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1.
Opt Express ; 26(6): 6943-6948, 2018 Mar 19.
Article in English | MEDLINE | ID: mdl-29609380

ABSTRACT

We demonstrate real-time transmission of 16 Tb/s (80x200Gb/s) over 1020km TeraWave ULL fiber with 170km span length using the world's first 200Gb/s CFP2-DCO module with a record low power consumption less than 0.1W/Gbps.

2.
Opt Express ; 24(22): 25291-25297, 2016 Oct 31.
Article in English | MEDLINE | ID: mdl-27828467

ABSTRACT

We demonstrate unrepeatered transmission of 8x128Gb/s PDM-QPSK signals over a 515k-m fiber link. This ultra-long distance of 800 Gb/s unrepeatered transmission in a single fiber configuration is achieved by employing enabling techniques such as large-effective-area ultra-low-attenuation fibers, co-propagating and counter-propagating 2nd-order-pumped distributed Raman amplification, and remote optically pumped amplifier (ROPA). The ROPA itself is also counter-propagating 2nd-order Raman pumped. The designs and characteristics of the ROPA and 2nd-order pumped distributed Raman amplification are described, and optimization of the transmission performance of this ultra-long reach 800Gb/s unrepeatered transmission fiber link is discussed in this paper.

3.
Herz ; 40 Suppl 3: 269-76, 2015 May.
Article in English | MEDLINE | ID: mdl-24305990

ABSTRACT

BACKGROUND: Upon coincubation with platelet aggregates, CD34(+) progenitor cells have the potential to differentiate into foam cells. There is evidence that progenitor cells from diabetic and nondiabetic patients have different properties, which may affect the patients' prognosis. In this study we investigated an in vitro model of foam cell formation based on patient-derived CD34(+) progenitor cells. We analyzed the growth characteristics as well as the M-CSF-release and matrix metalloproteinase (MMP) synthesis from CD34(+) progenitor cell-derived foam cells originating from diabetic and nondiabetic patients. METHODS AND RESULTS: Bone marrow samples were obtained from 38 patients who were elected for thoracic surgery. CD34(+) progenitor cells from diabetic and nondiabetic patients were isolated and incubated with platelets from healthy volunteers. Foam cell formation was confirmed by immunostaining (CD68) and quantified by light microscopy. Whereas the absolute number of foam cells was not affected, the negative slope in the growth curve was seen significantly later in the diabetic group. In supernatants derived from"diabetic" CD34(+) progenitor cells, MMP-9 was significantly enhanced, whereas MMP-2 activity or M-CSF-release was not affected significantly. CONCLUSION: In a coculture model of CD34(+) progenitor cells with platelets, we show for the first time that"diabetic" CD34(+) progenitor cells exhibit functional differences in their differentiation to foam cells concerning growth characteristics and release of MMP-9.


Subject(s)
Diabetes Mellitus/enzymology , Diabetes Mellitus/pathology , Foam Cells/enzymology , Foam Cells/pathology , Matrix Metalloproteinase 9/metabolism , Mesenchymal Stem Cells/pathology , Aged , Antigens, CD34/metabolism , Blood Platelets/enzymology , Blood Platelets/pathology , Cell Differentiation , Cell Proliferation , Cells, Cultured , Coculture Techniques , Enzyme Activation , Female , Humans , Male , Mesenchymal Stem Cells/enzymology
4.
Platelets ; 25(6): 439-46, 2014.
Article in English | MEDLINE | ID: mdl-24102318

ABSTRACT

High on-treatment platelet reactivity is associated with short-term major cardiovascular (CV) events in patients undergoing percutaneous coronary intervention (PCI). Maximum and final aggregation assessed by light transmission aggregometry (LTA) have both been used to predict short-term outcome after PCI, however their long-term prognostic impact remains controversial. There is currently no information regarding the prognostic role of deaggregation and its added value in combination with established aggregation parameters. About 1279 patients with symptomatic coronary artery disease (CAD) undergoing PCI were enrolled in this monocentric study. On-treatment platelet aggregation under clopidogrel maintenance therapy, as well as deaggregation was determined by maximum and final aggregation (5 min after adding of the agonist). Deaggregation was defined as slope of the tangent between Aggmax +0.5 min. Primary endpoints were the composite of myocardial infarction, stroke, and CV death or stent thrombosis according to the ARC criteria. Low deaggregation, defined as values in the lowest tertile (<1.5), was more frequent in patients with acute coronary syndromes (ACS) compared to patients with stable angina pectoris (SAP), ACS: 29.6% vs. SAP: 22.0%, p = 0.001. The combination of high on-treatment platelet reactivity, defined by the upper tertile of Aggmax and low deaggregation, was associated with significantly increased risk for combined long-term CV events. The combination of low deaggregation and high on-treatment platelet reactivity is associated with higher risk for recurrent events in patients with CAD undergoing PCI. Thus, deaggregation might be a more sensitive parameter providing added value in terms of risk prediction for long-term recurrent CV events in relation with established aggregation parameters.


Subject(s)
Blood Platelets/metabolism , Percutaneous Coronary Intervention/adverse effects , Platelet Aggregation Inhibitors/administration & dosage , Platelet Aggregation/drug effects , Postoperative Complications , Ticlopidine/analogs & derivatives , Aged , Aged, 80 and over , Clopidogrel , Coronary Artery Disease/blood , Coronary Artery Disease/mortality , Coronary Artery Disease/therapy , Disease-Free Survival , Follow-Up Studies , Humans , Male , Middle Aged , Postoperative Complications/blood , Postoperative Complications/drug therapy , Postoperative Complications/mortality , Predictive Value of Tests , Survival Rate , Ticlopidine/administration & dosage
5.
Clin Res Cardiol ; 112(2): 285-298, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36166067

ABSTRACT

BACKGROUND: Patients with coronary heart disease (CHD) with and without diabetes mellitus have an increased risk of recurrent events requiring multifactorial secondary prevention of cardiovascular risk factors. We compared prevalences of cardiovascular risk factors and its determinants including lifestyle, pharmacotherapy and diabetes mellitus among patients with chronic CHD examined within the fourth and fifth EUROASPIRE surveys (EA-IV, 2012-13; and EA-V, 2016-17) in Germany. METHODS: The EA initiative iteratively conducts European-wide multicenter surveys investigating the quality of secondary prevention in chronic CHD patients aged 18 to 79 years. The data collection in Germany was performed during a comprehensive baseline visit at study centers in Würzburg (EA-IV, EA-V), Halle (EA-V), and Tübingen (EA-V). RESULTS: 384 EA-V participants (median age 69.0 years, 81.3% male) and 536 EA-IV participants (median age 68.7 years, 82.3% male) were examined. Comparing EA-IV and EA-V, no relevant differences in risk factor prevalence and lifestyle changes were observed with the exception of lower LDL cholesterol levels in EA-V. Prevalence of unrecognized diabetes was significantly lower in EA-V as compared to EA-IV (11.8% vs. 19.6%) while the proportion of prediabetes was similarly high in the remaining population (62.1% vs. 61.0%). CONCLUSION: Between 2012 and 2017, a modest decrease in LDL cholesterol levels was observed, while no differences in blood pressure control and body weight were apparent in chronic CHD patients in Germany. Although the prevalence of unrecognized diabetes decreased in the later study period, the proportion of normoglycemic patients was low. As pharmacotherapy appeared fairly well implemented, stronger efforts towards lifestyle interventions, mental health programs and cardiac rehabilitation might help to improve risk factor profiles in chronic CHD patients.


Subject(s)
Coronary Disease , Diabetes Mellitus , Myocardial Ischemia , Humans , Male , Aged , Female , Secondary Prevention , Cholesterol, LDL , Diabetes Mellitus/epidemiology , Coronary Disease/epidemiology , Coronary Disease/prevention & control , Risk Factors , Myocardial Ischemia/complications , Europe/epidemiology
6.
Eur J Neurol ; 19(3): 395-401, 2012 Mar.
Article in English | MEDLINE | ID: mdl-21951424

ABSTRACT

BACKGROUND AND PURPOSE: Platelet stromal-cell-derived factor-1 (SDF-1) plays a pivotal role in angiogenesis and the regeneration of ischaemic tissue through the regulation of haematopoietic progenitor cells and is upregulated at the sites of vascular injury and platelet activation. Thus, SDF-1 has recently been discussed as a predictor in ischaemic diseases such as acute myocardial infarction. However, no clinical data pertinent to the investigation of the platelet SDF-1 expression in patients with stroke are available. METHODS: We consecutively evaluated 196 patients who were admitted to the stroke unit with symptoms suspected for stroke. Surface expression of the platelet activation markers (P-selectin and GPIb) and the expression of platelet-bound SDF-1 were determined by two-colour whole blood flow cytometry. RESULTS: Patients with transient ischaemic attack (TIA) as well as with ischaemic stroke showed similar levels of SDF-1 expression on hospital admission compared with patients with non-ischaemic (NI) events and with 30 healthy controls (TIA (mean fluorescence intensity±SD): 31.5±18.2 vs. NI: 26.4±15.7; P=0.361; stroke: 28.7±19.8 vs. NI; P=0.943; control: 26.1±11.3; P>0.05 compared with all). Platelet SDF-1 expression showed a trend with the severity of stroke according to National Institute of Health Stroke Scale score (r=0.125; P=0.085), but significantly correlated with the peak levels of C-reactive protein (r=0.218; P=0.002) and with the levels of platelet activation (P-selectin: r=0.389; P=0.001). Multifactorial analysis of covariance revealed a significant influence on platelet SDF-1 expression by smoking (P=0.019). CONCLUSIONS: Platelet SDF-1 surface expression did not show any significant difference in patients with TIA and ischaemic stroke compared with patients with NI events. Thus, single biomarker evaluation of platelet SDF-1 surface expression is not helpful to predict ischaemic stroke.


Subject(s)
Biomarkers/blood , Chemokine CXCL12/blood , Stroke/blood , Stroke/diagnosis , Aged , Aged, 80 and over , Blood Platelets/metabolism , Chemokine CXCL12/analysis , Female , Flow Cytometry , Humans , Ischemic Attack, Transient/blood , Ischemic Attack, Transient/diagnosis , Male
7.
Eur J Neurol ; 17(1): 111-7, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19686349

ABSTRACT

BACKGROUND AND PURPOSE: Platelet collagen receptor glycoprotein VI (GPVI) contributes significantly to platelet adhesion and thrombus formation. We aimed to investigate GPVI in patients presenting with symptoms of acute cerebrovascular disease and to define GPVI as biomarker for acute stroke. METHODS: We consecutively evaluated 205 patients, who admitted the stroke unit with symptoms for stroke. Surface expression of the platelet activation markers (GPVI, CD62P, GPIb) was determined by two-color whole blood flow cytometry. RESULTS: Patients with transient ischemic attack (TIA) (n = 18; 8.8%) as well as with stroke (n = 133; 64.9%) showed a significantly enhanced GPVI expression (mean fluorescence intensity +/- SD) on admission compared to patients with non-ischemic (NI) events (n = 54; 26.3%) (TIA: 20.9 +/- 7.1 vs. NI: 16.2 +/- 3.9; P = 0.002; stroke: 20.4 +/- 5.7 vs. NI; P = 0.002). Neither CD62P nor GPIb surface expression showed a significant difference. Logistic regression analysis revealed that on admission GPVI was associated with stroke independent of conventional laboratory markers such as C-reactive protein, blood glucose, and creatine kinase. Using a receiver operating characteristic curve on GPVI, we have determined the cut off value of 18.2 for stroke. Thus, patients with enhanced GPVI expression levels (>or=18.2) had a 2.4-fold relative risk for stroke. Patients with elevated platelet GPVI expression level had a poorer clinical outcome in cumulative event-free survival for stroke, myocardial infarction, and cerebro-/cardiovascular death at 3-month follow-up (log rank; P = 0.045). CONCLUSIONS: These findings indicate that platelet GPVI surface expression is significantly enhanced in patients with TIA and stroke compared to patients with NI events. Determination of platelet-specific GPVI may be useful as an early biomarker for cerebral ischemia.


Subject(s)
Intracranial Thrombosis/metabolism , Ischemic Attack, Transient/diagnosis , Platelet Membrane Glycoproteins/metabolism , Stroke/diagnosis , Aged , Biomarkers/analysis , Biomarkers/metabolism , Female , Flow Cytometry , Humans , Intracranial Thrombosis/diagnosis , Intracranial Thrombosis/physiopathology , Ischemic Attack, Transient/mortality , Ischemic Attack, Transient/physiopathology , Male , Middle Aged , Platelet Adhesiveness/physiology , Platelet Membrane Glycoproteins/analysis , Predictive Value of Tests , Risk Assessment , Risk Factors , Sensitivity and Specificity , Stroke/mortality , Stroke/physiopathology , Up-Regulation/physiology
8.
Hamostaseologie ; 29(4): 360-7, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19882075

ABSTRACT

Safeguarding of antiplatelet drug efficacy represents a cornerstone for the optimal treatment of patients with symptomatic coronary artery disease requiring coronary interventions. This means a challenge to modern cardiology since there has been cumulative evidence, that response to common oral antiplatelet therapy is a highly variable phenomenon underlying various mechanisms. It is known, that particular risk groups exhibit a high residual platelet aggregability (RPA) despite conventional antiplatelet therapy. Additionally, a relevant association between high RPA and recurrent ischaemic events after PCI exists. Individualization of antiplatelet therapy by dose increase or alternative application of novel P2Y12-receptor antagonists might lead to improved cardiovascular outcome in patients with poor responsiveness to conventional antiplatelet therapy. Identification of risk patients who might benefit from tailored therapy by increased net benefit without excess of major bleedings means a challenge. Clinical risk scores might help in the process of risk stratification and therapeutic decision. Subsequently, literature on risk assessment for antiplatelet drug responsiveness and different strategies will be discussed to identify patients who might benefit from personalized antiplatelet strategies.


Subject(s)
Platelet Aggregation Inhibitors/therapeutic use , Adult , Aged , Clopidogrel , Coronary Disease/chemically induced , Coronary Disease/drug therapy , Coronary Disease/epidemiology , Coronary Vessels/drug effects , Female , Humans , Male , Middle Aged , Platelet Aggregation/drug effects , Platelet Aggregation Inhibitors/adverse effects , Platelet Aggregation Inhibitors/pharmacology , Risk Assessment , Safety , Ticlopidine/analogs & derivatives , Ticlopidine/therapeutic use , Young Adult
9.
J Thromb Haemost ; 6(1): 54-61, 2008 Jan.
Article in English | MEDLINE | ID: mdl-17949474

ABSTRACT

BACKGROUND: Recent studies suggest a high interindividual variability of response to clopidogrel associated with adverse cardiovascular outcome. Different clinical factors are considered to influence a persistent residual platelet aggregation (RPA) despite conventional antiplatelet therapy. OBJECTIVES: To investigate clinical factors that affect RPA after 600-mg clopidogrel loading in a large unselected cohort of patients with symptomatic CAD. METHODS: The study population included a consecutive cohort of 1,092 patients treated with coronary stenting for stable angina and acute coronary syndromes (ACS). Residual platelet activity was assessed by ADP (20 micromol L(-1))-induced platelet aggregation >or= 6 h after LD. Eleven clinical factors were included in the primary analysis. RESULTS: In multivariate regression analysis increased RPA was significantly influenced by ACS, reduced LV-function, diabetes mellitus, renal failure (creatinine > 1.5 mg dL(-1)), and age > 65 years. In a factor-weighed model the risk for high RPA increased with higher score levels (OR for patients with a score of 1-3, 1.21, 95% CI 0.7-2.1; score 4-6, OR 2.0, 95% CI 1.17-3.5; P = 0.01; score 7-9, OR 3.3, 95% CI 1.8-6.0). During a 30-day follow-up the incidence of major adverse events was higher in patients with RPA in the upper tertile (4.8% vs. 2.5% in the 2nd and 1.5% in the 1st tertile; P < 0.05). CONCLUSIONS: The PREDICT score provides a good tool to estimate residual platelet activity after clopidogrel LD by easily available patient details. Additionally, we demonstrate its association with short-term outcome. Thus, patients with a high score may benefit from intensified antiplatelet therapy by improved platelet inhibition and risk reduction for thromboischemic events.


Subject(s)
Coronary Artery Disease/therapy , Models, Statistical , Platelet Aggregation , Platelet Function Tests , Stents , Acute Coronary Syndrome/blood , Acute Coronary Syndrome/therapy , Adenosine Diphosphate/pharmacology , Aged , Angina Pectoris/blood , Angina Pectoris/therapy , Clopidogrel , Cohort Studies , Coronary Artery Disease/blood , Female , Humans , Male , Middle Aged , Regression Analysis , Ticlopidine/analogs & derivatives , Ticlopidine/therapeutic use
10.
Med Biol Eng Comput ; 45(11): 1023-8, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17917755

ABSTRACT

In research, pharmacologic drug-screening and medical diagnostics, the trend towards the utilization of functional assays using living cells is persisting. Research groups working with living cells are confronted with the problem, that common endpoint measurement methods are not able to map dynamic changes. With consideration of time as a further dimension, the dynamic and networked molecular processes of cells in culture can be monitored. These processes can be investigated by measuring several extracellular parameters. This paper describes a high-content system that provides real-time monitoring data of cell parameters (metabolic and morphological alterations), e.g., upon treatment with drug compounds. Accessible are acidification rates, the oxygen consumption and changes in adhesion forces within 24 cell cultures in parallel. Addressing the rising interest in biomedical and pharmacological high-content screening assays, a concept has been developed, which integrates multi-parametric sensor readout, automated imaging and probe handling into a single embedded platform. A life-maintenance system keeps important environmental parameters (gas, humidity, sterility, temperature) constant.


Subject(s)
Biosensing Techniques/instrumentation , Microfluidic Analytical Techniques/instrumentation , Biosensing Techniques/methods , Drug Evaluation, Preclinical , Drug Screening Assays, Antitumor/methods , Equipment Design , Humans , Microfluidic Analytical Techniques/methods , Tumor Cells, Cultured
11.
Atherosclerosis ; 238(2): 289-95, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25544179

ABSTRACT

OBJECTIVE: Inhibition of components of the complement system or of its receptors has been postulated as a concept for primary and secondary prevention in atherosclerosis and was applied in clinical trials. Although the anaphylatoxin-receptors C3aR and C5aR are commonly associated with inflammatory cells, in vitro studies suggested their expression also on platelets. METHODS AND RESULTS: Expression levels of C3aR and C5aR were measured by flow cytometry in a collective of 302 patients with documented coronary artery disease (CAD) including patients with stable CAD (n = 152), unstable angina (n = 54), acute myocardial infarction (AMI; Non-ST elevation myocardial infarction, n = 70, ST elevation MI, n = 26) or healthy controls (n = 21). Patients with stable CAD, unstable angina or AMI had significantly higher expression of C5aR on platelets in comparison to healthy controls (MFI 14.68 (5.2), 14.56 (5.18) and 13.34 (4.52) versus 10.68 (3.1)); p < 0.001). In contrast, the expression of C3aR on platelets was significantly enhanced in patients with stable and unstable CAD but not in patients with AMI compared to controls. While there was a strong correlation between the soluble ligands of these receptors C3a and C5a, we observed only a weak correlation with their receptors on platelets. Similarly, agonist induced aggregation (MEA, ADP, and TRAP) showed only a weak correlation with the expression level of anaphylatoxin - receptors on platelets. Of note, the expression of both anaphylatoxin-receptors on platelets strongly correlated with platelet activation as assessed with the surface activation marker P-selectin (r = 0.47, p > 0.001 for C3aR, r = 0.76 for C5aR, p < 0.001). Likewise, we observed a positive correlation of C3aR with other molecules associated with platelet activation such as SDF-1. CONCLUSION: In summary, we observed a positive correlation between the expression of anaphylatoxin-receptors C3aR and C5aR with platelet activation in patients with CAD. Further investigations are needed to study the clinical and mechanistic relevance of these findings.


Subject(s)
Blood Platelets/chemistry , Coronary Disease/blood , Receptor, Anaphylatoxin C5a/blood , Receptors, Complement/blood , Aged , Angina, Unstable/blood , Case-Control Studies , Complement C3/analysis , Complement C5a/analysis , Coronary Artery Disease/blood , Coronary Disease/diagnosis , Female , Flow Cytometry , Humans , Ligands , Male , Middle Aged , Myocardial Infarction/blood , Platelet Aggregation , Platelet Function Tests , Up-Regulation
12.
J Thromb Haemost ; 13(5): 719-28, 2015 May.
Article in English | MEDLINE | ID: mdl-25660395

ABSTRACT

BACKGROUND: Surface expression of stromal cell-derived factor-1 (SDF-1, CXCL12) on platelets is enhanced during ischemic events and plays an important role in peripheral homing of stem cells and myocardial repair mechanisms. SDF-1 effects are mediated through CXCR4 and CXCR7. Both CXCR4 and CXCR7 are surface expressed on human platelets and to a higher degree in patients with coronary artery disease (CAD) compared with healthy controls. In this study, we investigated the prognostic role of platelet CXCR4- and CXCR7 surface expression in patients with symptomatic CAD. METHODS AND RESULTS: In a cohort study, platelet surface expression of CXCR4 and CXCR7 was measured by using flow cytometry in 284 patients with symptomatic CAD at the time of percutaneous coronary intervention (PCI). The primary combined end point was defined as all-cause death and/or myocardial infarction (MI) during 12-month follow-up. Secondary end points were defined as the single events of all-cause death and MI. We found significant differences of CXCR4 values in patients who developed a combined end point compared with event-free patients (mean MFIAUTHOR: Please define MFI at first use. 3.17 vs. 3.44, 95% confidence interval [CI] 0.09-0.45) and in patients who subsequently died (mean MFI 3.10 vs. 3.42, 95% CI 0.09-0.56). In multivariate Cox regression analysis, lower platelet CXCR4 levels were independently and significantly associated with all-cause mortality (hazard ratio 0.24, 95% CI 0.07-0.87) and the primary combined end point of all-cause death and/or MI (hazard ratio 0.30, 95% CI 0.13-0.72). CONCLUSION: These findings highlight a potential prognostic value of platelet expression CXCR4 on clinical outcomes in patients with CAD.


Subject(s)
Blood Platelets/metabolism , Chemokine CXCL12/blood , Coronary Artery Disease/blood , Receptors, CXCR4/blood , Receptors, CXCR/blood , Aged , Coronary Artery Disease/pathology , Female , Humans , Male , Prognosis
13.
Cardiovasc Ultrasound ; 2: 16, 2004 Sep 10.
Article in English | MEDLINE | ID: mdl-15357870

ABSTRACT

BACKGROUND: Ultrasound contrast agents (UCAs) allow the enhancement of vascular definition, thereby providing more diagnostic information. LK565 is a new second-generation UCA based on synthetic polymers of aspartic acid which is eliminated from the blood stream via phagocytosis. LK565 forms very stable air-filled microspheres and is capable of repeated passage through the pulmonary capillary bed after peripheral intravenous injection. This characteristic allows examination of the cardiac function or extracardiac vessel abnormalities up to 15 minutes. METHODS: A phase one clinical study was conducted on 15 healthy volunteers to identify the development of an undesirable immune response. Phagocytosis capacity, TNF-alpha secretion, and MHC class II upregulation of monocytes was monitored, as well as microsphere specific antibody development (IgM, IgG). Furthermore, the kinetics of the activation surface markers CD69, CD25, CD71, and CD11b on leukocytes were analyzed. RESULTS: Due to LK565-metabolism the administration of the UCA led to saturation of phagocytes which was reversible after 24 hrs. Compared to positive controls neither significant TNF-alpha elevation, neither MHC class II and activation surface markers upregulation, nor specific antibody development was detectable. CONCLUSION: The administration of LK565 provides a comfortable duration of signal enhancement, esp. in echocardiography, without causing a major activation cascade or triggering an adaptive immune response. To minimize the risk of undesirable adverse events such as anaphylactoid reactions, immunological studies should be included in clinical trials for new UCAs. The use of LK565 as another new ultrasound contrast agent should be encouraged as a safe means to provide additional diagnostic information.


Subject(s)
Aspartic Acid/administration & dosage , Aspartic Acid/adverse effects , Contrast Media/administration & dosage , Contrast Media/adverse effects , Echocardiography/adverse effects , Vasculitis/chemically induced , Vasculitis/immunology , Adult , Cytokines/immunology , Dose-Response Relationship, Drug , Humans , Image Enhancement/methods , Injections, Intravenous , Male , Microspheres , Phagocytosis/drug effects , Phagocytosis/immunology , Vasculitis/diagnosis
14.
Thromb Haemost ; 110(5): 876-87, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23702580

ABSTRACT

Platelets are critically involved in atherosclerosis and acute thrombosis. The platelet phenotype shows a wide variability documented by the inherited difference of platelet reactivity, platelet volume and count and function of platelet surface receptors. Several candidate genes have been put into focus and investigated for their functional and prognostic role in healthy individuals and patients with cardiovascular (CV) disease treated with antiplatelet agents. In addition to genetic variation, other clinical, disease-related and demographic factors are important so-called non-genetic factors. Due to the small effect sizes of single nucleotide polymorphisms (SNP) in candidate genes and due to the low allele frequencies of functional relevant candidate SNPs, the identification of genetic risk factors with high predictive values generally depends on the sample size of study cohorts. In the post-genome era new array and bioinformatic technologies facilitate high throughput genome-wide association studies (GWAS) for the identification of novel candidate genes in large cardiovascular cohorts. One of the crucial aspects of platelet genomic studies is the precise definition of a specific clinical phenotype (e.g. stent thrombosis) as this will impact importantly the findings of genomic studies like GWAS. Here, we provide an update on genetic variation of platelet receptors and drug metabolising enzymes under specific consideration of data derived by GWAS. The potential impact of this information and the role in personalised therapeutic concepts will be discussed.


Subject(s)
Blood Platelets/physiology , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/drug therapy , Platelet Aggregation Inhibitors/therapeutic use , Receptors, Collagen/genetics , Receptors, Fibrinogen/genetics , Receptors, Purinergic P2Y/genetics , Animals , Biomarkers, Pharmacological/metabolism , Cardiovascular Diseases/genetics , Genetic Predisposition to Disease , Genome-Wide Association Study , High-Throughput Nucleotide Sequencing , Humans , Platelet Aggregation Inhibitors/pharmacology , Polymorphism, Single Nucleotide , Prognosis , Receptors, Collagen/metabolism , Receptors, Fibrinogen/metabolism , Receptors, Purinergic P2Y/metabolism , Risk
15.
Sci Rep ; 3: 3497, 2013 Dec 13.
Article in English | MEDLINE | ID: mdl-24336573

ABSTRACT

Sponges are probably the earliest branching animals, and their fossil record dates back to the Precambrian. Identifying their skeletal structure and composition is thus a crucial step in improving our understanding of the early evolution of metazoans. Here, we present the discovery of 505-million-year-old chitin, found in exceptionally well preserved Vauxia gracilenta sponges from the Middle Cambrian Burgess Shale. Our new findings indicate that, given the right fossilization conditions, chitin is stable for much longer than previously suspected. The preservation of chitin in these fossils opens new avenues for research into other ancient fossil groups.


Subject(s)
Chitin , Fossils , Porifera/chemistry , Animals , Biological Evolution , Chitin/chemistry , Polysaccharides/chemistry
16.
Hamostaseologie ; 32(3): 191-194, 2012.
Article in English | MEDLINE | ID: mdl-29589361

ABSTRACT

The antiplatelet therapy with aspirin and the ADP-receptor blocker clopidogrel is currently the standard medication after coronary intervention or after acute coronary syndrome to prevent recurrent ischemic events and reduce mortality. However, high interindividual response variability to antiplatelet treatment is described in up to 44% of treated patients. A poor response to clopidogrel is caused by multifactorial mechanisms. Individual risk assessment including platelet function testing (PFT) can help to identify high risk patients, although recent randomized trials to investigate effects of PFT-guided therapy have failed to detect an impact on prognostic outcome. Poor response to standard antiplatelet agents can be overcome by switching to alternate substances. Elinogrel is a novel competitive, reversible ADP-receptor antagonist available in oral and intravenous formulation. Additional treatment with elinogrel showed advantages over clopidogrel, including more rapid, less variable, and more complete inhibition of platelet function without significantly increased bleeding complications. This review gives an overview over the investigational drug elinogrel for use in a personalized antiplatelet approach.

17.
Hamostaseologie ; 32(3): 191-4, 2012.
Article in English | MEDLINE | ID: mdl-22772894

ABSTRACT

The antiplatelet therapy with aspirin and the ADP-receptor blocker clopidogrel is currently the standard medication after coronary intervention or after acute coronary syndrome to prevent recurrent ischemic events and reduce mortality. However, high interindividual response variability to antiplatelet treatment is described in up to 44% of treated patients. A poor response to clopidogrel is caused by multifactorial mechanisms. Individual risk assessment including platelet function testing (PFT) can help to identify high risk patients, although recent randomized trials to investigate effects of PFT-guided therapy have failed to detect an impact on prognostic outcome. Poor response to standard antiplatelet agents can be overcome by switching to alternate substances. Elinogrel is a novel competitive, reversible ADP-receptor antagonist available in oral and intravenous formulation. Additional treatment with elinogrel showed advantages over clopidogrel, including more rapid, less variable, and more complete inhibition of platelet function without significantly increased bleeding complications. This review gives an overview over the investigational drug elinogrel for use in a personalized antiplatelet approach.


Subject(s)
Evidence-Based Medicine , Precision Medicine/methods , Quinazolinones/administration & dosage , Quinazolinones/adverse effects , Sulfonamides/administration & dosage , Sulfonamides/adverse effects , Thrombosis/drug therapy , Thrombosis/prevention & control , Administration, Oral , Fibrinolytic Agents/administration & dosage , Fibrinolytic Agents/adverse effects , Humans , Injections, Intravenous , Platelet Aggregation Inhibitors/administration & dosage , Platelet Aggregation Inhibitors/adverse effects , Purinergic P2Y Receptor Antagonists/administration & dosage , Purinergic P2Y Receptor Antagonists/adverse effects , Treatment Outcome
18.
J Thromb Haemost ; 10(1): 49-55, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22044645

ABSTRACT

AIMS: Blood cell infiltration and inflammation are involved in atrial remodelling during atrial fibrillation (AF) although the exact mechanisms of inflammatory cell recruitment remain poorly understood. Platelet-bound stromal cell-derived factor-1 (SDF-1) is increased in cases of ischemic myocardium and regulates recruitment of CXCR4(+) cells on the vascular wall. Whether platelet-bound SDF-1 expression is differentially influenced by non-valvular paroxysmal or permanent atrial fibrillation (AF) in patients with stable angina pectoris (SAP) or acute coronary syndrome (ACS) has not been reported so far. METHODS AND RESULTS: A total of 1291 consecutive patients with coronary artery disease (CAD) undergoing coronary angiography were recruited. Among the patients with SAP, platelet-bound-SDF-1 is increased in patients with paroxysmal AF compared with SR or to persistent/permanent AF (P < 0.05 for both). Platelet-bound SDF-1 correlated with plasma SDF-1 (r = 0.488, P = 0.013) in patients with AF and ACS, which was more pronounced among patients with persistent AF (r = 0.842, P = 0.009). Plasma SDF-1 was increased in persistent/permanent AF compared with SR. Patients with ACS presented with enhanced platelet-bound-SDF-1 compared with SAP. Interestingly, among patients with ACS, patients with paroxysmal or persistent/permanent AF presented with an impaired platelet-bound SDF-1 expression compared with patients with SR. CONCLUSIONS: Differential expression of platelet-bound and plasma SDF-1 was observed in patients with AF compared with SR which may be involved in progenitor cell mobilization and inflammatory cell recruitment in patients with AF and ischemic heart disease. Further in vivo studies are required to elucidate the role of SDF-1 in atrial remodeling and the atrial fibrillation course.


Subject(s)
Atrial Fibrillation/blood , Blood Platelets/pathology , Chemokine CXCL12/genetics , Gene Expression Regulation , Myocardial Ischemia/blood , Angina, Stable , Blood Platelets/metabolism , Cell Movement , Chemokine CXCL12/analysis , Humans , Stem Cells/pathology
19.
J Thromb Haemost ; 8(6): 1147-58, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20128862

ABSTRACT

Platelet responsiveness to conventional antiplatelet therapy underlies a high interindividual variability influenced by various factors. For instance, antiplatelet therapy does not curtail the expected effects in a relevant number of patients as demonstrated by the occurrence of repeated cardiovascular events including stent thrombosis and/or by inadequate platelet inhibition measured by in vitro platelet function assays. Besides non-genetic factors such as age, gender, liver and renal function and co-medication, considerable variation of antiplatelet drug responsiveness can be attributed to genetic factors including polymorphisms and genetic variants of platelet surface proteins and drug metabolizing enzymes. Nowadays, platelet pharmacogenomics has started a new field with the goal to link genetic information of various drug targets to interindividual variability of drug response. Evolving data from large cohort studies suggest a promising role for pharmacogenomics in the context of antiplatelet therapy. Additionally, with the revolution of low cost and high-throughput genotyping techniques, genetic testing has become affordable for clinical application and individualization of therapy. However, a key issue to define the future role of pharmacogenomics will rely on the benefit and the timeliness of implementing the genetic information into therapeutic decision. Hence, it warrants further investigations to document the prognostic effects of therapeutic alterations in distinct genotypes. Concerning the safety profile of emerging antiplatelet and antithrombotic drugs in certain risk groups it would be fatal to individualize treatment barely on behalf of an atherothrombotic genotype. In contrast, individual risk assessment combining non-genetic information and pharmacogenetic analysis represents a reasonable concept. Here, we provide a review on current data describing the role of pharmacogenomics in the field of antiplatelet drug treatment in cardiovascular patients with future directions.


Subject(s)
Blood Platelets/metabolism , Genomics , Pharmacogenetics , Aspirin/pharmacology , Clopidogrel , Cohort Studies , Humans , Platelet Aggregation Inhibitors/pharmacology , Platelet Glycoprotein GPIIb-IIIa Complex/antagonists & inhibitors , Ticlopidine/analogs & derivatives , Ticlopidine/pharmacology
20.
Dtsch Med Wochenschr ; 133(16): 817-22, 2008 Apr.
Article in German | MEDLINE | ID: mdl-18398789

ABSTRACT

BACKGROUND AND OBJECTIVE: Statins are frequently given in conjunction with clopidogrel for prophylaxis and therapy of coronary heart disease. The antiplatelet effect of clopidogrel may be attenuated by lipophilic statins such as atorvastatin. It was the aim of this study to measure the antiplatelet effect of clopidogrel and the incidence of cardiovascular events after stent implantation in patients with coronary artery stenting. PATIENTS AND METHODS: ADP-induced aggregometry was used in 319 patients after coronary artery stent implantation to determine whether added administration of clinically relevant statins would affect the antiplatelet action of clopidogrel. Also a three-month follow-up was undertaken to determine the incidence of cardiovascular events. RESULTS: There were no significant differences between the statin-receiving subgroups, either in platelet aggregation nor in clinical outcome in our cohort. CONCLUSION: No statin-clopidogrel interaction nor any clinically relevant events were documented in the studied cohort. No interaction between CYP3A4 statins and a single loading dose of 600 mg clopidogrel was documented in this cohort.


Subject(s)
Coronary Disease/therapy , Coronary Stenosis/therapy , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Platelet Aggregation Inhibitors/therapeutic use , Platelet Aggregation/drug effects , Stents , Ticlopidine/analogs & derivatives , Atorvastatin , Clopidogrel , Coronary Disease/blood , Coronary Disease/drug therapy , Coronary Stenosis/blood , Coronary Stenosis/drug therapy , Fatty Acids, Monounsaturated/therapeutic use , Fluvastatin , Heptanoic Acids/therapeutic use , Humans , Indoles/therapeutic use , Pyrroles/therapeutic use , Simvastatin/therapeutic use , Ticlopidine/therapeutic use
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