58 research outputs found
Risk management profile of etoricoxib: an example of personalized medicine
The development of nonsteroidal anti-inflammatory drugs (NSAIDs) selective for cyclooxygenase (COX)-2 (named coxibs) has been driven by the aim of reducing the incidence of serious gastrointestinal (GI) adverse events associated with the administration of traditional (t) NSAIDs – mainly dependent on the inhibition of COX-1 in GI tract and platelets. However, their use has unravelled the important protective role of COX-2 for the cardiovascular (CV) system, mainly through the generation of prostacyclin. In a recent nested-case control study, we found that patients taking NSAIDs (both coxibs and tNSAIDs) had a 35% increase risk of myocardial infarction. The increased incidence of thrombotic events associated with profound inhibition of COX-2-dependent prostacyclin by coxibs and tNSAIDs can be mitigated, even if not obliterated, by a complete suppression of platelet COX-1 activity. However, most tNSAIDs and coxibs are functional COX-2 selective for the platelet (ie, they cause a profound suppression of COX-2 associated with insufficient inhibition of platelet COX-1 to translate into inhibition of platelet function), which explains their shared CV toxicity. The development of genetic and biochemical markers will help to identify the responders to NSAIDs or who are uniquely susceptible at developing thrombotic or GI events by COX inhibition. We will describe possible strategies to reduce the side effects of etoricoxib by using biochemical markers of COX inhibition, such as whole blood COX-2 and the assessment of prostacyclin biosynthesis in vivo
Characterization of the acetylation of cyclooxygenase-isozymes and targeted lipidomics of eicosanoids in serum and colon cancer cells by the new aspirin formulation IP1867B versus aspirin in vitro
Background: Aspirin(acetylsalicylic acid, ASA) is recommended for the secondary prevention of atherothrombotic events and has shown anticancer effects. The current enteric-coated drug formulation may reduce aspirin bioavailability. Liquid formulations could improve aspirin pharmacokinetics and pharmacodynamics. IP1867B is a liquid-aspirin formulation that combines three ingredients, ASA/triacetin/saccharin.Methods: ASA and IP1867B(L-ASA) were assessed in human serum(obtained by allowing to clot human whole blood at 37 °C for 1h), washed platelets, and colonic adenocarcinoma HCA7 cells on eicosanoid generation and COX-isozyme acetylation at Serine529 and 516 by LC-MS/MS.Results: In serum, ASA and L-ASA acted by selectively affecting COX-1-derived eicosanoids, including thromboxane(TX)B2. L-ASA was more potent in inhibiting serum TXB2, a known biomarker of aspirin antiplatelet effect, than ASA. However, ASA and L-ASA were equipotent to acetylate COX-1 in washed platelets and COX-2 in HCA7 cells. In HCA7 cells, ASA and L-ASA acted by inhibiting prostaglandin(PG)E2(the most abundant prostanoid) and TXB2 biosynthesis. In the presence of a high arachidonic acid concentration(100 μM), 15R-hydroxyeicosatetraenoic acid(HETE) was generated at baseline by cancer cell COX-2 and was only slightly enhanced by supratherapeutic concentrations of ASA(1 mM). In whole blood and HCA7 cells treated with ASA or L-ASA, 15-epi-lipoxin(LX)A4 were undetectable.Conclusion: IP1867B was more potent in affecting serum TXB2 generation than ASA. The relevance of this finding deserves evaluation in vivo in humans. In cancer cells, ASA and IP1867B acted by inhibiting PGE2 and TXB2 generation via the acetylation of COX-2. ASA and IP867B at clinically relevant concentrations did not substantially induce the biosynthesis of 15R-HETE and 15-epi-LXA4
Glycopeptide resistance among coagulase- negative staphylococci that cause bacteremia: epidemiological and clinical findings from a case-control study
A 1-year prospective case-control study (ratio of control patients to case patients, 3:1) was performed to assess
the incidence, risk factors, and genotypic patterns of bacteremia caused by glycopeptide-resistant coagulasenegative
staphylococci (CoNS) and their correlation with hospital glycopeptide use. Among 535 subjects with
CoNS bacteremia, 20 subjects had a glycopeptide-resistant strain (19 strains were resistant to teicoplanin and
1 was resistant to both teicoplanin and vancomycin). The percentage of resistant isolates recovered in 1 year
was 8% in intensive care units and 3% and 2% in medical and surgical wards, respectively. Genotypic analysis
of resistant strains showed different patterns with a high degree of polymorphism. Use of glycopeptides in
individual wards was not statistically associated with the percentage of resistance. Previous exposure to β-lactams
and glycopeptides, multiple hospitalization in the previous year, and concomitant pneumonia were
significantly associated with the onset of glycopeptide-resistant CoNS bacteremia. Mortality rates were 25%
among case patients and 18% among control patients, and they were significantly higher among patients who
presented with concomitant pneumonia and a high Acute Physiology and Chronic Health Evaluation III score
De Novo Synthesis of Cyclooxygenase-1 Counteracts the Suppression of Platelet Thromboxane Biosynthesis by Aspirin
Aspirin affords cardioprotection through the acetylation of serine
529
in human cyclooxygenase-1 (COX-1) of anucleated platelets, inducing a permanent defect in thromboxane A
2
(TXA
2
)–dependent platelet function. However, heterogeneity of COX-1 suppression by aspirin has been detected in cardiovascular disease and may contribute to failure to prevent clinical events. The recent recognized capacity of platelets to make proteins de novo paves the way to identify new mechanisms involved in the variable response to aspirin. We found that in washed human platelets, the complete suppression of TXA
2
biosynthesis by aspirin, in vitro, recovered in response to thrombin and fibrinogen in a time-dependent fashion (at 0.5 and 24 hours, TXB
2
averaged 0.1±0.03 and 3±0.8 ng/mL; in the presence of arachidonic acid [10 μmol/L], it was 2±0.7 and 25±7 ng/mL, respectively), and it was blocked by translational inhibitors, by rapamycin, and by inhibitors of phosphatidylinositol 3-kinase. The results that COX-1 mRNA was readily detected in resting platelets and that [
35
S]-methionine was incorporated into COX-1 protein after stimulation strongly support the occurrence of de novo COX-1 synthesis in platelets. This process may interfere with the complete and persistent suppression of TXA
2
biosynthesis by aspirin necessary for cardioprotection
Low-dose Aspirin prevents hypertension and cardiac fibrosis when thromboxane A2 is unrestrained.
Abstract Enhanced platelet activation has been reported in patients with essential hypertension and heart failure. The possible contribution of platelet-derived thromboxane (TX)A2 in their pathophysiology remains unclear. We investigated the systemic TXA2 biosynthesis in vivo and gene expression of its receptor TP in 22 essential hypertension patients and a mouse model of salt-sensitive hypertension. The contribution of platelet TXA2 biosynthesis on enhanced blood pressure (BP) and overload-induced cardiac fibrosis was explored in mice by treating with low-dose Aspirin, resulting in selective inhibition of platelet cyclooxygenase (COX)-1-dependent TXA2 generation. In essential hypertensive patients, systemic biosynthesis of TXA2 [assessed by measuring its urinary metabolites (TXM) reflecting predominant platelet source] was enhanced together with higher gene expression of circulating leukocyte TP and TGF-β, vs. normotensive controls. Similarly, in hypertensive mice with prostacyclin (PGI2) receptor (IP) deletion (IPKO) fed with a high-salt diet, enhanced urinary TXM, and left ventricular TP overexpression were detected vs. normotensive wildtype (WT) mice. Increased cardiac collagen deposition and profibrotic gene expression (including TGF-β) was found. Low-dose Aspirin administration caused a selective inhibition of platelet TXA2 biosynthesis and mitigated enhanced blood pressure, cardiac fibrosis, and left ventricular profibrotic gene expression in IPKO but not WT mice. Moreover, the number of myofibroblasts and extravasated platelets in the heart was reduced. In cocultures of human platelets and myofibroblasts, platelet TXA2 induced profibrotic gene expression, including TGF-β1. In conclusion, our results support tailoring low-dose Aspirin treatment in hypertensive patients with unconstrained TXA2/TP pathway to reduce blood pressure and prevent early cardiac fibrosis
SARS-CoV-2 Breakthrough Infections: Incidence and Risk Factors in a Large European Multicentric Cohort of Health Workers
The research aimed to investigate the incidence of SARS-CoV-2 breakthrough infections and their determinants in a large European cohort of more than 60,000 health workers
Ten golden rules for optimal antibiotic use in hospital settings: the WARNING call to action
Antibiotics are recognized widely for their benefits when used appropriately. However, they are often used inappropriately despite the importance of responsible use within good clinical practice. Effective antibiotic treatment is an essential component of universal healthcare, and it is a global responsibility to ensure appropriate use. Currently, pharmaceutical companies have little incentive to develop new antibiotics due to scientific, regulatory, and financial barriers, further emphasizing the importance of appropriate antibiotic use. To address this issue, the Global Alliance for Infections in Surgery established an international multidisciplinary task force of 295 experts from 115 countries with different backgrounds. The task force developed a position statement called WARNING (Worldwide Antimicrobial Resistance National/International Network Group) aimed at raising awareness of antimicrobial resistance and improving antibiotic prescribing practices worldwide. The statement outlined is 10 axioms, or “golden rules,” for the appropriate use of antibiotics that all healthcare workers should consistently adhere in clinical practice
Grand challenges in pharmacotherapy of inflammation for the first decades of the 21st century
Inflammation is a complex set of interactions among soluble factors and cells that can arise in any tissue in response to traumatic, infectious, postischemic, toxic or autoimmune injury (Nathan, 2002; Gilroy et al., 2004). Inflammation, per se, does not cause disease. But unchecked inflammation that spreads possibly due to disruption of the resolution processes can lead to chronic persistent inflammation which plays a role in the progression of many diseases, such as atherosclerosis, asthma, neurodegeneration, inflammatory bowel diseases (IBDs) and cancer. Thus, inflammatio
P2Y12 Receptors in Tumorigenesis and Metastasis
Platelets, beyond their role in hemostasis and thrombosis, may sustain tumorigenesis and metastasis. These effects may occur via direct interaction of platelets with cancer and stromal cells and by the release of several platelet products. Platelets and tumor cells release several bioactive molecules among which a great amount of adenosine triphosphate (ATP) and adenosine diphosphate (ADP). ADP is also formed extracellularly from ATP breakdown by the ecto-nucleoside-triphosphate-diphosphohydrolases. Under ATP and ADP stimulation the purinergic P2Y1 receptor (R) initiates platelet activation followed by the ADP-P2Y12R-mediated amplification. P2Y12R stimulation amplifies also platelet response to several platelet agonists and to flow conditions, acting as a key positive feed-forward signal in intensifying platelet responses. P2Y12R represents a potential target for an anticancer therapy due to its involvement in platelet-cancer cell crosstalk. Thus, P2Y12R antagonists, including clopidogrel, ticagrelor, and prasugrel, might represent potential anti-cancer agents, in addition to their role as effective antithrombotic drugs. However, further studies, in experimental animals and patients, are required before the recommendation of the use of P2Y12R antagonists in cancer prevention and progression can be made
- …