calcium Mobilization and Platelet Activation in Metastatic Melanoma.

    Science.gov (United States)

    Muqaku, Besnik; Eisinger, Martin; Meier, Samuel M; Tahir, Ammar; Pukrop, Tobias; Haferkamp, Sebastian; Slany, Astrid; Reichle, Albrecht; Gerner, Christopher

    2017-01-01

    Pathophysiologies of cancer-associated syndromes such as cachexia are poorly understood and no routine biomarkers have been established, yet. Using shotgun proteomics, known marker molecules including PMEL, CRP, SAA, and CSPG4 were found deregulated in patients with metastatic melanoma. Targeted analysis of 58 selected proteins with multiple reaction monitoring was applied for independent data verification. In three patients, two of which suffered from cachexia, a tissue damage signature was determined, consisting of nine proteins, PLTP, CD14, TIMP1, S10A8, S10A9, GP1BA, PTPRJ, CD44, and C4A, as well as increased levels of glycine and asparagine, and decreased levels of polyunsaturated phosphatidylcholine concentrations, as determined by targeted metabolomics. Remarkably, these molecules are known to be involved in key processes of cancer cachexia. Based on these results, we propose a model how metastatic melanoma may lead to reprogramming of organ functions via formation of platelet activating factors from long-chain polyunsaturated phosphatidylcholines under oxidative conditions and via systemic induction of intracellular calcium mobilization. Calcium mobilization in platelets was demonstrated to alter levels of several of these marker molecules. Additionally, platelets from melanoma patients proved to be in a rather exhausted state, and platelet-derived eicosanoids implicated in tumor growth were found massively increased in blood from three melanoma patients. Platelets were thus identified as important source of serum protein and lipid alterations in late stage melanoma patients. As a result, the proposed model describes the crosstalk between lipolysis of fat tissue and muscle wasting mediated by oxidative stress, resulting in the metabolic deregulations characteristic for cachexia.

  15. The transcription factors IRF8 and PU.1 negatively regulate plasma cell differentiation.

    Science.gov (United States)

    Carotta, Sebastian; Willis, Simon N; Hasbold, Jhagvaral; Inouye, Michael; Pang, Swee Heng Milon; Emslie, Dianne; Light, Amanda; Chopin, Michael; Shi, Wei; Wang, Hongsheng; Morse, Herbert C; Tarlinton, David M; Corcoran, Lynn M; Hodgkin, Philip D; Nutt, Stephen L

    2014-10-20

    Activated B cells undergo immunoglobulin class-switch recombination (CSR) and differentiate into antibody-secreting plasma cells. The distinct transcriptomes of B cells and plasma cells are maintained by the antagonistic influences of two groups of transcription factors: those that maintain the B cell program, including BCL6 and PAX5, and plasma cell-promoting factors, such as IRF4 and BLIMP-1. We show that the complex of IRF8 and PU.1 controls the propensity of B cells to undergo CSR and plasma cell differentiation by concurrently promoting the expression of BCL6 and PAX5 and repressing AID and BLIMP-1. As the PU.1-IRF8 complex functions in a reciprocal manner to IRF4, we propose that concentration-dependent competition between these factors controls B cell terminal differentiation.

  16. [Detection of alloantibodies against Factor VIII in plasma of patients with hemophilia A and its relationship with Factor VIIIC domain].

    Science.gov (United States)

    Zhang, Lu-Lu; Yu, Zi-Qiang; Wan, Chu-Cheng; Zhang, Wei; Zhang, Zheng-Hua; Ruan, Chang-Geng

    2013-10-01

    This study was purposed to detect the alloantibodies against Factor VIII (FVIII) by ELISA for estimating the incidence of the alloantibodies against Factor VIII (FVIII) in patients with hemophilia A, and to investigate the relationship between factor VIIIC domain and alloantibodies. Total of 140 patients with hemophilia A and 80 normal controls were enrolled in this study, among them plasma FVIII level of 84 patients was less than 1%, plasma FVIII level of 34 patients was between 1% and 5%, and plasma FVIII level of 22 patients was more than 5%. All patients were treated with plasma-derived FVIII concentrate or plasma before. The ELISA plate was coated with McAb (SZ-132) against FVIII prepared in our laboratory, then human recombinant FVIII concentrates were applied. After incubation in room temperature for 2 hours, diluted plasma samples and HRP-conjugated goat anti-human IgG were added successively, finally A490 was recorded. The threshold of alloantibody of patient plasma was set as mean value>3 SD more than control. The plate was coated with antibody against His, then human recombinant FVIII-C1C2 prepared in our laboratory was added. After incubation in room temperature for 2 hours, diluted plasma samples and HRP-conjugated goat anti-human IgG were added successively, finally A490 were recorded. The threshold was set as the mean value>3 SD more than control. The results showed that the alloantibodies against FVIII were found in 56 patients (40%) by ELISA, and 82.1% (46/56) of this kind of alloantibody could interact with the C domain of FVIII. It is concluded that C domain of FVIII is one of the primary binding sites for the alloantibodies against FVIII in Chinese patients with hemophilia A.

  17. The Synergistic Effect between Electrical and Chemical Factors in Plasma Gene/Molecule-Transfection

    Science.gov (United States)

    Jinno, Masafumi

    2016-09-01

    This study has been done to know what kind of factors in plasma and processes on cells promote plasma gene/molecule transfection. We have discovered a new plasma source using a microcapillary electrode which enables high transfection efficiency and high cell survivability simultaneously. However, the mechanism of the transfection by plasma was not clear. To clarify the transfection mechanisms by micro plasma, we focused on the effects of electrical (current, charge, field, etc.) and chemical (radicals, RONS, etc.) factors generated by the micro plasma and evaluated the contribution weight of three groups of the effects and processes, i.e. electrical, chemical and biochemical ones. At first, the necessity of the electrical factors was estimated by the laser produced plasma (LPP). Mouse L-929 fibroblast cell was cultured on a 96-well plate or 12-well micro slide chamber. Plasmids pCX-EGFP in Tris-EDTA buffer was dropped on the cells and they were exposed to the capillary discharge plasma (CDP) or the LPP. In the case of the CDP, the plasma was generated between the tip of the capillary electrode and the cells so that both electrical and chemical factors were supplied to the cells. In this setup, about 20% of average transfection efficiency was obtained. In the case of the LPP, the plasma was generated apart from the cells so that electrical factors were not supplied to the cells. In this setup, no transfection was observed. These results show that the electrical factors are necessary for the plasma gene transfection. Next, the necessity of the chemical factors was estimated the effect of catalase to remove H2O2 in CDP. The transfection efficiency decreased to 0.4 by scavenging H2O2 with catalase. However, only the solution of H2O2 caused no gene transfection in cells. These results shows that H2O2 is important species to cause gene/molecule transfection but still needs a synergistic effect with electrical or other chemical factors. This work was partly supported by

  18. DIFFERENCES IN ERYTHROCYTE SODIUM-TRANSPORT BETWEEN HUMAN PLASMA AND ARTIFICIAL MEDIUM - THE ROLE AND CHARACTER OF SODIUM-EFFLUX AND INFLUX STIMULATING PLASMA FACTORS

    NARCIS (Netherlands)

    TEPPER, T; JILDERDA, JF; HUISMAN, RM; VANDERHEM, GK; DEZEEUW, D

    1992-01-01

    The main objective of this study was to further characterize the plasma factor(s) which stimulate sodium efflux from erythrocytes, which we reported previously. Dialysis of plasma against an artificial medium using membranes with varying molecular mass cut-off points revealed relative molecular

  19. Value research on thromboelastogram(TEG) in the monitoring of platelet activity variation tendency of PCI surgery patients

    Institute of Scientific and Technical Information of China (English)

    Xing-Bin Zou; He Huang

    2015-01-01

    Objective:To discuss the value research on thromboelastogram (TEG) in the monitoring of platelet activity variation tendency of PCI surgery patients.Method:180 cases of patients with coronary heart disease who have proceeded PCI surgery were selected and divided into AMI group, UAP group and AP group. To compare the coagulation indicator, TEG and pathological changes of these three groups; all patients were adopted conventional therapy, after operation, divided them into anti-platelet low reaction group (platelet high reaction group) and normal group according to platelet aggregation rate monitored by TEG, and compared the clotting all items, clinical indicator, PCI postoperative platelet aggregation inhibition rate and clinical ischemia cases occurrence rate within 6 months follow up visit of both groups.Results: TEG parametric R value and K value in AMI group and UAP group were obviously lower than that in AP group, MA value and angle value were obviously higher than AP group, significant difference; TEG image in AMI group and UAP group mainly featured hypercoagulability, while TEG image had no hypercoagulability in AP group; Chi-square test showed that hypercoagulability image percentage differences between these three groups had statistical significance; ADP and AA induced platelet inhibition rate determined by TEG in high reaction group was obviously lower than that in normal group; 6 cases in platelet high reaction group: CK-MB rose and exceeded normal value upper limit (10.90%), 9 cases: cTnI rose and exceeded normal value upper limit (19.6%), compared with normal group (3 cases, 2.4%; 5 cases, 4%), the value in platelet high reaction group was higher, and the difference was significant; platelet high reaction group: totally 10 cases of ischemia, occurrence rate was 10.5%, while platelet normal reaction group: totally 3 cases (2.4%), chi-square test showed that the difference between these two groups had statistical significance

  20. Plasma concentrations of blood coagulation factor VII measured by immunochemical and amidolytic methods

    DEFF Research Database (Denmark)

    Bladbjerg, E-M; Gram, J; Jespersen, J

    2000-01-01

    plasma, in cold activated plasma and in FVII deficient plasma. There was a positive correlation (r=0.96) between FVII:Ag and FVII:Am with slightly but significantly higher values for FVII:Ag (FVII:Ag= 106 U/ml and FVII:Am=100 U/ml; p ...Ever since the coagulant activity of blood coagulation factor VII (FVII:C) was identified as a risk indicator of cardiac death, a large number of studies have measured FVII protein concentrations in plasma. FVII protein concentrations are either measured immunologically with an ELISA method (FVII......:Ag) or estimated with an amidolytic method (FVII:Am). We have investigated whether FVII:Am is a valuable alternative to FVII:Ag. FVII:Ag and FVII:Am were measured in 147 plasma samples from blood donors, patients on oral anticoagulant therapy, postmenopausal women on hormone replacement therapy, in postprandial...

  1. Hydroxytyrosyl alkyl ether derivatives inhibit platelet activation after oral administration to rats.

    Science.gov (United States)

    Muñoz-Marín, Javier; De la Cruz, José Pedro; Reyes, José Julio; López-Villodres, Juan Antonio; Guerrero, Ana; López-Leiva, Inmaculada; Espartero, José Luis; Labajos, María Teresa; González-Correa, José Antonio

    2013-08-01

    The low lipophilicity of hydroxytyrosol (HT) has motivated efforts to synthesize homologous series with better lipid solubility, such as the ethers, which are more lipophilic than HT. Because HT inhibits platelet aggregation, the aim of the study was to assess the possible anti-platelet effect of five HT ether derivatives (ethyl, butyl, hexyl, octyl and dodecyl) after oral administration to rats. Whole blood collagen-induced platelet aggregation and calcium-induced thromboxane B2 (TxB2), aortic 6-keto-prostaglandin F1α (6-keto-PGF1α) and nitrites+nitrates, plasma concentration of lipid peroxides (TBARS) and red blood cell content of reduced glutathione (GSH) were measured. The administration of 20 mg/kg/day inhibited platelet aggregation, TxB2 and TBARS in a non-linear manner related to the length of the carbon chain, with a cut-off effect in the hexyl derivative. Aortic nitrite and red blood cell GSH production were also increased. The aortic production of 6-keto-PGF1α was unaltered except in the group treated with the dodecyl derivative. The administration of 50 mg/kg/day showed a similar pharmacodynamic profile but without the non-linear effect. In conclusion, HT ethers, especially the hexyl derivative, are a potential alternative to hydroxytyrosol, and their effect merits additional research to determine their role in the prophylaxis of vascular disease.

  2. Platelet Activation Determines Angiopoietin-1 and VEGF Levels in Malaria : Implications for Their Use as Biomarkers

    NARCIS (Netherlands)

    Brouwers, Judith; Noviyanti, Rintis; Fijnheer, Rob; de Groot, Philip G.; Trianty, Leily; Mudaliana, Siti; Roest, Mark; Syafruddin, Din; van der Ven, Andre; de Mast, Quirijn

    2013-01-01

    Introduction: The angiogenic proteins angiopoietin (Ang)-1, Ang-2 and vascular endothelial growth factor (VEGF) are regulators of endothelial inflammation and integrity. Since platelets store large amounts of Ang-1 and VEGF, measurement of circulation levels of these proteins is sensitive to platele

  3. Role of hormonal factors in plasma K alterations in acute respiratory and metabolic alkalosis in dogs.

    Science.gov (United States)

    Suzuki, H; Hishida, A; Ohishi, K; Kimura, M; Honda, N

    1990-02-01

    Studies were performed on previously nephrectomized dogs to examine roles of hormonal factors in plasma potassium alterations in acute alkalosis. Respiratory and metabolic alkalosis were induced by hyperventilation and intravenous NaHCO3 or tris(hydroxymethyl)aminomethane (Tris) infusion, respectively. Respiratory and NaHCO3-induced alkalosis provoked decreases in plasma potassium from the control value of 5.12 +/- 0.68 (SE) to 4.21 +/- 0.55 meq/l (P less than 0.01) and from 4.65 +/- 0.26 to 3.91 +/- 0.16 meq/l (P less than 0.01) within 180 min, respectively. In contrast, Tris-induced alkalosis elicited an increase in plasma potassium from the control value of 4.56 +/- 0.30 to 5.31 +/- 0.30 meq/l (P less than 0.01). Hypokalemia in respiratory alkalosis was associated with a decrease in the plasma norepinephrine concentration from the control level of 377 +/- 104 to 155 +/- 41 pg/ml (P less than 0.05) but not with changes in plasma levels of epinephrine, insulin, glucagon, cortisol, and aldosterone. However, this hypokalemia was not affected by phentolamine. Also, somatostatin did not modify the hypokalemic response. NaHCO3-induced hypokalemia was associated with a decline in the plasma aldosterone and norepinephrine concentrations. The decline in plasma norepinephrine in NaHCO3-induced alkalosis followed the decrease in plasma potassium. In Tris-induced alkalosis, plasma insulin increased but norepinephrine decreased. The findings do not suggest fundamental roles of the hormonal factors in the plasma potassium alterations in bilaterally nephrectomized dogs with acute alkalosis.

  4. Plasma prekallikrein as a risk factor for diabetic retinopathy.

    Science.gov (United States)

    Kedzierska, Karolina; Ciechanowski, Kazimierz; Gołembiewska, Edyta; Safranow, Krzysztof; Ciechanowicz, Andrzej; Domański, Leszek; Myślak, Marek; Róźański, Jacek

    2005-01-01

    The aim of the study was to verify the hypothesis that in diabetes there is an increased activation of coagulation system leading in consequence to diabetic retinopathy. Thirty three healthy subjects (controls, 16 males and 17 females) and 35 patients with diabetes type 1 (15 males and 20 females) were examined. We monitored plasma prekallikrein (PPK), glycemia, fructosamine, glycosylated hemoglobin, activated partial thromboplastin time (PTT), INR, fibrinolysis in euglobulins time (FET), level of antithrombin III (AT III), fibrinogen (Fb) and fibrinogen degradation products (FDP). In diabetic patients without retinopathy, PKK concentration was 16% higher (p PKK concentration was 50% higher (p <0.001) than in controls. In the subgroup of patients with proliferative retinopathy PTT was significantly shorter (p <0.001), and FET was significantly longer (p <0.001) than in control. In patients with diabetes higher FDP concentrations were found than in controls (p <0.05). Significant correlations were found between PPK and fructosamine levels in all diabetic patients (R(S)=+0.57 p <0.001), in diabetic patients without retinopathy (R(S)=+0.61, p <0.05), and in diabetic patients with retinopathy (R(S)=+0.62, p <0.005). We found negative correlation between PPK concentration and PTT (R(S)=-0.43, p <0.001) and positive correlation between PPK concentration and FET (R(S)=+0.59, p <0.00001) in the entire study group. The occurrence of diabetic retinopathy is connected with higher levels of plasma prekallikrein.

  5. Minimal change-like glomerular alterations induced by a human plasma factor

    NARCIS (Netherlands)

    Cheung, PK; Klok, PA; Bakker, WW

    1996-01-01

    Circulating factors, including the plasma protease (100KF) described previously, have been suspected to play a role in the pathogenesis of minimal change disease (MCD) for several decades. This factor was able to induce MCD-like alterations in kidney tissue in vitro, i.e. impairment of glomerular po

  6. Oxygen-dependent injury by a human plasma factor associated with minimal change disease

    NARCIS (Netherlands)

    Cheung, PK; Baller, JFW; Bakker, WW

    1998-01-01

    The mechanism by which a human plasma factor associated with proteinuria is able to cause experimental glomerular albumin leakage is unknown. This factor (called 100KF) is able to induce glomerular alterations in the rat kidney, similar to those seen in minimal change disease, including loss of glom

  7. Plasma levels of trefoil factors are increased in patients with advanced prostate cancer

    DEFF Research Database (Denmark)

    Vestergaard, E.M.; Borregaard, Michael Krabbe; Poulsen, Steen Seier;

    2006-01-01

    Through cDNA array analyses and immunohistochemistry on tissue microarrays, trefoil factor 3 (TFF3) was recently shown to be overexpressed in prostate cancer. The purpose of this study was to test the feasibility of using the levels of trefoil factors as a plasma marker for prostate cancer....

  8. [Epidermal growth factor receptor expression and epidermal growth factor blood plasma content in simple and complex endometrial hyperplasia].

    Science.gov (United States)

    Dznelashvili, N; Kasradze, D; Tavartkiladze, A; Mariamidze, A

    2014-01-01

    The goal of our study was to concurrently determine the prognostic significance of Epidermal Growth Factor Receptor (EGFR) expression in endometrium and Epidermal Growth Factor (EGF) blood content in simple and complex hyperplasia. In order to detect EGFR expression, immunohistochemical examination of endometrial scarp from 35 patients was done along with HPLC (High performance liquid chromatography) method, for measuring EGF blood plasma content. The numerical data obtained were processed statistically using computer program SPSS-12. According to the results: 1. A significant/marked increase in EGF blood plasma level together with pronounced EGFR expression in simple endometrial hyperplasia (without atypia) suggests that simple hyperplasia is likely to transform into complex form, while unchanged level of EGF against the background of mild EGFR expression is probably indicative of not very bad prognosis. 2. Normal indices of EGF blood plasma level in simple endometrial hyperplasia (without atypia), accompanied by mild EGFR expression is suggestive of good prognosis. 3. A sharp or extremely sharp increase in EGF blood plasma level with pronounced EGFR expression in complex endometrial hyperplasia (without atypia) is likely to indicate poor prognosis that may lead to the transformation into atypical form. However, unchanged EGF blood plasma level against the background of mild EGFR expression in complex endometrial hyperplasia (without atypia) is likely to point to not very bad prognosis. 4. A marked increase in EGF blood plasma level with a pronounced EGFR expression in complex endometrial hyperplasia (without atypia) is likely to indicate poor prognosis that may lead to the transformation into atypical form. Because it is evident that drastic increase in EGF blood plasma level is not necessary, other factor should be suspected to play the major role, i.e the substance that will (or will not) withstand neoplasia.

  9. Plasma levels of trefoil factors are increased in patients with advanced prostate cancer

    DEFF Research Database (Denmark)

    Vestergaard, Else Marie; Borre, Michael; Poulsen, Steen Seier;

    2006-01-01

    . EXPERIMENTAL DESIGN: In 79 patients with prostate cancer, 23 patients with benign prostatic hyperplasia, and 44 healthy individuals plasma TFF1, TFF2, and TFF3 were determined with ELISAs and compared with clinical stage and prostate-specific antigen (PSA) values. Plasma levels of TFF were compared......PURPOSE: Through cDNA array analyses and immunohistochemistry on tissue microarrays, trefoil factor 3 (TFF3) was recently shown to be overexpressed in prostate cancer. The purpose of this study was to test the feasibility of using the levels of trefoil factors as a plasma marker for prostate cancer...... with the immunohistochemical expression of TFF and chromogranin A in 30 prostate cancer tissue samples. RESULTS: Patients with advanced prostate cancer had significantly higher plasma concentrations of TFF1, TFF2, and TFF3 (P

  10. Involvement of Ca2+ Activated Cl- Channel Ano6 in Platelet Activation and Apoptosis

    Directory of Open Access Journals (Sweden)

    Guoxing Liu

    2015-11-01

    Full Text Available Background/Aims: The ubiquitously expressed Ca2+ Activated Cl- Channel Ano6 participates in the stimulation of cell membrane scrambling. Defective Ano6 underlies the Scott syndrome, an inherited bleeding disorder with impaired scrambling of plasma membrane phospholipids. At least in theory, the bleeding disorder of Scott syndrome may result from impaired platelet function. Activators of platelets include thrombin and collagen related peptide (CRP, which trigger increase of cytosolic Ca2+-activity ([Ca2+]i, production of reactive oxygen species (ROS, degranulation, integrin activation, as well as cell shrinkage and phospholipid scrambling of the cell membrane. The present study thus explored whether Ano6 modifies activation-induced alterations of cytosolic Ca2+-activity ([Ca2+]i, degranulation (P-selectin exposure, integrin activation, phosphatidylserine exposure on the platelet surface and platelet volume. Methods: Platelets from mice lacking Ano6 (ano6-/- were compared to platelets from corresponding wild-type mice (ano6+/+. [Ca2+]i was estimated from Fluo-3 fluorescence, ROS from DCFDA fluorescence, degranulation from P-selectin abundance, integrin activation from αIIbβ3-integrin abundance, phosphatidylserine abundance from annexin-V-binding, and cell volume from forward scatter. Results: Platelet number in blood was slightly higher in ano6-/- mice than in ano6+/+ mice. Without activation [Ca2+]i and volume were similar in ano6-/- and ano6+/+ platelets as well as ROS abundance, P-selectin abundance, αIIbβ3 integrin activation, and phosphatidylserine exposure were negligible in both genotypes. Thrombin (0.01 U/ml and CRP (2 or 5 µg/ml increased [Ca2+]i, ROS abundance, platelet degranulation, αIIbβ3 integrin activation, and triggered annexin-V-binding as well as cell shrinkage, all effects less pronounced in ano6-/- than in ano6+/+ platelets. Conclusions: Genetic knockout of Ano6 blunts thrombin- and CRP-induced activation and apoptosis

  11. Finite size effects in the static structure factor of dusty plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Davletov, A. E., E-mail: askar@physics.kz; Yerimbetova, L. T.; Mukhametkarimov, Ye. S.; Ospanova, A. K. [Department of Physics and Technology, Al-Farabi Kazakh National University, Al-Farabi av. 71, 050040 Almaty (Kazakhstan)

    2014-07-15

    Based on the previously developed pseudopotential model of the dust particles interaction, which takes into account both the finite size and screening effects, the equilibrium distribution functions are investigated in a broad range of plasma parameters. The treatment stems entirely from the renormalization theory of plasma particles interactions which leads to the so-called generalized Poisson-Boltzmann equation. In particular, an analytical expression for the static structure factor of the dust particles is proposed and its non-monotonic behavior in the hyper-netted chain approximation is found in a specified domain of plasma parameters to indicate the formation of short- or even long-range order in the system.

  12. Repetitive tabletop plasma focus to produce a tunable damage factor on materials for fusion reactors

    Science.gov (United States)

    Soto, Leopoldo; Pavez, Cristian; Inestrosa-Izurieta, Maria Jose; Moreno, Jose; Davis, Sergio; Bora, Biswajit; Avaria, Gonzalo; Jain, Jalaj; Altamirano, Luis; Panizo, Miguel; Gonzalez, Raquel; Rivera, Antonio

    2016-10-01

    Future thermonuclear reactors, both magnetic and inertial confinement approaches, need materials capable of withstanding the extreme radiation and heat loads expected from high repetition rate plasma. A damage factor (F = qτ1/2) in the order of 104 (W/cm2) s1/2 is expected. The axial plasma dynamics after the pinch in a tabletop plasma focus of hundred joules, PF-400J, was characterized by means of pulsed optical refractive diagnostics. The energy, interaction time and power flux of the plasma burst interacting with targets was obtained. Results show a high dependence of the damage factor with the distance from the anode top where the sample is located. A tunable damage factor in the range 10- 105(W/cm2) s1/2 can be obtained. At present the PF-400J operating at 0.077 Hz is being used to study the effects of fusion-relevant pulses on material target, including nanostructured materials. A new tabletop device to be operated up to 1Hz including tunable damage factor has been designed and is being constructed, thus thousand cumulative shots on materials could be obtained in few minutes. The scaling of the damage factor for plasma foci operating at different energies is discussed. Supported by CONICYT: PIA ACT-1115, PAI 79130026.

  13. Alkali treatment of microrough titanium surfaces affects macrophage/monocyte adhesion, platelet activation and architecture of blood clot formation

    Directory of Open Access Journals (Sweden)

    V Milleret

    2011-05-01

    Full Text Available Titanium implants are most commonly used for bone augmentation and replacement due to their favorable osseointegration properties. Here, hyperhydrophilic sand-blasted and acid-etched (SBA titanium surfaces were produced by alkali treatment and their responses to partially heparinized whole human blood were analyzed. Blood clot formation, platelet activation and activation of the complement system was analyzed revealing that exposure time between blood and the material surface is crucial as increasing exposure time results in higher amount of activated platelets, more blood clots formed and stronger complement activation. In contrast, the number of macrophages/monocytes found on alkali-treated surfaces was significantly reduced as compared to untreated SBA Ti surfaces. Interestingly, when comparing untreated to modified SBA Ti surfaces very different blood clots formed on their surfaces. On untreated Ti surfaces blood clots remain thin (below 15 mm, patchy and non-structured lacking large fibrin fiber networks whereas blood clots on differentiated surfaces assemble in an organized and layered architecture of more than 30 mm thickness. Close to the material surface most nucleated cells adhere, above large amounts of non-nucleated platelets remain entrapped within a dense fibrin fiber network providing a continuous cover of the entire surface. These findings might indicate that, combined with findings of previous in vivo studies demonstrating that alkali-treated SBA Ti surfaces perform better in terms of osseointegration, a continuous and structured layer of blood components on the blood-facing surface supports later tissue integration of an endosseous implant.

  14. Surface characterization and platelet adhesion studies on fluorocarbons prepared by plasma-induced graft polymerization.

    Science.gov (United States)

    Lin, J C; Tiong, S L; Chen, C Y

    2000-01-01

    It is believed that the interactions between the biological environment and biomaterial surface are the key factors influencing its biocompatibility. Therefore, plasma processing, which can vary the surface properties without altering the bulk properties, has been considered as one of the important techniques for improving a materials' biocompatibility. In this investigation, plasma-induced grafting polymerization of vinylidene fluoride (VDF) and chlorotrifluoroethylene (CTFE), instead of direct plasma polymerization, was attempted with an aim to improve the substrate blood compatibility. Contact angle measurement indicated both fluorocarbon-grafted Pdyethylenes (PEs) are hydrophobic. Due to the additional fluorine and chlorine atoms on the CTFE chain, the PCTFE-grafted PE exhibited a higher hydrophobicity than the PVDF-grafted one. ESCA analysis has revealed that these two plasma-induced fluorocarbon deposits contain almost no CFx (x > 2) binding on the surface layer, indicating the grafting polymerization mainly follows the free radical mechanism instead of the molecule-highly-fragmented reaction steps commonly seen in the direct plasma polymerization treatment. In addition, ATR-FTIR has shown the surface chemical configuration of these PVDF- and PCTFE-grafted PEs to be very similar to those of the bulk samples of PVDF and PCTFE. The surface roughness decreased after oxygen plasma treatment and was further reduced by VDF and CTFE grafting polymerization. In vitro platelet adhesion testing indicated these two fluorocarbon grafted PEs are less platelet-activating than the nontreated PE control and oxygen plasma activated one.

  15. Evaluation of factors important in modeling plasma concentrations of tetracycline hydrochloride administered in water in swine.

    Science.gov (United States)

    Mason, Sharon E; Almond, Glen W; Riviere, Jim E; Baynes, Ronald E

    2012-10-01

    To model the plasma tetracycline concentrations in swine (Sus scrofa domestica) treated with medication administered in water and determine the factors that contribute to the most accurate predictions of measured plasma drug concentrations. Plasma tetracycline concentrations measured in blood samples from 3 populations of swine. Data from previous studies provided plasma tetracycline concentrations that were measured in blood samples collected from 1 swine population at 0, 4, 8, 12, 24, 32, 48, 56, 72, 80, 96, and 104 hours and from 2 swine populations at 0, 12, 24, 48, and 72 hours hours during administration of tetracycline hydrochloride dissolved in water. A 1-compartment pharmacostatistical model was used to analyze 5 potential covariate schemes and determine factors most important in predicting the plasma concentrations of tetracycline in swine. 2 models most accurately predicted the tetracycline plasma concentrations in the 3 populations of swine. Factors of importance were body weight or age of pig, ambient temperature, concentration of tetracycline in water, and water use per unit of time. The factors found to be of importance, combined with knowledge of the individual pharmacokinetic and chemical properties of medications currently approved for administration in water, may be useful in more prudent administration of approved medications administered to swine. Factors found to be important in pharmacostatistical models may allow prediction of plasma concentrations of tetracycline or other commonly used medications administered in water. The ability to predict in vivo concentrations of medication in a population of food animals can be combined with bacterial minimum inhibitory concentrations to decrease the risk of developing antimicrobial resistance.

  16. Plasma transforming growth factor beta levels in breast cancer patients

    NARCIS (Netherlands)

    Sminia, P; Barten, AD; Van Waarde, MAWH; Vujaskovic, Z; Van Tienhoven, G

    1998-01-01

    We investigated whether the concentration of circulating transforming growth factor beta (TGF beta) yields diagnostic value in breast cancer. Blood was collected from twenty stage I and II breast cancer patients both prior to treatment and after surgical excision of the tumour. Both latent and activ

  17. Plasma zinc's alter ego is a low-molecular-weight humoral factor.

    Science.gov (United States)

    Ou, Ou; Allen-Redpath, Keith; Urgast, Dagmar; Gordon, Margaret-Jane; Campbell, Gill; Feldmann, Jörg; Nixon, Graeme F; Mayer, Claus-Dieter; Kwun, In-Sook; Beattie, John H

    2013-09-01

    Mild dietary zinc deprivation in humans and rodents has little effect on blood plasma zinc levels, and yet cellular consequences of zinc depletion can be detected in vascular and other tissues. We proposed that a zinc-regulated humoral factor might mediate the effects of zinc deprivation. Using a novel approach, primary rat vascular smooth muscle cells (VSMCs) were treated with plasma from zinc-deficient (2500 genes, compared to incubation of cells with zinc-adequate rat plasma. We demonstrated that this effect was caused by a low-molecular-weight (∼2-kDa) zinc-regulated humoral factor but that changes in gene expression were mostly reversed by adding zinc back to zinc-deficient plasma. Strongly regulated genes were overrepresented in pathways associated with immune function and development. We conclude that zinc deficiency induces the production of a low-molecular-weight humoral factor whose influence on VSMC gene expression is blocked by plasma zinc. This factor is therefore under dual control by zinc.

  18. Lipid effects on neutrophil calcium signaling induced by opsonized particles: platelet activating factor is only part of the story.

    NARCIS (Netherlands)

    Wanten, G.J.A.; Kusters, A.; Emst-de Vries, S.E. van; Tool, A.; Roos, D.; Naber, A.H.J.; Willems, P.

    2004-01-01

    BACKGROUND & METHODS: Total parenteral nutrition is frequently used in clinical practice to improve the nutritional status of patients. However, the risk for infectious complications remains a drawback in which immune-modulating effects of the lipid component may play a role. To characterize these l

  19. Catalytic synthesis of enantiopure mixed diacylglycerols - synthesis of a major M. tuberculosis phospholipid and platelet activating factor

    NARCIS (Netherlands)

    Fodran, Peter; Minnaard, Adriaan J.

    2013-01-01

    An efficient catalytic one-pot synthesis of TBDMS-protected diacylglycerols has been developed, starting from enantiopure glycidol. Subsequent migration-free deprotection leads to stereo- and regiochemically pure diacylglycerols. This novel strategy has been applied to the synthesis of a major Mycob

  20. Catalytic synthesis of enantiopure mixed diacylglycerols - synthesis of a major M. tuberculosis phospholipid and platelet activating factor

    NARCIS (Netherlands)

    Fodran, Peter; Minnaard, Adriaan J.

    2013-01-01

    An efficient catalytic one-pot synthesis of TBDMS-protected diacylglycerols has been developed, starting from enantiopure glycidol. Subsequent migration-free deprotection leads to stereo- and regiochemically pure diacylglycerols. This novel strategy has been applied to the synthesis of a major

  1. PLENARY LECTURES-PL3 Vascular dysfunctions and platelet activations by arsenic: two major contributing factors to cardiovascular disease

    Institute of Scientific and Technical Information of China (English)

    JH CHUNG

    2006-01-01

    @@ Arsenic in drinking water is a worldwide health problem that is associated with cardiovascular disease, but the cause is currently unknown. In order to examine whether arsenic affects vasomotor tone in blood vessels, we investigated the effect of arsenic on agonist-induced vasorelaxation and vasoconstriction using the isolated rat aortic rings in in vitro organ bath system.

  2. Factors Associated With Plasma IL-6 Levels During HIV Infection

    DEFF Research Database (Denmark)

    Borges, Álvaro H; O'Connor, Jemma L; Phillips, Andrew N

    2015-01-01

    BACKGROUND: Elevated interleukin 6 (IL-6) levels have been linked to cardiovascular disease, cancer and death. Persons with human immunodeficiency virus (HIV) infection receiving treatment have higher IL-6 levels, but few data are available on factors associated with circulating IL-6. METHODS......: Participants in 3 trials with IL-6 measured at baseline were included (N = 9864). Factors associated with IL-6 were identified by linear regression. Demographic and HIV variables (nadir/entry CD4(+) cell count, HIV RNA level, antiretroviral therapy regimen) were investigated in all 3 trials. In the SMART...... education, whereas black race was associated with lower IL-6. Higher HIV RNA levels were associated with higher IL-6 levels, and higher nadir CD4(+) cell counts with lower IL-6 levels. Compared with efavirenz, protease inhibitors were associated with higher and nevirapine with lower IL-6 levels. Smoking...

  3. Platelet Activation and Thrombus Formation over IgG Immune Complexes Requires Integrin αIIbβ3 and Lyn Kinase.

    Science.gov (United States)

    Zhi, Huiying; Dai, Jing; Liu, Junling; Zhu, Jieqing; Newman, Debra K; Gao, Cunji; Newman, Peter J

    2015-01-01

    IgG immune complexes contribute to the etiology and pathogenesis of numerous autoimmune disorders, including heparin-induced thrombocytopenia, systemic lupus erythematosus, rheumatoid- and collagen-induced arthritis, and chronic glomerulonephritis. Patients suffering from immune complex-related disorders are known to be susceptible to platelet-mediated thrombotic events. Though the role of the Fc receptor, FcγRIIa, in initiating platelet activation is well understood, the role of the major platelet adhesion receptor, integrin αIIbβ3, in amplifying platelet activation and mediating adhesion and aggregation downstream of encountering IgG immune complexes is poorly understood. The goal of this investigation was to gain a better understanding of the relative roles of these two receptor systems in immune complex-mediated thrombotic complications. Human platelets, and mouse platelets genetically engineered to differentially express FcγRIIa and αIIbβ3, were allowed to interact with IgG-coated surfaces under both static and flow conditions, and their ability to spread and form thrombi evaluated in the presence and absence of clinically-used fibrinogen receptor antagonists. Although binding of IgG immune complexes to FcγRIIa was sufficient for platelet adhesion and initial signal transduction events, platelet spreading and thrombus formation over IgG-coated surfaces showed an absolute requirement for αIIbβ3 and its ligands. Tyrosine kinases Lyn and Syk were found to play key roles in IgG-induced platelet activation events. Taken together, our data suggest a complex functional interplay between FcγRIIa, Lyn, and αIIbβ3 in immune complex-induced platelet activation. Future studies may be warranted to determine whether patients suffering from immune complex disorders might benefit from treatment with anti-αIIbβ3-directed therapeutics.

  4. High-dose aspirin in addition to daily low-dose aspirin decreases platelet activation in patients before and after percutaneous coronary intervention.

    Science.gov (United States)

    ten Berg, Jurriën M; Gerritsen, Wim B M; Haas, Fred J L M; Kelder, Hans C; Verheugt, Freek W A; Plokker, H W Thijs

    2002-03-01

    Activated platelets play a major role in acute vessel closure after coronary angioplasty. Although aspirin is the routine therapy during angioplasty, it only incompletely prevents acute closure. This might be due to suboptimal dosing. First, to study the effect of additional high-dose aspirin on platelet activation during coronary angioplasty. Second, to assess the potential of the new PFA-100 analyzer to evaluate the effect of different doses of aspirin in patients undergoing angioplasty. Fifty-one patients on 100 mg aspirin/day for at least 1 month were randomized to continuation of 100 mg aspirin/day only (Group A=24 patients), or to this regime plus a bolus of 1000 mg of aspirin given 1 day before angioplasty (Group B=27 patients). Results were compared with 15 controls. Platelet function was measured before angioplasty by the PFA-100 analyzer; platelet activation was measured by flow cytometry just before and 1 h after angioplasty. At baseline, Group A had significantly more activated platelets than the control group (P<.001). High-dose aspirin in Group B resulted in significantly lower platelet activation as compared with both controls (P<.001) and Group A (P<.001). During angioplasty, the number of activated platelets decreased significantly in Group A (P<.001), while there was no change in Group B (P=.6). The PFA-100 analyzer was unable to detect differences between the two treatment groups. The addition of high-dose aspirin to daily low-dose aspirin, 1 day before coronary angioplasty, significantly reduced the platelet activation state before and after intervention. The PFA-100 analyzer did not detect differences in the effect of low- versus high-dose aspirin on platelet function.

  5. Platelet Activation and Thrombus Formation over IgG Immune Complexes Requires Integrin αIIbβ3 and Lyn Kinase.

    Directory of Open Access Journals (Sweden)

    Huiying Zhi

    Full Text Available IgG immune complexes contribute to the etiology and pathogenesis of numerous autoimmune disorders, including heparin-induced thrombocytopenia, systemic lupus erythematosus, rheumatoid- and collagen-induced arthritis, and chronic glomerulonephritis. Patients suffering from immune complex-related disorders are known to be susceptible to platelet-mediated thrombotic events. Though the role of the Fc receptor, FcγRIIa, in initiating platelet activation is well understood, the role of the major platelet adhesion receptor, integrin αIIbβ3, in amplifying platelet activation and mediating adhesion and aggregation downstream of encountering IgG immune complexes is poorly understood. The goal of this investigation was to gain a better understanding of the relative roles of these two receptor systems in immune complex-mediated thrombotic complications. Human platelets, and mouse platelets genetically engineered to differentially express FcγRIIa and αIIbβ3, were allowed to interact with IgG-coated surfaces under both static and flow conditions, and their ability to spread and form thrombi evaluated in the presence and absence of clinically-used fibrinogen receptor antagonists. Although binding of IgG immune complexes to FcγRIIa was sufficient for platelet adhesion and initial signal transduction events, platelet spreading and thrombus formation over IgG-coated surfaces showed an absolute requirement for αIIbβ3 and its ligands. Tyrosine kinases Lyn and Syk were found to play key roles in IgG-induced platelet activation events. Taken together, our data suggest a complex functional interplay between FcγRIIa, Lyn, and αIIbβ3 in immune complex-induced platelet activation. Future studies may be warranted to determine whether patients suffering from immune complex disorders might benefit from treatment with anti-αIIbβ3-directed therapeutics.

  6. Ingestion of onion soup high in quercetin inhibits platelet aggregation and essential components of the collagen-stimulated platelet activation pathway in man: a pilot study

    OpenAIRE

    Hubbard, G; Wolffram, S; Vos, de, W.M.; Bovy, A.G.; Gibbins, J.; Lovegrove, J

    2006-01-01

    Epidemiological data suggest that those who consume a diet rich in quercetin-containing foods may have a reduced risk of CVD. Furthermore, in vitro and ex vivo studies have observed the inhibition of collagen-induced platelet activation by quercetin. The aim of the present study was to investigate the possible inhibitory effects of quercetin ingestion from a dietary source on collagen-stimulated platelet aggregation and signalling. A double-blind randomised cross-over pilot study was undertak...

  7. Relationship and significance between anti-β2-glycoproteinI antibodies and platelet activation state in patients with ulcerative colitis

    Science.gov (United States)

    Gao, Yan-Hang; Gao, Pu-Jun; Wang, Chun-Guang; Wang, Xiao-Cong; Piao, Yun-Feng

    2008-01-01

    AIM: To study the relationship between anti-β2-glycoprotein I (aβ2GPI) antibodies and platelet activation state in patients with ulcerative colitis (UC) and its significance. METHODS: Peripheral blood samples were collected from 56 UC patients (34 males and 22 females, aged 43.5 years, range 21-66 years), including 36 at active stage and 20 at remission stage, and 25 sex-and age-matched controls. The level of aβ2GPI was measured by ELISA. The platelet activation markers, platelet activation complex-I (PAC-I) and P-selectin (CD62P) were detected by flow cytometry. RESULTS: The A value for IgG aβ2GPI in the active UC group was 0.61 ± 0.13, significantly higher than that in the remittent UC and control groups (0.50 ± 0.13 and 0.22 ± 0.14, P 0.05). The PAC-I positive rate for the active and remittent UC groups was 30.6% ± 7.6% and 19.6% ± 7.8% respectively, significantly higher than that for the control group (6.3% ± 1.7%, P FPAC-I (%) = 5.346, P < 0.01; and FCD62P (%) = 5. 418, P < 0.01). Meanwhile, in the same state of illness, the A value for IgG aβ2GPI was positively correlated to the positive rates for PAC-I and CD62P. CONCLUSION: aβ2GPI level, platelet activation state and their relationship of them are closely correlated with the pathogenesis and development of UC. PMID:18205270

  8. Modelling plasma response to RMP fields in ASDEX Upgrade with varying edge safety factor and triangularity

    Science.gov (United States)

    Li, L.; Liu, Y. Q.; Kirk, A.; Wang, N.; Liang, Y.; Ryan, D.; Suttrop, W.; Dunne, M.; Fischer, R.; Fuchs, J. C.; Kurzan, B.; Piovesan, P.; Willensdorfer, M.; Zhong, F. C.; the ASDEX Upgrade Team; the EUROfusion MST1 Team

    2016-12-01

    Toroidal computations are performed using the MARS-F code (Liu et al 2000 Phys. Plasmas 7 3681), in order to understand correlations between the plasma response and the observed mitigation of the edge localized modes (ELM) using resonant magnetic perturbation fields in ASDEX Upgrade. In particular, systematic numerical scans of the edge safety factor reveal that the amplitude of the resonant poloidal harmonic of the response radial magnetic field near the plasma edge, as well as the plasma radial displacement near the X-point, can serve as good indicators for predicting the optimal toroidal phasing between the upper and lower rows of coils in ASDEX Upgrade. The optimal coil phasing scales roughly linearly with the edge safety factor {{q}95} , for various choices of the toroidal mode number n  =  1-4 of the coil configuration. The optimal coil phasing is also predicted to vary with the upper triangularity of the plasma shape in ASDEX Upgrade. Furthermore, multiple resonance effects of the plasma response, with continuously varying {{q}95} , are computationally observed and investigated.

  9. Ovulation-inducing factor: a protein component of llama seminal plasma

    Directory of Open Access Journals (Sweden)

    Huanca Wilfredo

    2010-05-01

    Full Text Available Abstract Background Previously, we documented the presence of ovulation-inducing factor (OIF in the seminal plasma of llamas and alpacas. The purpose of the study was to define the biochemical characteristics of the molecule(s in seminal plasma responsible for inducing ovulation. Methods In Experiment 1, llama seminal plasma was centrifuged using filtration devices with nominal molecular mass cut-offs of 30, 10 and 5 kDa. Female llamas (n = 9 per group were treated i.m. with whole seminal plasma (positive control, phosphate-buffered saline (negative control, or the fraction of seminal plasma equal or higher than 30 kDa, 10 to 30 kDa, 5 to 10 kDa, or Results In Experiment 1, all llamas in the equal or higher than 30 kDa and positive control groups ovulated (9/9 in each, but none ovulated in the other groups (P Conclusions We conclude that ovulation-inducing factor (OIF in llama seminal plasma is a protein molecule that is resistant to heat and enzymatic digestion with proteinase K, and has a molecular mass of approximately equal or higher than 30 kDa.

  10. Establishment of Epithelial Attachment on Titanium Surface Coated with Platelet Activating Peptide

    Science.gov (United States)

    Sugawara, Shiho; Maeno, Masahiko; Lee, Cliff; Nagai, Shigemi; Kim, David M.; Da Silva, John; Kondo, Hisatomo

    2016-01-01

    The aim of this study was to produce epithelial attachment on a typical implant abutment surface of smooth titanium. A challenging complication that hinders the success of dental implants is peri-implantitis. A common cause of peri-implantitis may results from the lack of epithelial sealing at the peri-implant collar. Histologically, epithelial sealing is recognized as the attachment of the basement membrane (BM). BM-attachment is promoted by activated platelet aggregates at surgical wound sites. On the other hand, platelets did not aggregate on smooth titanium, the surface typical of the implant abutment. We then hypothesized that epithelial BM-attachment was produced when titanium surface was modified to allow platelet aggregation. Titanium surfaces were coated with a protease activated receptor 4-activating peptide (PAR4-AP). PAR4-AP coating yielded rapid aggregation of platelets on the titanium surface. Platelet aggregates released robust amount of epithelial chemoattractants (IGF-I, TGF-β) and growth factors (EGF, VEGF) on the titanium surface. Human gingival epithelial cells, when they were co-cultured on the platelet aggregates, successfully attached to the PAR4-AP coated titanium surface with spread laminin5 positive BM and consecutive staining of the epithelial tight junction component ZO1, indicating the formation of complete epithelial sheet. These in-vitro results indicate the establishment of epithelial BM-attachment to the titanium surface. PMID:27741287

  11. Anemia as a factor that elevates plasma brain natriuretic peptide concentration in apparently healthy subjects.

    Science.gov (United States)

    Matsumoto, Mika; Tsujino, Takeshi; Naito, Yoshiro; Lee-Kawabata, Masaaki; Ezumi, Akira; Yamamoto, Kazuhiro; Mano, Toshiaki; Masuyama, Tohru

    2008-09-01

    Plasma brain natriuretic peptide (BNP) is widely used as a biomarker of heart failure (HF); however, its concentration is often found to be high even in apparently healthy subjects and little is known about which factors contribute to physiological change in plasma BNP concentration in subjects without HF. We examined the effects of gender, age, and anemia on plasma BNP concentration in apparently healthy subjects. The study population consisted of 1036 healthy subjects who underwent an annual health examination at their company in 2005. There were 874 women, ranging in age from 30 to 63 years (mean, 41 years). Plasma BNP concentration was abnormal (> 18.4 pg/mL) in 292 subjects. The incidence was significantly higher in women than in men (31% versus 14%, P < 0.01). Mean plasma BNP concentration was higher in women than in men. The difference in plasma BNP concentration was associated with the difference in blood hemoglobin and age. Logarithmically transformed BNP concentration correlated inversely with blood hemoglobin (r = -0.30, P < 0.01 for all; r = -0.21, P < 0.01 for women; r = -0.20, P < 0.01 for men). By multiple regression analysis, logarithmically transformed BNP concentration correlated with hemoglobin, age, and gender. In conclusion, anemia is likely a critical determinant that elevates plasma BNP concentration in apparently healthy subjects.

  12. Whole blood flow cytometry measurements of in vivo platelet activation in critically-Ill patients are influenced by variability in blood sampling techniques.

    Science.gov (United States)

    Rondina, Matthew T; Grissom, Colin K; Men, Shaohua; Harris, Estelle S; Schwertz, Hansjorg; Zimmerman, Guy A; Weyrich, Andrew S

    2012-06-01

    Flow cytometry is often used to measure in vivo platelet activation in critically-ill patients. Variability in blood sampling techniques, which may confound these measurements, remains poorly characterized. Platelet activation was measured by flow cytometry performed on arterial and venous blood from 116 critically-ill patients. We determined how variability in vascular sampling site, processing times, and platelet counts influenced levels of platelet-monocyte aggregates (PMA), PAC-1 binding (for glycoprotein (GP) IIbIIIa), and P-selectin (P-SEL) expression. Levels of PMA, but not PAC-1 binding or P-SEL expression, were significantly affected by variability in vascular sampling site. Average PMA levels were approximately 60% higher in whole blood drawn from an arterial vessel compared to venous blood (16.2±1.8% vs. 10.7±1.2%, psampling site, processing times, and platelet counts influence levels of PMA, but not PAC-1 binding or P-SEL expression. These data demonstrate the need for rigorous adherence to blood sampling protocols, particularly when levels of PMA, which are most sensitive to variations in blood collection, are measured for detection of in vivo platelet activation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Relationship between Platelet Activation and Coronary Heart Disease%血小板活化功能与冠心病的关系

    Institute of Scientific and Technical Information of China (English)

    张冰

    2012-01-01

    血小板活化在冠心病的发生、发展过程中发挥着重要作用.活化的血小板通过其表达和释放的内容物而发挥其黏附、变形、聚集和释放等病理生理作用.通过研究血小板活化功能和冠心病的关系,检测血小板活化功能,有利于心血管事件的预报和预防,同时也可以为临床合理应用抗血小板药物提供依据,从而减少急性心血管事件的发生.%Platelet activation plays an important role in the occurrence and development of coronary heart disease. Activated platelets through its contents to play its adhesion, deformation, aggregation and release and other pathophysiological role. By studying the relationship between platelet activation and coronary heart disease, detection of platelet activation,will be conducive to predict and prevent cardiovascular events,but also for the clinical application of antiplatelet drugs to provide a reasonable basis, thereby reducing the occurrence of a-cute cardiovascular events.

  14. In vivo and protease-activated receptor-1-mediated platelet activation but not response to antiplatelet therapy predict two-year outcomes after peripheral angioplasty with stent implantation.

    Science.gov (United States)

    Gremmel, T; Steiner, S; Seidinger, D; Koppensteiner, R; Panzer, S; Kopp, C W

    2014-03-01

    Data linking the response to antiplatelet therapy with clinical outcomes after angioplasty and stenting for lower extremity artery disease (LEAD) are scarce. Moreover, associations of in vivo and thrombin-inducible platelet activation with the occurrence of adverse events have not been investigated in these patients, so far. We therefore assessed clinical outcomes and on-treatment platelet reactivity by four test systems in 108 patients receiving dual antiplatelet therapy after infrainguinal angioplasty and stenting for LEAD. Further, in vivo and thrombin receptor-activating peptide (TRAP)-6-inducible glycoprotein (GP) IIb/IIIa activation and P-selectin expression were measured as sensitive parameters of platelet activation. The primary endpoint was defined as the composite of atherothrombotic events and target vessel restenosis or reocclusion. Residual platelet reactivity to adenosine diphosphate and arachidonic acid was similar between patients without and with adverse outcomes within two-year follow-up (all p>0.05). Further, the occurrence of clinical endpoints did not differ significantly between patients without and with high on-treatment residual platelet reactivity by all test systems (all p>0.05). In contrast, in vivo and TRAP-6-inducible platelet activation were significantly more pronounced in patients with subsequent adverse events (all pangioplasty and stenting for LEAD.

  15. GPVI and GPIbα mediate staphylococcal superantigen-like protein 5 (SSL5 induced platelet activation and direct toward glycans as potential inhibitors.

    Directory of Open Access Journals (Sweden)

    Houyuan Hu

    Full Text Available BACKGROUND: Staphylococcus aureus (S. aureus is a common pathogen capable of causing life-threatening infections. Staphylococcal superantigen-like protein 5 (SSL5 has recently been shown to bind to platelet glycoproteins and induce platelet activation. This study investigates further the interaction between SSL5 and platelet glycoproteins. Moreover, using a glycan discovery approach, we aim to identify potential glycans to therapeutically target this interaction and prevent SSL5-induced effects. METHODOLOGY/PRINCIPAL FINDINGS: In addition to platelet activation experiments, flow cytometry, immunoprecipitation, surface plasmon resonance and a glycan binding array, were used to identify specific SSL5 binding regions and mediators. We independently confirm SSL5 to interact with platelets via GPIbα and identify the sulphated-tyrosine residues as an important region for SSL5 binding. We also identify the novel direct interaction between SSL5 and the platelet collagen receptor GPVI. Together, these receptors offer one mechanistic explanation for the unique functional influences SSL5 exerts on platelets. A role for specific families of platelet glycans in mediating SSL5-platelet interactions was also discovered and used to identify and demonstrate effectiveness of potential glycan based inhibitors in vitro. CONCLUSIONS/SIGNIFICANCE: These findings further elucidate the functional interactions between SSL5 and platelets, including the novel finding of a role for the GPVI receptor. We demonstrate efficacy of possible glycan-based approaches to inhibit the SSL5-induced platelet activation. Our data warrant further work to prove SSL5-platelet effects in vivo.

  16. The Relationship between Plasma Tumor Necrosis Factor and Pneumonia of Tibetan Neonates

    Institute of Scientific and Technical Information of China (English)

    ZHOU Cuojie; DEJI Meiduo; ZHAO Min

    2002-01-01

    This study was to discuss the changing characteristics of plasma tumor necrosis factor (TNF) in Tibetan neonates with pneumonia. Radioimmunoassay was applied to determine the plasma level of TNF in 48 tibetan neonates with pneumonia and 20 healthy term newborns. The results showed that the plasma level of TNF in severe group with pneumonia( 16.075 ± 13. 1603ug/mt) was higher than that in mild group(14.705 ± 13.0162), P < 0.001. The TNF level of these two groups were significantly higher than that of healthy control group(7. 8650 ± 2. 5173ug/mt), P < 0. 001. So, the plasma level of TNF was closely related with the severity of pneumonia. Severer pneumonia was, higher TNF level was.It suggested that TNF was involved in the regulating process in pneumonia.

  17. Ionization-potential depression and dynamical structure factor in dense plasmas

    Science.gov (United States)

    Lin, Chengliang; Röpke, Gerd; Kraeft, Wolf-Dietrich; Reinholz, Heidi

    2017-07-01

    The properties of a bound electron system immersed in a plasma environment are strongly modified by the surrounding plasma. The modification of an essential quantity, the ionization energy, is described by the electronic and ionic self-energies, including dynamical screening within the framework of the quantum statistical theory. Introducing the ionic dynamical structure factor as the indicator for the ionic microfield, we demonstrate that ionic correlations and fluctuations play a critical role in determining the ionization potential depression. This is, in particular, true for mixtures of different ions with large mass and charge asymmetry. The ionization potential depression is calculated for dense aluminum plasmas as well as for a CH plasma and compared to the experimental data and more phenomenological approaches used so far.

  18. Dimensionless factors for an alternating-current non-thermal arc plasma

    Science.gov (United States)

    Zhang, Si-Yuan; Li, Xiao-Song; Liu, Jin-Bao; Liu, Jing-Lin; Li, He-Ping; Zhu, Ai-Min

    2016-12-01

    A gliding arc discharge, as a source of warm plasma combining advantages of both thermal and cold plasmas, would have promising application prospects in the fields of fuel conversion, combustion enhancement, material synthesis, surface modifications, pollution control, etc. In order to gain insight into the features of an alternating-current gliding arc discharge plasma, three dimensionless factors, i.e., the extinction span (ψ), current lag (δ), and heating lag (χ) factors are proposed in this letter based on the measured waveforms of the discharge voltage and current in an AC gliding arc discharge plasma. The influences of the driving frequency of the power supply (f) on these three dimensionless parameters are investigated experimentally with the explanations on the physical meanings of these factors. The experimental results show that a higher value of f would lead to the lower values of ψ and δ, as well as a higher value of χ. These experimental phenomena indicate a lower threshold ignition voltage of the discharges, a lower current-growth inertia of the gliding arcs and a larger relative thermal inertia of the plasmas with increase the driving frequency of the power supply in the operating parameter range studied in this letter.

  19. Negative interference by rheumatoid factor of plasma B-type natriuretic peptide in chemiluminescent microparticle immunoassays.

    Directory of Open Access Journals (Sweden)

    Wen Fan

    Full Text Available BACKGROUND: The chemiluminescent microparticle immunoassay (CMIA is widely used for the quantitative determination of B-type natriuretic peptide (BNP in human ethylenediaminetetraacetic acid plasma. Rheumatoid factor (RF is usually thought to result in a positive interference in immunoassays, but it is not clear whether its presence in plasma can lead to interferences in the CMIA of BNP. METHODS: The estimation of BNP recovery was carried out by diluting high-concentration BNP samples with RF-positive or RF-negative plasma at a ratio of 1:9. The diluted samples were then tested using the ARCHITECT i2000 System and ARCHITECT BNP Reagent Kits and the recovery was then calculated. RESULTS: When the RF level ranged from 48 to 1420 IU/mL, the average recovery of BNP was 79.29% and 91.61% in the RF-positive and RF-negative plasma samples, respectively, and was thus significantly lower in the group of RF-positive plasma samples than in the group of RF-negative plasma samples. At a dilution of 1:16, the measured BNP level increased by >36% in six of the seven RF-positive plasma samples. The recovery of BNP increased significantly in the RF-positive plasma samples after pretreatment with IgG-sensitive latex particles. In addition, The BNP recovery was not significantly related to the plasma RF at concentrations ranging from 48 to 2720 IU/mL. CONCLUSIONS: Measurement of BNP by CMIA is susceptible to interference from RF leading to predominantly (but not exclusively lower results. Pretreatment of samples with blocking reagents is advisable prior to the initiation of denying patient's necessary treatment.

  20. Negative interference by rheumatoid factor of plasma B-type natriuretic peptide in chemiluminescent microparticle immunoassays.

    Science.gov (United States)

    Fan, Wen; Xu, Lei; Xie, Liangcai; Yang, Decai; Liu, Xuezheng; Zhang, Jiajun; Li, Yirong; Yi, Cunjian

    2014-01-01

    The chemiluminescent microparticle immunoassay (CMIA) is widely used for the quantitative determination of B-type natriuretic peptide (BNP) in human ethylenediaminetetraacetic acid plasma. Rheumatoid factor (RF) is usually thought to result in a positive interference in immunoassays, but it is not clear whether its presence in plasma can lead to interferences in the CMIA of BNP. The estimation of BNP recovery was carried out by diluting high-concentration BNP samples with RF-positive or RF-negative plasma at a ratio of 1:9. The diluted samples were then tested using the ARCHITECT i2000 System and ARCHITECT BNP Reagent Kits and the recovery was then calculated. When the RF level ranged from 48 to 1420 IU/mL, the average recovery of BNP was 79.29% and 91.61% in the RF-positive and RF-negative plasma samples, respectively, and was thus significantly lower in the group of RF-positive plasma samples than in the group of RF-negative plasma samples. At a dilution of 1:16, the measured BNP level increased by >36% in six of the seven RF-positive plasma samples. The recovery of BNP increased significantly in the RF-positive plasma samples after pretreatment with IgG-sensitive latex particles. In addition, The BNP recovery was not significantly related to the plasma RF at concentrations ranging from 48 to 2720 IU/mL. Measurement of BNP by CMIA is susceptible to interference from RF leading to predominantly (but not exclusively) lower results. Pretreatment of samples with blocking reagents is advisable prior to the initiation of denying patient's necessary treatment.

  1. Role of focal adhesion tyrosine kinases in GPVI-dependent platelet activation and reactive oxygen species formation.

    Directory of Open Access Journals (Sweden)

    Naadiya Carrim

    Full Text Available We have previously shown the presence of a TRAF4/p47phox/Hic5/Pyk2 complex associated with the platelet collagen receptor, GPVI, consistent with a potential role of this complex in GPVI-dependent ROS formation. In other cell systems, NOX-dependent ROS formation is facilitated by Pyk2, which along with its closely related homologue FAK are known to be activated and phosphorylated downstream of ligand binding to GPVI.To evaluate the relative roles of Pyk2 and FAK in GPVI-dependent ROS formation and to determine their location within the GPVI signaling pathway.Human and mouse washed platelets (from WT or Pyk2 KO mice were pre-treated with pharmacological inhibitors targeting FAK or Pyk2 (PF-228 and Tyrphostin A9, respectively and stimulated with the GPVI-specific agonist, CRP. FAK, but not Pyk2, was found to be essential for GPVI-dependent ROS production and aggregation. Subsequent human platelet studies with PF-228 confirmed FAK is essential for GPVI-mediated phosphatidylserine exposure, α-granule secretion (P-selectin (CD62P surface expression and integrin αIIbβ3 activation. To determine the precise location of FAK within the GPVI pathway, we analyzed the effect of PF-228 inhibition in CRP-stimulated platelets in conjunction with immunoprecipitation and pulldown analysis to show that FAK is downstream of Lyn, Spleen tyrosine kinase (Syk, PI3-K and Bruton's tyrosine kinase (Btk and upstream of Rac1, PLCγ2, Ca2+ release, PKC, Hic-5, NOX1 and αIIbβ3 activation.Overall, these data suggest a novel role for FAK in GPVI-dependent ROS formation and platelet activation and elucidate a proximal signaling role for FAK within the GPVI pathway.

  2. Critical temperature ranges of hypothermia-induced platelet activation: possible implications for cooling patients in cardiac surgery.

    Science.gov (United States)

    Straub, Andreas; Breuer, Melanie; Wendel, Hans P; Peter, Karlheinz; Dietz, Klaus; Ziemer, Gerhard

    2007-04-01

    Cooling of the patient is routinely applied in cardiac surgery to protect organs against ischemia. Hypothermia induces activation of platelets, but the effects of temperatures such as used during cardiac surgery are not well described. To investigate this in an in-vitro study heparinized whole blood was incubated at different temperatures (37 degrees C, 34.5 degrees C, 32 degrees C, 29.5 degrees C, 27 degrees C, 24.5 degrees C, 22 degrees C, 19.5 degrees C and 17 degrees C). The effect of these temperatures on aggregation, P-selectin expression, GP IIb/IIIa activation and platelet microparticle (PMP) formation of unstimulated and ADP-stimulated platelets of 36 subjects was evaluated in flow cytometry. A four-parametric logistic model was fitted to depict the temperature effect on platelet parameters. Lower temperatures increased aggregates, P-selectin expression, and GP IIb/IIIa activation. The number of PMPs decreases with hypothermia. Additional experiments revealed a slight influence of heparin on platelet P-selectin expression but excluded an effect of this anticoagulant on the other evaluated parameters. Threshold temperatures, which mark 5% changes of platelet parameters compared to values at 37 degrees C, were calculated. On ADP-stimulated platelets the thresholds for P-selectin expression and GP IIb/IIa activation are 34.0 degrees C and 36.4 degrees C, respectively, and lie in the temperature range routinely applied in cardiac surgery. Hypothermia-induced platelet activation may develop in most patients undergoing cardiac surgery, possibly resulting in thromboembolic events, coagulation defects, and proinflammatory leukocyte bridging by P-selectin bearing platelets and PMPs. These findings suggest that pharmacological protection of platelets against hypothermia-induced damage may be beneficial during cardiac surgery.

  3. Increased platelet activation in early symptomatic versus asymptomatic carotid stenosis and relationship with microembolic status: Results from the Platelets And Carotid Stenosis (PACS) Study.

    LENUS (Irish Health Repository)

    Kinsella, Ja

    2013-04-26

    BACKGROUND: Cerebral microembolic signals (MES) may predict increased stroke risk in carotid stenosis. However, the relationship between platelet counts or platelet activation status and MES in symptomatic versus asymptomatic carotid stenosis has not been comprehensively assessed. SETTING: University teaching hospitals. METHODS: This prospective, pilot observational study assessed platelet counts and platelet activation status, and the relationship between platelet activation and MES in asymptomatic versus early (≤4 weeks after TIA\\/stroke) and late phase (≥3 months) symptomatic moderate or severe (≥50%) carotid stenosis patients. Full blood count measurements were performed, and whole blood flow cytometry was used to quantify platelet surface activation marker expression (CD62P and CD63) and circulating leucocyte-platelet complexes. Bilateral simultaneous transcranial Doppler ultrasound monitoring of the middle cerebral arteries was performed for 1 hour to classify patients as MES-positive or MES-negative. RESULTS: Data from 31 asymptomatic patients were compared with 46 symptomatic patients in the early phase, and 35 of these patients followed up to the late phase after symptom onset. The median platelet count (211 vs. 200 x 10(9) \\/L; p=0.03) and the median% lymphocyte-platelet complexes were higher in early symptomatic than asymptomatic patients (2.8 vs. 2.4%, p=0.001). The% lymphocyte-platelet complexes was higher in early symptomatic than asymptomatic patients with ≥70% carotid stenosis (p=0.0005), and in symptomatic patients recruited within 7 days of symptom onset (p=0.028). Complete TCD data were available in 25 asymptomatic and 31 early phase symptomatic, and 27 late phase symptomatic patients. 12% of asymptomatic versus 32% of early phase symptomatic (p=0.02) and 19% of late phase symptomatic patients (p=0.2) were MES-positive. Early symptomatic MES-negative patients had a higher% lymphocyte-platelet complexes than asymptomatic MES

  4. 川芎嗪对血小板活化钙信号的影响及作用机制%Tetramethylpyrazine Effects Calcium Signalingunder Platelet Activation

    Institute of Scientific and Technical Information of China (English)

    吴鸿; 阎赟梦; 高水波; 王振涛; 索红亮

    2012-01-01

    分析国内外在研究川芎嗪与血小板活化时游离钙离子浓度关系方面的文献报道,为进一步研究川芎嗪的药理作用提供参考.通过检索中国知网、万方及PubMed等数据库,查阅整理上述研究领域的相关文献25篇.目前研究显示,血小板活化时血小板胞质内钙离子浓度升高,其升高取决于细胞外血小板膜外基质中的钙内流和血小板细胞内钙池的钙释放.川芎嗪主要通过抑制血小板内钙离子浓度升高,发挥抑制血小板活化的药理作用.川芎嗪抑制血小板活化的具体作用途径机制仍不明了,目前的研究大多支持川芎嗪通过抑制胞内游离钙离子浓度升高进而抑制血小板活化这一结论,但这些研究多为描述性的,缺少动态观察川芎嗪对钙离子作用的相关研究.%To analyze the reports on the relationships between tetramethylpyrazine ( TMPZ) and the intracellular free calcium concentration under platelet activation, and to provide hint for further study of the pharmacological actions of TMPZ. By retrieving the following databases such CNKI, Wanfang, PubMed, and so on, to read relative publications. The current studies show that the intracellular calcium concentration in platelets increases due to platelet activation, which depends on the entry of calcium in the extracellular matrix and the release of calcium in endoplasmic reticulum. TMPZ plays its inhibitory role on platelet activation mainly through the suppression on the increase of the intracellular calcium concentration. It still remains unknown about the mechanism underlying the inhibition on platelet activation by TMPZ, and most of the studies suggest that TMPZ inhibits the intracellular free calcium concentration, leading to the suppression of platelet activation. However, those studies are much descriptive, instead of time-lapse observation on it.

  5. Impairment of endothelial and subendothelial sites by a circulating plasma factor associated with minimal change disease

    NARCIS (Netherlands)

    Cheung, PK; Baller, JFW; Bakker, WW

    1996-01-01

    Background. The pathogenesis of albuminuria in minimal change disease (MCD) is unknown. A human plasma factor (denoted as 100KF) is able to induce minimal change-like glomerular alterations, i.e. loss of glomerular sialoglycoproteins and decreased expression of glomerular ecto-ATPase, following in v

  6. Effect of GFR on plasma N-terminal connective tissue growth factor (CTGF) concentrations.

    NARCIS (Netherlands)

    Gerritsen, K.G.; Abrahams, A.C.; Peters, H.P.E.; Nguyen, T.Q.; Koeners, M.P.; Hoedt, C.H. den; Dendooven, A.; Dorpel, M.A. van den; Blankestijn, P.J.; Wetzels, J.F.M.; Joles, J.A.; Goldschmeding, R.; Kok, R.J.

    2012-01-01

    BACKGROUND: Connective tissue growth factor (CTGF) has a key role in the pathogenesis of renal and cardiac fibrosis. Its amino-terminal fragment (N-CTGF), the predominant form of CTGF detected in plasma, has a molecular weight in the middle molecular range (18 kDa). However, it is unknown whether N-

  7. FACTOR-XII FRAGMENT AND KALLIKREIN GENERATION IN PLASMA DURING INCUBATION WITH BIOMATERIALS

    NARCIS (Netherlands)

    VANDERKAMP, KWHJ; VANOEVEREN, W

    Blood biocompatibility of medical devices is in many ways dependent on surface characteristics and biochemical blood material interactions. In this study, the contact system, in which the activation of factor XII and plasma kallikrein is included, is highlighted. This article describes a simple

  8. Impairment of endothelial and subendothelial sites by a circulating plasma factor associated with minimal change disease

    NARCIS (Netherlands)

    Cheung, PK; Baller, JFW; Bakker, WW

    1996-01-01

    Background. The pathogenesis of albuminuria in minimal change disease (MCD) is unknown. A human plasma factor (denoted as 100KF) is able to induce minimal change-like glomerular alterations, i.e. loss of glomerular sialoglycoproteins and decreased expression of glomerular ecto-ATPase, following in

  9. Impairment of endothelial and subendothelial sites by a circulating plasma factor associated with minimal change disease

    NARCIS (Netherlands)

    Cheung, PK; Baller, JFW; Bakker, WW

    1996-01-01

    Background. The pathogenesis of albuminuria in minimal change disease (MCD) is unknown. A human plasma factor (denoted as 100KF) is able to induce minimal change-like glomerular alterations, i.e. loss of glomerular sialoglycoproteins and decreased expression of glomerular ecto-ATPase, following in v

  10. Binding of von Willebrand factor and plasma proteins to the eggshell of Schistosoma mansoni

    NARCIS (Netherlands)

    Dewalick, Saskia; Hensbergen, Paul J; Bexkens, Michiel L; Grosserichter-Wagener, Christina; Hokke, Cornelis H; Deelder, André M; de Groot, Philip G; Tielens, Aloysius G M; van Hellemond, Jaap J

    2014-01-01

    Schistosoma mansoni eggs have to cross the endothelium and intestinal wall to leave the host and continue the life cycle. Mechanisms involved in this essential step are largely unknown. Here we describe direct binding to the S. mansoni eggshell of von Willebrand factor and other plasma proteins invo

  11. Binding of von Willebrand factor and plasma proteins to the eggshell of Schistosoma mansoni

    NARCIS (Netherlands)

    Dewalick, Saskia; Hensbergen, Paul J; Bexkens, Michiel L; Grosserichter-Wagener, Christina; Hokke, Cornelis H; Deelder, André M; de Groot, Philip G; Tielens, Aloysius G M; van Hellemond, Jaap J

    Schistosoma mansoni eggs have to cross the endothelium and intestinal wall to leave the host and continue the life cycle. Mechanisms involved in this essential step are largely unknown. Here we describe direct binding to the S. mansoni eggshell of von Willebrand factor and other plasma proteins

  12. Expression of B-nerve growth factor in rabbit male tract and seminal plasma

    OpenAIRE

    García García, R. M.; Masdeu, M.; A. Sánchez Rodríguez; Bautista, J. M.; Arias Álvarez, María; LORENZO, P. L.; Garcia Rebollar, Pilar

    2015-01-01

    Nerve growth factor (NGF) has been recently identified as an ovulation inductor factor (OIF) in the seminal plasma (SP) (Ratto et al. PNAS 2012; 109:15042-7). The presence of OIF in rabbit has been suggested but this protein has not yet been identified. Our aim was to study the mRNA expression in the rabbit male reproductive tract and to identify the protein β-NGF in the SP.

  13. DOES SINGLE INTRAMUSCULAR APPLICATION OF AUTOLOGOUS CONDITIONED PLASMA INFLUENCE SYSTEMIC CIRCULATING GROWTH FACTORS?

    Directory of Open Access Journals (Sweden)

    Gert Schippinger

    2012-09-01

    Full Text Available Platelet-rich plasma (PRP has been employed to treat sports injuries to possibly accelerate healing and regeneration. This method offers some potential, especially for athletes. Growth factors are generally prohibited by the World Anti Doping Agency with exception to PRP which may induce adverse effects. The aim of this study was to evaluate any systemic increase of growth factors such as Insulin Like Growth Factor-1, Endothelial Growth Factors, Platelet-Derived Growth Factors, Fibroblast Growth Factors, Vascular-Endothelial Growth Factor and Transforming Growth Factors after local intramuscular administration of PRP in young, healthy male subjects keeping in mind adverse treatment effects. Enriched plasma from centrifuged blood samples was injected into the gluteus muscle. Venous blood was collected and serum prepared before as well as 0.5, 3 and 24 hours after PRP administration. Growth factors were analyzed using ELISA test kits. No significant systemic increase of growth factor levels was found after PRP injection except TGF-ß2. For that reason the PRP method may be applied for muscle injury treatment in elite athletes although further studies are necessary to clarify the response to the unspecific increased TGF-ß2 blood levels, which could increase the risk for local fibrosis

  14. Effects of molecular size and chemical factor on plasma gene transfection

    Science.gov (United States)

    Ikeda, Yoshihisa; Motomura, Hideki; Kido, Yugo; Satoh, Susumu; Jinno, Masafumi

    2016-07-01

    In order to clarify the mechanism of plasma gene transfection, the relationship between transfection efficiency and transferred molecular size was investigated. Molecules with low molecular mass (less than 50 kDa; dye or dye-labeled oligonucleotide) and high molecular mass (more than 1 MDa; plasmid DNA or fragment of plasmid DNA) were transferred to L-929 cells. It was found that the transfection efficiency decreases with increasing in transferred molecular size and also depends on the tertiary structure of transferred molecules. Moreover, it was suggested the transfection mechanism is different between the molecules with low (less than 50 kDa) and high molecular mass (higher than 1 MDa). For the amount of gene transfection after plasma irradiation, which is comparable to that during plasma irradiation, it is shown that H2O2 molecules are the main contributor. The transfection efficiency decreased to 0.40 ± 0.22 upon scavenging the H2O2 generated by plasma irradiation using the catalase. On the other hand, when the H2O2 solution is dropped into the cell suspension without plasma irradiation, the transfection efficiency is almost 0%. In these results, it is also suggested that there is a synergetic effect of H2O2 with electrical factors or other reactive species generated by plasma irradiation.

  15. Effects of antinutritional factors on plasma lipoprotein levels in Japanese flounder Paralichthys olivaceus.

    Science.gov (United States)

    Deng, J M; Mai, K S; Ai, Q H; Zhang, W B; Wang, X J; Xu, W; Liufu, Z G; Cai, Y H; Chen, W

    2012-02-01

    This study examined the effects of four types of antinutritional factor (phytic acid, stachyose, soy saponins and soy isoflavones) on lipoprotein levels in plasma of Japanese flounder Paralichthys olivaceus. A basal diet was prepared with fish meal as primary protein source, the other diets were supplemented with 0·2, 0·4 or 0·8% phytic acid, 0·4, 0·8 or 1·5% stachyose, 0·1, 0·35 or 0·7% soy saponins and 0·10, 0·35 or 0·70% soy isoflavones, by dry mass, in place of white flour in the basal diet. Total cholesterol (TC) and triglyceride (TG) levels in plasma of P. olivaceus were not affected by phytic acid or stachyose. In general, addition of 0·2-0·8% phytic acid or 0·4-1·5% stachyose decreased plasma high-density lipoprotein cholesterol (HDL-C) levels, increased plasma low-density lipoprotein cholesterol (LDL-C) levels, thereby increasing the LDL-C:HDL-C ratio. By contrast, supplementation with 0·35-0·7% soy saponins generally depressed plasma TC levels and the LDL-C:HDL-C ratio. Supplementation with 0·35-0·7% soy isoflavones, however, increased plasma TC and TG levels. These results indicate that soy saponins may be partly responsible for the cholesterol-lowering effects of soybean meal.

  16. A key inactivation factor of HeLa cell viability by a plasma flow

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Takehiko; Yokoyama, Mayo [Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Johkura, Kohei, E-mail: sato@ifs.tohoku.ac.jp [Department of Histology and Embryology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621 (Japan)

    2011-09-21

    Recently, a plasma flow has been applied to medical treatment using effects of various kinds of stimuli such as chemical species, charged particles, heat, light, shock wave and electric fields. Among them, the chemical species are known to cause an inactivation of cell viability. However, the mechanisms and key factors of this event are not yet clear. In this study, we focused on the effect of H{sub 2}O{sub 2} in plasma-treated culture medium because it is generated in the culture medium and it is also chemically stable compared with free radicals generated by the plasma flow. To elucidate the significance of H{sub 2}O{sub 2}, we assessed the differences in the effects of plasma-treated medium and H{sub 2}O{sub 2}-added medium against inactivation of HeLa cell viability. These two media showed comparable effects on HeLa cells in terms of the survival ratios, morphological features of damage processes, permeations of H{sub 2}O{sub 2} into the cells, response to H{sub 2}O{sub 2} decomposition by catalase and comprehensive gene expression. The results supported that among chemical species generated in a plasma-treated culture medium, H{sub 2}O{sub 2} is one of the main factors responsible for inactivation of HeLa cell viability. (fast track communication)

  17. Clastogenic factors in the plasma of Chernobyl accident recovery workers: Anticlastogenic effect of Ginkgo biloba extract

    Energy Technology Data Exchange (ETDEWEB)

    Emerit, I.; Levy, A.; Cernjavski, L. [Universite Paris (France)] [and others

    1995-11-01

    Clastogenic factors are found in the plasma of persons irradiated accidentally or therapeutically. They persisted in the plasma of A-bomb survivors over 30 years. Clastogenic factors were found in 33 or 47 Chernobyl accident recovery workers (often referred to as liquidators) in a previous study. In the present study, we show that there is a positive correlation between clastogenic activity and dose and that these biomarkers of oxidative stress can be influenced successfully by appropriate antioxidant treatment. With the authorization of the Armenian Ministry of Health, 30 workers were treated with antioxidants from Ginkgo biloba leaves. The extract EGb 761 containing flavonoids and terpenoids was given at a daily dose of 3 x 40 mg (Tanakan, IPSEN, France) during 2 months. The clastogenic activity of the plasma was reduced to control levels on the first day after the end of the treatment. A 1-year follow-up showed that the benefit of the treatment persisted for at least 7 months. One-third of the workers again had clastogenic factors after 1 year, demonstrating that the process which produced clastogenic factors continued. However, the observation that antioxidants do not have to be given continuously is encouraging for intervention trials on a large-scale basis. These appear justified, since clastogenic factors are thought to be risk factors for the development of late effects of irradiation. 43 refs., 6 tabs.

  18. The effect of different methods of leucoreduction on plasma coagulation factors.

    Science.gov (United States)

    Aboul Enein, Azza A; Abdel Rahman, Hala A; Abdel Maged, Mohamed M M; El Sissy, Maha H

    2017-03-01

    Removal of leucocytes from blood products, namely leucoreduction, improves the safety of blood transfusion by reducing adverse events associated with the incidental transfusion of leucocytes. Coagulation factors might be compromised during leucoreduction because of exposure of plasma to a variety of filter materials. The aim of the current study was to assess the effect of different methods of prestorage leucofiltration (apheresis and whole blood filters) on prothrombin time, international normalized ratio, partial thromboplastin time and factors V and VIII. There was a significant prolongation of prothrombin time as well as elevation of international normalized ratio in plasma after leucoreduction (14.5 ± 0.7 s vs. 13.9 ± 0.7 s, P = 0.008 and 1.14 ± 0.07 vs. 1.09 ± 0.07, P = 0.005, respectively). Also, there was a statistically significant prolongation of activated partial thromboplastin time in nonleucoreduced plasma (55.6 ± 9.9 s vs. 43.2 ± 12.8 s, P = 0.001). There was no significant filtration effect on factors V and VIII levels. Furthermore, there was no significant difference in factors V and VIII levels between plasma filtered by inline whole blood filters and apheresis machine. Leucodepleted plasma originating from both inline whole blood filter and apheresis machine maintained satisfactory levels of factors V and VIII.

  19. Anticoagulants and other preanalytical factors interfere in plasma nitrate/nitrite quantification by the Griess method.

    Science.gov (United States)

    Ricart-Jané, D; Llobera, M; López-Tejero, M D

    2002-03-01

    Nitric oxide (NO) is a signal molecule with functions such as neurotransmission, local vascular relaxation, and anti-inflammation in many physiological and pathological processes. Various factors regulate its intracellular lifetime. Due to its high reactivity in biological systems, it is transformed in the bloodstream into nitrates (NO(-)(3)) by oxyhemoglobin. The Griess reaction is a technically simple method (spectrophotometric, 540 nm) for the analysis of nitrites (NO(-)(2)) in aqueous solutions. We studied the interference of common anticoagulants in the quantification of nitrate and nitrite in plasma samples by the Griess method. We obtained rat plasma using heparin or sodium EDTA as anticoagulants, then added, or otherwise, known NO(-)(3) amounts in order to calculate their recovery. We also studied the effect of ultra-filtration performed before Griess reaction on plasma and aqueous solutions of various anticoagulants (heparin, EDTA, and also sodium citrate) to compare the recoveries of added NO(-)(3) or NO(-)(2). We used standards of NO(-)(3) or NO(-)(2) for quantification. We conclude that: (i) The bacterial nitrate reductase used to reduce NO(-)(3) to NO(-)(2) is unstable in certain storage conditions and interferes with different volumes of plasma used. (ii) The ultrafiltration (which is sometimes performed before the Griess reaction) of plasma obtained with EDTA or citrate is not recommended because it leads to overestimation of NO(minus sign)(3). In contrast, ultrafiltration is necessary when heparin is used. (iii) The absorbance at 540 nm attributed to plasma itself (basal value or background) interferes in final quantification, especially when ultrafiltration is not performed. For the quantification of plasma NO(-)(3) we recommend: sodium EDTA as anticoagulant, no ultrafiltration of plasma, and measurement of the absorbance background of each sample.

  20. Biochemical isolation and purification of ovulation-inducing factor (OIF in seminal plasma of llamas

    Directory of Open Access Journals (Sweden)

    Pierson Roger A

    2011-02-01

    Full Text Available Abstract Background The objective of the present study was to isolate and purify the protein fraction(s of llama seminal plasma responsible for the ovulation-inducing effect of the ejaculate. Methods Semen collected from male llamas by artificial vagina was centrifuged and the seminal plasma was harvested and stored frozen. Seminal plasma was thawed and loaded onto a Type 1 macro-prep ceramic hydroxylapatite column and elution was carried out using a lineal gradient with 350 mM sodium phosphate. Three protein fractions were identified clearly (Fractions A, B, and C, where a prominent protein band with a mass of 14 kDa was identified in Fraction C. Fraction C was loaded into a sephacryl gel filtration column for further purification using fast protein liquid chromatography (FPLC. Isocratic elution resulted in 2 distinct protein fractions (Fractions C1 and C2. An in vivo bioassay (n = 10 to 11 llamas per group was used to determine the ovarian effect of each fraction involving treatment with saline (negative control, whole seminal plasma (positive control, or seminal plasma Fractions A, B or C2. Ultrasonography was done to detect ovulation and CL formation, and blood samples were taken to measure plasma progesterone and LH concentrations. Results Ovulation and CL formation was detected in 0/10, 10/11, 0/10, 2/11, and 10/11 llamas treated with saline, whole seminal plasma, Fractions A, B and C2 respectively (P Conclusion Ovulation-inducing factor was isolated from llama seminal plasma as a 14 kDa protein molecule that elicits a preovulatory LH surge followed by ovulation and CL formation in llamas, suggesting an endocrine effect at the level of the hypothalamus (release of GnRH or the pituitary (gonadotrophs.

  1. Cisplatin triggers platelet activation.

    Science.gov (United States)

    Togna, G I; Togna, A R; Franconi, M; Caprino, L

    2000-09-01

    Clinical observations suggest that anticancer drugs could contribute to the thrombotic complications of malignancy in treated patients. Thrombotic microangiopathy, myocardial infarction, and cerebrovascular thrombotic events have been reported for cisplatin, a drug widely used in the treatment of many solid tumours. The aim of this study is to explore in vitro cisplatin effect on human platelet reactivity in order to define the potentially active role of platelets in the pathogenesis of cisplatin-induced thrombotic complications. Our results demonstrate that cisplatin increases human platelet reactivity (onset of platelet aggregation wave and thromboxane production) to non-aggregating concentrations of the agonists involving arachidonic acid metabolism. Direct or indirect activation of platelet phospholipase A(2) appears to be implicated. This finding contributes to a better understanding of the pathogenesis of thrombotic complications occurring during cisplatin-based chemotherapy.

  2. Platelet activation and aggregation

    DEFF Research Database (Denmark)

    Jensen, Maria Sander; Larsen, O H; Christiansen, Kirsten

    2013-01-01

    This study introduces a new laboratory model of whole blood platelet aggregation stimulated by endogenously generated thrombin, and explores this aspect in haemophilia A in which impaired thrombin generation is a major hallmark. The method was established to measure platelet aggregation initiated...

  3. Development of a microplate coagulation assay for Factor V in human plasma

    Directory of Open Access Journals (Sweden)

    Samis John A

    2011-06-01

    Full Text Available Abstract Background Factor V (FV in its activated form, FVa, is a critical regulator of thrombin generation during fibrin clot formation. There is a need of a simple, fast, and inexpensive microplate-based coagulation assay to measure the functional activity of FV in human plasma. The objective of this study was to develop a microplate-based assay that measures FV coagulation activity during clot formation in human plasma, which is currently not available. Methods The FV assay requires a kinetic microplate reader to measure the change in absorbance at 405nm during fibrin formation in human plasma. The FV assay accurately measures the time, initial rate, and extent of fibrin clot formation in human plasma. Results The FV microplate assay is simple, fast, economical, sensitive to approx 24-80pM, and multiple samples may be analyzed simultaneously. All the required materials are commercially available. Standard curves of time or initial rate of fibrin clot formation vs FV activity in the 1-stage assay (Without activation by thrombin may be used to measure FV activity in samples of human plasma. The assay was used to demonstrate that in nine patients with disseminated intravascular coagulation (DIC, the FV 1-stage, 2-stage (With activation by thrombin, and total (2-stage activity - 1-stage activity activities were decreased, on average, by approximately 54%, 44%, and 42%, respectively, from prolonged clot times when compared to normal pooled human reference plasma (NHP. The results indicate that the FV in the DIC patient plasmas supported both a delayed and slower rate of fibrin clot formation compared with NHP; however, the extent of fibrin clot formation in the DIC patients remained largely unchanged from that observed with NHP. Conclusions The FV microplate assay may be easily adapted to measure the activity of any coagulation factor using the appropriate factor-deficient plasma and clot initiating reagent. The microplate assay will find use in

  4. Refreezing previously thawed fresh-frozen plasma. Stability of coagulation factors V and VIII:C.

    Science.gov (United States)

    Dzik, W H; Riibner, M A; Linehan, S K

    1989-09-01

    With the growth in autologous blood programs and the increased scrutiny of the indications for transfusion of fresh-frozen plasma (FFP), an increase has been seen in the number of occasions on which FFP was requested and thawed but then not transfused. The coagulation properties of FFP units that were refrozen and then rethawed were therefore studied. Fifty-eight units of plasma were studied, with each experimental unit of FFP paired with an identical control unit. Experimental units were frozen, stored at -65 degrees C, thawed, stored at 1 to 6 degrees C for various periods of time up to 24 hours, and then refrozen, stored at -65 degrees C, rethawed, and stored again in the refrigerator for up to 24 hours. Control units were frozen once at the time the experimental units were first frozen and thawed once at the time of the second thaw of the experimental units. Aliquots of plasma were sampled periodically and were later batch-tested for prothrombin time (PT), activated partial thromboplastin time (aPTT), and factor V and VIII:C activity. The results of coagulation testing of the twice-frozen plasmas were always within the normal range. There was a slight but statistically valid prolongation of the PT and aPTT and a decrease in the factor V and VIII:C levels for twice-frozen plasma compared with control plasma. The greatest decline occurred in the level of factor VIII:C. The measured deterioration in coagulation of twice-frozen FFP is unlikely to be of clinical importance. Refreezing FFP may eventually prove useful for rare donor, autologous, and massive transfusion programs.

  5. Plasma brain-derived neurotrophic factor and reverse dipping pattern of nocturnal blood pressure in patients with cardiovascular risk factors.

    Directory of Open Access Journals (Sweden)

    Manabu Kadoya

    Full Text Available Basic studies have shown that brain-derived neurotrophic factor (BDNF has critical roles in the survival, growth, maintenance, and death of central and peripheral neurons, while it is also involved in regulation of the autonomic nervous system. Furthermore, recent clinical studies have suggested potential role of plasma BDNF in the circulatory system.We investigated the mutual relationships among plasma BDNF, patterns of nocturnal blood pressure changes (dippers, non-dippers, extra-dippers, and reverse-dippers, and cardiac autonomic function as determined by heart rate variability (HRV.This was a cross-sectional study of patients registered in the Hyogo Sleep Cardio-Autonomic Atherosclerosis (HSCAA Study from October 2010 to November 2012.Two-hundred fifty patients with 1 or more cardiovascular risk factor(s (obesity, smoking, presence of cardiovascular event history, hypertension, dyslipidemia, diabetes mellitus, chronic kidney disease were enrolled.Plasma BDNF levels (natural logarithm transformed were significantly (p = 0.001 lower in reverse-dipper patients (7.18±0.69 pg/ml, mean ± SD, n = 36 as compared to dippers (7.86±0.86 pg/ml, n = 100. Multiple logistic regression analysis showed that BDNF (odds ratios: 0.417, 95% confidence interval: 0.228-0.762, P = 0.004 was the sole factor significantly and independently associated with the reverse-dippers as compared with dippers. Furthermore, plasma BDNF level was significantly and positively correlated with the time-domain (SDNN, SDANN5, CVRR and frequency-domain (LF of HRV parameters. Finally, multiple logistic regression analyses showed that the relationship between plasma BDNF and the reverse-dippers was weakened, yet remained significant or borderline significant even after adjusting for HRV parameters.Low plasma BDNF was independently associated with patients showing a reverse-dipper pattern of nocturnal blood pressure, in which an imbalance of cardiac autonomic function

  6. Edge safety factor at the onset of plasma disruption during VDEs in JT-60U

    Science.gov (United States)

    Sugihara, Masayoshi; Lukash, Victor; Khayrutdinov, Rustam; Neyatani, Yuzuru

    2004-10-01

    Detailed examinations of the value of the edge safety factor (qa) at the onset of thermal quench (TQ) during intentional vertical displacement event (VDE) experiments in JT-60U are carried out using two different reconstruction methods, FBI/FBEQU and DINA. The results from the two methods are very similar and show that the TQ occurs when the qa value is in the range between 1.5 and 2. This result suggests that the predictive simulations for VDEs should be performed within this range of q to examine the subsequent differences in the halo currents, plasma movement and other plasma behaviour during the current quench.

  7. Characterization of the gene for the a subunit of human factor XIII (plasma transglutaminase), a blood coagulation factor

    Energy Technology Data Exchange (ETDEWEB)

    Ichinose, A.; Davie, E.W. (Univ. of Washington, Seattle (USA))

    1988-08-01

    Factor XIII (plasma transglutaminase, fibrin stabilizing factor) is a glycoprotein that circulates in blood as a tetramer (a{sub 2}b{sub 2}) consisting of two a and two b subunits. The primary structures of the a and b subunits of human factor XIII have been reported by a combination of cDNA cloning and amino acid sequence analysis. To establish the gene structure of the a subunit for factor XIII, several human genomic libraries were screened by using the cDNA encoding the a subunit as a probe. Among {approx}5 {times} 10{sup 7} recombinant phage, 121 have been shown to contain an insert encoding a portion of the a subunit. Twenty-five unique clones were than characterized by restriction mapping, Southern blotting, and DNA sequencing. Overlapping clones encoding the a subunit of factor XIII span >160 kilobases. DNA sequence analysis revealed that the activation peptide released by thrombin, the active site cysteine region, the two putative calcium-binding regions, and the thrombin cleavage site leading to inactivation are encoded by separate exons. This suggest that the introns may separate the a subunit into functional and structural domains. A comparison of the amino acid sequence deduced from the genomic DNA sequence with those deduced from cDNA or determined by amino acid sequence analysis of the plasma and placental proteins revealed apparent amino acid polymorphisms in six positions of the polypeptide chain of the a subunit.

  8. Inverse Bremsstrahlung in Astrophysical Plasmas: The Absorption Coefficients and Gaunt Factors

    Indian Academy of Sciences (India)

    A. A. Mihajlov; V. A. Srećković; N. M. Sakan

    2015-12-01

    The electron–ion inverse Bremsstrahlung is considered here as a factor of the influence on the opacity of the different stellar atmospheres and other astrophysical plasmas. It is shown that this process can be successfully described in the frames of cut-off Coulomb potential model within the regions of the electron densities and temperatures. The relevant quantum mechanical method of the calculation of the corresponding spectral coefficient processes is described and discussed. The results obtained for the plasmas with the electron densities from 1014 cm$^{-3}$ to 2 · 1019 cm$^{−3}$ and temperatures from 5 · 103 K to 3 · 104 K in the wavelength region 100 nm < < 3000 nm are presented. Also, these results can be of interest for different laboratory plasmas.

  9. Decreased plasma brain-derived neurotrophic factor levels in institutionalized elderly with depressive disorder.

    Science.gov (United States)

    Chu, Chin-Liang; Liang, Chih-Kuang; Chou, Ming-Yueh; Lin, Yu-Te; Pan, Chih-Chuan; Lu, Ti; Chen, Liang-Kung; Chow, Philip C

    2012-06-01

    To compare the differences in plasma brain-derived neurotrophic factor (BDNF) levels among institutionalized ethnic Chinese elderly participants with major depression, those with subclinical depression, and a nondepressed control group. A cross-sectional study. The veterans' home in southern Taiwan. One hundred sixty-seven residents. Questionnaires including the Minimum Data Set Nursing Home 2.1, Chinese-language version, and the short-form Geriatric Depression Scale, Chinese-language version. Depressive disorder was diagnosed by a well-trained psychiatrist using DSM-IV-TR (Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revision) criteria. We measured plasma BDNF levels in the following 3 groups: nondepressive subjects (n = 122), subclinically depressive subjects (n = 33), and subjects with major depression (n = 12). Plasma BDNF was assayed using the sandwich ELISA method. We noted a significantly negative association between age and plasma BDNF in the regression model. There was no significant correlation between BDNF plasma levels and body weight or platelet counts. We found that plasma BDNF was significantly lower in the major depressive group (mean, 115.1 pg/mL; SD, 57.2) than in the nondepressive group (mean, 548.8 pg/mL; SD, 370.6; P depressive group (mean, 231.8 pg/mL; SD, 92.4; P depressive disorder but also in those with subclinical depression. This makes the plasma BDNF level a potential biological marker for clinical or subclinical depression. Copyright © 2012 American Medical Directors Association, Inc. Published by Elsevier Inc. All rights reserved.

  10. The AP-1 transcription factor Fra1 inhibits follicular B cell differentiation into plasma cells.

    Science.gov (United States)

    Grötsch, Bettina; Brachs, Sebastian; Lang, Christiane; Luther, Julia; Derer, Anja; Schlötzer-Schrehardt, Ursula; Bozec, Aline; Fillatreau, Simon; Berberich, Ingolf; Hobeika, Elias; Reth, Michael; Wagner, Erwin F; Schett, Georg; Mielenz, Dirk; David, Jean-Pierre

    2014-10-20

    The cornerstone of humoral immunity is the differentiation of B cells into antibody-secreting plasma cells. This process is tightly controlled by a regulatory gene network centered on the transcriptional repressor B lymphocyte-induced maturation protein 1 (Blimp1). Proliferation of activated B cells is required to foster Blimp1 expression but needs to be terminated to avoid overshooting immune reactions. Activator protein 1 (AP-1) transcription factors become quickly up-regulated upon B cell activation. We demonstrate that Fra1, a Fos member of AP-1, enhances activation-induced cell death upon induction in activated B cells. Moreover, mice with B cell-specific deletion of Fra1 show enhanced plasma cell differentiation and exacerbated antibody responses. In contrast, transgenic overexpression of Fra1 blocks plasma cell differentiation and immunoglobulin production, which cannot be rescued by Bcl2. On the molecular level, Fra1 represses Blimp1 expression and interferes with binding of the activating AP-1 member c-Fos to the Blimp1 promoter. Conversely, overexpression of c-Fos in Fra1 transgenic B cells releases Blimp1 repression. As Fra1 lacks transcriptional transactivation domains, we propose that Fra1 inhibits Blimp1 expression and negatively controls plasma cell differentiation through binding to the Blimp1 promoter. In summary, we demonstrate that Fra1 negatively controls plasma cell differentiation by repressing Blimp1 expression.

  11. Fibrinogen γ' increases the sensitivity to activated protein C in normal and factor V Leiden plasma.

    Science.gov (United States)

    Omarova, Farida; Uitte de Willige, Shirley; Simioni, Paolo; Ariëns, Robert A S; Bertina, Rogier M; Rosing, Jan; Castoldi, Elisabetta

    2014-08-28

    Activated protein C (APC) resistance, often associated with the factor V (FV) Leiden mutation, is the most common risk factor for venous thrombosis. We observed increased APC resistance in carriers of fibrinogen γ gene (FGG) haplotype 2, which is associated with reduced levels of the alternatively spliced fibrinogen γ' chain. This finding prompted us to study the effects of fibrinogen and its γ' chain on APC resistance. Fibrinogen, and particularly the γA/γ' isoform, improved the response of plasma to added APC in the thrombin generation-based assay. Similarly, a synthetic peptide mimicking the C-terminus of the fibrinogen γ' chain, which binds thrombin and inhibits its activities, greatly increased the APC sensitivity of normal and FV Leiden plasma, likely due to its ability to inhibit thrombin-mediated activation of FV and FVIII. Although the fibrinogen γ' peptide also inhibited protein C activation by the thrombin/thrombomodulin complex, it still increased the sensitivity of plasma to endogenously formed APC when thrombin generation was measured in the presence of soluble thrombomodulin. We conclude that fibrinogen, and particularly fibrinogen γ', increases plasma APC sensitivity. The fibrinogen γ' peptide might form the basis for pharmacologic interventions to counteract APC resistance. © 2014 by The American Society of Hematology.

  12. A Comparison of Blood Factor XII Autoactivation in Buffer, Protein Cocktail, Serum, and Plasma Solutions

    Science.gov (United States)

    Golas, Avantika; Yeh, Chyi-Huey Josh; Pitakjakpipop, Harit; Siedlecki, Christopher A.; Vogler, Erwin A.

    2012-01-01

    Activation of blood plasma coagulation in vitro by contact with material surfaces is demonstrably dependent on plasma-volume-to-activator-surface-area ratio. The only plausible explanation consistent with current understanding of coagulation-cascade biochemistry is that procoagulant stimulus arising from the activation complex of the intrinsic pathway is dependent on activator surface area. And yet, it is herein shown that activation of the blood zymogen factor XII (Hageman factor, FXII) dissolved in buffer, protein cocktail, heat-denatured serum, and FXI deficient plasma does not exhibit activator surface-area dependence. Instead, a highly-variable burst of procoagulant-enzyme yield is measured that exhibits no measurable kinetics, sensitivity to mixing, or solution-temperature dependence. Thus, FXII activation in both buffer and protein-containing solutions does not exhibit characteristics of a biochemical reaction but rather appears to be a “mechanochemical” reaction induced by FXII molecule interactions with hydrophilic activator particles that do not formally adsorb blood proteins from solution. Results of this study strongly suggest that activator surface-area dependence observed in contact activation of plasma coagulation does not solely arise at the FXII activation step of the intrinsic pathway. PMID:23117212

  13. Plasma factor VII-activating protease is increased by oral contraceptives and induces factor VII activation in-vivo

    DEFF Research Database (Denmark)

    Sidelmann, Johannes J; Skouby, Sven O; Kluft, Cornelis

    2011-01-01

    Oral contraceptive (OC) use influences the hemostatic system significantly and is a risk factor for development of cardiovascular disease. Factor VII-activating protease (FSAP) has potential effects on hemostasis. The 1601GA genotype of the 1601G/A polymorphism in the FSAP gene expresses a FSAP...... alloenzyme with reduced pro-fibrinolytic activity. Presently, we address whether OC use and OC formulation affect FSAP measures in human blood. Healthy women (n=588) were allocated to six cycles of OCs with estrogen contents of 20µg (n=158), 30µg (n=284), 35µg (n=79) or 50µg (n=67) combined with various...... progestins. FSAP genotypes, FSAP and factor VII (FVII) plasma measures were assessed at baseline and after 6 cycles of OC. The 1601GA genotype was present in 49 (8.3%) of the women and was associated with significantly reduced levels of FSAP (P=0.001). OC use increased FSAP antigen by 25% and FSAP activity...

  14. High Complement Factor I Activity in the Plasma of Children with Autism Spectrum Disorders

    Directory of Open Access Journals (Sweden)

    Naghi Momeni

    2012-01-01

    Full Text Available Autism spectrum disorders (ASDs are neurodevelopmental and behavioural syndromes affecting social orientation, behaviour, and communication that can be classified as developmental disorders. ASD is also associated with immune system abnormality. Immune system abnormalities may be caused partly by complement system factor I deficiency. Complement factor I is a serine protease present in human plasma that is involved in the degradation of complement protein C3b, which is a major opsonin of the complement system. Deficiency in factor I activity is associated with an increased incidence of infections in humans. In this paper, we show that the mean level of factor I activity in the ASD group is significantly higher than in the control group of typically developed and healthy children, suggesting that high activity of complement factor I might have an impact on the development of ASD.

  15. Association between lifestyle factors and plasma adiponectin levels in Japanese men

    Directory of Open Access Journals (Sweden)

    Nakayama Kunio

    2005-11-01

    Full Text Available Abstract Background Adiponectin is an adipocyte-specific protein that plays a role in obesity, insulin resistant, lipid metabolism, and anti-inflammation. Hypoadiponectinemia may be associated with a higher risk for type 2 diabetes and cardiovascular disease. Some studies suggest that adiponectin levels are modulated by lifestyle factors, but little is known about the associations between lifestyle factors and plasma adiponectin levels in Japanese people. We therefore investigated the associations between lifestyle factors and plasma adiponectin levels in general Japanese men. Methods The subjects were 202 Japanese male workers who participated in an annual health check. They provided details about anthropometrical data, blood collection, their use of prescribed medication, and the clinical history of their families. They also completed a self-administered questionnaire about their lifestyles. Results Subjects with plasma adiponectin levels below 4.0 μg/ml had significantly lower levels of HDL cholesterol and higher levels of BMI, SBP, DBP, total cholesterol, FBG, and platelets than did subjects with higher adiponectin levels. In multiple logistic regression after multiple adjustment, a plasma adiponectin level below 4.0 μg/ml was significantly associated with smoking (odds ratio [OR] = 2.08, 95% confidence interval [CI] = 1.01–4.30, a daily diet rich in deep-yellow vegetables (OR = 0.25, 95% CI= 0.07–0.91, frequent eating out (OR = 2.45, 95% CI = 1.19–5.08, and physical exercise two or more times a week (OR = 0.21, 95% CI = 0.06–0.74. Conclusion Our findings show that adiponectin levels in general Japanese men are independently related to smoking, dietary factors, and physical exercise. We think that lifestyle habits might independently modulate adiponectin levels and that adiponectin might be the useful biomarker helping people to avoid developing type 2 diabetes and cardiovascular disease by modifying their lifestyles.

  16. Clinical Significance and Expression of PAF and TNF-alpha in Seminal Plasma of Leukocytospermic Patients

    Directory of Open Access Journals (Sweden)

    Chaodong Liu

    2012-01-01

    Full Text Available Objective. Discuss the changes and roles of PAF in the reproductive tract infection by observing the expression of platelet activating factor (PAF and tumor necrosis factor α (TNF-α in seminal plasma of patients with leukocytospermia. Methods. The seminal plasma was obtained from 22 cases of leukocytospermia and 15 cases of normal males; the peroxidase dyeing method was adopted for seminal plasma white blood count; the ELISA was adopted to test PAF and TNF-α concentration in seminal plasma. Result. PAF concentration ( ng/mL of leukocytospermia group was significantly lower than the normal group ( ng/mL, while TNF-α ( ng/mL was significantly higher than that of normal group ( ng/mL. There was negative correlation between PAF and TNF-α , (, ; the same situation existed in PAF and WBC (, ; but TNF-α was positively correlated to WBC (, . Conclusion. (1 Low expression of PAF and high expression of TNF-α in leukocytospermia affect the sperm motility, which is one of the reasons that leads to infertility. (2 Lower expression of PAF has its particularity during the reproductive tract infection.

  17. Fresh frozen plasma in the pediatric age group and in congenital coagulation factor deficiency.

    Science.gov (United States)

    Muntean, Wolfgang

    2002-10-31

    Generally, the rules of good practice in transfusion medicine apply also to the pediatric age group. However, the frequency of specific diseases that might necessitate the administration of fresh frozen plasma (FFP) differs from that in adults. Physiologic differences to the later age exist in the neonatal period and in young infants, especially with respect to the hemostatic system, that must be recognized when considering administration of FFP. The plasma levels of many procoagulant factors and important anticoagulants are lower in neonates than in other age groups. Despite these findings, healthy neonates show no easy bruising, no increased bleeding during surgery, and excellent wound healing. The same discrepancy obtains between in vitro and clinical findings with primary hemostasis in neonates. The good primary hemostasis in neonates despite poor in vitro platelet function seems to be due mainly to a very high von Willebrand factor and the presence of more high-multimeric subunits of von Willebrand factor than later in life. We must assume that these particular plasma levels of procoagulant and anticoagulant proteins are essential for the correct function of neonatal hemostasis. Evidence that the hemostatic system of neonates works best with physiologic concentrations of procoagulants and anticoagulants can also be inferred from studies where the administration of clotting factor concentrates gave poor results.Since healthy neonates and young infants have excellent hemostasis, there is absolutely no indication to 'correct' these values to adult's norms prior to invasive procedures by administering FFP. Indications for FFP, met more frequently in the pediatric age group than later in life, are exchange transfusion and extracorporeal membrane oxygenation. Indications applying equally to adults are other extracorporeal life support systems, disseminated intravascular coagulation, hepatic coagulopathy, and 'complex unclear coagulopathies'. In congenital clotting

  18. Change in plasma vascular endothelial growth factor after gamma knife radiosurgery for meningioma: a preliminary study.

    Science.gov (United States)

    Park, Seong-Hyun; Hwang, Jeong-Hyun; Hwang, Sung-Kyoo

    2015-02-01

    The purpose of this study was to investigate changes in the plasma level of vascular endothelial growth factor (VEGF) after Gamma Knife radiosurgery (GKRS) for the treatment of meningioma. Fourteen patients with meningiomas had peripheral venous blood collected at the time of GKRS and at 1 week, 1 month, 3 month and 6 month visits. Plasma VEGF levels were measured using commercially available enzyme-linked immunosorbent assay. For controls, peripheral blood samples were obtained from 20 healthy volunteers. The mean plasma VEGF level (29.6 pg/mL) in patients with meningiomas before GKRS was significantly lower than that of the control group (62.4 pg/mL, p=0.019). At 1 week after GKRS, the mean plasma VEGF levels decreased to 23.4 pg/mL, and dropped to 13.9 pg/mL at 1 month, 14.8 pg/mL at 3 months, then increased to 27.7 pg/mL at 6 months. Two patients (14.3%) with peritumoral edema (PTE) showed a level of VEGF 6 months after GKRS higher than their preradiosurgical level. There was no significant association found in an analysis of correlation between PTE and tumor size, marginal dose, age, and sex. Our study is first in demonstrating changes of plasma VEGF after stereotactic radiosurgery (SRS) for meningioma. This study may provide a stimulus for more work related to whether measurement of plasma level has a correlation with tumor response after SRS for meningioma.

  19. Induction of ovulation in rabbit does using purified nerve growth factor and camel seminal plasma

    OpenAIRE

    Masdeu, M.; García García, R. M.; Cardinali, R.; Millán, P.; Arias Álvarez, M.; C. Castellini; LORENZO, P. L.; Garcia Rebollar, Pilar

    2015-01-01

    The presence of an ovulation-inducing factor (OIF) in the seminal plasma (SP) of several species with spontaneous and induced ovulation, including the rabbit, has been documented. Recent studies have demonstrated that the OIF in the SP of camels (SPCAM) is a nerve growth factor (β-NGF). The aim of this study was to determine if purified β-NGF from mouse submandibular glands or SPCAM could provoke ovulation induction in the rabbit doe. A total of 35 females were synchronized with 25 IU of equi...

  20. Plasma-derived versus recombinant factor concentrates in PUPs: a never ending debate?

    Science.gov (United States)

    Berntorp, Erik

    2017-01-31

    Inhibitor development in haemophilia is a serious complication to treatment with factor concentrates. Since the advent of more pure products, especially developed using recombinant DNA technology, some studies have shown an increased incidence of inhibitors in previously untreated patients (PUPs) receiving recombinant products whereas plasma-derived concentrates sometimes have been claimed to have a protective role, probably due to the content of von Willebrand factor (VWF). In fact, experiments indicate that the VWF may block uptake of factor VIII into macrophages for further processing to the immune system. Also, a competition between VWF and inhibitor binding to the C2 domain of factor VIII has been suggested. Recently, large cohort and surveillance studies have created a vigorous debate about the role of product class for inhibitor development as results have been conflicting. The only randomised prospective study, the SIPPET study, was published in 2016, and substantiated previous reports claiming that plasma derived concentrates give less inhibitors in patients with severe haemophilia A, previously not exposed to factor VIII. The debate will continue.

  1. Plasma brain derived neurotrophic factor (BDNF) and response to ketamine in treatment-resistant depression.

    Science.gov (United States)

    Haile, C N; Murrough, J W; Iosifescu, D V; Chang, L C; Al Jurdi, R K; Foulkes, A; Iqbal, S; Mahoney, J J; De La Garza, R; Charney, D S; Newton, T F; Mathew, S J

    2014-02-01

    Ketamine produces rapid antidepressant effects in treatment-resistant depression (TRD), but the magnitude of response varies considerably between individual patients. Brain-derived neurotrophic factor (BDNF) has been investigated as a biomarker of treatment response in depression and has been implicated in the mechanism of action of ketamine. We evaluated plasma BDNF and associations with symptoms in 22 patients with TRD enrolled in a randomized controlled trial of ketamine compared to an anaesthetic control (midazolam). Ketamine significantly increased plasma BDNF levels in responders compared to non-responders 240 min post-infusion, and Montgomery-Åsberg Depression Rating Scale (MADRS) scores were negatively correlated with BDNF (r=-0.701, p = 0.008). Plasma BDNF levels at 240 min post-infusion were highly negatively associated with MADRS scores at 240 min (r = -0.897, p=.002), 24 h (r = -0.791, p = 0.038), 48 h (r = -0.944, p = 0.001) and 72 h (r = -0.977, p = 0.010). No associations with BDNF were found for patients receiving midazolam. These data support plasma BDNF as a peripheral biomarker relevant to ketamine antidepressant response.

  2. Further evaluation of plasma sphingomyelin levels as a risk factor for coronary artery disease

    Directory of Open Access Journals (Sweden)

    Lackner Karl J

    2006-01-01

    Full Text Available Abstract Background Sphingomyelin (SM is the major phospholipid in cell membranes and in lipoproteins. In human plasma, SM is mainly found in atherogenic lipoproteins; thus, high levels of SM may promote atherogenesis. Methods We investigated in a median follow up of 6.0 years the association of SM with the incidence of a combined endpoint (myocardial infarction and cardiovascular death in stable and unstable patients, and its relation to other marker of atherosclerosis in 1,102 patients with angiographically documented CAD and 444 healthy controls. Results and discussion Logistic regression analysis showed that SM categorized by median was associated with an elevated risk for CAD (HR 3.2, 95%CI 2.5–4.0, p Conclusion The results of our study reveal that 1 human plasma SM levels are a risk factor for CAD; 2 the pro-atherogenic property of plasma SM might be related to metabolism of apoB-containing or triglyceride-rich lipoproteins; and 3 plasma SM levels are a predictor for outcome of patients with acute coronary syndrome.

  3. Serum and seminal plasma insulin-like growth factor-1 in male infertility.

    Science.gov (United States)

    Lee, Hyo Serk; Park, Yong-Seog; Lee, Joong Shik; Seo, Ju Tae

    2016-06-01

    Growth hormone and its mediator, insulin-like growth factor-1 (IGF-1), have been suggested to exert gonadotropic actions in both humans and animals. The present study was conducted to assess the relationship between serum IGF-1 concentration, seminal plasma concentration, and sperm parameter abnormalities. A total of 79 men were enrolled in this study from December 2011 to July 2012 and were prospectively analyzed. Patient parameters analyzed included age, body mass index, smoking status, urological history, and fertility history. Patients were divided into four groups based on their semen parameters: normal (A, n=31), abnormal sperm motility (B, n=12), abnormal sperm morphology (C, n=20), and two or more abnormal parameters (D, n=16). Patient seminal plasma and serum IGF-1 concentrations were determined. Patient baseline characteristics were not significantly different between any of the groups. The serum IGF-1 levels in groups B, C, and D were significantly lower than the levels in group A; however, the seminal plasma IGF-1 levels were not significantly different between any of the groups. Men with abnormal sperm parameters had significantly lower levels of serum IGF-1 compared with men with normal sperm parameters. Seminal plasma IGF-1 levels, however, did not differ significantly between the groups investigated here. Further investigations will be required to determine the exact mechanisms by which growth hormone and IGF-1 affect sperm quality.

  4. Serum and seminal plasma insulin-like growth factor-1 in male infertility

    Science.gov (United States)

    Lee, Hyo Serk; Park, Yong-Seog; Lee, Joong Shik

    2016-01-01

    Objective Growth hormone and its mediator, insulin-like growth factor-1 (IGF-1), have been suggested to exert gonadotropic actions in both humans and animals. The present study was conducted to assess the relationship between serum IGF-1 concentration, seminal plasma concentration, and sperm parameter abnormalities. Methods A total of 79 men were enrolled in this study from December 2011 to July 2012 and were prospectively analyzed. Patient parameters analyzed included age, body mass index, smoking status, urological history, and fertility history. Patients were divided into four groups based on their semen parameters: normal (A, n=31), abnormal sperm motility (B, n=12), abnormal sperm morphology (C, n=20), and two or more abnormal parameters (D, n=16). Patient seminal plasma and serum IGF-1 concentrations were determined. Results Patient baseline characteristics were not significantly different between any of the groups. The serum IGF-1 levels in groups B, C, and D were significantly lower than the levels in group A; however, the seminal plasma IGF-1 levels were not significantly different between any of the groups. Conclusion Men with abnormal sperm parameters had significantly lower levels of serum IGF-1 compared with men with normal sperm parameters. Seminal plasma IGF-1 levels, however, did not differ significantly between the groups investigated here. Further investigations will be required to determine the exact mechanisms by which growth hormone and IGF-1 affect sperm quality. PMID:27358827

  5. Association of Plasma Viscosity with Cardiovascular Risk Factors in Obesity: As an old marker, a new insight

    Science.gov (United States)

    Meltem, Ercan; Dildar, Konukoglu; Tijen, Yeşim Erdem

    2007-04-01

    Although obesity is related with cardiovascular disease, the exact mechanism of the relationship is not fully understood. We aim to examine the relationship between plasma viscosity and obesity as a cardiovascular disease risk factor in obese and non-obese groups. We recruited 75 obese subjects who were admitted to the Cerrahpasa Medical Faculty. Plasma viscosity and lipid profile were measured and atherogenic index was calculated as atherogenic risk factors. Plasma viscosity, total cholesterol and LDL-cholesterol levels and atherogenic index were significantly increased in obese group compared to non-obese group for each. Plasma viscosity was weakly correlated with total cholesterol and atherogenic index only in the obese group. Plasma viscosity, an early atherosclerotic risk factor, might be helpful in the assessment of cardiovascular risk in obese subjects.

  6. Measurement of factor v activity in human plasma using a microplate coagulation assay.

    Science.gov (United States)

    Tilley, Derek; Levit, Irina; Samis, John A

    2012-09-09

    In response to injury, blood coagulation is activated and results in generation of the clotting protease, thrombin. Thrombin cleaves fibrinogen to fibrin which forms an insoluble clot that stops hemorrhage. Factor V (FV) in its activated form, FVa, is a critical cofactor for the protease FXa and accelerator of thrombin generation during fibrin clot formation as part of prothrombinase (1, 2). Manual FV assays have been described (3, 4), but they are time consuming and subjective. Automated FV assays have been reported (5-7), but the analyzer and reagents are expensive and generally provide only the clot time, not the rate and extent of fibrin formation. The microplate platform is preferred for measuring enzyme-catalyzed events because of convenience, time, cost, small volume, continuous monitoring, and high-throughput (8, 9). Microplate assays have been reported for clot lysis (10), platelet aggregation (11), and coagulation Factors (12), but not for FV activity in human plasma. The goal of the method was to develop a microplate assay that measures FV activity during fibrin formation in human plasma. This novel microplate method outlines a simple, inexpensive, and rapid assay of FV activity in human plasma. The assay utilizes a kinetic microplate reader to monitor the absorbance change at 405 nm during fibrin formation in human plasma (Figure 1) (13). The assay accurately measures the time, initial rate, and extent of fibrin clot formation. It requires only μl quantities of plasma, is complete in 6 min, has high-throughput, is sensitive to 24-80 pM FV, and measures the amount of unintentionally activated (1-stage activity) and thrombin-activated FV (2-stage activity) to obtain a complete assessment of its total functional activity (2-stage activity - 1-stage activity). Disseminated intravascular coagulation (DIC) is an acquired coagulopathy that most often develops from pre-existing infections (14). DIC is associated with a poor prognosis and increases mortality

  7. Label-free Detection of Protein Released during Platelet Activation by CNT-Enhanced Love Mode SAW Sensors.

    Science.gov (United States)

    Wu, Huiyan; Zu, Hongfei; Wang, Qing-Ming; Zhao, Gangyi; Wang, Jamesu H-C

    2014-09-01

    Platelet-rich plasma (PRP) has been applied in a series of clinical treatments. PRP contains high-concentrated platelets, which, when activated, could secret a variety of growth factors and cytokines, to promote and/or enhance healing of injured tissues. Non-activated platelets suspension could be prepared by an isolation method of centrifugation and washing currently. However, it is not clear whether platelets, if any, are already activated during this process and there is no simple method to monitor their activation accordingly. Shear-Horizontal Surface Acoustic Wave sensors (SH-SAW, Love Mode) are promising in fundamental biology as well as biomedical engineering, detecting cell behaviors in liquid in a non-invasive, simple and quantitative manner. In this study, Love mode sensors are adopted for the label-free detection of protein secreted by platelets. Carbon nanotube (CNT) is reported as an advisable platform of both non-specific protein adsorption and specific protein binding. For further improvement of Love mode sensor performance, novel CNT -coated parylene-C film is prepared on its surface as both the acoustic-wave-guiding layer and bio-interface layer. The S21 loss curves of Love mode sensors were recorded and the corresponding resonance frequencies were extracted. The results showed that the CNT-enhanced sensor possessed an increased resonance frequency shift when compared to normal sensor with single parylene-C film under identical collagen concentrations. Then, the modified sensor is used for label-free detection of protein released by various concentrations of platelets. The results revealed high sensitivity and consistency, indicating the potential of CNT-enhanced Love mode sensors in cell-based applications.

  8. Cystamine immobilization on TiO{sub 2} film surfaces and the influence on inhibition of collagen-induced platelet activation

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Yujuan [Key Lab. of Advanced Technology for Materials of Chinese Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Weng Yajun, E-mail: wengyj7032@sohu.com [Key Lab. of Advanced Technology for Materials of Chinese Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Zhang Liping; Jing Fengjuan; Huang Nan [Key Lab. of Advanced Technology for Materials of Chinese Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Chen Junying, E-mail: chenjy@263.net [Key Lab. of Advanced Technology for Materials of Chinese Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China)

    2011-12-15

    Poor haemocompatibility is a main issue of artificial cardiovascular materials in clinical application. Nitric oxide (NO), produced by vascular endothelial cells, is a well known inhibitor of platelet adhesion and activation. Thus, NO-releasing biomaterials are beneficial for improving haemocompatibility of blood-contacting biomedical devices. In this paper, a novel method was developed for enhancement of haemocompatibility by exploiting endogenous NO donors. TiO{sub 2} films were firstly synthesized on Si (1 0 0) wafers via unbalanced magnetron sputtering technology, and then polydopamine was grafted on TiO{sub 2} films and used as a linker for further immobilization of cystamine. The obtained surfaces were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis. NO generation is evaluated by saville-griess reagents, and it shows that cystamine immobilized samples are able to catalytically generate NO by decomposing endogenous S-nitrosothiols (RSNO). In vitro platelet adhesion results reveal that cystamine modified surfaces can inhibit collagen-induced platelet activation. ELISA analysis reveals that cGMP in platelets obviously increases on cystamine immobilized surface, which suggests the reducing of platelet activation is through NO/cGMP signal channel. It can be concluded that cystamine immobilized surface shows better blood compatibility by catalyzing NO release from the endogenous NO donor. It may be a promising method for improvement of haemocompatibility of blood-contacting implants.

  9. The NLRP3 inflammasome and bruton's tyrosine kinase in platelets co-regulate platelet activation, aggregation, and in vitro thrombus formation.

    Science.gov (United States)

    Murthy, Pranav; Durco, Filip; Miller-Ocuin, Jennifer L; Takedai, Teiko; Shankar, Shruthi; Liang, Xiaoyan; Liu, Xiao; Cui, Xiangdong; Sachdev, Ulka; Rath, Dominik; Lotze, Michael T; Zeh, Herbert J; Gawaz, Meinrad; Weber, Alexander N; Vogel, Sebastian

    2017-01-29

    Cleavage of interleukin-1β (IL-1β) is a key inflammatory event in immune cells and platelets, which is mediated by nucleotide-binding domain leucine rich repeat containing protein (NLRP3)-dependent activation of caspase-1. In immune cells, NLRP3 and caspase-1 form inflammasome complexes with the adaptor proteins apoptosis-associated speck-like protein containing a CARD (ASC) and bruton's tyrosine kinase (BTK). In platelets, however, the regulatory triggers and the functional effects of the NLRP3 inflammasome are unknown. Here, we show in vitro that the platelet NLRP3 inflammasome contributes to platelet activation, aggregation, and thrombus formation. NLRP3 activity, as monitored by caspase-1 activation and cleavage and secretion of IL-1β, was upregulated in activated platelets, which was dependent on platelet BTK. Pharmacological inhibition or genetic ablation of BTK in platelets led to decreased platelet activation, aggregation, and in vitro thrombus formation. We identify a functionally relevant link between BTK and NLRP3 in platelets, with potential implications in disease states associated with abnormal coagulation and inflammation. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Interleukin-3 and granulocyte-macrophage colony-stimulating factor levels of cord blood plasma in term neonates

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@ AIM: Umbilical cord blood plasma contain higher hematopoietic stimulatory activities than adult peripheral blood plasma. IL-3 is regarded as multilineage hematopoietic growth factor that acts on primitive pluripotential stem cells and progenitor cells of every lineage except T and B-lymphoid lineage.

  11. Study on the related risk factors with atherogenic index of plasma in male type 2 diabetic patients

    Institute of Scientific and Technical Information of China (English)

    吴晓明

    2012-01-01

    Objective To study related factors with atherogenic index of plasma in male type 2 diabetic patients. Methods 133 male patients with type 2 diabetes mellitus were divided into non-atherogenic phenom (N group) and atherogemic phenom(A group) according to the cutpoint of atherogenic index of plasma

  12. Human Plasma Lipidome Is Pleiotropically Associated with Cardiovascular Risk Factors and Death

    Science.gov (United States)

    Mamtani, Manju; Kent, Jack W.; Wong, Gerard; Weir, Jacquelyn M.; Barlow, Christopher K.; Diego, Vincent; Almeida, Marcio; Dyer, Thomas D.; Göring, Harald H.H.; Almasy, Laura; Mahaney, Michael C.; Comuzzie, Anthony G.; Williams-Blangero, Sarah; Meikle, Peter J.; Blangero, John; Curran, Joanne E.

    2014-01-01

    Background Cardiovascular disease (CVD) is the most common cause of death in the United States and is associated with a high economic burden. Prevention of CVD focuses on controlling or improving the lipid profile of patients at risk. The human lipidome is made up of thousands of ubiquitous lipid species. By studying biologically simple canonical lipid species, we investigated whether the lipidome is genetically redundant and whether its genetic influences can provide clinically relevant clues of CVD risk. Methods and Results We performed a genetic study of the human lipidome in 1,212 individuals from 42 extended Mexican American families. High-throughput mass spectrometry enabled rapid capture of precise lipidomic profiles, providing 319 unique species. Using variance-component based heritability analyses and bivariate trait analyses, we detected significant genetic influences on each lipid assayed. Median heritability of the plasma lipid species was 0.37. Hierarchical clustering based on complex genetic correlation patterns identified 12 genetic clusters that characterized the plasma lipidome. These genetic clusters were differentially but consistently associated with risk factors of CVD, including central obesity, obesity, type 2 diabetes, raised serum triglycerides and metabolic syndrome. Also these clusters consistently predicted occurrence of cardiovascular deaths during follow-up. Conclusions The human plasma lipidome is heritable. Shared genetic influences reduce the dimensionality of the human lipidome into clusters that are associated with risk factors of CVD. PMID:25363705

  13. The Geometric Factor of Electrostatic Plasma Analyzers: A Case Study from the Fast Plasma Investigation for the Magnetospheric Multiscale mission

    Science.gov (United States)

    Collinson, Glyn A.; Dorelli, John Charles; Avanov, Leon A.; Lewis, Gethyn R.; Moore, Thomas E.; Pollock, Craig; Kataria, Dhiren O.; Bedington, Robert; Arridge, Chris S.; Chornay, Dennis J.; Gliese,Ulrik; Mariano, Al.; Barrie, Alexander C; Tucker, Corey; Owen, Christopher J.; Walsh, Andrew P.; Shappirio, Mark D.; Adrian, Mark L.

    2012-01-01

    We report our findings comparing the geometric factor (GF) as determined from simulations and laboratory measurements of the new Dual Electron Spectrometer (DES) being developed at NASA Goddard Space Flight Center as part of the Fast Plasma Investigation on NASA's Magnetospheric Multiscale mission. Particle simulations are increasingly playing an essential role in the design and calibration of electrostatic analyzers, facilitating the identification and mitigation of the many sources of systematic error present in laboratory calibration. While equations for laboratory measurement of the Geometric Factpr (GF) have been described in the literature, these are not directly applicable to simulation since the two are carried out under substantially different assumptions and conditions, making direct comparison very challenging. Starting from first principles, we derive generalized expressions for the determination of the GF in simulation and laboratory, and discuss how we have estimated errors in both cases. Finally, we apply these equations to the new DES instrument and show that the results agree within errors. Thus we show that the techniques presented here will produce consistent results between laboratory and simulation, and present the first description of the performance of the new DES instrument in the literature.

  14. The geometric factor of electrostatic plasma analyzers: A case study from the Fast Plasma Investigation for the Magnetospheric Multiscale mission

    Energy Technology Data Exchange (ETDEWEB)

    Collinson, Glyn A. [Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, Maryland 20071 (United States); Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Surrey (United Kingdom); Dorelli, John C.; Moore, Thomas E.; Pollock, Craig; Mariano, Al; Shappirio, Mark D.; Adrian, Mark L. [Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, Maryland 20071 (United States); Avanov, Levon A. [Innovim, 7501 Greenway Center Drive, Maryland Trade Center III, Greenbelt, Maryland 20770 (United States); Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, Maryland 20071 (United States); Lewis, Gethyn R.; Kataria, Dhiren O.; Bedington, Robert; Owen, Christopher J.; Walsh, Andrew P. [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Surrey (United Kingdom); Arridge, Chris S. [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Surrey (United Kingdom); The Centre for Planetary Sciences, UCL/Birkbeck (United Kingdom); Chornay, Dennis J. [University of Maryland, 7403 Hopkins Avenue, College Park, Maryland 20740 (United States); Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, Maryland 20071 (United States); Gliese, Ulrik [SGT, Inc., 7515 Mission Drive, Suite 30, Lanham, Maryland 20706 (United States); Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, Maryland 20071 (United States); Barrie, Alexander C. [Millennium Engineering and Integration, 2231 Crystal Dr., Arlington, Virginia 22202 (United States); Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, Maryland 20071 (United States); Tucker, Corey [Global Science and Technology Inc., 7855 Walker Drive, Greenbelt, Maryland 20770 (United States); Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, Maryland 20071 (United States)

    2012-03-15

    We report our findings comparing the geometric factor (GF) as determined from simulations and laboratory measurements of the new Dual Electron Spectrometer (DES) being developed at NASA Goddard Space Flight Center as part of the Fast Plasma Investigation on NASA's Magnetospheric Multiscale mission. Particle simulations are increasingly playing an essential role in the design and calibration of electrostatic analyzers, facilitating the identification and mitigation of the many sources of systematic error present in laboratory calibration. While equations for laboratory measurement of the GF have been described in the literature, these are not directly applicable to simulation since the two are carried out under substantially different assumptions and conditions, making direct comparison very challenging. Starting from first principles, we derive generalized expressions for the determination of the GF in simulation and laboratory, and discuss how we have estimated errors in both cases. Finally, we apply these equations to the new DES instrument and show that the results agree within errors. Thus we show that the techniques presented here will produce consistent results between laboratory and simulation, and present the first description of the performance of the new DES instrument in the literature.

  15. Quarantine versus pathogen-reduced plasma-coagulation factor content and rotational thromboelastometry coagulation.

    Science.gov (United States)

    Theusinger, Oliver M; Goslings, David; Studt, Jan-Dirk; Brand-Staufer, Brigitte; Seifert, Burkhardt; Spahn, Donat R; Frey, Beat M

    2017-03-01

    Different types of fresh-frozen plasma (FFP) exist, and the concentrations of plasma proteins vary between individuals and blood groups. Furthermore, processing may also influence the content. Quarantine-stored plasma (qFFP) and plasma that was pathogen-reduced using blood-safety (Intercept) technology (piFFP) were analyzed regarding procoagulant and anticoagulant hemostasis proteins, including endogenous thrombin (thrombin-generation) potential (ETP). Thirty-five samples of each type of FFP were analyzed using only male Blood Group O donors. FFP units were stored frozen for comparable periods of time before plasma protein content was assessed. Once the units were thawed, all tests were completed within 4 hours. The results are presented as means ± standard deviations or as median (minimum; maximum) and were compared using independent-sample t tests (significance, p < 0.01). Significantly higher concentrations of adintegrin-like and metalloprotease with thrombospondin type-13 motifs (ADAMTS13), fibrinogen, Factor (F)V, FVIII, FXIII, protein S, protein S activity, antithrombin, microvesicle (<900 nm), and α2 antiplasmin were observed in qFFP. The variability of factors was significantly lower in piFFP. Tissue factor (TF) at 1 picomolar (pM) exhibited significantly longer lag time, a lower peak, lower ETP, and a lower velocity index in qFFP compared with piFFP. In TF at 5 pM, significant differences in lag time (longer in qFFP), velocity index (lower in qFFP), and peak (lower in qFFP) were observed. Rotational thromboelastometry revealed a significantly longer (p = 0.002) clot-formation time with intrinsic thromboelastometry for piFFP and a significantly shorter clotting time (p = 0.004) with thromboelastometry fibrinogen testing for piFFP. Pathogen reduction reduces procoagulant and anticoagulant coagulation factors as well as variability. A thrombin-generation assay showed no reduced ETP and no supraphysiological thrombin generation. None of the

  16. Dynamic form factor of two-component plasmas beyond the static local field approximation

    CERN Document Server

    Daligault, J

    2003-01-01

    The spectrum of ion density fluctuations in a strongly coupled plasma is described both within the static G(k, 0) and high-frequency G(k, infinity) local field approximation. By a direct comparison with molecular dynamics data, we find that for large coupling, G(k, 0) is inadequate. Based on this result, we employ the Zwanzig-Mori memory function approach to model the Thomson scattering cross section, i.e. the electron dynamic form factor S sub e sub e (k, omega) of a dense two-component plasma. We show the sensitivity of S sub e sub e (k, omega) to three approximations for G(k, omega).

  17. Plasma intact fibroblast growth factor 23 levels in women with anorexia nervosa

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    Otani Makoto

    2008-04-01

    Full Text Available Abstract Background Fibroblast growth factor (FGF23 is a novel phosphaturic factor associated with inorganic phosphate homeostasis. Previous human studies have shown that serum FGF23 levels increase in response to a high phosphate diet. For anorexia nervosa (AN patients, inorganic phosphate homeostasis is important in the clinical course, such as in refeeding syndrome. The purpose of this study was to determine plasma levels of intact FGF23 (iFGF23 in restricting-type AN (AN-R patients, binge-eating/purging-type AN (AN-BP patients, and healthy controls. Methods The subjects consisted of 6 female AN-R patients, 6 female AN-BP patients, and 11 healthy female controls; both inpatients and outpatients were included. Plasma iFGF23, 1,25-dihydroxyvitamin D (1,25-(OH2D, and 25-hydroxyvitamin D (25-OHD levels were measured. Data are presented as the median and the range. A two-tailed Mann-Whitney U-test with Bonferroni correction was used to assess differences among the three groups, and a value of p Results There were no differences between AN-R patients and controls in the iFGF23 and 1,25-(OH2D levels. In AN-BP patients, the iFGF23 level (41.3 pg/ml; range, 6.1–155.5 pg/ml was significantly higher than in controls (3.8 pg/ml; range, not detected-21.3 pg/ml; p = 0.001, and the 1,25-(OH2D was significantly lower in AN-BP patients (7.0 pg/ml; range, 4.2–33.7 pg/ml than in controls (39.7 pg/ml; range, 6.3–58.5 pg/ml; p = 0.015. No differences in plasma 25-OHD levels were observed among the groups. Conclusion This preliminary study is the first to show that plasma iFGF23 levels are increased in AN-BP patients, and that these elevated plasma FGF23 levels might be related to the decrease in plasma 1,25-(OH2D levels.

  18. Bothrops jararaca venom metalloproteinases are essential for coagulopathy and increase plasma tissue factor levels during envenomation.

    Directory of Open Access Journals (Sweden)

    Karine M Yamashita

    2014-05-01

    Full Text Available BACKGROUND/AIMS: Bleeding tendency, coagulopathy and platelet disorders are recurrent manifestations in snakebites occurring worldwide. We reasoned that by damaging tissues and/or activating cells at the site of the bite and systemically, snake venom toxins might release or decrypt tissue factor (TF, resulting in activation of blood coagulation and aggravation of the bleeding tendency. Thus, we addressed (a whether TF and protein disulfide isomerase (PDI, an oxireductase involved in TF encryption/decryption, were altered in experimental snake envenomation; (b the involvement and significance of snake venom metalloproteinases (SVMP and serine proteinases (SVSP to hemostatic disturbances. METHODS/PRINCIPAL FINDINGS: Crude Bothrops jararaca venom (BjV was preincubated with Na2-EDTA or AEBSF, which are inhibitors of SVMP and SVSP, respectively, and injected subcutaneously or intravenously into rats to analyze the contribution of local lesion to the development of hemostatic disturbances. Samples of blood, lung and skin were collected and analyzed at 3 and 6 h. Platelet counts were markedly diminished in rats, and neither Na2-EDTA nor AEBSF could effectively abrogate this fall. However, Na2-EDTA markedly reduced plasma fibrinogen consumption and hemorrhage at the site of BjV inoculation. Na2-EDTA also abolished the marked elevation in TF levels in plasma at 3 and 6 h, by both administration routes. Moreover, increased TF activity was also noticed in lung and skin tissue samples at 6 h. However, factor VII levels did not decrease over time. PDI expression in skin was normal at 3 h, and downregulated at 6 h in all groups treated with BjV. CONCLUSIONS: SVMP induce coagulopathy, hemorrhage and increased TF levels in plasma, but neither SVMP nor SVSP are directly involved in thrombocytopenia. High levels of TF in plasma and TF decryption occur during snake envenomation, like true disseminated intravascular coagulation syndrome, and might be implicated in

  19. Bothrops jararaca venom metalloproteinases are essential for coagulopathy and increase plasma tissue factor levels during envenomation.

    Science.gov (United States)

    Yamashita, Karine M; Alves, André F; Barbaro, Katia C; Santoro, Marcelo L

    2014-05-01

    Bleeding tendency, coagulopathy and platelet disorders are recurrent manifestations in snakebites occurring worldwide. We reasoned that by damaging tissues and/or activating cells at the site of the bite and systemically, snake venom toxins might release or decrypt tissue factor (TF), resulting in activation of blood coagulation and aggravation of the bleeding tendency. Thus, we addressed (a) whether TF and protein disulfide isomerase (PDI), an oxireductase involved in TF encryption/decryption, were altered in experimental snake envenomation; (b) the involvement and significance of snake venom metalloproteinases (SVMP) and serine proteinases (SVSP) to hemostatic disturbances. Crude Bothrops jararaca venom (BjV) was preincubated with Na2-EDTA or AEBSF, which are inhibitors of SVMP and SVSP, respectively, and injected subcutaneously or intravenously into rats to analyze the contribution of local lesion to the development of hemostatic disturbances. Samples of blood, lung and skin were collected and analyzed at 3 and 6 h. Platelet counts were markedly diminished in rats, and neither Na2-EDTA nor AEBSF could effectively abrogate this fall. However, Na2-EDTA markedly reduced plasma fibrinogen consumption and hemorrhage at the site of BjV inoculation. Na2-EDTA also abolished the marked elevation in TF levels in plasma at 3 and 6 h, by both administration routes. Moreover, increased TF activity was also noticed in lung and skin tissue samples at 6 h. However, factor VII levels did not decrease over time. PDI expression in skin was normal at 3 h, and downregulated at 6 h in all groups treated with BjV. SVMP induce coagulopathy, hemorrhage and increased TF levels in plasma, but neither SVMP nor SVSP are directly involved in thrombocytopenia. High levels of TF in plasma and TF decryption occur during snake envenomation, like true disseminated intravascular coagulation syndrome, and might be implicated in engendering bleeding manifestations in severely-envenomed patients.

  20. Bothrops jararaca venom metalloproteinases are essential for coagulopathy and increase plasma tissue factor levels during envenomation.

    Directory of Open Access Journals (Sweden)

    Karine M Yamashita

    2014-05-01

    Full Text Available BACKGROUND/AIMS: Bleeding tendency, coagulopathy and platelet disorders are recurrent manifestations in snakebites occurring worldwide. We reasoned that by damaging tissues and/or activating cells at the site of the bite and systemically, snake venom toxins might release or decrypt tissue factor (TF, resulting in activation of blood coagulation and aggravation of the bleeding tendency. Thus, we addressed (a whether TF and protein disulfide isomerase (PDI, an oxireductase involved in TF encryption/decryption, were altered in experimental snake envenomation; (b the involvement and significance of snake venom metalloproteinases (SVMP and serine proteinases (SVSP to hemostatic disturbances. METHODS/PRINCIPAL FINDINGS: Crude Bothrops jararaca venom (BjV was preincubated with Na2-EDTA or AEBSF, which are inhibitors of SVMP and SVSP, respectively, and injected subcutaneously or intravenously into rats to analyze the contribution of local lesion to the development of hemostatic disturbances. Samples of blood, lung and skin were collected and analyzed at 3 and 6 h. Platelet counts were markedly diminished in rats, and neither Na2-EDTA nor AEBSF could effectively abrogate this fall. However, Na2-EDTA markedly reduced plasma fibrinogen consumption and hemorrhage at the site of BjV inoculation. Na2-EDTA also abolished the marked elevation in TF levels in plasma at 3 and 6 h, by both administration routes. Moreover, increased TF activity was also noticed in lung and skin tissue samples at 6 h. However, factor VII levels did not decrease over time. PDI expression in skin was normal at 3 h, and downregulated at 6 h in all groups treated with BjV. CONCLUSIONS: SVMP induce coagulopathy, hemorrhage and increased TF levels in plasma, but neither SVMP nor SVSP are directly involved in thrombocytopenia. High levels of TF in plasma and TF decryption occur during snake envenomation, like true disseminated intravascular coagulation syndrome, and might be implicated in

  1. Plasma homocysteine level is a risk factor for osteoporotic fractures in elderly patients

    Directory of Open Access Journals (Sweden)

    Zhu Y

    2016-08-01

    .Conclusion: In this study, we found that the plasma Hcy level in elderly patients with OPF is higher than that of nonosteoporotic patients. It is not correlated with BMD, but positively correlated with bone resorption markers. An increased Hcy level appears to be a risk factor for OPFs in elderly people. Keywords: elderly patient, osteoporosis, fracture, homocysteine, bone mineral density, bone turnover marker

  2. Bioactivity of ovulation inducing factor (or nerve growth factor) in bovine seminal plasma and its effects on ovarian function in cattle.

    Science.gov (United States)

    Tribulo, P; Bogle, O; Mapletoft, R J; Adams, G P

    2015-06-01

    To understand the role of ovulation-inducing factor (or nerve growth factor) (OIF [NGF]) in bovine seminal plasma, we (1) used an in vivo llama bioassay to test the hypothesis that bovine seminal plasma induces ovulation and CL development in llamas similar to that of llama seminal plasma when the dose of seminal plasma is adjusted to ovulation-inducing factor content (experiment 1) and (2) determined the effect of bovine seminal plasma on the interval to ovulation and luteal development in heifers (experiment 2). Within species, seminal plasma was pooled (n = 160 bulls, n = 4 llamas), and the volume of seminal plasma used for treatment was adjusted to a total dose of 250 μg of ovulation-inducing factor. In experiment 1, mature female llamas were assigned randomly to four groups and treated intramuscularly with either 10 mL of PBS (negative control, n = 5), 50-μg GnRH (positive control, n = 5), 6-mL of llama seminal plasma (n = 6), or 12 mL of bull seminal plasma (n = 6). Ovulation and CL development were monitored by transrectal ultrasonography. In experiment 2, beef heifers were given a luteolytic dose of prostaglandin followed by 25-mg porcine LH (pLH) 12 hours later to induce ovulation. Heifers were assigned randomly to three groups and given 12 mL bovine seminal plasma intramuscularly 12 hours after pLH treatment (n = 10), within 4 hours after ovulation (n = 9), or no treatment (control, n = 10). Ovulation was monitored by ultrasonography every 4 hours, and the CL development was monitored daily until the next ovulation. In experiment 1, ovulation was detected in 0/5, 4/5, 4/6, 4/6 llamas in the PBS, GnRH, llama seminal plasma, and bovine seminal plasma groups, respectively (P pLH. Plasma progesterone concentration tended to be higher in heifers given bovine seminal plasma within 4 hours after ovulation, suggesting that bovine ovulation-inducing factor is luteotrophic.

  3. Neuroprotective effect of salvianolic acid B against cerebral ischemic injury in rats via the CD40/NF-κB pathway associated with suppression of platelets activation and neuroinflammation.

    Science.gov (United States)

    Xu, Shixin; Zhong, Aiqin; Ma, Huining; Li, Dan; Hu, Yue; Xu, Yingzhi; Zhang, Junping

    2017-04-15

    Neuroinflammation plays a critical role in the pathogenesis of ischemia/reperfusion (I/R) injury. Activated platelets are increasingly regarded as initiators and/or amplifiers of inflammatory processes in cerebral I/R injury. Salvianolic acid B (SAB) is the most abundant bioactive compound of Salviae miltiorrhizae, a well-known Chinese herb used to promote blood circulation and eliminating blood stasis. S. miltiorrhizae has been used clinically in Asia for the treatment of ischemic cerebrovascular diseases. In the present study, a rat model of transient middle cerebral artery occlusion (tMCAO) was established to investigate the neuroprotective effects and mechanisms of SAB treatment against focal cerebral I/R insult. The results showed that SAB treatment (3mg/kg, 6mg/kg and 12mg/kg, i.p.) dose-dependently decreased I/R-induced neurological deficits at 24, 48, and 72h after reperfusion and decreased plasma-soluble P-selectin and soluble CD40 ligand as early as 6h after onset of I/R insult. At 24h after reperfusion, SAB treatment significantly reduced neuronal and DNA damage in the hippocampal CA1 region and decreased neural cell loss in the ischemic core. The I/R-induced pro-inflammatory mediator mRNA and protein overexpression in the penumbra cortex, including ICAM-1, IL-1β, IL-6, IL-8, and MCP-1, were significantly inhibited by SAB in a dose-dependent manner. Further studies suggested SAB treatment attenuated CD40 expression and NF-κB activation, which involved NF-κB/p65 phosphorylation and IκBα phosphorylation and degradation. In conclusion, our findings indicated that the neuroprotective effects of SAB post cerebral I/R injury are associated with the inhibition of both platelets activation and production of pro-inflammatory mediators and the downregulation of the CD40/NF-κB pathway.

  4. Plasma Levels of Monocyte Chemotactic Protein 3 and Beta-Nerve Growth Factor Increase with Amnestic Mild Cognitive Impairment

    Institute of Scientific and Technical Information of China (English)

    Kang Soo Lee; Ji Hyung Chung; Kyung Hye Lee; Min-Jeong Shin; Byoung Hoon Oh; Soo Hyung Lee; Chang Hyung Hong

    2009-01-01

    A number of studies have investigated peripheral inflammatory indices, including plasma cytokines and related molecules according to subtypes of dementia, but not in mild cognitive impairment (MCI). In this study, we used multiplex cytokine assay to assess the plasma levels of 22 cytokines in patients with MCI subtyped as amnestic and non-amnestic, according to cognitive features. When comparing the levels of plasma growth factors, chemokines and cytokines, plasma levels of monocyte chemotactic protein 3 (MCP-3), and beta-nerve growth factor (β-NGF) in these two groups, they were found to be significantly higher in amnestic MCI patients than in non-amnestic MCI patients, after adjusting for age and gender. This suggests that plasma MCP-3 and β-NGF may be useful in differentiating subtypes of MCI. Cellular & Molecular Immunology.

  5. Glycosaminoglycans affect the interaction of human plasma kallikrein with plasminogen, factor XII and inhibitors

    Directory of Open Access Journals (Sweden)

    Gozzo A.J.

    2003-01-01

    Full Text Available Human plasma kallikrein, a serine proteinase, plays a key role in intrinsic blood clotting, in the kallikrein-kinin system, and in fibrinolysis. The proteolytic enzymes involved in these processes are usually controlled by specific inhibitors and may be influenced by several factors including glycosaminoglycans, as recently demonstrated by our group. The aim of the present study was to investigate the effect of glycosaminoglycans (30 to 250 µg/ml on kallikrein activity on plasminogen and factor XII and on the inhibition of kallikrein by the plasma proteins C1-inhibitor and antithrombin. Almost all available glycosaminoglycans (heparin, heparan sulfate, bovine and tuna dermatan sulfate, chondroitin 4- and 6-sulfates reduced (1.2 to 3.0 times the catalytic efficiency of kallikrein (in a nanomolar range on the hydrolysis of plasminogen (0.3 to 1.8 µM and increased (1.9 to 7.7 times the enzyme efficiency in factor XII (0.1 to 10 µM activation. On the other hand, heparin, heparan sulfate, and bovine and tuna dermatan sulfate improved (1.2 to 3.4 times kallikrein inhibition by antithrombin (1.4 µM, while chondroitin 4- and 6-sulfates reduced it (1.3 times. Heparin and heparan sulfate increased (1.4 times the enzyme inhibition by the C1-inhibitor (150 nM.

  6. A simple 3D plasma instrument with an electrically adjustable geometric factor for space research

    Science.gov (United States)

    Rohner, U.; Saul, L.; Wurz, P.; Allegrini, F.; Scheer, J.; McComas, D.

    2012-02-01

    We report on the design and experimental verification of a novel charged particle detector and an energy spectrometer with variable geometric factor functionality. Charged particle populations in the inner heliosphere create fluxes that can vary over many orders of magnitude in flux intensity. Space missions that plan to observe plasma fluxes, for example when travelling close to the Sun or to a planetary magnetosphere, require rapid particle measurements over the full three-dimensional velocity distribution. Traditionally, such measurements are carried out with plasma instrumentation with a fixed geometrical factor, which can only operate in a limited range of flux intensity. Here we report on the design and testing of a prototype sensor, which is capable of measuring particle flux with high angular and energy resolution, yet has a variable geometric factor that is controlled without moving parts. This prototype was designed in support of a proposal to make fast electron measurements on the Solar Probe Plus (SP+) mission planned by NASA. We simulated the ion optics inside the instrument and optimized the performance to design and build our prototype. This prototype was then tested in the MEFISTO facility at the University of Bern and its performance was verified over the full range of azimuth, elevation, energy and intensity.

  7. Plasma Tissue Factor Pathway Inhibitor Levels in Angiographically Defined Coronary Artery Disease Among Saudis

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    Syed Shahid Habib

    2013-05-01

    Full Text Available Objectives: This study was aimed to determine plasma levels of total (TFPI-T and free (TFPI-F tissue factor pathway inhibitor, plasminogen activator inhibitor-1 (PAI-1, and tissue plasminogen activator (t-PA in a cohort of Saudi patients with chronic stable angiographically defined coronary artery disease (CAD and to determine its correlation with its severity.Methods: This cross sectional study was conducted in the department of physiology and department of cardiology, College of Medicine, and King Khalid University Hospital and King Saud University, Riyadh. Sixty known cases of CAD who had undergone angiography (35 males and 25 females were selected. A control group included 39 (20 males and 19 females healthy subjects. Fasting venous blood samples were analyzed for total (TFPI-T and free (TFPI-F tissue factor pathway inhibitor, plasminogen activator inhibitor-1 (PAI-1, and tissue plasminogen activator (t-PA. Gensini scores and vessel scores were determined for assessing CAD severity.Results: There were non-significant differences between age, body mass index (BMI and Blood pressure between the controls and CAD subjects. A comparison of hemostatic markers between control and CAD patients showed significantly higher levels of Fibrinogen, PAI-1, TFPI-T and TFPI-F in CAD patients compared to control subjects. But there was no difference in plasma t-PA levels. TFPI-T had a significant positive correlation with severity of disease determined by Gensini Scores (r=0.344; p=0.006 and vessel scores (r=0.338; p=0.015.Conclusion: Plasma levels of total tissue factor pathway inhibitor are significantly related with the presence and severity of CAD. Elevated levels of TFPI-T may be considered as useful diagnostic and prognostic markers in patients with CAD.

  8. Perspectives and challenges in regenerative medicine using plasma rich in growth factors.

    Science.gov (United States)

    Anitua, Eduardo; Alkhraisat, Mohammad H; Orive, Gorka

    2012-01-10

    Plasma rich in growth factors (PRGF-Endoret) is an endogenous therapeutic technology that is gaining interest in regenerative medicine due to its potential to stimulate and accelerate tissue healing and bone regeneration. This autologous biotechnology is designed for the in situ delivery of multiple cellular modulators and the formation of a fibrin scaffold, thereby providing different formulations that can be widely used in numerous medical and scientific fields including dentistry, oral implantology, orthopedics, ulcer treatment and tissue engineering among others. Here we discuss the important progress that has been accomplished in this field. Furthermore, a comprehensive outlook of the intriguing therapeutic applications of this technology is presented.

  9. Decreased brain-derived neurotrophic factor plasma levels in psoriasis patients

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    A.R. Brunoni

    2015-08-01

    Full Text Available Brain-derived neurotrophic factor (BDNF is associated with neuroplasticity and synaptic strength, and is decreased in conditions associated with chronic stress. Nevertheless, BDNF has not yet been investigated in psoriasis, a chronic inflammatory systemic disease that is exacerbated by stress. Therefore, our aim was to determine BDNF plasma levels in psoriasis patients and healthy controls. Adult patients (n=94 presenting with psoriasis for at least 1 year were enrolled, and age- and gender-matched with healthy controls (n=307 from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil. Participants had neither a previous history of coronary artery disease nor current episode of major depression. BDNF plasma levels were determined using the Promega ELISA kit. A general linear model was used to compare BDNF levels in psoriasis patients and controls, with age, gender, systolic blood pressure, serum fasting glucose, blood lipid levels, triglycerides, smoking status, and body mass index examined. After adjusting for clinical and demographic variables, significantly decreased BNDF plasma levels were observed in psoriasis patients (P=0.01 (estimated marginal means of 3922 pg/mL; 95%CI=2660-5135 compared with controls (5788 pg/mL; 95%CI=5185-6442. Similar BDNF levels were found in both mild and severe cases of psoriasis. Our finding, that BDNF is decreased in psoriasis, supports the concept of a brain-skin connection in psoriasis. Further studies should determine if BDNF is increased after specific psoriasis treatments, and associated with different disease stages.

  10. Transcription factor ABF-1 suppresses plasma cell differentiation but facilitates memory B cell formation.

    Science.gov (United States)

    Chiu, Yi-Kai; Lin, I-Ying; Su, Shin-Tang; Wang, Kuan-Hsiung; Yang, Shii-Yi; Tsai, Dong-Yan; Hsieh, Yi-Ting; Lin, Kuo-I

    2014-09-01

    Ag-primed B cells that result from an immune response can form either memory B cells or Ab-secreting plasma cells; however, the molecular machinery that controls this cellular fate is poorly understood. In this study, we show that activated B cell factor-1 (ABF-1), which encodes a basic helix-loop-helix transcriptional repressor, participates in this regulation. ABF-1 was prevalently expressed in purified memory B cells and induced by T follicular helper cell-mediated signals. ABF-1 expression declined by the direct repression of B lymphocyte-induced maturation protein-1 during differentiation. Ectopic expression of ABF-1 reduced the formation of Ab-secreting cells in an in vitro differentiation system of human memory B cells. Accordingly, knockdown of ABF-1 potentiates the formation of Ab-secreting cells. A transgenic mouse that expresses inducible ABF-1 in a B cell-specific manner was generated to demonstrate that the formation of germinal center and memory B cells was augmented by induced ABF-1 in an immune response, whereas the Ag-specific plasma cell response was dampened. This effect was associated with the ability of ABF-1 to limit cell proliferation. Together, our results demonstrate that ABF-1 facilitates formation of memory B cells but prevents plasma cell differentiation.

  11. von Willebrand factor antigen levels in plasma of patients with malignant breast disease

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    L.M. Röhsig

    2001-09-01

    Full Text Available von Willebrand factor (vWF is a protein that mediates platelet adherence to the subendothelium during primary hemostasis. High plasma vWF concentrations have been reported in patients with various types of cancer, such as head and neck, laryngeal and prostatic cancer, probably representing an acute phase reactant. In the present study we determined the plasma levels of vWF antigen (vWF:Ag by quantitative immunoelectrophoresis in 128 female patients with breast cancer as well as in 47 women with benign breast disease and in 27 healthy female controls. The levels of vWF:Ag were 170.7 ± 78 U/dl in patients with cancer, 148.4 ± 59 U/dl in patients with benign disease and 130.6 ± 45 U/dl in controls (P<0.005. We also detected a significant increase in the levels of vWF:Ag (P<0.0001 in patients with advanced stages of the disease (stage IV = 263.3 ± 113 U/dl, stage IIIB = 194.0 ± 44 U/dl as compared to those with earlier stages of the disease (stage I = 155.3 ± 65 U/dl, stage IIA = 146.9 ± 75 U/dl. In conclusion, vWF levels were increased in plasma of patients with malignant breast disease, and these levels correlated with tumor progression.

  12. Skepinone-L, a Novel Potent and Highly Selective Inhibitor of p38 MAP Kinase, Effectively Impairs Platelet Activation and Thrombus Formation

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    Oliver Borst

    2013-06-01

    Full Text Available Background/Aims: Platelets are critically important for primary haemostasis and the major players in thrombotic vascular occlusion. Platelets are activated by agonists, such as thrombin and collagen-related peptide as well as second-wave mediators including thromboxane A2 via different intracellular signaling pathways resulting in degranulation, aggregation and thrombus formation. Platelet activation is paralleled by phosphorylation and activation of p38 MAPK. The limited specificity of hitherto known p38 MAPK inhibitors precluded safe conclusions on the precise role of p38 MAPK in the regulation of platelet function. The present study examined the impact of Skepinone-L, a novel and highly selective inhibitor of p38 mitogen-activated protein kinase (p38 MAPK, on platelet activation and thrombus formation. Methods: Experiments were performed in freshly isolated human platelets. Protein phosphorylation was quantified by Western blotting, thromboxane B2 synthesis by enzyme immunoassay, ATP release by ChronoLume luciferin assay, cytosolic Ca2+ concentration by Fura-2 fluorescence-measurements, platelet aggregation by a light transmissions measurement and in vitro thrombus formation by a flow chamber. Results: Skepinone-L (1 μM virtually abrogated the phosphorylation of platelet p38 MAPK substrate Hsp27 following stimulation with CRP (1 μg/ml, thrombin (5 mU/ml or thromboxane A2 analogue U-46619 (1 μM. Furthermore, Skepinone-L significantly blunted activation-dependent platelet secretion and aggregation following threshold concentrations of CRP, thrombin and thromboxane A2 analogue U-46619. Skepinone-L did not impair platelet Ca2+ signaling but prevented agonist-induced thromboxane A2 synthesis through abrogation of p38 MAPK-dependent phosphorylation of platelet cytosolic phospholipase A2 (cPLA2. Skepinone-L further markedly blunted thrombus formation under low (500-s and high (1700-s arterial shear rates. Conclusions: The present study discloses

  13. Purification and Characterization of a Sperm Motility Inhibiting Factor from Caprine Epididymal Plasma

    Science.gov (United States)

    Das, Sujoy; Saha, Sudipta; Majumder, Gopal Chandra; Dungdung, Sandhya Rekha

    2010-01-01

    Several studies have been reported on the occurrence of sperm motility inhibiting factors in the male reproductive fluids of different mammalian species, but these proteins have not been adequately purified and characterized. A novel sperm motility inhibiting factor (MIF-II) has been purified from caprine epididymal plasma (EP) by Hydroxylapatite gel adsorption chromatography, DEAE-Cellulose ion-exchange chromatography and chromatofocusing. The MIF-II has been purified to apparent homogeneity and the molecular weight estimated by Sephacryl S-300 gel filtration is 160 kDa. MIF-II is a dimeric protein, made up of two subunits each having a molecular mass of 80 kDa as shown by SDS-PAGE. The isoelectric point of MIF-II is 5.1 as determined by chromatofocusing and isoelectric focusing. It is a heat labile protein and maximal active at the pH 6.9 to 7.5. The sperm motility inhibiting protein factor at 2 µg/ml (12.5 nM) level showed maximal motility-inhibiting activity. The observation that the epididymal plasma factor lowered the intracellular cAMP level of spermatozoa in a concentration-dependent manner suggests that it may block the motility of caprine cauda spermatozoa by interfering the cAMP dependent motility function. The results revealed that the purified protein factor has the potential of sperm motility inhibition and may serve as a vaginal contraceptive. The antibody raised against the MIF-II has the potential for enhancement of forward motility of cauda-spermatozoa. This antibody may thus be useful for solving some of the problems of male infertility due to low sperm motility. PMID:20706623

  14. Purification and characterization of a sperm motility inhibiting factor from caprine epididymal plasma.

    Directory of Open Access Journals (Sweden)

    Sujoy Das

    Full Text Available Several studies have been reported on the occurrence of sperm motility inhibiting factors in the male reproductive fluids of different mammalian species, but these proteins have not been adequately purified and characterized. A novel sperm motility inhibiting factor (MIF-II has been purified from caprine epididymal plasma (EP by Hydroxylapatite gel adsorption chromatography, DEAE-Cellulose ion-exchange chromatography and chromatofocusing. The MIF-II has been purified to apparent homogeneity and the molecular weight estimated by Sephacryl S-300 gel filtration is 160 kDa. MIF-II is a dimeric protein, made up of two subunits each having a molecular mass of 80 kDa as shown by SDS-PAGE. The isoelectric point of MIF-II is 5.1 as determined by chromatofocusing and isoelectric focusing. It is a heat labile protein and maximal active at the pH 6.9 to 7.5. The sperm motility inhibiting protein factor at 2 microg/ml (12.5 nM level showed maximal motility-inhibiting activity. The observation that the epididymal plasma factor lowered the intracellular cAMP level of spermatozoa in a concentration-dependent manner suggests that it may block the motility of caprine cauda spermatozoa by interfering the cAMP dependent motility function. The results revealed that the purified protein factor has the potential of sperm motility inhibition and may serve as a vaginal contraceptive. The antibody raised against the MIF-II has the potential for enhancement of forward motility of cauda-spermatozoa. This antibody may thus be useful for solving some of the problems of male infertility due to low sperm motility.

  15. Streptococcal Serum Opacity Factor Increases Hepatocyte Uptake of Human Plasma High Density Lipoprotein-Cholesterol1

    Science.gov (United States)

    Gillard, Baiba K.; Rosales, Corina; Pillai, Biju K.; Lin, Hu Yu; Courtney, Harry S.; Pownall, Henry J.

    2010-01-01

    Serum opacity factor (SOF), a virulence determinant of Streptococcus pyogenes, converts plasma high density lipoproteins (HDL) to three distinct species: lipid-free apolipoprotein (apo) A-I, neo HDL, a small discoidal HDL-like particle, and a large cholesteryl ester-rich microemulsion (CERM), that contains the cholesterol esters (CE) of up to ~400,000 HDL particles and apo E as its major protein. Similar SOF reaction products are obtained with HDL, total plasma lipoproteins and whole plasma. We hypothesized that hepatic uptake of CERM-CE via multiple apo E dependent receptors would be faster than that of HDL-CE. We tested our hypothesis using human hepatoma cells and lipoprotein receptor-specific Chinese hamster ovary (CHO) cells. [3H]CE uptake by HepG2 and Huh7 cells from HDL after SOF treatment, which transfers >90% of HDL-CE to CERM, was respectively 2.4 and 4.5 times faster than from control HDL. CERM-[3H]CE uptake was inhibited by LDL and HDL, suggestive of uptake by both the LDL receptor (LDL-R) and scavenger receptor class B type I (SR-BI). Studies in CHO cells specifically expressing LDL-R and SR-BI confirmed CERM-[3H]CE uptake by both receptors. RAP and heparin inhibit CERM-[3H]CE but not HDL-[3H]CE uptake thereby implicating LRP-1 and cell surface proteoglycans in this process. These data demonstrate that SOF treatment of HDL increases CE uptake via multiple hepatic apo E receptors. In so doing, SOF might increase hepatic disposal of plasma cholesterol in a way that is therapeutically useful. PMID:20879789

  16. Decisive factors affecting plasma resistance and roughness formation in ArF photoresist

    Energy Technology Data Exchange (ETDEWEB)

    Jinnai, Butsurin; Uesugi, Takuji; Koyama, Koji; Samukawa, Seiji [Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Kato, Keisuke; Yasuda, Atsushi; Maeda, Shinichi [Yokohama Research Laboratories, Mitsubishi Rayon Co., Ltd, 10-1 Daikoku-cho, Tsurumi-ku, Yokohama 230-0053 (Japan); Momose, Hikaru, E-mail: samukawa@ifs.tohoku.ac.j [Corporate Research Laboratories, Mitsubishi Rayon Co., Ltd, 2-1 Miyuki-cho, Otake, Hiroshima 739-0693 (Japan)

    2010-10-06

    Low plasma resistance and roughness formation in an ArF photoresist are serious issues in plasma processes. To resolve these issues, we investigated several factors that affect the roughness formation and plasma resistance in an ArF photoresist. We used our neutral beam process to categorize the effects of species from the plasma on the ArF photoresist into physical bombardment, chemical reactions and ultraviolet/vacuum ultraviolet (UV/VUV) radiation. The UV/VUV radiation drastically increased the etching rates of the ArF photoresist films, and, in contrast, chemical reactions increased the formation of surface roughness. FTIR analysis indicated that the UV/VUV radiation preferentially dissociates C-H bonds in the ArF photoresist, rather than C=O bonds, because of the dissociation energies of the bonds. This indicated that the etching rates of the ArF photoresist are determined by the UV/VUV radiation because this radiation can break C-H bonds, which account for the majority of structures in the ArF photoresist. In contrast, FTIR analysis showed that chemical species such as radicals and ions were likely to react with C=O bonds, in particular C=O bonds in the lactone groups of the ArF photoresist, due to the structural and electronic effects of the lactone groups. As a result, the etching rates of the ArF photoresist can vary in different bond structures, leading to increased surface roughness in the ArF photoresist.

  17. Static and Dynamic Structure Factors with Account of the Ion Structure for High-temperature Alkali and Alkaline Earth Plasmas

    CERN Document Server

    Sadykova, S P; Tkachenko, I M

    2010-01-01

    The $e-e$, $e-i$, $i-i$ and charge-charge static structure factors are calculated for alkali and Be$^{2+}$ plasmas using the method described by Gregori et al. in \\cite{bibGreg2006}. The dynamic structure factors for alkali plasmas are calculated using the method of moments \\cite{bibAdam83}, \\cite{bibAdam93}. In both methods the screened Hellmann-Gurskii-Krasko potential, obtained on the basis of Bogolyubov's method, has been used taking into account not only the quantum-mechanical effects but also the ion structure \\cite{bib73}. PACS: 52.27.Aj (Alkali and alkaline earth plasmas, Static and dynamic structure factors), 52.25.Kn (Thermodynamics of plasmas), 52.38.Ph (X-ray scattering)

  18. Plasma factor VII-activating protease is increased by oral contraceptives and induces factor VII activation in-vivo

    DEFF Research Database (Denmark)

    Sidelmann, Johannes Jakobsen; Skouby, Sven O.; Kluft, Cornelis

    2011-01-01

    Oral contraceptive (OC) use influences the hemostatic system significantly and is a risk factor for development of cardiovascular disease. Factor VII-activating protease (FSAP) has potential effects on hemostasis. The 1601GA genotype of the 1601G/A polymorphism in the FSAP gene expresses a FSAP...... alloenzyme with reduced pro-fibrinolytic activity. Presently, we address whether OC use and OC formulation affect FSAP measures in human blood. Healthy women (n=588) were allocated to six cycles of OCs with estrogen contents of 20μg (n=158), 30μg (n=284), 35μg (n=79) or 50μg (n=67) combined with various...... progestins. FSAP genotypes, FSAP and factor VII (FVII) plasma measures were assessed at baseline and after 6 cycles of OC. The 1601GA genotype was present in 49 (8.3%) of the women and was associated with significantly reduced levels of FSAP (P≤0.001). OC use increased FSAP antigen by 25% and FSAP activity...

  19. Purification and characterization of an insulin-like growth factor II variant from human plasma.

    Science.gov (United States)

    Hampton, B; Burgess, W H; Marshak, D R; Cullen, K J; Perdue, J F

    1989-11-15

    An insulin-like growth factor II variant (IGF-II variant) was purified from Cohn fraction IV1 of human plasma by ion exchange, gel filtration, and reversed-phase high pressure liquid chromatography. The amino-terminal sequence of the first 35 amino acid residues showed a replacement of Ser-29 of IGF-II with the tetrapeptide Arg-Leu-Pro-Gly of IGF-II variant. Peptides isolated and sequenced after digestion with endoproteinase Asp-N and endoproteinase Glu-C disclosed no differences with the sequence predicted from an IGF-II variant cDNA clone isolated by Jansen, M., van Shaik, F. M. A., van Tol, H., Van den Brande, J. L., and Sussenbach, J. S. (1985) FEBS Lett., 179, 243-246. The molecular ion of intact IGF-II variant was 7809.4 mass units, as measured by plasma desorption mass spectrometry. This is in close agreement with the molecular ion of 7812.8 mass units calculated from the determined sequence and indicates the entire amino acid sequence had been accounted for. Binding of IGF-II variant to purified insulin-like growth factor I (IGF-I) receptors demonstrated a 2-3-fold lower affinity for this receptor compared with IGF-I or IGF-II. The dissociation constants for IGF-I, IGF-II, and IGF-II variant are 0.23, 0.38, and 0.80 nM, respectively. In a growth assay, the concentration of IGF-II and IGF-II variant required to stimulate the half-maximal growth of MCF-7 cells was 4 and 13 nM, respectively. Finally, the amount of IGF-II variant that can be purified by this method constitutes approximately 25% of the total IGF-II isolated from Cohn fraction IV1 of human plasma.

  20. Assessment of quality of platelets preserved in plasma and platelet additive solution: A Malaysian experience

    Directory of Open Access Journals (Sweden)

    Munirah Binti Mokhtar

    2016-01-01

    Full Text Available Background: A use of platelet additives solution (PAS improves storage conditions so as to give increased shelf life to platelets and to maintain hemostatic function. Objective: The present study was aimed to compare in vitro quality of platelet rich plasma (PRP-derived platelet concentrate (PC during extended period of storage in plasma and in additive solution (Composol PS and Fresenius. Study Design: Randomized 19 PCs each were used in the study for plasma and PAS as the storage medium. The measurement parameters, including pH, total white blood cell (WBC count, total platelet count, and platelet activation rate, were studied on day 1, day 5, and day 8 of the storage period. The sterility test was carried out on the eighth day of storage. Results: pH of PC suspended in PAS was significantly lower as compared to that in plasma (P < 0.001 for all the three days of sampling. The WBC count, both in plasma and in PAS, showed an acceptable values of being <0.2 Χ 10 9 /unit during the storage period. Platelet count in PAS was higher as compared to that in plasma, though it was not statistically significant. While both the groups showed increased platelet activation rate during the storage, the PCs suspended in PAS showed significantly higher platelet activation rate (p0.001. Results from sterility test showed no bacterial growth in the PCs in both the groups. Conclusion: Most parameters studied on platelet storage in suspending medium of native plasma and PAS remained well within the acceptable limits. However, the pH values and platelet activation rate significantly differed in PAS as compared with plasma.

  1. Model-independent determination of the astrophysical S-factor in laser-induced fusion plasmas

    CERN Document Server

    Lattuada, D; Bonasera, A; Bang, W; Quevedo, H J; Warren, M; Consoli, F; De Angelis, R; Andreoli, P; Kimura, S; Dyer, G; Bernstein, A C; Hagel, K; Barbui, M; Schmidt, K; Gaul, E; Donovan, M E; Natowitz, J B; Ditmire, T

    2016-01-01

    In this work, we present a new and general method for measuring the astrophysical S-factor of nuclear reactions in laser-induced plasmas and we apply it to d(d,n)$^{3}$He. The experiment was performed with the Texas Petawatt laser, which delivered 150-270 fs pulses of energy ranging from 90 to 180 J to D$_{2}$ or CD$_{4}$ molecular clusters. After removing the background noise, we used the measured time-of-flight data of energetic deuterium ions to obtain their energy distribution. We derive the S-factor using the measured energy distribution of the ions, the measured volume of the fusion plasma and the measured fusion yields. This method is model-independent in the sense that no assumption on the state of the system is required, but it requires an accurate measurement of the ion energy distribution especially at high energies and of the relevant fusion yields. In the d(d,n)$^{3}$He and $^{3}$He(d,p)$^{4}$He cases discussed here, it is very important to apply the background subtraction for the energetic ions ...

  2. Dogs with hearth diseases causing turbulent high-velocity blood flow have changes in patelet function and von Willebrand factor multimer distribution

    DEFF Research Database (Denmark)

    Tarnow, Inge; Kristensen, Annemarie Thuri; Olsen, Lisbeth Høier

    2005-01-01

    and echocardiography were performed in all dogs. PFA100 closure times (the ability of platelets to occlude a hole in a membrane at high shear rates), platelet activation markers (plasma thromboxane B2 concentration, platelet surface P-selectin expression), platelet aggregation (in whole blood and platelet-rich plasma...

  3. Cold Plasma Inactivation of Bacterial Biofilms and Reduction of Quorum Sensing Regulated Virulence Factors.

    Directory of Open Access Journals (Sweden)

    Dana Ziuzina

    Full Text Available The main objectives of this work were to investigate the effect of atmospheric cold plasma (ACP against a range of microbial biofilms commonly implicated in foodborne and healthcare associated human infections and against P. aeruginosa quorum sensing (QS-regulated virulence factors, such as pyocyanin, elastase (Las B and biofilm formation capacity post-ACP treatment. The effect of processing factors, namely treatment time and mode of plasma exposure on antimicrobial activity of ACP were also examined. Antibiofilm activity was assessed for E. coli, L. monocytogenes and S. aureus in terms of reduction of culturability and retention of metabolic activity using colony count and XTT assays, respectively. All samples were treated 'inpack' using sealed polypropylene containers with a high voltage dielectric barrier discharge ACP generated at 80 kV for 0, 60, 120 and 300 s and a post treatment storage time of 24 h. According to colony counts, ACP treatment for 60 s reduced populations of E. coli to undetectable levels, whereas 300 s was necessary to significantly reduce populations of L. monocytogenes and S. aureus biofilms. The results obtained from XTT assay indicated possible induction of viable but non culturable state of bacteria. With respect to P. aeruginosa QS-related virulence factors, the production of pyocyanin was significantly inhibited after short treatment times, but reduction of elastase was notable only after 300 s and no reduction in actual biofilm formation was achieved post-ACP treatment. Importantly, reduction of virulence factors was associated with reduction of the cytotoxic effects of the bacterial supernatant on CHO-K1 cells, regardless of mode and duration of treatment. The results of this study point to ACP technology as an effective strategy for inactivation of established biofilms and may play an important role in attenuation of virulence of pathogenic bacteria. Further investigation is warranted to propose direct evidence

  4. Comparison of the centrifugal and roller pump in elective coronary artery bypass surgery--a prospective, randomized study with special emphasis upon platelet activation.

    Science.gov (United States)

    Andersen, Knut S; Nygreen, Else L; Grong, Ketil; Leirvaag, Beryl; Holmsen, Holm

    2003-12-01

    Objective--Evaluation of the centrifugal pump vs roller pump concerning effects upon platelet function, hemolysis and clinical outcome in elective coronary artery bypass surgery. Design--Thirty-four patients were randomized to centrifugal or roller pump. Platelet activation was studied by flow cytometry before, during and up to 3 days after bypass. Results--Duration of bypass, ischemic period, peripheral anastomoses, hospital stay and mortality did not differ. In roller pump patients, platelet aggregates increased by 250% between end of bypass and 3 h postoperatively (p centrifugal pump group, these changes were not significant. Hemolysis increased (20%) at end of bypass and 3 h postoperatively (p centrifugal pump patients, indicating higher susceptibility to postoperative thrombotic complications with the roller pump. Otherwise, there was no clinical evidence for superiority of the centrifugal pump.

  5. The P2Y(12 antagonists, 2MeSAMP and cangrelor, inhibit platelet activation through P2Y(12/G(i-dependent mechanism.

    Directory of Open Access Journals (Sweden)

    Binggang Xiang

    Full Text Available BACKGROUND: ADP is an important physiological agonist that induces integrin activation and platelet aggregation through its receptors P2Y(1 (Gα(q-coupled and P2Y(12 (Gα(i-coupled. P2Y(12 plays a critical role in platelet activation and thrombosis. Adenosine-based P2Y(12 antagonists, 2-methylthioadenosine 5'-monophosphate triethylammonium salt hydrate (2MeSAMP and Cangrelor (AR-C69931MX have been widely used to demonstrate the role of P2Y(12 in platelet function. Cangrelor is being evaluated in clinical trials of thrombotic diseases. However, a recent study reported that both 2MeSAMP and Cangrelor raise intra-platelet cAMP levels and inhibit platelet aggregation through a P2Y(12-independent mechanism. METHODOLOGY/PRINCIPAL FINDINGS: The present work, using P2Y(12 deficient mice, sought to clarify previous conflicting reports and to elucidate the mechanisms by which 2MeSAMP and Cangrelor inhibit platelet activation and thrombosis. 2MeSAMP and Cangrelor inhibited aggregation and ATP release of wild-type but not P2Y(12 deficient platelets. 2MeSAMP and Cangrelor neither raised intracellular cAMP concentrations nor induced phosphorylation of vasodilator-stimulated phosphoprotein (VASP in washed human or mouse platelets. Furthermore, unlike the activators (PGI(2 and forskolin of the cAMP pathway, 2MeSAMP and Cangrelor failed to inhibit Ca(2+ mobilization, Akt phosphorylation, and Rap1b activation in P2Y(12 deficient platelets. Importantly, while injection of Cangrelor inhibited thrombus formation in a FeCl(3-induced thrombosis model in wild-type mice, it failed to affect thrombus formation in P2Y(12 deficient mice. CONCLUSIONS: These data together demonstrate that 2MeSAMP and Cangrelor inhibit platelet function through the P2Y(12-dependent mechanism both in vitro and in vivo.

  6. The changes of blood platelet activation in breast cancer patients before surgery, after surgery, and in various phases of the chemotherapy.

    Science.gov (United States)

    Kedzierska, Magdalena; Czernek, Urszula; Szydłowska-Pazera, Katarzyna; Potemski, Piotr; Piekarski, Janusz; Jeziorski, Arkadiusz; Olas, Beata

    2013-01-01

    Blood platelets from patients with cancer (before or after the surgery) exhibit a variety of qualitative abnormalities. Different anti-cancer drugs may also induce the oxidative/nitrative stress in blood platelets and change their hemostatic properties. The aim of our study was to explain the effect of superoxide anion radicals ([Formula: see text]) production on hemostatic properties of blood platelets (activated by a strong physiological agonist - thrombin) from breast cancer patients before the surgery, after the surgery, and after various phases (I-IV) of chemotherapy (doxorubicin and cyclophosphamide). Patients were hospitalized in the Department of Oncological Surgery and at the Department of Chemotherapy, Medical University of Lodz, Poland. We measured the platelet aggregation as the marker of hemostatic activity of blood platelets. We observed an increase of [Formula: see text] in thrombin-activated blood platelets from patients with breast cancer (before or after the surgery and after various phases of the chemotherapy) compared to the healthy group. Our other experiments demonstrated that aggregation (induced by thrombin) of blood platelets from patients with breast cancer before the surgery, after the surgery, and after various phases of the chemotherapy differs from aggregation of platelets obtained from healthy volunteers. Moreover, our results showed the correlation between the [Formula: see text] generation and changes of platelet aggregation in breast cancer patients before the surgery, after the surgery, and after the chemotherapy (I and IV phases). Considering the data presented in this study, we suggest that the production of [Formula: see text] in blood platelets (activated by thrombin) obtained from breast cancer patients may induce the changes of platelet aggregation, which may contribute in thrombosis in these patients.

  7. Escape factors for Paschen 2p-1s emission lines in low-temperature Ar, Kr, and Xe plasmas

    Science.gov (United States)

    Zhu, Xi-Ming; Cheng, Zhi-Wen; Pu, Yi-Kang; Czarnetzki, Uwe

    2016-06-01

    Radiation trapping phenomenon is often observed when investigating low-temperature plasmas. Photons emitted from the upper excited states may be reabsorbed by the lower states before they leave the plasmas. In order to account for this effect in the modelling and optical diagnostics of plasmas, either an ‘escape factor’ of a function of the optical depth or a strict solution of the radiation transfer equation can be employed. However, the former is more convenient in comparison and thus is widely adopted. Previous literatures have provided several simple expressions of the escape factor for the uniform plasmas. The emission line profiles are assumed to be dominated by the Doppler broadening, and the line splitting due to the hyperfine structure is not considered. This kind of expression is only valid for small atoms, e.g. Ar in low-pressure uniform discharges. Actually, the excited state density in many of the low-temperature plasmas is non-uniform and the emission line profile can be significantly influenced by the collisional broadening at medium and high pressures. In these cases, a new escape factor equation should be calculated. In this work, we study the escape factor equations for the often used 2p-1s transitions (Paschen’s notation) of the Ar, Kr, and Xe atoms. Possible non-uniform density profiles are considered. In addition, we include the line splitting due to the hyperfine structure for Kr and Xe. For the low-pressure plasmas, an escape factor expression mainly based on the Gaussian line profile is given and particularly verified by an experiment in a low-pressure capacitive discharge. For the high-pressure plasmas, an equation based on the Voigt line profile is also calculated. In this way, the new escape factor expression is ready for use in the modelling of the Ar, Kr, and Xe plasmas from low to atmospheric pressure.

  8. Acute strength exercise and the involvement of small or large muscle mass on plasma brain-derived neurotrophic factor levels

    Directory of Open Access Journals (Sweden)

    Paulo Roberto Correia

    2010-01-01

    Full Text Available OBJECTIVE: Blood neurotrophins, such as the brain-derived neurotrophic factor, are considered to be of great importance in mediating the benefits of physical exercise. In this study, the effect of acute strength exercise and the involvement of small versus large muscle mass on the levels of plasma brain-derived neurotrophic factor were evaluated in healthy individuals. METHODS: The concentric strengths of knee (large and elbow (small flexor and extensor muscles were measured on two separate days. Venous blood samples were obtained from 16 healthy subjects before and after exercise. RESULTS: The levels of brain-derived neurotrophic factor in the plasma did not significantly increase after both arm and leg exercise. There was no significant difference in the plasma levels of the brain-derived neurotrophic factor in the arms and legs. CONCLUSION: The present results demonstrate that acute strength exercise does not induce significant alterations in the levels of brain-derived neurotrophic factor plasma concentrations in healthy individuals. Considering that its levels may be affected by various factors, such as exercise, these findings suggest that the type of exercise program may be a decisive factor in altering peripheral brain-derived neurotrophic factor.

  9. Evaluation of Some Plasma Coagulation Factors in Women with Spontaneous Miscarriage

    Directory of Open Access Journals (Sweden)

    Mahsa Besharat

    2015-10-01

    Full Text Available Background: It has been reported that 15-20% of parous female have experienced at least one miscarriage, while 3% of them have experienced two miscarriages. The goal of this study was to evaluate the plasma level of coagulation factors in women with a history of spontaneous abortions. Materials and Methods: In this case-control study, 82 women with a history of two or more abortions referred to the six private gynecologic clinics in Gorgan city without any structural abnormality were recruited during 2011-2012. Plasma levels of antithrombin III (ATIII using colorimetric assay, protein C, protein S, factor V Leiden and lupus anticoagulant (LAC using coagulation method were measured. The control group was women with a history of normal delivery and no abortions. Those under anti-coagulant therapy were excluded from the study. Data were entered into the computer using the Statistical Package for the Social Sciences (SPSS, SPSS Inc., Chicago, IL, USA version 16 and analyzed by Chi-square, t test and non-parametric tests. Results: At least one abnormality was reported in 35 cases (42.7%. Among them, protein C deficiency was the most prevalent (30.5%. ATIII was abnormal in 17.1% and lupus anti-coagulant was abnormal in 8.5%. Factor V Leiden was normal in all cases and protein S deficiency was only seen in one case. Conclusion: We suggest to perform these tests in regards to the thrombophilia in cases with spontaneous abortions in order to find an early cure for this treatable disorder.

  10. The angiogenic growth factors HGF and VEGF in serum and plasma from neuroblastoma patients.

    Science.gov (United States)

    Sköldenberg, Erik G; Larsson, Anders; Jakobson, Ake; Hedborg, Fredrik; Kogner, Per; Christofferson, Rolf H; Azarbayjani, Faranak

    2009-08-01

    To determine whether concentrations of the angiogenic growth factors hepatocyte growth factor (HGF) and vascular endothelial growth factor A (VEGF-A) correlate with clinical and genetic markers in samples taken at diagnosis in children with neuroblastoma (NB). Heparin plasma (P-) and serum (S-) samples of healthy controls (n=73, mean age +/- SD 3.5+/-2.1; females/males: 23/50) and patients with NB (n=62; 2.2+/-1.8; 26/36) were collected between 1988 and 1999. Clinical data included age at diagnosis, gender, stage, outcome, amplification of the oncogene MYCN, loss of heterozygosity at the short arm of chromosome 1 (1p LOH) and ploidy. HGF and S-VEGF-A were elevated in NB as compared to controls (38/62 patients, p<0.0001 and p<0.05, Mann-Whitney U test). HGF concentrations were higher in high-stage (stage 3-4) as compared to low-stage (stage 1-2) disease (p<0.01). P-HGF was elevated in patients with 1p LOH (p<0.01), MYCN amplification (p<0.001) and di- or tetraploidy (p<0.001). S-HGF concentration was elevated in patients MYCN-amplified tumors only. Plasma and S-HGF concentrations were higher in the deceased group (p<0.05), but not P or S-VEGF-A. This study showed that concentrations of HGF and S-VEGF-A are elevated in patients with NB. Furthermore, HGF and S-VEGF-A concentrations correlate to higher stage disease and HGF correlates to genetic markers known to indicate a poor outcome. These observations imply that HGF and VEGF-A have biological roles in NB and suggest the possibility of interference with HGF or VEGF-A signaling as a therapeutic strategy.

  11. Plasma rich in growth factors: preliminary results of use in the preparation of future sites for implants.

    Science.gov (United States)

    Anitua, E

    1999-01-01

    This article presents preliminary clinical evidence of the beneficial effect of the use of plasma rich in growth factors of autologous origin. The plasma is obtained from the individual patient by plasmapheresis. The macroscopic and microscopic results obtained with bone regeneration using this technique, which uses no membrane or barrier, can be observed. The incorporation of these concepts can introduce several advantages, including the enhancement and acceleration of bone regeneration and more rapid and predictable soft tissue healing.

  12. Plasma level of brain-derived neurotrophic factor and the related analysis in depressive patients with suicide attempt

    Institute of Scientific and Technical Information of China (English)

    操军

    2014-01-01

    Objective To explore the association between brainderived neurotrophic factor(BDNF)and suicidal behavior through analyzing and detecting the alteration of plasma BDNF level in depressive patients with suicide attempt.Methods Using enzyme-linked immunosorbent analysis(ELISA)to test the plasma level of BDNF in 27suicidal depressed patients,33 non-suicidal depressed patients and 30 normal controls.Meanwhile,the Hamilton Depression Scale(HAMD)and Beck

  13. Factors associated with fasting plasma ghrelin levels in children and adolescents

    Institute of Scientific and Technical Information of China (English)

    Chao-Chun Zou; Li Liang; Zheng-Yan Zhao

    2008-01-01

    AIM:To measure plasma ghrelin levels in children and adolescents,analyze the associated factors,and investigate the role of ghrelin in obesity,insulin resistance and reproductive physiology.METHODS:A total of 283 subjects aged 4.8-15.8 year were enrolled.Fasting blood samples were collected and plasma ghrelin levels were measured by radioimmunoassay.Fasting glucose (FG),fasting insulin (FI),baseline testosterone (T),estradiol (E2),prolactin (PRL),luteinizing hormone (LH),follicle-stimulating hormone (FSH),serum total cholesterol (TC),triglyceride (TG),alanine aminotransferase (ALT) and uric acid (UA) were measured.Body mass index (BMI),insulin resistance by homeostasis model (HOMA-IR) and beta cell function by homeostasis model (HOMA-β) were calculated.RESULTS:The median ghrelin level was 290 ng/L (15.0-1325.0 ng/i).Bivariate correlation analysis showed that ghrelin levels were inversely correlated with BMI,ALT,TG,UA,LH,FI and HOMA-IR (all P<0.05).No other significant correlation was found between ghrelin levels and age,gender,TC,E2,FSH,PRL,FG and HOMA-β.Stepwise multiple regression analysis showed that only BMI and FI were independent determinants of plasma ghrelin levels in these children and adolescents (P = 0.018 and P = 0.046,respectively),which explained 25.4% of the variance.CONCLUSION:These data suggest that the lower ghrelin levels in obese subjects may be the result of obesity and hyperinsulinemia,which is very common in obese subjects.Moreover,ghrelin may regulate human reproductive physiology indirectly.

  14. Tramadol Induced QTc-Interval Prolongation: Prevalence, Clinical Factors and Correlation to Plasma Concentrations.

    Science.gov (United States)

    Keller, Guillermo A; Etchegoyen, María C V; Fernandez, Nicolás; Olivera, Nancy M; Quiroga, Patricia N; Belloso, Waldo H; Diez, Roberto A; Di Girolamo, Guillermo

    2016-01-01

    In recent years, several cases of torsade de pointes have been associated with many opioids. However, to present no cases have been reported with tramadol. To evaluate the effect of tramadol on QT-interval in the clinical setting. Medical history and comorbidities predisposing to QT interval prolongation were registered for patients requiring medical assistance that involved tramadol administration. Ionograms and ECGs were performed at baseline and intratreatment; QT interval was analyzed after correction with Bazzet, Fridericia, Framinghan and Hogdes formula. 115 patients were studied (50.4% males) All patients had received tramadol 150-400 mg/day during 3.0-5.0 days at the moment of intratreatment control. Plasma concentrations of tramadol were 201-1613 ng/mL. Intratreatment electrocardiographic control, as mean ± SD (range), showed QTcB 372±32 (305 to 433), QTcFri 356±37 (281 to 429), QTcFra 363±33 (299 to 429), QTcH 362±30 (304 to 427), ΔQTcB 26±40 (-73 to 110), ΔQTcFri 24±48 (-97 to 121), ΔQTcFra 22±42 (-81 to 109) and .QTcH 22±38 (-68 to 110) ms. QTc interval presents high correlation with plasma tramadol concentrations (for .QTc, R>0.77). Renal failure was associated with a relative risk for ΔQTc > 30 ms of 1.90 (IC95% 1.31-2.74) and for ΔQTc > 60 ms of 4.74 (IC95% 2.57-8.74). No patient had evidence of arrhythmia during the present study. Tramadol produces QTc interval prolongation in good correlation with plasma drug concentrations; renal failure is a risk factor for higher concentration and QT prolongation by tramadol.

  15. Risk factors for a low linezolid trough plasma concentration in acute infections.

    Science.gov (United States)

    Morata, Laura; Cuesta, Marta; Rojas, Jhon F; Rodriguez, Sebastian; Brunet, Merce; Casals, Gregori; Cobos, Nazareth; Hernandez, Cristina; Martínez, José A; Mensa, Josep; Soriano, Alex

    2013-04-01

    Linezolid is an antibiotic with time-dependent activity, and both the percentage of time that plasma concentrations exceed the MIC and the area under the concentration-time curve over 24 h in the steady state divided by the MIC (AUC24/MIC ratio) are associated with clinical response. The aim of this study was to analyze the linezolid trough plasma concentration (C(min)) and to determine factors associated with a C(min) 80 ml/min, in intensive care unit (ICU) patients, and in patients with an infection due to Staphylococcus aureus. The independent predictors of C(min) 80 ml/min (odds ratio [OR], 10; 95% confidence interval [CI], 2.732 to 37.037; P = 0.001) and infection due to S. aureus (OR, 5.906; 95% CI, 1.651 to 21.126; P = 0.006). A linezolid C(min) of 80 ml/min and in infections due to S. aureus. In patients with severe sepsis, a loading dose or continuous infusion and drug monitoring could improve the pharmacodynamic parameters associated with linezolid efficacy.

  16. The plasma concentration of the B cell activating factor is increased in children with acute malaria.

    Science.gov (United States)

    Nduati, Eunice; Gwela, Agnes; Karanja, Henry; Mugyenyi, Cleopatra; Langhorne, Jean; Marsh, Kevin; Urban, Britta C

    2011-09-15

    Malaria-specific antibody responses in children often appear to be short-lived but the mechanisms underlying this phenomenon are not well understood. In this study, we investigated the relationship between the B-cell activating factor (BAFF) and its receptors expressed on B cells with antibody responses during and after acute malaria in children. Our results demonstrate that BAFF plasma levels increased during acute malarial disease and reflected disease severity. The expression profiles for BAFF receptors on B cells agreed with rapid activation and differentiation of a proportion of B cells to plasma cells. However, BAFF receptor (BAFF-R) expression was reduced on all peripheral blood B cells during acute infection, but those children with the highest level of BAFF-R expression on B cells maintained schizont-specific immunoglobin G (IgG) over a period of 4 months, indicating that dysregulation of BAFF-R expression on B cells may contribute to short-lived antibody responses to malarial antigens in children. In summary, this study suggests a potential role for BAFF during malaria disease, both as a marker for disease severity and in shaping the differentiation pattern of antigen-specific B cells.

  17. Plasma levels of soluble tumour necrosis factor receptors are increased in coal miners with pneumoconiosis.

    Science.gov (United States)

    Schins, R P; Borm, P J

    1995-10-01

    Among other cytokines, tumour necrosis factor (TNF)-alpha is considered to play a key role in the development of mineral dust related fibrosis. Previously, we showed that ex-vivo release of TNF by peripheral blood monocytes is a marker for progression of coal workers' pneumoconiosis (CWP). Since soluble TNF receptors (sTNF-Rs) are believed to play an important regulatory role in systemic effects of TNF, we measured plasma levels of sTNF-R55 and sTNF-R75 in coal miners with (n = 28) or without (n = 76) CWP and in nonexposed controls (n = 29). sTNF-R75 levels were significantly increased in miners with CWP (2.09 +/- 0.44 ng.mL-1) versus the nonexposed controls (1.86 +/- 0.23 ng.mL-1). Neither sTNF-R55 nor sTNF-R75 were related to exposure, stage of pneumoconiosis, smoking, or (spontaneous or ex-vivo induced) monocyte TNF-release. sTNF-R55 was increased in subjects with medication (especially those using cardiovascular drugs); upon exclusion of these subjects, sTNF-R55 was found also to be significantly increased in CWP. In conclusion, bearing in mind a confounding effect of medication, soluble TNF receptors are elevated in plasma of retired miners with coal workers' pneumoconiosis. These observations further support the important role of TNF-mediated pathways in the pathogenesis of mineral dust related fibrosis.

  18. Plasma Levels of Tumor Necrosis Factor-Alpha and Interleukin-6 in Obsessive Compulsive Disorder

    Directory of Open Access Journals (Sweden)

    N. Konuk

    2007-01-01

    Full Text Available Aim. Recent research implicated place of an immune mechanism in the pathophysiology of obsessive-compulsive disorder (OCD. Despite increasing evidence involvement of cytokine release in OCD, results of the studies are inconsistent. The aim of this study was to evaluate the plasma levels of the cytokines; tumor necrosis factor-alpha (TNF-α and interleukin-6 (IL-6 in OCD patients. Methods. Plasma concentrations of TNF-α and IL-6 were measured in 31 drug-free outpatients with OCD, and 31-year age and sex-matched healthy controls. TNF-α and IL-6 concentrations in blood were determined by enzyme-linked immunosorbent assay (ELISA. Results. Both TNF-α and IL-6 levels showed statistically significant increases in OCD patients compared to controls (P<.000, P<.001, resp.. In addition, the age of onset was negatively correlated with TNF-α level (r=−.402, P=.025 and duration of illness was weakly correlated with IL-6 levels (r:.357; P:.048 in patients group. Conclusion. OCD patients showed increases in TNF-α and IL-6 levels compared to the healthy controls. This study provides evidence for alterations in the proinflamatory cytokines which suggest the involvement of the immune system in the pathophysiology of OCD.

  19. Risk Factors for a Low Linezolid Trough Plasma Concentration in Acute Infections

    Science.gov (United States)

    Morata, Laura; Cuesta, Marta; Rojas, Jhon F.; Rodriguez, Sebastian; Brunet, Merce; Casals, Gregori; Cobos, Nazareth; Hernandez, Cristina; Martínez, José A.; Mensa, Josep

    2013-01-01

    Linezolid is an antibiotic with time-dependent activity, and both the percentage of time that plasma concentrations exceed the MIC and the area under the concentration-time curve over 24 h in the steady state divided by the MIC (AUC24/MIC ratio) are associated with clinical response. The aim of this study was to analyze the linezolid trough plasma concentration (Cmin) and to determine factors associated with a Cmin 80 ml/min, in intensive care unit (ICU) patients, and in patients with an infection due to Staphylococcus aureus. The independent predictors of Cmin 80 ml/min (odds ratio [OR], 10; 95% confidence interval [CI], 2.732 to 37.037; P = 0.001) and infection due to S. aureus (OR, 5.906; 95% CI, 1.651 to 21.126; P = 0.006). A linezolid Cmin of 80 ml/min and in infections due to S. aureus. In patients with severe sepsis, a loading dose or continuous infusion and drug monitoring could improve the pharmacodynamic parameters associated with linezolid efficacy. PMID:23403416

  20. Factors Influencing Plasma Electrolytic Oxidation(PEO) Coatings on Magnesium Alloys: A Review

    Energy Technology Data Exchange (ETDEWEB)

    Shim, Gunchoo [KISTI ReSEAT Program, Daejon (Korea, Republic of)

    2017-05-15

    Magnesium alloys, which possess excellent specific strength and castability, are highly susceptible to corrosion. Although anodizing is widely used to resolve this problem, it requires toxic electrolytes and produces relatively thin and weak surface coatings. Recently, plasma electrolytic oxidation (PEO) has emerged as an alternative to anodizing. Although it is derived from conventional anodizing, it uses eco-friendly electrolytes and forms thicker, denser, and harder coatings on the surface of magnesium alloys. However, PEO is a complex process involving physical, chemical, and electrochemical reactions, and it is influenced by various factors such as the alloy substrate composition, electrolyte/additive composition, and the electrical variables including the mode of power supply, applied voltage/current density, frequency, and duty cycle. In this article, the detailed effects of these parameters on the microstructure and properties of the PEO coatings are reviewed, and methods of improving the coatings are proposed.

  1. Elevated levels of plasma brain derived neurotrophic factor in rapid cycling bipolar disorder patients

    DEFF Research Database (Denmark)

    Munkholm, Klaus; Pedersen, Bente Klarlund; Kessing, Lars Vedel

    2014-01-01

    Impaired neuroplasticity may be implicated in the pathophysiology of bipolar disorder, involving peripheral alterations of the neurotrophins brain derived neurotrophic factor (BDNF) and neurotrophin 3 (NT-3). Evidence is limited by methodological issues and is based primarily on case......-control designs. The aim of this study was to investigate whether BDNF and NT-3 levels differ between patients with rapid cycling bipolar disorder and healthy control subjects and whether BDNF and NT-3 levels alter with affective states in rapid cycling bipolar disorder patients. Plasma levels of BDNF and NT-3...... were measured in 37 rapid cycling bipolar disorder patients and in 40 age- and gender matched healthy control subjects using enzyme-linked immunosorbent assay (ELISA). In a longitudinal design, repeated measurements of BDNF and NT-3 were evaluated in various affective states in bipolar disorder...

  2. Inhibition of vascular permeability by antisense-mediated inhibition of plasma kallikrein and coagulation factor 12.

    Science.gov (United States)

    Bhattacharjee, Gourab; Revenko, Alexey S; Crosby, Jeffrey R; May, Chris; Gao, Dacao; Zhao, Chenguang; Monia, Brett P; MacLeod, A Robert

    2013-06-01

    Hereditary angioedema (HAE) is a rare disorder characterized by recurrent, acute, and painful episodes of swelling involving multiple tissues. Deficiency or malfunction of the serine protease inhibitor C1 esterase inhibitor (C1-INH) results in HAE types 1 and 2, respectively, whereas mutations in coagulation factor 12 (f12) have been associated with HAE type 3. C1-INH is the primary inhibitor of multiple plasma cascade pathways known to be altered in HAE patients, including the complement, fibrinolytic, coagulation, and kinin-kallikrein pathways. We have selectively inhibited several components of both the kinin-kallikrein system and the coagulation cascades with potent and selective antisense oligonucleotides (ASOs) to investigate their relative contributions to vascular permeability. We have also developed ASO inhibitors of C1-INH and characterized their effects on vascular permeability in mice as an inducible model of HAE. Our studies demonstrate that ASO-mediated reduction in C1-INH plasma levels results in increased vascular permeability and that inhibition of proteases of the kinin-kallikrein system, either f12 or prekallikrein (PKK) reverse the effects of C1-INH depletion with similar effects on both basal and angiotensin converting enzyme (ACE) inhibitor-induced permeability. In contrast, inhibition of coagulation factors 11 (f11) or 7 (f7) had no effect. These results suggest that the vascular defects observed in C1-INH deficiency are dependent on the kinin-kallikrein system proteases f12 and PKK, and not mediated through the coagulation pathways. In addition, our results highlight a novel therapeutic modality that can potentially be employed prophylactically to prevent attacks in HAE patients.

  3. Apolipoprotein modulation of streptococcal serum opacity factor activity against human plasma high-density lipoproteins.

    Science.gov (United States)

    Rosales, Corina; Gillard, Baiba K; Courtney, Harry S; Blanco-Vaca, Francisco; Pownall, Henry J

    2009-08-25

    Human plasma HDL are the target of streptococcal serum opacity factor (SOF), a virulence factor that clouds human plasma. Recombinant (r) SOF transfers cholesteryl esters (CE) from approximately 400,000 HDL particles to a CE-rich microemulsion (CERM), forms a cholesterol-poor HDL-like particle (neo HDL), and releases lipid-free (LF) apo A-I. Whereas the rSOF reaction requires labile apo A-I, the modulation effects of other apos are not known. We compared the products and rates of the rSOF reaction against human HDL and HDL from mice overexpressing apos A-I and A-II. Kinetic studies showed that the reactivity of various HDL species is apo-specific. LpA-I reacts faster than LpA-I/A-II. Adding apos A-I and A-II inhibited the SOF reaction, an effect that was more profound for apo A-II. The rate of SOF-mediated CERM formation was slower against HDL from mice expressing human apos A-I and A-II than against WT mice HDL and slowest against HDL from apo A-II overexpressing mice. The lower reactivity of SOF against HDL containing human apos is due to the higher hydropathy of human apo A-I, particularly its C-terminus relative to mouse apo A-I, and the higher lipophilicity of human apo A-II. The SOF-catalyzed reaction is the first to target HDL rather than its transporters and receptors in a way that enhances reverse cholesterol transport (RCT). Thus, effects of apos on the SOF reaction are highly relevant. Our studies show that the "humanized" apo A-I-expressing mouse is a good animal model for studies of rSOF effects on RCT in vivo.

  4. Plasma IP-10, apoptotic and angiogenic factors associated with fatal cerebral malaria in India

    Directory of Open Access Journals (Sweden)

    Dash AP

    2008-05-01

    Full Text Available Abstract Background Plasmodium falciparum in a subset of patients can lead to cerebral malaria (CM, a major contributor to malaria-associated mortality. Despite treatment, CM mortality can be as high as 30%, while 10% of survivors of the disease may experience short- and long-term neurological complications. The pathogenesis of CM is mediated by alterations in cytokine and chemokine homeostasis, inflammation as well as vascular injury and repair processes although their roles are not fully understood. The hypothesis for this study is that CM-induced changes in inflammatory, apoptotic and angiogenic factors mediate severity of CM and that their identification will enable development of new prognostic markers and adjunctive therapies for preventing CM mortalities. Methods Plasma samples (133 were obtained from healthy controls (HC, 25, mild malaria (MM, 48, cerebral malaria survivors (CMS, 48, and cerebral malaria non-survivors (CMNS, 12 at admission to the hospital in Jabalpur, India. Plasma levels of 30 biomarkers ((IL-1β, IL-1ra, IL-2, IL-4, IL-5, IL-6, IL-8, IL-9, IL-10, IL-12 (p70, IL-13, IL-15, IL-17, Eotaxin, FGF basic protein, G-CSF, GM-CSF, IFN-γ, IP-10, MCP-1 (MCAF, MIP-1α, MIP-1β, RANTES, TNF-α, Fas-ligand (Fas-L, soluble Fas (sFas, soluble TNF receptor 1 (sTNF-R1 and soluble TNF receptor 2 (sTNFR-2, PDGF bb and VEGF were simultaneously measured in an initial subset of ten samples from each group. Only those biomarkers which showed significant differences in the pilot analysis were chosen for testing on all remaining samples. The results were then compared between the four groups to determine their role in CM severity. Results IP-10, sTNF-R2 and sFas were independently associated with increased risk of CM associated mortality. CMNS patients had a significantly lower level of the neuroprotective factor VEGF when compared to other groups (P Conclusion The results suggest that plasma levels of IP-10, sTNF-R2 and sFas may be potential

  5. Influence of platelet-derived growth factor-AB on tissue development in autologous platelet-rich plasma gels.

    Science.gov (United States)

    Wirz, Simone; Dietrich, Maren; Flanagan, Thomas C; Bokermann, Gudrun; Wagner, Wolfgang; Schmitz-Rode, Thomas; Jockenhoevel, Stefan

    2011-07-01

    Fibrin-based scaffolds are widely used in tissue engineering. We postulated that the use of platelet-rich plasma (PRP) in contrast to platelet-poor plasma and pure fibrinogen as the basic material leads to an increased release of autologous platelet-derived growth factor (PDGF)-AB, which may have a consequent positive effect on tissue development. Therefore, we evaluated the release of PDGF-AB during the production process and the course of PDGF release during cultivation of plasma gels with and w/o platelets. The influence of PDGF-AB on the proliferation rate of human umbilical cord artery smooth muscle cells (HUASMCs) was studied using XTT assay. The synthesis of extracellular matrix by HUASMCs in plasma- and fibrin gels was measured using hydroxyproline assay. The use of PRP led to an increase in autologous PDGF-AB release. Further, the platelet-containing plasma gels showed a prolonged release of growth factor during cultivation. Both PRP and platelet-poor plasma gels had a positive effect on the production of collagen. However, PDGF-AB as a supplement in medium and in pure fibrin gel had neither an effect on cell proliferation nor on the collagen synthesis rate. This observation may be due to an absence of PDGF receptors in HUASMCs as determined by flow cytometry. In conclusion, although the prolonged autologous production of PDGF-AB in PRP gels is possible, the enhanced tissue development by HUASMCs within such gels is not PDGF related.

  6. Platelet adhesion and plasma protein adsorption control of collagen surfaces by He{sup +} ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Kurotobi, K. E-mail: kurotobi@postman.riken.go.jp; Suzuki, Y.; Nakajima, H.; Suzuki, H.; Iwaki, M

    2003-05-01

    He{sup +} ion implanted collagen-coated tubes with a fluence of 1 x 10{sup 14} ions/cm{sup 2} were exhibited antithrombogenicity. To investigate the mechanisms of antithrombogenicity of these samples, plasma protein adsorption assay and platelet adhesion experiments were performed. The adsorption of fibrinogen (Fg) and von Willebrand factor (vWf) was minimum on the He{sup +} ion implanted collagen with a fluence of 1 x 10{sup 14} ions/cm{sup 2}. Platelet adhesion (using platelet rich plasma) was inhibited on the He{sup +} ion implanted collagen with a fluence of 1 x 10{sup 14} ions/cm{sup 2} and was accelerated on the untreated collagen and ion implanted collagen with fluences of 1 x 10{sup 13}, 1 x 10{sup 15} and 1 x 10{sup 16} ions/cm{sup 2}. Platelet activation with washed platelets was observed on untreated collagen and He{sup +} ion implanted collagen with a fluence of 1 x 10{sup 14} ions/cm{sup 2} and was inhibited with fluences of 1 x 10{sup 13}, 1 x 10{sup 15} and 1 x 10{sup 16} ions/cm{sup 2}. Generally, platelets can react with a specific ligand inside the collagen (GFOGER sequence). The results of platelets adhesion experiments using washed platelets indicated that there were no ligands such as GFOGER on the He{sup +} ion implanted collagen over a fluence of 1 x 10{sup 13} ions/cm{sup 2}. On the 1 x 10{sup 14} ions/cm{sup 2} implanted collagen, no platelet activation was observed due to the influence of plasma proteins. >From the above, it is concluded that the decrease of adsorbed Fg and vWf caused the antithrombogenicity of He{sup +} ion implanted collagen with a fluence of 1 x 10{sup 14} ions/cm{sup 2} and that plasma protein adsorption took an important role repairing the graft surface.

  7. The protein concentration of blood coagulation factor VII can be measured equally well in plasma and serum

    DEFF Research Database (Denmark)

    Bladbjerg, E-M; Overgaard, K; Gram, J

    1995-01-01

    In the Northwick Park Heart Study, the coagulant activity of factor VII (FVII:C) has been identified as a risk marker of ischaemic heart disease. In the fasting state, the protein concentration of FVII (FVII:Ag) might be an even better risk marker, because of the low coefficient of variation...... samples. Results were compared by means of linear regression, where y = 0.984 x +0.770, r = 0.96. No systematic variation existed between FVII:Ag in plasma and serum. The mean difference in FVII:Ag between plasma and serum was -1.17 (SD 11.92) arbitrary units, compared with a mean difference of 0.18 (SD 8.......31) arbitrary units between duplicate measurements of the same plasma dilution. Our findings indicate that there is a good agreement between FVII:Ag in plasma and serum. Udgivelsesdato: 1995-May...

  8. Predictive factors of plasma HIV suppression during pregnancy: a prospective cohort study in Benin.

    Directory of Open Access Journals (Sweden)

    Lise Denoeud-Ndam

    Full Text Available OBJECTIVE: To investigate the factors associated with HIV1 RNA plasma viral load (pVL below 40 copies/mL at the third trimester of pregnancy, as part of prevention of mother-to-child transmission (PMTCT in Benin. DESIGN: Sub study of the PACOME clinical trial of malaria prophylaxis in HIV-infected pregnant women, conducted before and after the implementation of the WHO 2009 revised guidelines for PMTCT. METHODS: HIV-infected women were enrolled in the second trimester of pregnancy. Socio-economic characteristics, HIV history, clinical and biological characteristics were recorded. Malaria prevention and PMTCT involving antiretroviral therapy (ART for mothers and infants were provided. Logistic regression helped identifying factors associated with virologic suppression at the end of pregnancy. RESULTS: Overall 217 third trimester pVLs were available, and 71% showed undetectability. Virologic suppression was more frequent in women enrolled after the change in PMTCT recommendations, advising to start ART at 14 weeks instead of 28 weeks of pregnancy. In multivariate analysis, Fon ethnic group (the predominant ethnic group in the study area, regular job, first and second pregnancy, higher baseline pVL and impaired adherence to ART were negative factors whereas higher weight, higher antenatal care attendance and longer ART duration were favorable factors to achieve virologic suppression. CONCLUSIONS: This study provides more evidence that ART has to be initiated before the last trimester of pregnancy to achieve an undetectable pVL before delivery. In Benin, new recommendations supporting early initiation were well implemented and, together with a high antenatal care attendance, led to high rate of virologic control.

  9. Eicosanoid and cytokine levels in plasma of patients during mesenteric infarction.

    Science.gov (United States)

    Nathan, N; Denizot, Y; Feiss, P

    1997-01-01

    Multible organ failure (MOF) induced by mesenteric infarction is associated with a high mortality rate. This study reports eicosanoid and cytokine levels in the blood of three atherosclerotic patients who ultimately died from MOF induced by mesenteric infarction. High plasma levels of 6- keto-prostaglandin (PG) F(1alpha) (the stable metabolite of PGI(2)), interleukin (IL)-6 and IL-8 are observed whereas plasma tumour necrosis factor alpha (TNFalpha), TxB(2) (the stable metabolite of TxA(2)), PGE(2), leukotrienes (LT)B(4) and LTC(4), and whole blood platelet-activating factor levels are not different from values obtained in similarly severe atherosclerotic patients. This short report questioned the clinical involvement of TNFalpha during such a pathology where a persistent translocation of endotoxin has been observed through the gut endothelial barrier. Activation of phospholipase A(2) is suggested by the increase in the stable metabolite of PGI(2) and might be by itself or through lipidic metabolites, a major systemic stimulus of IL-6 and IL-8 production.

  10. Eicosanoid and cytokine levels in plasma of patients during mesenteric infarction

    Directory of Open Access Journals (Sweden)

    N. Nathan

    1997-01-01

    Full Text Available Multible organ failure (MOF induced by mesenteric infarction is associated with a high mortality rate. This study reports eicosanoid and cytokine levels in the blood of three atherosclerotic patients who ultimately died from MOF induced by mesenteric infarction. High plasma levels of 6- keto-prostaglandin (PG F1α (the stable metabolite of PGI2, interleukin (IL-6 and IL-8 are observed whereas plasma tumour necrosis factor alpha (TNFα, TxB2 (the stable metabolite of TxA2, PGE2, leukotrienes (LTB4 and LTC4, and whole blood platelet-activating factor levels are not different from values obtained in similarly severe atherosclerotic patients. This short report questioned the clinical involvement of TNFα during such a pathology where a persistent translocation of endotoxin has been observed through the gut endothelial barrier. Activation of phospholipase A2 is suggested by the increase in the stable metabolite of PGI2 and might be by itself or through lipidic metabolites, a major systemic stimulus of IL-6 and IL-8 production.

  11. On Variable Geometric Factor Systems for Top-Hat Electrostatic Space Plasma Analyzers

    Science.gov (United States)

    Kataria, Dhiren O.; Collinson, Glyn A.

    2010-01-01

    Even in the relatively small region of space that is the Earth's magnetosphere, ion and electron fluxes can vary by several orders of magnitude. Top-hat electrostatic analyzers currently do not possess the dynamic range required to sample plasma under all conditions. The purpose of this study was to compare, through computer simulation, three new electrostatic methods that would allow the sensitivity of a sensor to be varied through control of its geometric factor (GF) (much like an aperture on a camera). The methods studied were inner filter plates, split hemispherical analyzer (SHA) and top-cap electrode. This is the first discussion of the filter plate concept and also the first study where all three systems are studied within a common analyzer design, so that their relative merits could be fairly compared. Filter plates were found to have the important advantage that they facilitate the reduction in instrument sensitivity whilst keeping all other instrument parameters constant. However, it was discovered that filter plates have numerous disadvantages that make such a system impracticable for a top-hat electrostatic analyzer. It was found that both the top-cap electrode and SHA are promising variable geometric factor system (VGFS) concepts for implementation into a top-hat electrostatic analyzer, each with distinct advantages over the other.

  12. Association of cardiovascular factors and Alzheimer's disease plasma amyloid-beta protein in subjective memory complainers.

    Science.gov (United States)

    Bates, Kristyn A; Sohrabi, Hamid R; Rodrigues, Mark; Beilby, John; Dhaliwal, Satvinder S; Taddei, Kevin; Criddle, Arthur; Wraith, Megan; Howard, Matthew; Martins, Georgia; Paton, Athena; Mehta, Pankaj; Foster, Jonathan K; Martins, Ian J; Lautenschlager, Nicola T; Mastaglia, Frank L; Laws, Simon M; Gandy, Samuel E; Martins, Ralph N

    2009-01-01

    A strong link is indicated between cardiovascular disease (CVD) and risk for developing Alzheimer's disease (AD), which may be exacerbated by the major AD genetic risk factor apolipoprotein Eepsilon4 (APOEepsilon4). Since subjective memory complaint (SMC) may potentially be an early indicator for cognitive decline, we examined CVD risk factors in a cohort of SMC. As amyloid-beta (Abeta) is considered to play a central role in AD, we hypothesized that the CVD risk profile (increased LDL, reduced HDL, and increased body fat) would be associated with plasma Abeta levels. We explored this in 198 individuals with and without SMC (average age = 63 years). Correlations between Abeta40 and HDL were observed, which were stronger in non-APOEepsilon4 carriers (rho = -0.315, p association between HDL and Abeta, which if demonstrated to be causal has implications for the development of lifestyle interventions and/or novel therapeutics. The relationship between HDL and Abeta and the potential significance of such an association needs to be validated in a larger longitudinal study.

  13. ADAM10 regulates transcription factor expression required for plasma cell function.

    Directory of Open Access Journals (Sweden)

    Natalia S Chaimowitz

    Full Text Available A disintegrin and metalloprotease 10 (ADAM10 is a key regulator of cellular processes by shedding extracellular domains of transmembrane proteins. We have previously demonstrated that deletion of B cell expressed ADAM10 results in changes in lymphoid tissue architecture and impaired germinal center (GC formation. In this study, mice were generated in which ADAM10 is deleted in B cells following class switch recombination (ADAM10(Δ/ΔIgG1-cre(+/- mice. Despite normal GC formation, antibody responses were impaired in ADAM10(Δ/ΔIgG1-cre(+/- mice, implicating ADAM10 in post-GC and extrafollicular B cell terminal differentiation. Surprisingly, plasma cell (PC numbers were normal in ADAM10(Δ/ΔIgG1-cre(+/- mice when compared to controls. However, PCs isolated from ADAM10(Δ/ΔIgG1-cre(+/- mice exhibited decreased expression of transcription factors important for PC function: Prdm1, Xbp1 and Irf4. Bcl6 is a GC transcriptional repressor that inhibits the PC transcriptional program and thus must be downregulated for PC differentiation to occur. Bcl6 expression was increased in PCs isolated from ADAM10(Δ/ΔIgG1-cre(+/- mice at both the mRNA and protein level. These results demonstrate that ADAM10 is required for proper transcription factor expression in PCs and thus, for normal PC function.

  14. Surgical treatment of denture-induced fibrous hyperplasia with plasma rich in growth factors.

    Science.gov (United States)

    Mozzati, Marco; Mortellaro, Carmen; Gallesio, Giorgia; Ruggiero, Tiziana; Pol, Renato

    2015-05-01

    Denture-induced fibrous hyperplasia is a fibrous connective tissue lesion that commonly occurs in oral mucosa in patients showing important alveolar ridge atrophy. In this study, we propose Plasma Rich in Growth Factors (PRGF) to overcome constrains of traditional surgical treatment. Herein, we demonstrated that PRGF represents an autologous source of growth factors able to reduce the healing time of the alveolar mucosa and the discomfort of those patients. These properties are the result of PRGF's precise biological features that result in the following: reduction of duration and intensity of postsurgical pain, acceleration of re-epithelialization of the wound, and reduction of bleeding events and of edema. In conclusion, we showed that using PRGF on patients affected by denture-induced fibrous hyperplasia allows a short healing time, thereby reducing complications and overall improving their quality of life. The aims of this study were to evaluate the influence of PRGF-ENDORET on secondary re-epithelialization in vestibuloplasty after excision of denture irritation fibrous hyperplasia, with an explorative randomized case control trial with 10 patients, 5 patients treated with PRGF and 5 patients with traditional hemostasis, and to analyze differences with simple surgery, considering postoperative rapidity of re-epithelialization, comfort, and discomfort of patients, pain, swelling, and infections.

  15. Plasma Adiponectin, clinical factors, and patient outcomes during the acute respiratory distress syndrome.

    Directory of Open Access Journals (Sweden)

    Allan J Walkey

    Full Text Available Adiponectin (APN is an anti-inflammatory hormone derived from adipose tissue that attenuates acute lung injury in rodents. In this study, we investigated the association between circulating APN and outcomes among patients with acute respiratory distress syndrome (ARDS.We performed a retrospective cohort study using data and plasma samples from participants in the multicenter ARDS Network Fluid and Catheter Treatment Trial.Plasma APN concentrations were measured in 816 (81.6% trial participants at baseline and in 568 (56.8% subjects at both baseline and day 7 after enrollment. Clinical factors associated with baseline APN levels in multivariable-adjusted models included sex, body mass index, past medical history of cirrhosis, and central venous pressure (model R2 = 9.7%. We did not observe an association between baseline APN and either severity of illness (APACHE III or extent of lung injury (Lung Injury Score. Among patients who received right heart catheterization (n = 384, baseline APN was inversely related to mean pulmonary artery pressure (β = -0.015, R2 1.5%, p = 0.02; however, this association did not persist in multivariable models (β = -0.009, R2 0.5%, p = 0.20. Neither baseline APN levels [HR per quartile1.04 (95% CI 0.91-1.18, p = 0.61], nor change in APN level from baseline to day 7 [HR 1.04 (95% CI 0.89-1.23, p = 0.62] were associated with 60 day mortality in Cox proportional hazards regression models. However, subgroup analysis identified an association between APN and mortality among patients who developed ARDS from extra-pulmonary etiologies [HR per quartile 1.31 (95% CI 1.08-1.57]. APN levels did not correlate with mortality among patients developing ARDS in association with direct pulmonary injury [HR 0.96 (95% CI 0.83-1.13], pinteraction = 0.016.Plasma APN levels did not correlate with disease severity or mortality in a large cohort of patients with ARDS. However, higher APN levels were

  16. Cytokine, chemokine, and growth factor profile of platelet-rich plasma.

    Science.gov (United States)

    Mussano, F; Genova, T; Munaron, L; Petrillo, S; Erovigni, F; Carossa, S

    2016-07-01

    During wound healing, biologically active molecules are released from platelets. The rationale of using platelet-rich plasma (PRP) relies on the concentration of bioactive molecules and subsequent delivery to healing sites. These bioactive molecules have been seldom simultaneously quantified within the same PRP preparation. In the present study, the flexible Bio-Plex system was employed to assess the concentration of a large range of cytokines, chemokines, and growth factors in 16 healthy volunteers so as to determine whether significant baseline differences may be found. Besides IL-1b, IL-1ra, IL-4, IL-6, IL-8, IL-12, IL-13, IL-17, INF-γ, TNF-α, MCP-1, MIP-1a, RANTES, bFGF, PDGF, and VEGF that were already quantified elsewhere, the authors reported also on the presence of IL-2, IL-5, IL-7, IL-9, IL-10, IL-15 G-CSF, GM-CSF, Eotaxin, CXCL10 chemokine (IP-10), and MIP 1b. Among the most interesting results, it is convenient to mention the high concentrations of the HIV-suppressive and inflammatory cytokine RANTES and a statistically significant difference between males and females in the content of PDGF-BB. These data are consistent with previous reports pointing out that gender, diet, and test system affect the results of platelet function in healthy subjects, but seem contradictory when compared to other quantification assays in serum and plasma. The inconsistencies affecting the experimental results found in literature, along with the variability found in the content of bioactive molecules, urge further research, hopefully in form of randomized controlled clinical trials, in order to find definitive evidence of the efficacy of PRP treatment in various pathologic and regenerative conditions.

  17. Platelet factor 4 impairs the anticoagulant activity of activated protein C.

    LENUS (Irish Health Repository)

    Preston, Roger J S

    2009-02-27

    Platelet factor 4 (PF4) is an abundant platelet alpha-granule chemokine released following platelet activation. PF4 interacts with thrombomodulin and the gamma-carboxyglutamic acid (Gla) domain of protein C, thereby enhancing activated protein C (APC) generation by the thrombin-thrombomodulin complex. However, the protein C Gla domain not only mediates protein C activation in vivo, but also plays a critical role in modulating the diverse functional properties of APC once generated. In this study we demonstrate that PF4 significantly inhibits APC anti-coagulant activity. PF4 inhibited both protein S-dependent APC anticoagulant function in plasma and protein S-dependent factor Va (FVa) proteolysis 3- to 5-fold, demonstrating that PF4 impairs protein S cofactor enhancement of APC anticoagulant function. Using recombinant factor Va variants FVa-R506Q\\/R679Q and FVa-R306Q\\/R679Q, PF4 was shown to impair APC proteolysis of FVa at position Arg(306) by 3-fold both in the presence and absence of protein S. These data suggest that PF4 contributes to the poorly understood APC resistance phenotype associated with activated platelets. Finally, despite PF4 binding to the APC Gla domain, we show that APC in the presence of PF4 retains its ability to initiate PAR-1-mediated cytoprotective signaling. In summary, we propose that PF4 acts as a critical regulator of APC generation, but also differentially targets APC toward cytoprotective, rather than anticoagulant function at sites of vascular injury with concurrent platelet activation.

  18. Platelet factor 4 impairs the anticoagulant activity of activated protein C.

    LENUS (Irish Health Repository)

    Preston, Roger J S

    2012-02-01

    Platelet factor 4 (PF4) is an abundant platelet alpha-granule chemokine released following platelet activation. PF4 interacts with thrombomodulin and the gamma-carboxyglutamic acid (Gla) domain of protein C, thereby enhancing activated protein C (APC) generation by the thrombin-thrombomodulin complex. However, the protein C Gla domain not only mediates protein C activation in vivo, but also plays a critical role in modulating the diverse functional properties of APC once generated. In this study we demonstrate that PF4 significantly inhibits APC anti-coagulant activity. PF4 inhibited both protein S-dependent APC anticoagulant function in plasma and protein S-dependent factor Va (FVa) proteolysis 3- to 5-fold, demonstrating that PF4 impairs protein S cofactor enhancement of APC anticoagulant function. Using recombinant factor Va variants FVa-R506Q\\/R679Q and FVa-R306Q\\/R679Q, PF4 was shown to impair APC proteolysis of FVa at position Arg(306) by 3-fold both in the presence and absence of protein S. These data suggest that PF4 contributes to the poorly understood APC resistance phenotype associated with activated platelets. Finally, despite PF4 binding to the APC Gla domain, we show that APC in the presence of PF4 retains its ability to initiate PAR-1-mediated cytoprotective signaling. In summary, we propose that PF4 acts as a critical regulator of APC generation, but also differentially targets APC toward cytoprotective, rather than anticoagulant function at sites of vascular injury with concurrent platelet activation.

  19. Growth factor and pro-inflammatory cytokine contents in platelet-rich plasma (PRP), plasma rich in growth factors (PRGF), advanced platelet-rich fibrin (A-PRF), and concentrated growth factors (CGF).

    Science.gov (United States)

    Masuki, Hideo; Okudera, Toshimitsu; Watanebe, Taisuke; Suzuki, Masashi; Nishiyama, Kazuhiko; Okudera, Hajime; Nakata, Koh; Uematsu, Kohya; Su, Chen-Yao; Kawase, Tomoyuki

    2016-12-01

    The development of platelet-rich fibrin (PRF) drastically simplified the preparation procedure of platelet-concentrated biomaterials, such as platelet-rich plasma (PRP), and facilitated their clinical application. PRF's clinical effectiveness has often been demonstrated in pre-clinical and clinical studies; however, it is still controversial whether growth factors are significantly concentrated in PRF preparations to facilitate wound healing and tissue regeneration. To address this matter, we performed a comparative study of growth factor contents in PRP and its derivatives, such as advanced PRF (A-PRF) and concentrated growth factors (CGF). PRP and its derivatives were prepared from the same peripheral blood samples collected from healthy donors. A-PRF and CGF preparations were homogenized and centrifuged to produce extracts. Platelet and white blood cell counts in A-PRF and CGF preparations were determined by subtracting those counts in red blood cell fractions, supernatant acellular serum fractions, and A-PRF/CGF exudate fractions from those counts of whole blood samples. Concentrations of growth factors (TGF-β1, PDGF-BB, VEGF) and pro-inflammatory cytokines (IL-1β, IL-6) were determined using ELISA kits. Compared to PRP preparations, both A-PRF and CGF extracts contained compatible or higher levels of platelets and platelet-derived growth factors. In a cell proliferation assay, both A-PRF and CGF extracts significantly stimulated the proliferation of human periosteal cells without significant reduction at higher doses. These data clearly demonstrate that both A-PRF and CGF preparations contain significant amounts of growth factors capable of stimulating periosteal cell proliferation, suggesting that A-PRF and CGF preparations function not only as a scaffolding material but also as a reservoir to deliver certain growth factors at the site of application.

  20. Danger signal-dependent activation of human dendritic cells by plasma-derived factor VIII products.

    Science.gov (United States)

    Miller, L; Weissmüller, S; Ringler, E; Crauwels, P; van Zandbergen, G; Seitz, R; Waibler, Z

    2015-08-01

    Treatment of haemophilia A by infusions of the clotting factor VIII (FVIII) results in the development of inhibitors/anti-drug antibodies in up to 25 % of patients. Mechanisms leading to immunogenicity of FVIII products are not yet fully understood. Amongst other factors, danger signals as elicited upon infection or surgery have been proposed to play a role. In the present study, we focused on effects of danger signals on maturation and activation of dendritic cells (DC) in the context of FVIII application. Human monocyte-derived DC were treated with FVIII alone, with a danger signal alone or a combination of both. By testing more than 60 different healthy donors, we show that FVIII and the bacterial danger signal lipopolysaccharide synergise in increasing DC activation, as characterised by increased expression of co-stimulatory molecules and secretion of pro-inflammatory cytokines. The degree and frequency of this synergistic activation correlate with CD86 expression levels on immature DC prior to stimulation. In our assay system, plasma-derived but not recombinant FVIII products activate human DC in a danger signal-dependent manner. Further tested danger signals, such as R848 also induced DC activation in combination with FVIII, albeit not in every tested donor. In our hands, human DC but not human B cells or macrophages could be activated by FVIII in a danger signal-dependent manner. Our results suggest that immunogenicity of FVIII is a result of multiple factors including the presence of danger, predisposition of the patient, and the choice of a FVIII product for treatment.

  1. Transforming growth factor-beta plasma dynamics and post-irradiation lung injury in lung cancer patients

    NARCIS (Netherlands)

    Novakova-Jiresova, A; van Gameren, MM; Coppes, RP; Kampinga, HH; Groen, HJM

    2004-01-01

    Purpose: To investigate the relevance of transforming growth factor-beta (TGF-beta) dynamics in plasma for identification of patients at low risk for developing pneumonitis as a complication of thoracic radiotherapy (RT). Patients and methods: Non-small cell lung cancer patients undergoing conventio

  2. Protective Mechanisms of S. lycopersicum Aqueous Fraction (Nucleosides and Flavonoids on Platelet Activation and Thrombus Formation: In Vitro, Ex Vivo and In Vivo Studies

    Directory of Open Access Journals (Sweden)

    Eduardo Fuentes

    2013-01-01

    Full Text Available The purpose of this research was to investigate mechanisms of antiplatelet action of bioactive principle from S. lycopersicum. Aqueous fraction had a high content of nucleosides (adenosine, guanosine, and adenosine 5′-monophosphate by HPLC analysis. Also aqueous fraction presented flavonoids content. Aqueous fraction inhibited platelet activation by 15 ± 6% (P<0.05. Fully spread of human platelets on collagen in the presence of aqueous fraction was inhibited from 15 ± 1 to 9 ± 1 μm2 (P<0.001. After incubation of whole blood with aqueous fraction, the platelet coverage was inhibited by 55 ± 12% (P<0.001. Platelet ATP secretion and aggregation were significantly inhibited by the aqueous fraction. At the same concentrations that aqueous fraction inhibits platelet aggregation, levels of sCD40L significantly decreased and the intraplatelet cAMP levels increased. In addition, SQ22536, an adenylate cyclase inhibitor, attenuated the effect of aqueous fraction toward ADP-induced platelet aggregation and intraplatelet level of cAMP. Platelet aggregation ex vivo (human study and thrombosis formation in vivo (murine model were inhibited by aqueous fraction. Finally, aqueous fraction may be used as a functional ingredient adding antiplatelet activities (nucleosides and flavonoids to processed foods.

  3. Exogenous L-arginine and HDL can alter LDL and ox-LDL-mediated platelet