Platelet dysfunction and inhibition of multiple electrode platelet aggregometry caused by penicillin

Beta-lactam antibiotics, e.g. penicillin, may inhibit platelet function and lead to reduced response in light transmission aggregometry and adhesion. However, influence on platelet function tests more commonly used in clinical practice, such as multiple electrode platelet aggregometry (MEA), have not been described so far. We report a case of a patient with local streptococcus infection. Treatment with penicillin resulted in mild bleeding tendency after 3 days. While coagulation parameters were normal, assessment of platelet function by MEA revealed strong platelet inhibition of both ADP and arachidonic acid induced platelet aggregation comparable to normal responders to antiplatelet therapy. Change of antibiotic regime resulted in recovery of platelet function. Thus, penicillin therapy may impact on platelet function and consecutively commonly used platelet function assays, e.g. MEA

Plasma TF activity predicts cardiovascular mortality in patients with acute myocardial infarction

<p>Abstract</p> <p>Objectives and Background</p> <p>Tissue factor (TF) contributes to thrombosis following plaque disruption in acute coronary syndromes (ACS). Aim of the study was to investigate the impact of plasma TF activity on prognosis in patients with ACS.</p> <p>Methods and Results</p> <p>One-hundred seventy-four patients with unstable Angina pectoris (uAP) and 112 patients with acute myocardial infarction (AMI) were included with a mean follow up time of 3.26 years. On admission, plasma TF activity was assessed. Patients were categorized into 2 groups: a high-TF activity group with TF >24 pmol/L and low TF activity group with TF ≤ 24 pmol/L. Fifteen cardiovascular deaths occurred in the uAP group and 16 in the AMI group. In AMI TF activity was 24,9 ± 2,78 pmol/l (mean ± SEM) in survivors and 40,9 ± 7,96 pmol/l in nonsurvivors (P = 0.024). In uAP no differences were observed (25.0 ± 8.04 pmol/L nonsurvivors vs. 25.7 ± 2.14 pmol/L survivors; P = 0.586). Kaplan-Meier estimates of survival at 3.26 years regarding TF activity in AMI were 81.3% and 92.2% with an hazard ratio of 3.02 (95% CI [1.05–8.79], P = 0.03). The Cox proportional hazards model adjusting for correlates of age and risk factors showed that plasma TF activity was an independent correlate of survival (hazard ratio 9.27, 95% CI [1.24–69.12], P = 0.03). In an additional group of patients with uAP and AMI, we identified circulating microparticles as the prevailing reservoir of plasma TF activity in acute coronary syndromes.</p> <p>Conclusion</p> <p>Systemic TF activity in AMI has an unfavorable prognostic value and as a marker for dysregulated coagulation may add to predict the atherothrombotic risk.</p

Clinical Considerations with the Use of Antiplatelet Therapy in Patients Undergoing Percutaneous Coronary Intervention

Despite the proven benefits of using antiplatelet therapy in patients undergoing percutaneous coronary intervention (PCI), a number of key questions remain to be answered. In recent years, clopidogrel dosing strategies among such patients have evolved considerably, with newer approaches involving loading doses prior to PCI and increases in the time interval and loading dosage in an effort to overcome variable responsiveness/hyporesponsiveness to platelet inhibition. Further, the role of glycoprotein (GP) IIb/IIIa antagonists in elective stenting continues to be defined, with recent evidence suggesting that most appropriate use of these agents is in high-risk patients with elevated troponin levels. There appears to be a relationship between the use of GP IIb/IIIa antagonists with clopidogrel loading and attenuation of early inflammatory and cardiac marker release. Strategies to minimize the chance of late stent thrombosis in patients who receive drug-eluting stents (DES) are also under intense investigation. Among some patients receiving sirolimus and paclitaxel DES, current standard long-term antiplatelet strategies may be insufficient. Patient nonadherence to treatment and premature discontinuation and underutilization of antiplatelet therapies by physicians remain important clinical problems with potentially dire consequences. Copyright © 2008 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58553/1/20359_ftp.pd

Synthesis, structural characterization, antimicrobial and cytotoxic effects of aziridine, 2-aminoethylaziridine and azirine complexes of copper(II) and palladium(II).

The synthesis, spectroscopic and X-ray structural characterization of copper(II) and palladium(II) complexes with aziridine ligands as 2-dimethylaziridine HNCH2CMe2 (a), the bidentate N-(2-aminoethyl)aziridines C2H4NC2H4NH2 (b) or CH2CMe2NCH2CMe2NH2 (c) as well as the unsaturated azirine NCH2CPh (d) are reported. Cleavage of the cyclometallated Pd(II) dimer [μ-Cl(C6H4CHMeNMe2-C,N)Pd]2 with ligand a yielded compound [Cl(NHCH2CMe2)(C6H4CHMe2NMe2-C,N)Pd] (1a). The reaction of the aziridine complex trans-[Cl2Pd(HNC2H4)2] with an excess of aziridine in the presence of AgOTf gave the ionic chelate complex trans-[(C2H4NC2H4NH2-N,N′)2Pd](OTf)2 (2b) which contains the new ligand b formed by an unexpected insertion and ring opening reaction of two aziridines (“aziridine dimerization”). CuCl2 reacted in pure HNC2H4 or HNCH2CMe2 (b) again by “dimerization” to give the tris-chelated ionic complex [Cu(C2H4NC2H4NH2-N,N′)3]Cl2 (3b) or the bis-chelated complex [CuCl(C2H2Me2NC2H2Me2NH2-N,N′)2]Cl (4c). By addition of 2H-3-phenylazirine (d) to PdCl2, trans-[Cl2Pd(NCH2CPh)2] (5d) was formed. All new compounds were characterized by NMR, IR and mass spectra and also by X-ray structure analyses (except 3b). Additionally the cytotoxic effects of these complexes were examined on HL-60 and NALM-6 human leukemia cells and melanoma WM-115 cells. The antimicrobial activity was also determined. The growth of Gram-positive bacterial strains (S. aureus, S. epidermidis, E. faecalis) was inhibited by almost all tested complexes at the concentrations of 37.5–300.0 μg mL−1. However, MIC values of complexes obtained for Gram-negative E. coli and P. aeruginosa, as well as for C. albicans yeast, mostly exceeded 300 μg mL−1. The highest antibacterial activity was achieved by complexes 1a and 2b. Complex 2b also inhibited the growth of Gram-negative bacteria. Graphical abstract: Synthesis, structural characterization, antimicrobial and cytotoxic effects of aziridine, 2-aminoethylaziridine and azirine complexes of copper(ii) and palladium(ii

Is there any relationship between ABO/Rh blood group and patients with pre-eclampsia?

Objectives: The purpose of the present study was to evaluate the association between pre-eclampsia and blood groups in a group of pregnant women hospitalized in a University Hospital in Porto Alegre, Brazil -Hospital São Lucas (HSL)/PUCRS. Study design: Our sample consisted of 10.040 pregnant women admitted to the maternity department of HSL between 2005 and 2010. The patients were reviewed retrospectively for inclusion. Medical records of 414 women were diagnosed as preeclampsia/eclampsia and were identified 9611 women to the control group. The patients were divided into two groups: the group with preeclampsia/eclampsia and the control group, and their blood groups were considered. Data were analyzed using SPSS for Windows version 17.0. Categorical data were summarized by counts and percentages, with the statistical significance evaluated by the Chi-square test. The null hypothesis was rejected when p<0.05. Main outcome measures: Maternal parameters were compared between control group and pre-eclampsia, respectively, Systolic Blood Pressure (117±19,98 vs. 165±19,99); Diastolic Blood Pressure (73±14,23 vs. 106±14,24) and maternal weight at booking (73± 33 vs. 83± 33). For all data: mean+SD; P<0.05. In relation to blood groups, firstly they were stratified by Rh and ABO phenotypes, separately. After that the groups were stand together Results: No differences in blood group distribution were observed between controls and pre-eclampsia for any analysis. (p>0.05). Conclusions: When we adopted stricter criteria for pre-eclampsia and a large sample from the same region we noted that the results did not show any association between blood groups and the development of pre-eclampsia

Antiplatelet Strategies: Evaluating Their Current Role in the Setting of Acute Coronary Syndromes

Numerous clinical trials have established the value of antiplatelet therapies for acute coronary syndromes (ACS). Aspirin (ASA), thienopyridines (i.e., clopidogrel and ticlopidine) and GP IIb/IIIa antagonists comprise the major classes of antiplatelet therapies demonstrated to be of benefit in the treatment of ACS and for the prevention of thrombotic complications of percutaneous coronary intervention (PCI). Clopidogrel is beneficial when administered before and after PCI, and is more effective when combined with either ASA or GP IIb/IIIa inhibitors in preventing post-PCI complications, coronary subacute stent thrombosis, and thrombotic events in general. It is currently unclear whether a higher loading dose of clopidogrel (600 mg) is better than the standard loading dose (300 mg), how long therapy should continue, and which maintenance dose is optimal. The role of the GP IIb/IIIa antagonists in ACS is less clear due to conflicting data from several studies with different patient populations. Currently, it appears that the use of GP IIb/IIIa antagonists might be most beneficial in high-risk ACS patients scheduled to undergo PCI, who demonstrate non-ST-segment elevation myocardial infarction and elevated troponin levels. Copyright © 2008 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58556/1/20362_ftp.pd