HAS-BLED for predicting transfemoral transcatheter aortic valve replacement outcomes: Enough to tamponade the problem?

As indications for TAVR expand, there is a need for predictive models of procedural complications. Application of the HAS-BLED score demonstrated patient comorbidities that contribute to increased bleeding events and mortality. Further adequately powered studies will be needed to validate the HAS-BLED score for use in the TAVR population or further elucidate important risk factor to incorporate into future predictive risk models.

Rescuing cocaine-induced prefrontal cortex hypoactivity prevents compulsive cocaine seeking.

Loss of control over harmful drug seeking is one of the most intractable aspects of addiction, as human substance abusers continue to pursue drugs despite incurring significant negative consequences. Human studies have suggested that deficits in prefrontal cortical function and consequential loss of inhibitory control could be crucial in promoting compulsive drug use. However, it remains unknown whether chronic drug use compromises cortical activity and, equally important, whether this deficit promotes compulsive cocaine seeking. Here we use a rat model of compulsive drug seeking in which cocaine seeking persists in a subgroup of rats despite delivery of noxious foot shocks. We show that prolonged cocaine self-administration decreases ex vivo intrinsic excitability of deep-layer pyramidal neurons in the prelimbic cortex, which was significantly more pronounced in compulsive drug-seeking animals. Furthermore, compensating for hypoactive prelimbic cortex neurons with in vivo optogenetic prelimbic cortex stimulation significantly prevented compulsive cocaine seeking, whereas optogenetic prelimbic cortex inhibition significantly increased compulsive cocaine seeking. Our results show a marked reduction in prelimbic cortex excitability in compulsive cocaine-seeking rats, and that in vivo optogenetic prelimbic cortex stimulation decreased compulsive drug-seeking behaviours. Thus, targeted stimulation of the prefrontal cortex could serve as a promising therapy for treating compulsive drug use.

Central role for the insular cortex in mediating conditioned responses to anticipatory cues.

Reward-related circuits are fundamental for initiating feeding on the basis of food-predicting cues, whereas gustatory circuits are believed to be involved in the evaluation of food during consumption. However, accumulating evidence challenges such a rigid separation. The insular cortex (IC), an area largely studied in rodents for its role in taste processing, is involved in representing anticipatory cues. Although IC responses to anticipatory cues are well established, the role of IC cue-related activity in mediating feeding behaviors is poorly understood. Here, we examined the involvement of the IC in the expression of cue-triggered food approach in mice trained with a Pavlovian conditioning paradigm. We observed a significant change in neuronal firing during presentation of the cue. Pharmacological silencing of the IC inhibited food port approach. Such a behavior could be recapitulated by temporally selective inactivation during the cue. These findings represent the first evidence, to our knowledge, that cue-evoked neuronal activity in the mouse IC modulates behavioral output, and demonstrate a causal link between cue responses and feeding behaviors.

Dorsal medial prefrontal cortex (MPFC) circuitry in rodent models of cocaine use: implications for drug addiction therapies.

Although the importance of the medial prefrontal cortex (MPFC) in cocaine addiction is well established, its precise contribution to cocaine seeking, taking and relapse remains incompletely understood. In particular, across two different models of cocaine self-administration, pharmacological or optogenetic activation of the dorsal MPFC has been reported to sometimes promote and sometimes inhibit cocaine seeking. We highlight important methodological differences between the two experimental paradigms and propose a framework to potentially reconcile the apparent discrepancy. We also draw parallels between these pre-clinical models of cocaine self-administration and human neuro-imaging studies in cocaine users, and argue that both lines of evidence point to dynamic interactions between cue-reactivity processes and control processes within the dorsal MPFC circuitry. From a translational perspective, these findings underscore the importance of interventions and therapeutics targeting not just a brain region, but a specific computational process within that brain region, and may have implications for the design and implementation of more effective treatments for human cocaine addiction.

Optogenetic inhibition of dorsal medial prefrontal cortex attenuates stress-induced reinstatement of palatable food seeking in female rats.

Relapse to maladaptive eating habits during dieting is often provoked by stress. Recently, we identified a role of dorsal medial prefrontal cortex (mPFC) neurons in stress-induced reinstatement of palatable food seeking in male rats. It is unknown whether endogenous neural activity in dorsal mPFC drives stress-induced reinstatement in female rats. Here, we used an optogenetic approach, in which female rats received bilateral dorsal mPFC microinjections of viral constructs coding light-sensitive eNpHR3.0-eYFP or control eYFP protein and intracranial fiber optic implants. Rats were food restricted and trained to lever press for palatable food pellets. Subsequently, pellets were removed, and lever pressing was extinguished; then the effect of bilateral dorsal mPFC light delivery on reinstatement of food seeking was assessed after injections of the pharmacological stressor yohimbine (an α-2 andrenoceptor antagonist) or pellet priming, a manipulation known to provoke food seeking in hungry rats. Dorsal mPFC light delivery attenuated yohimbine-induced reinstatement of food seeking in eNpHR3.0-injected but not eYFP-injected rats. This optical manipulation had no effect on pellet-priming-induced reinstatement or ongoing food-reinforced responding. Dorsal mPFC light delivery attenuated yohimbine-induced Fos immunoreactivity and disrupted neural activity during in vivo electrophysiological recording in awake rats. Optical stimulation caused significant outward currents and blocked electrically evoked action potentials in eNpHR3.0-injected but not eYFP-injected mPFC hemispheres. Light delivery alone caused no significant inflammatory response in mPFC. These findings indicate that intracranial light delivery in eNpHR3.0 rats disrupts endogenous dorsal mPFC neural activity that plays a role in stress-induced relapse to food seeking in female rats.

26S proteasome regulation of Ankrd1/CARP in adult rat ventricular myocytes and human microvascular endothelial cells.

Ankyrin repeat domain 1 protein (Ankrd1), also known as cardiac ankyrin repeat protein (CARP), increases dramatically after tissue injury, and its overexpression improves aspects of wound healing. Reports that Ankrd1/CARP protein stability may affect cardiovascular organization, together with our findings that the protein is crucial to stability of the cardiomyocyte sarcomere and increased in wound healing, led us to compare the contribution of Ankrd1/CARP stability to its abundance. We found that the 26S proteasome is the dominant regulator of Ankrd1/CARP degradation, and that Ankrd1/CARP half-life is significantly longer in cardiomyocytes (h) than endothelial cells (min). In addition, higher endothelial cell density decreased the abundance of the protein without affecting steady state mRNA levels. Taken together, our data and that of others indicate that Ankrd1/CARP is highly regulated at multiple levels of its expression. The striking difference in protein half-life between a muscle and a non-muscle cell type suggests that post-translational proteolysis is correlated with the predominantly structural versus regulatory role of the protein in the two cell types.

Prognostic significance of plaque location in non-obstructive coronary artery disease: from the CONFIRM registry.

AIM: Obstructive coronary artery disease (CAD) in proximal coronary segments is associated with a poor prognosis. However, the relative importance of plaque location regarding the risk for major adverse cardiovascular events (MACE) in patients with non-obstructive CAD has not been well defined. METHODS AND RESULTS: From the Coronary CT Angiography Evaluation for Clinical Outcomes: An International Multicenter (CONFIRM) registry, 4644 patients without obstructive CAD were included in this study. The degree of stenosis was classified as 0 (no) and 1-49% (non-obstructive). Proximal involvement was defined as any plaque present in the left main or the proximal segment of the left anterior descending artery, left circumflex artery, and right coronary artery. Extensive CAD was defined as segment involvement score of >4. During a median follow-up of 5.2 years (interquartile range 4.1-6.0), 340 (7.3%) MACE occurred. Within the non-obstructive CAD group (n = 2065), proximal involvement was observed in 1767 (85.6%) cases. When compared to non-obstructive CAD patients without proximal involvement, those with proximal involvement had an increased MACE risk (log-rank P = 0.033). Multivariate Cox analysis showed when compared to patients with no CAD, proximal non-obstructive CAD was associated with increased MACE risk [hazard ratio (HR) 1.90, 95% confidence interval (CI) 1.47-2.45, P < 0.001] after adjusting for extensive CAD and conventional cardiovascular risk factors; however, non-proximal non-obstructive CAD did not increase MACE risk (HR 1.26, 95% CI 0.79-2.01, P = 0.339). CONCLUSIONS: Independent of plaque extent, proximal coronary involvement was associated with increased MACE risk in patients with non-obstructive CAD. The plaque location information by coronary computed tomography angiography may provide additional risk prediction over CAD extent in patients with non-obstructive CAD.

Neuregulin-1ß regulation of embryonic endothelial progenitor cell survival.

Endothelial progenitor cells (EPCs) are mobilized into the vascular space and home to damaged tissues, where they promote repair in part through a process of angiogenesis. Neuregulins (NRGs) are ligands in the epidermal growth factor family that signal through type I receptor tyrosine kinases in the erbB family (erbB2, erbB3, and erbB4) and regulate endothelial cell biology, promoting angiogenesis. Stimuli such as ischemia and exercise that promote EPC mobilization also induce cleavage and release of transmembrane NRG from cardiac microvascular endothelial cells (CMECs). We hypothesized that NRG/erbB signaling may regulate EPC biology. Using an embryonic (e)EPC cell line that homes to and repairs injured myocardium, we were able to detect erbB2 and erbB3 transcripts. Identical receptor expression was found in EPCs isolated from rat bone marrow and human whole blood. NRG treatment of eEPCs induces phosphorylation of kinases including Akt, GSK-3ß, and Erk1/2 and the nuclear accumulation and transcriptional activation of ß-catenin. NRG does not induce eEPC proliferation or migration but does protect eEPCs against serum deprivation-induced apoptosis. These results suggest a role for tissue-derived NRG in the regulation of EPC survival.

The accuracy of coronary CT angiography in patients with coronary calcium score above 1000 Agatston Units: Comparison with quantitative coronary angiography.

BACKGROUND: High amounts of coronary artery calcium (CAC) pose challenges in interpretation of coronary CT angiography (CCTA). The accuracy of stenosis assessment by CCTA in patients with very extensive CAC is uncertain. METHODS: Retrospective study was performed including patients who underwent clinically directed CCTA with CAC score >1000 and invasive coronary angiography within 90 days. Segmental stenosis on CCTA was graded by visual inspection with two-observer consensus using categories of 0%, 1-24%, 25-49%, 50-69%, 70-99%, 100% stenosis, or uninterpretable. Blinded quantitative coronary angiography (QCA) was performed on all segments with stenosis ≥25% by CCTA. The primary outcome was vessel-based agreement between CCTA and QCA, using significant stenosis defined by diameter stenosis ≥70%. Secondary analyses on a per-patient basis and inclusive of uninterpretable segments were performed. RESULTS: 726 segments with stenosis ≥25% in 346 vessels within 119 patients were analyzed. Median coronary calcium score was 1616 (1221-2118). CCTA identification of QCA-based stenosis resulted in a per-vessel sensitivity of 79%, specificity of 75%, positive predictive value (PPV) of 45%, negative predictive value (NPV) of 93%, and accuracy 76% (68 false positive and 15 false negative). Per-patient analysis had sensitivity 94%, specificity 55%, PPV 63%, NPV 92%, and accuracy 72% (30 false-positive and 3 false-negative). Inclusion of uninterpretable segments had variable effect on sensitivity and specificity, depending on whether they are considered as significant or non-significant stenosis. CONCLUSIONS: In patients with very extensive CAC (>1000 Agatston units), CCTA retained a negative predictive value â€‹> â€‹90% to identify lack of significant stenosis on a per-vessel and per-patient level, but frequently overestimated stenosis.

Orexin A/hypocretin-1 selectively promotes motivation for positive reinforcers.

Orexin A/hypocretin-1 (oxA/hcrt-1) is known to be a modulator of dopamine-dependent neuronal activity and behaviors. However, the role of this system in driving motivated behaviors remains poorly understood. Here, we show that orexin/hypocretin receptor-1 (ox/hcrt-1R) signaling is important for motivation for highly salient, positive reinforcement. Blockade of ox/hcrt-1R selectively reduced work to self-administer cocaine or high fat food pellets. Moreover, oxA/hcrt-1 strengthened presynaptic glutamatergic inputs to the ventral tegmental area (VTA) only in cocaine or high fat self-administering rats. Finally, oxA/hcrt-1-mediated excitatory synaptic transmission onto VTA neurons was not potentiated following an arousing, aversive stimulus, suggesting that oxA/hcrt-1-mediated glutamatergic synaptic transmission was potentiated selectively with highly salient positive reinforcers. These experiments provide evidence for a selective role of oxA/hcrt-1 signaling in motivation for highly salient reinforcers and may represent a unique opportunity to design novel therapies that selectively reduce excessive drive to consume positive reinforcers of high salience.

The small-conductance calcium-activated potassium channel is a key modulator of firing and long-term depression in the dorsal striatum.

The striatum is considered to be critical for the control of goal-directed action, with the lateral dorsal striatum (latDS) being implicated in modulation of habits and the nucleus accumbens thought to represent a limbic-motor interface. Although medium spiny neurons from different striatal subregions exhibit many similar properties, differential firing and synaptic plasticity could contribute to the varied behavioral roles across subregions. Here, we examined the contribution of small-conductance calcium-activated potassium channels (SKs) to action potential generation and synaptic plasticity in adult rat latDS and nucleus accumbens shell (NAS) projection neurons in vitro. The SK-selective antagonist apamin exerted a prominent effect on latDS firing, significantly decreasing the interspike interval. Furthermore, prolonged latDS depolarization increased the interspike interval and reduced firing, and this enhancement was reversed by apamin. In contrast, NAS neurons exhibited greater basal firing rates and less regulation of firing by SK inhibition and prolonged depolarization. LatDS neurons also had greater SK currents than NAS neurons under voltage-clamp. Importantly, SK inhibition with apamin facilitated long-term depression (LTD) induction in the latDS but not the NAS, without alterations in glutamate release. In addition, SK activation in the latDS prevented LTD induction. Greater SK function in the latDS than in the NAS was not secondary to differences in sodium or inwardly rectifying potassium channel function, and apamin enhancement of firing did not reflect indirect action through cholinergic interneurons. Thus, these data demonstrate that SKs are potent modulators of action potential generation and LTD in the dorsal striatum, and could represent a fundamental cellular mechanism through which habits are regulated.

Cocaine self-administration selectively abolishes LTD in the core of the nucleus accumbens.

The core and shell of the nucleus accumbens have critical, differential roles in drug-dependent behaviors. Here we show that operant cocaine self-administration inhibits long-term depression (LTD) in both structures after 1 d of abstinence. However, after 21 d of abstinence, LTD was abolished exclusively in the nucleus accumbens core of cocaine self-administering rats, suggesting that voluntary cocaine self-administration induced long-lasting neuroadaptations in the core that could underlie drug-seeking behavior and relapse.

Development and Validation of the Gene Expression Predictor of High-grade Serous Ovarian Carcinoma Molecular SubTYPE (PrOTYPE).

PURPOSE: Gene expression-based molecular subtypes of high-grade serous tubo-ovarian cancer (HGSOC), demonstrated across multiple studies, may provide improved stratification for molecularly targeted trials. However, evaluation of clinical utility has been hindered by nonstandardized methods, which are not applicable in a clinical setting. We sought to generate a clinical grade minimal gene set assay for classification of individual tumor specimens into HGSOC subtypes and confirm previously reported subtype-associated features. EXPERIMENTAL DESIGN: Adopting two independent approaches, we derived and internally validated algorithms for subtype prediction using published gene expression data from 1,650 tumors. We applied resulting models to NanoString data on 3,829 HGSOCs from the Ovarian Tumor Tissue Analysis consortium. We further developed, confirmed, and validated a reduced, minimal gene set predictor, with methods suitable for a single-patient setting. RESULTS: Gene expression data were used to derive the predictor of high-grade serous ovarian carcinoma molecular subtype (PrOTYPE) assay. We established a de facto standard as a consensus of two parallel approaches. PrOTYPE subtypes are significantly associated with age, stage, residual disease, tumor-infiltrating lymphocytes, and outcome. The locked-down clinical grade PrOTYPE test includes a model with 55 genes that predicted gene expression subtype with >95% accuracy that was maintained in all analytic and biological validations. CONCLUSIONS: We validated the PrOTYPE assay following the Institute of Medicine guidelines for the development of omics-based tests. This fully defined and locked-down clinical grade assay will enable trial design with molecular subtype stratification and allow for objective assessment of the predictive value of HGSOC molecular subtypes in precision medicine applications.See related commentary by McMullen et al., p. 5271.

Human embryonic stem cell-derived cardiomyocytes restore function in infarcted hearts of non-human primates.

Pluripotent stem cell-derived cardiomyocyte grafts can remuscularize substantial amounts of infarcted myocardium and beat in synchrony with the heart, but in some settings cause ventricular arrhythmias. It is unknown whether human cardiomyocytes can restore cardiac function in a physiologically relevant large animal model. Here we show that transplantation of ∼750 million cryopreserved human embryonic stem cell-derived cardiomyocytes (hESC-CMs) enhances cardiac function in macaque monkeys with large myocardial infarctions. One month after hESC-CM transplantation, global left ventricular ejection fraction improved 10.6 ± 0.9% vs. 2.5 ± 0.8% in controls, and by 3 months there was an additional 12.4% improvement in treated vs. a 3.5% decline in controls. Grafts averaged 11.6% of infarct size, formed electromechanical junctions with the host heart, and by 3 months contained ∼99% ventricular myocytes. A subset of animals experienced graft-associated ventricular arrhythmias, shown by electrical mapping to originate from a point-source acting as an ectopic pacemaker. Our data demonstrate that remuscularization of the infarcted macaque heart with human myocardium provides durable improvement in left ventricular function.

Cocaine enhances NMDA receptor-mediated currents in ventral tegmental area cells via dopamine D5 receptor-dependent redistribution of NMDA receptors.

Cocaine-induced plasticity of glutamatergic synaptic transmission in the ventral tegmental area (VTA) plays an important role in brain adaptations that promote addictive behaviors. However, the mechanisms responsible for triggering these synaptic changes are unknown. Here, we examined the effects of acute cocaine application on glutamatergic synaptic transmission in rat midbrain slices. Cocaine caused a delayed increase in NMDA receptor (NMDAR)-mediated synaptic currents in putative VTA dopamine (DA) cells. This effect was mimicked by a specific DA reuptake inhibitor and by a DA D1/D5 receptor agonist. The effect of cocaine was blocked by a DA D1/D5 receptor antagonist as well as by inhibitors of the cAMP/cAMP-dependent protein kinase A (PKA) pathway. Furthermore, biochemical analysis showed an increase in the immunoreactivity of the NMDAR subunits NR1 and NR2B and their redistribution to the synaptic membranes in VTA neurons. Accordingly, NMDAR-mediated EPSC decay time kinetics were significantly slower after cocaine, suggesting an increased number of NR2B-containing NMDARs. Finally, pharmacological analysis indicates that NR2B subunits might be incorporated in triheteromeric NR1/NR2A/NR2B complexes rather than in "pure" NR1/NR2B NMDA receptors. Together, our data suggest that acute cocaine increases NMDAR function in the VTA via activation of the cAMP/PKA pathway mediated by a DA D5-like receptor, leading to the insertion of NR2B-containing NMDARs in the membrane. These results provide a potential mechanism by which acute cocaine promotes synaptic plasticity of VTA neurons, which could ultimately lead to the development of addictive behaviors.

Acamprosate attenuates cocaine- and cue-induced reinstatement of cocaine-seeking behavior in rats.

RATIONALE: Acamprosate (calcium acetylhomotaurinate) is a glutamatergic neuromodulator used for the treatment of alcoholism, but its potential efficacy in the treatment of psychostimulant addiction has not been explored. OBJECTIVES: The purpose of this study was to assess the effects of acamprosate on cocaine-stimulated locomotor activity, cocaine self-administration, and cue- and cocaine-induced reinstatement of cocaine-seeking behavior. MATERIALS AND METHODS: All experiments utilized once-daily treatment for 5 consecutive days. First, the effects of saline or acamprosate (100, 300, or 500 mg/kg intraperitoneally) on body weight were examined. On the last day of treatment, locomotor activity was assessed before and after drug treatment, after which all animals received an acute challenge of cocaine (10 mg/kg). Next, a separate group of rats were trained to intravenously (IV) self-administer cocaine (0.6 mg/kg per infusion), subjected to extinction procedures, and then tested for effects of acamprosate on cue- or cocaine-induced reinstatement. A third group of rats was trained to self-administer cocaine as described above and were treated with saline or acamprosate before daily IV self-administration sessions. RESULTS: Repeated administration of 500 mg/kg acamprosate but not lower doses produced reductions in both body weight and spontaneous locomotor activity, and thus this dose was not tested further. Acamprosate at 300 mg/kg but not 100 mg/kg attenuated both cocaine- and cue-induced reinstatement without altering baseline patterns of cocaine self-administration or cocaine-stimulated hyperlocomotion. CONCLUSIONS: Acamprosate attenuates both drug- and cue-induced reinstatement of cocaine-seeking behavior, suggesting that this compound may serve as a potential treatment for preventing relapse in cocaine-addicted humans.

Molecular and cellular mechanisms of anthracycline cardiotoxicity.

The molecular and cellular mechanisms that cause cumulative dose-dependent anthracycline-cardiotoxicity remain controversial and incompletely understood. Studies examining the effects of anthracyclines in cardiac myocytes inA vitro have demonstrated several forms of cellular injury. Cell death in response to anthracyclines can be observed by one of several mechanisms including apoptosis and necrosis. Cell death by apoptosis can be inhibited by dexrazoxane, the iron chelator that is known to prevent clinical development of heart failure at high cumulative anthracycline exposure. Together with clinical evidence for myocyte death after anthracycline exposure, in the form of elevations in serum troponin, make myocyte cell death a probable mechanism for anthracycline-induced cardiac injury. Other mechanisms of myocyte injury include the development of cellular \'sarcopenia\' characterized by disruption of normal sarcomere structure. Anthracyclines suppress expression of several cardiac transcription factors, and this may play a role in the development of myocyte death as well as sarcopenia. Degradation of the giant myofilament protein titin may represent an important proximal step that leads to accelerated myofilament degradation. Titin is an entropic spring element in the sarcomere that regulates length-dependent calcium sensitivity. Thus titin degradation may lead to impaired diastolic as well as systolic dysfunction, as well as potentiate the effect of suppression of transcription of sarcomere proteins. An interesting interaction has been noted clinically between anthracyclines and newer cancer therapies that target the erbB2 receptor tyrosine kinase. Studies of erbB2 function in viro suggest that signaling through erbB2 by the growth factor neuregulin may regulate cardiac myocyte sarcomere turnover, as well as myocyte-myocyte/myocyte-matrix force coupling. A combination of further in vitro studies, with more careful monitoring of cardiac function after exposure to these cancer therapies, may help to understand to what extent these mechanisms are at work during clinical exposure of the heart to these important pharmaceuticals.

Enantioselective Synthesis of 4'-Ethynyl-2-fluoro-2'-deoxyadenosine (EFdA) via Enzymatic Desymmetrization.

An enantioselective synthesis of the potent anti-HIV nucleoside EFdA is presented. Key features of stereocontrol include construction of the fully substituted 4'-carbon via a biocatalytic desymmetrization of 2-hydroxy-2-((triisopropylsilyl)ethynyl)propane-1,3-diyl diacetate and a Noyori-type asymmetric transfer hydrogenation to control the stereochemistry of the 3'-hydroxyl bearing carbon. The discovery of a selective crystallization of an N-silyl nucleoside intermediate enabled isolation of the desired ß-anomer from the glycosylation step.