Aspirin and antiplatelet treatments in cancer.

Platelets have been hypothesized to promote certain neoplastic malignancies; however, antiplatelet drugs are still not part of routine pharmacological cancer prevention and treatment protocols. Paracrine interactions between platelets and cancer cells have been implicated in potentiating the dissemination, survival within the circulation, and extravasation of cancer cells at distant sites of metastasis. Signals from platelets have also been suggested to confer epigenetic alterations, including upregulating oncoproteins in circulating tumor cells, and secretion of potent growth factors may play roles in promoting mitogenesis, angiogenesis, and metastatic outgrowth. Thrombocytosis remains a marker of poor prognosis in patients with solid tumors. Experimental data suggest that lowering of platelet count may reduce tumor growth and metastasis. On the basis of the mechanisms by which platelets could contribute to cancer growth and metastasis, it is conceivable that drugs reducing platelet count or platelet activation might attenuate cancer progression and improve outcomes. We will review select pharmacological approaches that inhibit platelets and may affect cancer development and propagation. We begin by presenting an overview of clinical cancer prevention and outcome studies with low-dose aspirin. We then review current nonclinical development of drugs targeted to platelet binding, activation, and count as potential mitigating agents in cancer.

The role of coagulation and platelets in colon cancer-associated thrombosis.

Cancer-associated thrombosis is a common first presenting sign of malignancy and is currently the second leading cause of death in cancer patients after their malignancy. However, the molecular mechanisms underlying cancer-associated thrombosis remain undefined. In this study, we aimed to develop a better understanding of how cancer cells affect the coagulation cascade and platelet activation to induce a prothrombotic phenotype. Our results show that colon cancer cells trigger platelet activation in a manner dependent on cancer cell tissue factor (TF) expression, thrombin generation, activation of the protease-activated receptor 4 (PAR4) on platelets and consequent release of ADP and thromboxane A2. Platelet-colon cancer cell interactions potentiated the release of platelet-derived extracellular vesicles (EVs) rather than cancer cell-derived EVs. Our data show that single colon cancer cells were capable of recruiting and activating platelets and generating fibrin in plasma under shear flow. Finally, in a retrospective analysis of colon cancer patients, we found that the number of venous thromboembolism events was 4.5 times higher in colon cancer patients than in a control population. In conclusion, our data suggest that platelet-cancer cell interactions and perhaps platelet procoagulant EVs may contribute to the prothrombotic phenotype of colon cancer patients. Our work may provide rationale for targeting platelet-cancer cell interactions with PAR4 antagonists together with aspirin and/or ADP receptor antagonists as a potential intervention to limit cancer-associated thrombosis, balancing safety with efficacy.

Carpe low-dose aspirin: the new anti-cancer face of an old anti-platelet drug.

Cancer metastasis is a dynamic process during which cancer cells separate from a primary tumor, migrate through the vessel wall into the bloodstream, and extravasate at distant sites to form secondary colonies. During this process, circulating tumor cells are subjected to shear stress forces from blood flow, and in contact with plasma proteins and blood cells of the immune and hemostatic system, including platelets. Many studies have shown an association between high platelet count and cancer metastasis, suggesting that platelets may play an occult role in tumorigenesis. This mini-review summarizes recent and emerging discoveries of mechanisms by which cancer cells activate platelets and the role of activated platelets in promoting tumor growth and metastasis. Moreover, the review discusses how aspirin has the potential for being clinically used as an adjuvant in cancer therapy.

Potentiation of TRAP-6-induced platelet dense granule release by blockade of P2Y12 signaling with MRS2395.

The release of ADP from platelet dense granules and its binding to platelet P2Y12 receptors is key to amplifying the initial hemostatic response and propagating thrombus formation. P2Y12 has thus emerged as a therapeutic target to safely and effectively prevent secondary thrombotic events in patients with acute coronary syndrome or a history of myocardial infarction. Pharmacological inhibition of P2Y12 receptors represents a useful approach to better understand the signaling mediated by these receptors and to elucidate the role of these receptors in a multitude of platelet hemostatic and thrombotic responses. The present work examined and compared the effects of four different P2Y12 inhibitors (MRS2395, ticagrelor, PSB 0739, and AR-C 66096) on platelet function in a series of in vitro studies of platelet dense granule secretion and trafficking, calcium generation, and protein phosphorylation. Our results show that in platelets activated with the PAR-1 agonist TRAP-6 (thrombin receptor-activating peptide), inhibition of P2Y12 with the antagonist MRS2395, but not ticagrelor, PSB 0739 or AR-C 66096, potentiated human platelet dense granule trafficking to the plasma membrane and release into the extracellular space, cytosolic Ca2+ influx, and phosphorylation of GSK3ß-Ser9 through a PKC-dependent pathway. These results suggest that inhibition of P2Y12 with MRS2395 may act in concert with PAR-1 signaling and result in the aberrant release of ADP by platelet dense granules, thus reducing or counteracting the anticipated anti-platelet efficacy of this inhibitor.

Aspirin therapy reduces the ability of platelets to promote colon and pancreatic cancer cell proliferation: Implications for the oncoprotein c-MYC.

Aspirin, an anti-inflammatory and antithrombotic drug, has become the focus of intense research as a potential anticancer agent owing to its ability to reduce tumor proliferation in vitro and to prevent tumorigenesis in patients. Studies have found an anticancer effect of aspirin when used in low, antiplatelet doses. However, the mechanisms through which low-dose aspirin works are poorly understood. In this study, we aimed to determine the effect of aspirin on the cross talk between platelets and cancer cells. For our study, we used two colon cancer cell lines isolated from the same donor but characterized by different metastatic potential, SW480 (nonmetastatic) and SW620 (metastatic) cancer cells, and a pancreatic cancer cell line, PANC-1 (nonmetastatic). We found that SW480 and PANC-1 cancer cell proliferation was potentiated by human platelets in a manner dependent on the upregulation and activation of the oncoprotein c-MYC. The ability of platelets to upregulate c-MYC and cancer cell proliferation was reversed by an antiplatelet concentration of aspirin. In conclusion, we show for the first time that inhibition of platelets by aspirin can affect their ability to induce cancer cell proliferation through the modulation of the c-MYC oncoprotein.

Effect of antiplatelet agents and tyrosine kinase inhibitors on oxLDL-mediated procoagulant platelet activity.

Low-density lipoprotein (LDL) contributes to atherogenesis and cardiovascular disease through interactions with peripheral blood cells, especially platelets. However, mechanisms by which LDL affects platelet activation and atherothrombosis, and how to best therapeutically target and safely prevent such responses remain unclear. Here, we investigate how oxidized low-density lipoprotein (oxLDL) enhances glycoprotein VI (GPVI)-mediated platelet hemostatic and procoagulant responses, and how traditional and emerging antiplatelet therapies affect oxLDL-enhanced platelet procoagulant activity ex vivo. Human platelets were treated with oxLDL and the GPVI-specific agonist, crosslinked collagen-related peptide, and assayed for hemostatic and procoagulant responses in the presence of inhibitors of purinergic receptors (P2YR), cyclooxygenase (COX), and tyrosine kinases. Ex vivo, oxLDL enhanced GPVI-mediated platelet dense granule secretion, α-granule secretion, integrin activation, thromboxane generation and aggregation, as well as procoagulant phosphatidylserine exposure and fibrin generation. Studies of washed human platelets, as well as platelets from mouse and nonhuman primate models of hyperlipidemia, further determined that P2YR antagonists (eg, ticagrelor) and Bruton tyrosine kinase inhibitors (eg, ibrutinib) reduced oxLDL-mediated platelet responses and procoagulant activity, whereas COX inhibitors (eg, aspirin) had no significant effect. Together, our results demonstrate that oxLDL enhances GPVI-mediated platelet procoagulant activity in a manner that may be more effectively reduced by P2YR antagonists and tyrosine kinase inhibitors compared with COX inhibitors.

What combination therapy with a statin, if any, would you recommend?

The latest recommended goals for blood lipid levels may require multiple lipid drugs. Lower doses in combination may render more efficacy and safety than highest doses of single agents. Except for isolated hypoalphalipoproteinemia (a low level of high-density lipoprotein cholesterol), therapies will start with a statin. All marketed statins are acceptable. The choice may be based on dose- efficacy and patient's tolerability. High-potency statins (eg, atorvastatin, simvastatin, or rosuvastatin) are often chosen. Currently, generic statins, such as simvastatin, lovastatin, pravastatin, and fluvastatin, offer cost benefits. The choice of added agent depends on the "residual lipoprotein abnormalities" after statin therapy, efficacy, compliance issues, and cost. Approved "combined" preparations improve cost and compliance. To further lower low-density lipoprotein cholesterol, ezetimibe is a safe, efficacious choice, pending resolution of a controversial trial's results. Colesevelam is moderately effective and the best tolerated bile acids sequestrant. In combined dyslipidemias, extended-release niacin is the best tolerated niacin preparation; other quality-controlled immediate-release preparations have similar safety and efficacy but produce more flushing of the skin. Niacin or fenofibrate is effective in normalizing high-density lipoprotein and triglyceride levels persisting after statin therapy. Agents approved by the US Food and Drug Administration and the latest guidelines of the National Cholesterol Education Program, American Heart Association/American College of Cardiology provide choices and indications of drug combinations.

Clinical Management of Pharmacokinetic Drug Interactions with Direct Oral Anticoagulants (DOACs).

Compared with warfarin, the direct-acting oral anticoagulants (DOAC) have fewer pharmacokinetic drug interactions. However, significant drug interactions do exist with documented changes in DOAC concentrations, which can exceed 100%. Unlike warfarin, DOACs have no validated surrogate test to monitor the intensity of anticoagulation. However, several analyses of major outcomes trials with DOACs have demonstrated that serum concentrations do affect both the thrombotic benefits and the hemorrhagic risks of these agents. This paper reviews the known significant pharmacokinetic interactions with DOACs and includes considerations for their use in the presence of interacting medications.

Healthcare-associated urinary tract infections with onset post hospital discharge.

OBJECTIVE: Current surveillance for healthcare-associated (HA) urinary tract infection (UTI) is focused on catheter-associated infection with hospital onset (HO-CAUTI), yet this surveillance does not represent the full burden of HA-UTI to patients. Our objective was to measure the incidence of potentially HA, community-onset (CO) UTI in a retrospective cohort of hospitalized patients. DESIGN: Retrospective cohort study. SETTING: Academic, quaternary care, referral center. PATIENTS: Hospitalized adults at risk for HA-UTI from May 2009 to December 2011 were included. METHODS: Patients who did not experience a UTI during the index hospitalization were followed for 30 days post discharge to identify cases of potentially HA-CO UTI. RESULTS: We identified 3,273 patients at risk for potentially HA-CO UTI. The incidence of HA-CO UTI in the 30 days post discharge was 29.8 per 1,000 patients. Independent risk factors of HA-CO UTI included paraplegia or quadriplegia (adjusted odds ratio [aOR], 4.6; 95% confidence interval [CI], 1.2-18.0), indwelling catheter during index hospitalization (aOR, 1.5; 95% CI, 1.0-2.3), prior piperacillin-tazobactam prescription (aOR, 2.3; 95% CI, 1.1-4.5), prior penicillin class prescription (aOR, 1.7; 95% CI, 1.0-2.8), and private insurance (aOR, 0.6; 95% CI, 0.4-0.9). CONCLUSIONS: HA-CO UTI may be common within 30 days following hospital discharge. These data suggest that surveillance efforts may need to be expanded to capture the full burden to patients and better inform antibiotic prescribing decisions for patients with a history of hospitalization.

Aspirin use among adults in the U.S.: results of a national survey.

INTRODUCTION: The use of aspirin in patients without cardiovascular disease remains controversial. Patients' understanding of the risks and benefits of aspirin likely contribute to the decision of whether or not to use aspirin regularly. The purpose of this study is to assess patients' knowledge of aspirin and identify factors contributing to regular use. METHODS: A survey of U.S. adults aged 45-75 years was performed to ascertain aspirin use and factors that may be associated with use. Multivariate logistic regression was used to identify predictors of current use of aspirin among those with a primary prevention indication. The survey was completed in 2012 with data analysis performed in 2013. RESULTS: Among 2,509 respondents, 52% reported current aspirin use. Among 2,039 respondents without a history of cardiovascular disease, current use of aspirin was 47%. Regular use of aspirin for primary prevention was associated with the presence of major cardiovascular disease risk factors (OR=3.0, 95% CI=2.4, 3.7), high self-assessed knowledge of aspirin (OR=9.1, 95% CI=5.2, 15.7), and having discussed aspirin therapy with a provider (OR=25.9, 95% CI=19.7, 34.1). Several markers of healthy lifestyle choices were also associated with regular use. After multivariate analysis, the strongest independent predictor of regular aspirin use was having discussed aspirin therapy with a provider (OR=23.79, 95% CI=17.8, 31.5). CONCLUSIONS: Approximately half of the nationwide survey of U.S. adults reported regular aspirin use. Among those with a primary prevention indication, having discussed aspirin with a provider was the strongest predictor of regular use.

Reporting Bias in Clinical Trials Investigating the Efficacy of Second-Generation Antidepressants in the Treatment of Anxiety Disorders: A Report of 2 Meta-analyses.

IMPORTANCE: Studies have shown that the scientific literature has overestimated the efficacy of antidepressants for depression, but other indications for these drugs have not been considered. OBJECTIVE: To examine reporting biases in double-blind, placebo-controlled trials on the pharmacologic treatment of anxiety disorders and quantify the extent to which these biases inflate estimates of drug efficacy. DATA SOURCES AND STUDY SELECTION: We included reviews obtained from the US Food and Drug Administration (FDA) for premarketing trials of 9 second-generation antidepressants in the treatment of anxiety disorders. A systematic search for matching publications (until December 19, 2012) was performed using PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials. DATA EXTRACTION AND SYNTHESIS: Double data extraction was performed for the FDA reviews and the journal articles. The Hedges g value was calculated as the measure of effect size. MAIN OUTCOMES AND MEASURES: Reporting bias was examined and classified as study publication bias, outcome reporting bias, or spin (abstract conclusion not consistent with published results on primary end point). Separate meta-analyses were conducted for the 2 sources, and the effect of publication status on the effect estimates was examined using meta-regression. RESULTS: The findings of 41 of the 57 trials (72%) were positive according to the FDA, but 43 of the 45 published article conclusions (96%) were positive (P < .001). Trials that the FDA determined as positive were 5 times more likely to be published in agreement with that determination compared with trials determined as not positive (risk ratio, 5.20; 95% CI, 1.87 to 14.45; P < .001). We found evidence for study publication bias (P < .001), outcome reporting bias (P = .02), and spin (P = .02). The pooled effect size based on the published literature (Hedges g, 0.38; 95% CI, 0.33 to 0.42; P < .001) was 15% higher than the effect size based on the FDA data (Hedges g, 0.33; 95% CI, 0.29 to 0.38; P < .001), but this difference was not statistically significant (ß = 0.04; 95% CI, -0.02 to 0.10; P = .18). CONCLUSIONS AND RELEVANCE: Various reporting biases were present for trials on the efficacy of FDA-approved second-generation antidepressants for anxiety disorders. Although these biases did not significantly inflate estimates of drug efficacy, reporting biases led to significant increases in the number of positive findings in the literature.

Efficient methane/nitrogen separation with low-sodium clinoptilolite.

The presence of sodium is shown to have a highly detrimental effect on the gas separation ability of clinoptilolite towards methane and nitrogen.

Synthesis of high silicon content SAPO(4)-5 using anionic surfactants in a hexanol/aqueous two phase media.

High silicon content SAPO(4)-5 (up to 0.511 atoms per unit cell) has been synthesised, using sodium 3-bromopropanesulfonate, sodium 1-butanesulfonate, sodium naphthalene-1-sulfonate or sodium n-decyl sulfate as surfactants; the SiO2 in the reaction gels ranged up to 3.0 (molar ratio), silicon incorporation was confirmed by XRD, XRF, TG-DTA, FT-IR and SEM techniques.

Pharmacotherapy for hypertension in older adults: a systematic review.

BACKGROUND: Hypertension increases with increasing age. Optimal treatment of hypertension is important to reduce cardiovascular disease. Recent guidelines for hypertension have made recommendations for older adults but are supported by evidence that includes younger individuals. This systematic review evaluates the benefits and harms of antihypertensive agents in adults aged ≥65 years. METHODS: We searched MEDLINE and ClinicalTrials.gov for studies from 1996 to 2014. Eligible studies included participants aged ≥65 years with hypertension. Eligible studies had clearly defined treatment assignments, blood pressure (BP) targets, and evaluated endpoints of cardiovascular morbidity, mortality, and/or harms of antihypertensive medications. We abstracted study characteristics, cardiovascular benefits, and harms. RESULTS: Thirty-one articles met the inclusion criteria. Most studies compared different antihypertensive agents and/or placebo groups. These studies consistently demonstrated reduced cardiovascular morbidity and mortality compared with no treatment. Seven studies examined optimal BP targets. Strict control [systolic BP (SBP)<140 mmHg] was not consistently better than mild control (SBP<150 mmHg) for adults aged ≥65 years. Mild SBP control benefitted subjects in all age ranges over 65 years. Few studies assessed and explicitly reported harms. CONCLUSIONS: In this review, older adults with hypertension had decreased cardiovascular morbidity and mortality with antihypertensives compared with no treatment. Strict control was not consistently better than mild control in older adults. There was enormous heterogeneity in these studies, and reporting of harms stratified by age is lacking. The current evidence is insufficient to determine the safest, most beneficial hypertension regimen in older adults.

Antithrombotics for secondary prevention of noncardioembolic ischaemic stroke.

Antiplatelet therapy is more effective than anticoagulation for the prevention of noncardioembolic ischaemic stroke. The choice of antiplatelet regimen, however, remains contentious. Recent controversies regarding aspirin resistance and the optimal dosing of aspirin, as well as recognition of the variable bioactivation of clopidogrel, have added further confusion to the debate. The American Heart Association (AHA) and American Stroke Association (ASA) recently released their third joint guideline in the past 5 years on secondary stroke prevention. The European Stroke Organisation has published three guidelines on this issue since 2000. These frequent updates have been necessary because of rapidly accumulating data from clinical trials. Careful consideration of the sometimes confusing trial results reveals that the 2011 AHA-ASA guidelines are correct in no longer specifying a 'preferred' antiplatelet regimen from among the choices recently studied. This recommendation does not, however, mean that all antiplatelet regimens should be considered equal. This Review discusses the various antiplatelet regimens, and the trials that led to the rapid evolution of the guidelines for secondary prevention of ischaemic stroke.

Let's Get Healthy! Health awareness through public participation in an education and research exhibit.

BACKGROUND: Health information technology (HIT) offers a resource for public empowerment through tailored information. OBJECTIVE: Use interactive community health events to improve awareness of chronic disease risk factors while collecting data to improve health. METHODS: Let's Get Healthy! is an education and research program in which participants visit interactive research stations to learn about their own health (diet, body composition, blood chemistry). HIT enables computerized data collection that presents participants with immediate results and tailored educational feedback. An anonymous wristband number links collected data in a population database. RESULTS AND LESSONS LEARNED: Communities tailor events to meet community health needs with volunteers trained to conduct research. Participants experience being a research participant and contribute to an anonymous population database for both traditional research purposes and open-source community use. CONCLUSIONS: By integrating HIT with community involvement, health fairs become an interactive method for engaging communities in research and raising health awareness.

Production of polyhydroxyalkanoates from waste frying oil by Cupriavidus necator.

Polyhydroxyalkanoates (PHAs) are biopolymers, which can replace petrochemical plastics in many applications. However, these bioplastics are currently far more expensive than petrochemical plastics. Many researchers are investigating the use of inexpensive substrates derived from waste streams. Waste frying oil is abundant and can be used in PHA production without filtration.Cupriavidus necator (formerly known as Ralstonia eutropha) is a versatile organism for the production of PHAs. Small-scale batch fermentation studies have been set up, using different concentrations of pure vegetable oil, heated vegetable oil and waste frying oil. These oils are all rapeseed oils.It has been shown that Cupriavidus necator produced the homopolymer polyhydroxybutyrate (PHB) from the rapeseed oils. The achieved PHB concentration from waste frying oil was 1.2 g/l, which is similar to a concentration that can be obtained from glucose. The PHB harvest from pure oil and heated oil was 0.62 g/l and 0.9 g/l respectively. A feed of waste frying oil could thus achieve more biopolymer than pure vegetable oil. While the use of a waste product is beneficial from a life-cycle perspective, PHB is not the only product that can be made from waste oil. The collection of waste frying oil is becoming more widespread, making waste oil a good alternative to purified oil or glucose for PHB production.

Aspirin for primary prevention of cardiovascular disease in diabetes mellitus.

Aspirin is effective for the prevention of cardiovascular events in patients with a history of vascular disease, as so-called secondary prevention. In general populations with no history of previous myocardial infarction or stroke, aspirin also seems useful for primary prevention of cardiovascular events, although the absolute benefits are smaller than those seen in patients with previous cardiovascular disease. Patients with diabetes mellitus are at an increased risk of cardiovascular events, but new trials have raised questions about the benefit of aspirin for primary prevention in patients with this disorder. This Review comprehensively examines the basic pharmacology of aspirin and provides an overview of the randomized, controlled trials of aspirin therapy that have included patients with diabetes mellitus. On the basis of currently available evidence from primary prevention trials, aspirin is estimated to reduce the relative risk of myocardial infarction and stroke by about 10% in patients with diabetes mellitus; however, aspirin also increases the risk of gastrointestinal bleeding. As such, low-dose aspirin therapy (75-162 mg) is reasonable for patients with diabetes mellitus and a 10-year risk of cardiovascular events >10%. Results from upcoming large trials will help clarify the effects of aspirin with greater precision, including whether the benefits differ between men and women.