Evidence for chronic platelet hyperaggregability and in vivo activation in cyclosporin-treated renal allograft recipients

Evidence for chronic in vivo platelet activation and hyperaggregability has been assessed in 21 renal allograft recipients. All patients received long term immunosuppression with cyclosporin (CS) and low dose prednisolone and were studied serially for 1 year post-transplantation. Spontaneous platelet aggregation in PRP was observed on 10 occasions in 5 patients. Platelet aggregation responses in PRP to low doses of ADP (0.5 and 1.0 microM) were significantly increased up to 1 year post-transplantation (p less than 0.02-less than 0.002). Total platelet nucleotide (ATP and ADP) content and release to 20 micrograms/ml of collagen were significantly decreased for 2 months post-transplantation, indicative of in vivo platelet activation (p less than 0.05-less than 0.002), and plasma PF4 levels were increased up to 1 year post-transplantation suggesting continued platelet activation of a lesser degree. Platelet sensitivity to the prostacyclin analogue Iloprost decreased after 1 month (p less than 0.05) and this persisted up to 1 year (p less than 0.01) compared with sensitivity at 1 week post-transplantation. These prothrombotic changes persisted when trough whole blood CS levels were within the therapeutic range and plasma creatinine levels were approaching or were in the normal range. These data indicate that CS-treated renal allograft recipients exhibit chronic platelet hyperactivity.     

Human brain imaging of nicotinic acetylcholine α4β2* receptors using [18F]Nifene: Selectivity,functional activity,toxicity, aging effects,gender effects,and extrathalamic pathways

Nicotinic acetylcholinergic receptors (nAChR's) have been implicated in several brain disorders, including addiction, Parkinson's disease, Alzheimer's disease and schizophrenia. Here we report in vitro selectivity and functional properties, toxicity in rats, in vivo evaluation in humans, and comparison across species of [¹⁸F]Nifene, a fast acting PET imaging agent for α4β2* nAChRs. Nifene had subnanomolar affinities for hα2β2 (0.34 nM), hα3β2 (0.80 nM) and hα4β2 (0.83 nM) nAChR but weaker (27–219 nM) for hβ4 nAChR subtypes and 169 nM for hα7 nAChR. In functional assays, Nifene (100 μM) exhibited 14% agonist and >50% antagonist characteristics. In 14‐day acute toxicity in rats, the maximum tolerated dose (MTD) and the no observed adverse effect level (NOAEL) were estimated to exceed 40 μg/kg/day (278 μg/m²/day). In human PET studies, [¹⁸F]Nifene (185 MBq; <0.10 μg) was well tolerated with no adverse effects. Distribution volume ratios (DVR) of [¹⁸F]Nifene in white matter thalamic radiations were ～1.6 (anterior) and ～1.5 (superior longitudinal fasciculus). Habenula known to contain α3β2 nAChR exhibited low levels of [¹⁸F]Nifene binding while the red nucleus with α2β2 nAChR had DVR ～1.6–1.7. Females had higher [¹⁸F]Nifene binding in all brain regions, with thalamus showing >15% than males. No significant aging effect was observed in [¹⁸F]Nifene binding over 5 decades. In all species (mice, rats, monkeys, and humans) thalamus showed highest [¹⁸F]Nifene binding with reference region ratios >2 compared to extrathalamic regions. Our findings suggest that [¹⁸F]Nifene PET may be used to study α4β2* nAChRs in various CNS disorders and for translational research.     

Coronary Artery Disease in Patients with Ischemic Stroke and TIA

Background and ObjectivesIschemic stroke (IS) and coronary artery disease (CAD) share common risk factors and one may be the harbinger of the other. We aimed to study prevalence of symptomatic and asymptomatic CAD in a cohort of consecutive patients with IS and assess its relationship with intracranial and extracranial large artery cerebrovascular disease (LAD).MethodsAll consecutive eligible IS and Transient Ischemic Attack (TIA) patients were recruited into the study. Both clinically suspected and asymptomatic patients (N = 259) underwent myocardial Stress-rest Gated Technetium-99m (Tc99m) MIBI Myocardial Perfusion SPECT scan performed on a dual head SPECT-CT to estimate evidence of myocardial ischemia.ResultsThree hundred patients completed the study. Forty one patients were previously diagnosed cases of definitive CAD. Twelve patients were clinically suspected to have CAD and 247 patients were asymptomatic. Among these, 12 patients (4.81%) had a positive SPECT. The overall prevalence of CAD was 17.67% (n = 53). Presence of diabetes was an independent predictor of CAD (OR 1.98, 95% CI 1.07-3.67. P .02). No significant association was found between the presence of LAD and CAD in all subgroup comparisons. However, there was a suggestion of higher LAD among patients with known CAD compared with others.ConclusionsCAD is prevalent in patients with ischemic stroke. No definitive relationship was found between CAD and intracranial or extracranial LAD. Population based stratification tools are needed to further assess the need to detect subclinical CAD in patients with stroke.     

In vivo induction of massive proliferation, directed migration, and differentiation of neural cells in the adult mammalian brain

The development of an in vivo procedure for the induction of massive proliferation, directed migration, and neurodifferentiation (PMD) in the damaged adult central nervous system would hold promise for the treatment of human neurodegenerative disorders such as Parkinson's disease. We investigated the in vivo induction of PMD in the forebrain of the adult rat by using a combination of 6-hydroxydopamine lesion of the substantia nigra dopaminergic neurons and infusions of transforming growth factor alpha (TGFalpha) into forebrain structures. Only in animals with both lesion and infusion of TGFalpha was there a rapid proliferation of forebrain stem cells followed by a timed migration of a ridge of neuronal and glial progenitors directed toward the region of the TGFalpha infusion site. Subsequently, increasing numbers of differentiated neurons were observed in the striatum. In behavioral experiments, there was a significant reduction of apomorphine-induced rotations in animals receiving the TGFalpha infusions. These results show that the brain contains stem cells capable of PMD in response to an exogenously administered growth factor. This finding has significant implications with respect to the development of treatments for both acute neural trauma and neurodegenerative diseases.     

Biological therapies for eosinophilic asthma

Introduction: Severe uncontrolled asthma is by definition refractory to traditional therapies or can be controlled only with therapies that have intolerable side effects. Monoclonal antibodies that target interleukin (IL)-5/IL-5Rα, IgE, and IL-4Rα have shown favorable results in clinical trials, including reductions in asthma exacerbations and other important clinical outcomes. These biological agents offer treatment alternatives to patients with uncontrolled severe eosinophilic asthma.

Areas covered: This article reviews how the shifting emphasis toward identifying distinct asthma phenotypes has led to the approval of biological therapies that preferentially benefit patients with severe eosinophilic asthma. The clinical trials that led to the approval of these biologic treatments are discussed in detail.

Expert opinion: Biologic therapies targeting the IL-5, IgE, IL-4/IL-13 signaling pathways have been successful in clinical trials in subjects with severe eosinophilic asthma. Some of these agents have also been successful regardless of peripheral blood eosinophil counts. These treatments have shown a relatively favorable safety profile in clinical trials, although long-term safety data for some of these agents are limited. Due to the high costs associated with these medications, they should be reserved for select patients where they yield a therapeutic and pharmacoeconomic advantage.     

Comparative Efficacy of Once-Daily Umeclidinium/Vilanterol and Tiotropium/Olodaterol Therapy in Symptomatic Chronic Obstructive Pulmonary Disease: A Randomized Study

Introduction

We report the results of the first direct comparison of the once-daily fixed-dose long-acting muscarinic antagonist/long-acting β₂-agonist (LAMA/LABA) combinations umeclidinium/vilanterol (UMEC/VI) and tiotropium/olodaterol (TIO/OLO) in patients with COPD.

Methods

This was a randomized, two-period crossover open-label study in symptomatic patients with COPD [age 40 years or older, postbronchodilator forced expiratory volume in 1 s (FEV₁) of 70% or less and 50% or more of predicted normal values, and modified Medical Research Council Dyspnoea Scale score of 2 or greater] not receiving inhaled corticosteroid therapy. Patients were randomized to receive UMEC/VI (62.5/25 µg once daily) via a multidose dry powder inhaler (ELLIPTA) followed by TIO/OLO (5/5 µg once daily) via a soft mist inhaler (Respimat), each for 8 weeks with an interim 3-week washout or vice versa. The primary end point was the change from baseline in trough FEV₁ at week 8 with a noninferiority margin of ? 50 mL in the per-protocol (PP) population. The incidence of adverse events was also assessed.

Results

In total, 236 patients (mean age 64.4 years, 60% male) were included in the intent-to-treat population and 227 were included in the PP population. UMEC/VI treatment was noninferior in the PP population and superior in the intent-to-treat population to TIO/OLO treatment with regard to trough FEV₁ at week 8 [FEV₁ change from baseline 180 mL vs 128 mL; difference 52 mL (95% confidence interval 28–77 mL); p < 0.001]. Patients receiving UMEC/VI had twofold increased odds of experiencing a clinically meaningful increase (100 mL or more) from baseline in trough FEV₁ at week 8 compared with patients receiving TIO/OLO (odds ratio 2.05; 95% confidence interval 1.34–3.14). Adverse events occurred in 25% of patients in the UMEC/VI group and in 31% of patients in the TIO/OLO group.

Conclusion

In this first direct comparison of two once-daily fixed-dose LAMA/LABA combinations, superiority was observed for the primary end point of trough FEV₁ at week 8 with UMEC/VI compared with TIO/OLO in patients with symptomatic COPD. Both treatments had similar safety profiles. These findings confirm the results of previous indirect LAMA/LABA comparisons, and show that an efficacy gradient exists within the LAMA/LABA class.

Trial Registration

ClinicalTrials.gov identifier NCT02799784.

Funding

GlaxoSmithKline.

     

Chronic Pain and Telomere Length in Community-Dwelling Adults: Findings From the 1999 to 2002 National Health and Nutrition Examination Survey

Chronic pain is a common condition associated with psychological distress, functional impairments, and age-associated comorbidity. Preliminary studies, on the basis of relatively small sample sizes, suggest that the combination of chronic pain and stress is associated with telomere shortening, a widely recognized marker of cellular aging. We sought to determine the cross-sectional association of chronic pain with telomere length in 7,816 community-dwelling adults ages 20 years and older who participated in the 1999 to 2002 National Health and Nutrition Examination Survey. Consistent with previous studies, leukocyte telomere length was assessed using the quantitative polymerase chain reaction method and compared with a DNA reference standard to compute a telomere to single copy gene ratio. Standardized, in-person interviews were used to identify chronic regional pain and chronic widespread pain in 784 (10.0%) and 266 (3.4%) participants, respectively. Older age, male sex, obesity, and less physical activity were associated with shorter telomere length (P?<.05 for all comparisons); however, there was no association of chronic pain with telomere length. The age-adjusted means (standard error) of telomere length telomere to single copy gene ratios were 1.04 (.02), 1.03 (.02), and 1.02 (.02) in participants with no chronic pain, chronic regional pain, and chronic widespread pain, respectively (P?=?.69). In addition, chronic pain did not modify the effects of age, sex, race/ethnicity, education, or psychological distress on telomere length. In summary, chronic regional and widespread pain were not associated with telomere length in this nationally representative study; however, we could not determine associations of pain duration and severity with telomere length because of limitations in pain assessment data.

Cardioprotective Effect of Propranolol From Alcohol-Induced Heart Muscle Damage as Assessed by Plasma Cardiac Troponin-T

BACKGROUND: Heavy alcohol consumption from either long-term misuse or binge drinking is associated with poor cardiac contractility, mitochondrial dysfunction, and ventricular arrhythmias. The aim of this study was to measure circulating cardiac troponin-T as a marker for myocardial damage following acute and chronic alcohol administration. METHODS: In acute studies, male Wistar rats were treated with alcohol (75 mmol/kg body weight, intraperitoneal) and plasma was collected 2.5 hr after alcohol administration for analysis of rat cardiac troponin-T. In addition, rats were pretreated with cyanamide (an inhibitor of acetaldehyde dehydrogenase), various beta-blockers, xanthine oxidase inhibitors, or lisinopril before acute alcohol dosing. In chronic studies, rats were fed alcohol (as 35% of total dietary calories) for 6 weeks. RESULTS: The results of the time course study showed that acute alcohol administration significantly raised plasma cardiac troponin-T levels after 2.5 hr and 6 hr, but not after 24 hr. The effects of alcohol on cardiac troponin-T were potentiated with cyanamide pretreatment. Acute ethanol, alone or with cyanamide pretreatment, decreased systolic blood pressure and increased heart rates. Beta-blocker pretreatment with propranolol reduced the alcohol-induced increase in plasma troponin-T, whereas lisinopril potentiated this effect. The beta-blockers, atenolol and metoprolol, and the xanthine oxidase inhibitors, allopurinol and oxypurinol, were unable to reduce elevated troponin-T. However, pretreatment with the beta-blocker timolol moderated the acute alcohol-induced increase in troponin-T. In the chronic alcohol rat model, no differences were observed between alcohol and control pair-fed rats, suggesting the inducement of tolerance. CONCLUSIONS: In conditions of acute exposure, ethanol-induced lesions are characterized by raised plasma cardiac troponin-T possibly due to beta1 and/or beta2 adrenergic activation.