Differential inhibition of platelet function by cilostazol in combination with clopidogrel.

PURPOSE: To assess the antiplatelet effect of cilostazol clinically, we compared the effects of cilostazol in combination with clopidogrel on various platelet function tests. METHODS: We recruited patients with ischemic stroke at high risk of recurrence who were treated with clopidogrel alone within 180 days after stroke onset. Subjects underwent baseline platelet function tests, and were then randomly assigned to receive dual antiplatelet therapy (DAPT) comprising clopidogrel and cilostazol or clopidogrel monotherapy (SAPT). After 6 months, platelet function was measured again and compared to that at baseline in each group, and the rate of change was compared between groups. RESULTS: Thirty-four patients were enrolled, but 4 patients were excluded for various reasons. In total, 30 subjects (13 in DAPT and 17 in SAPT group) were analyzed. Adenosine diphosphate- and collagen-induced aggregation, VerifyNow P2Y12 reaction units, vasodilator-stimulated phosphoprotein (platelet reactivity index: PRI) and plasma p-selectin concentration were significantly lower (P = 0.004, 0.042, 0.049, 0.003 and 0.006 respectively), while VerifyNow % inhibition was significantly higher at 6 months compared to baseline (P = 0.003) in the DAPT group only. Comparison of the rate of change in each parameter from baseline to 6 months showed that while PRI decreased at a greater rate (P = 0.012), VerifyNow % inhibition increased at a greater rate (P = 0.003) in the DAPT group than the SAPT group. CONCLUSIONS: The inhibitory effects of adjunctive cilostazol added to clopidogrel on platelet function differed by type of platelet function test. VerifyNow % inhibition and PRI were more inhibited than the other platelet function tests. TRIAL REGISTRATION: CSPS.com substudy in TWMU (UMIN000026672), registered on April 1, 2017. This study was performed as a substudy of CSPS.com (UMIN000012180, registered on October 31, 2013) and was retrospectively registered.

Disengagement of Motor Cortex during Long-Term Learning Tracks the Performance Level of Learned Movements.

Not all movements require the motor cortex for execution. Intriguingly, dependence on motor cortex of a given movement is not fixed, but instead can dynamically change over the course of long-term learning. For instance, rodent forelimb movements that initially require motor cortex can become independent of the motor cortex after an extended period of training. However, it remains unclear whether long-term neural changes rendering the motor cortex dispensable are a simple function of the training length. To address this issue, we trained mice (both male and female) to perform two distinct forelimb movements, forward versus downward reaches with a joystick, concomitantly over several weeks, and then compared the involvement of the motor cortex between the two movements. Most mice achieved different levels of motor performance between the two movements after long-term training. Of the two movements, the one that achieved higher trial-to-trial consistency (i.e., consistent-direction movement) was significantly less affected by inactivation of motor cortex than the other (i.e., variable-direction movement). Two-photon calcium imaging of motor cortical neurons revealed that the consistent-direction movement activates fewer neurons, producing weaker and less consistent population activity than the variable-direction movement. Together, the motor cortex was less engaged and less necessary for learned movements that achieved higher levels of consistency. Thus, the long-term reorganization of neural circuits that frees the motor cortex from the learned movement is not a mere function of training length. Rather, this reorganization tracks the level of motor performance that the animal achieves during training.SIGNIFICANCE STATEMENT Long-term training of a movement reshapes motor circuits, disengaging motor cortex potentially for automatized execution of the learned movement. Acquiring new motor skills often involves learning of multiple movements (e.g., forehand and backhand strokes when learning tennis), but different movements do not always improve at the same time nor reach the same level of proficiency. Here we showed that the involvement of motor cortex after long-term training differs between similar yet distinct movements that reached different levels of expertise. Motor cortex was less engaged and less necessary for the more proficient movement. Thus, disengagement of motor cortex is not a simple function of training time, but instead tracks the level of expertise of a learned movement.

Clinical validation of AggreGuide A-100 ADP, a novel assay for assessing the antiplatelet effect of oral P2Y12 antagonists.

In this prospective, 3-arm, repeated-measure multicenter investigation in 280 patients with cardiovascular risk factors, platelet aggregation was measured with the novel AggreGuide A-100 ADP (A-100 ADP) and VerifyNow (VN)-PRU assays at baseline, and after United States Food and Drug Administration approved loading and 7 days maintenance doses of clopidogrel (n = 94), prasugrel (n = 43) or ticagrelor, (n = 143). Based on the predetermined cutoff values of < 4.7 platelet activity index with A-100 ADP assay to indicate antiplatelet response, more than 91% of patients met the criteria following loading and maintenance doses of prasugrel and more than 84% patients met the criteria following loading and maintenance doses of ticagrelor whereas only 32% and 51% of patients met the criteria following loading and maintenance doses of clopidogrel, respectively. The total percent agreement between the A-100 ADP and VN-PRU assays was 89%. The A-100 ADP assay, which includes whole blood in motion, performs comparably to the VN-PRU assay in a study of patients with cardiovascular risk factors treated with P2Y12 inhibitors possessing known differences in antiplatelet potencies. Trial registration ClinicalTrials.gov Identifier: NCT3111420.

Activity regulates functional connectivity from the vomeronasal organ to the accessory olfactory bulb.

The mammalian accessory olfactory system is specialized for the detection of chemicals that identify kin and conspecifics. Vomeronasal sensory neurons (VSNs) residing in the vomeronasal organ project axons to the accessory olfactory bulb (AOB), where they form synapses with principal neurons known as mitral cells. The organization of this projection is quite precise and is believed to be essential for appropriate function of this system. However, how this precise connectivity is established is unknown. We show here that in mice the vomeronasal duct is open at birth, allowing external chemical stimuli access to sensory neurons, and that these sensory neurons are capable of releasing neurotransmitter to downstream neurons as early as the first postnatal day (P). Using major histocompatibility complex class I peptides to activate a selective subset of VSNs during the first few postnatal days of development, we show that increased activity results in exuberant VSN axonal projections and a delay in axonal coalescence into well defined glomeruli in the AOB. Finally, we show that mitral cell dendritic refinement occurs just after the coalescence of presynaptic axons. Such a mechanism may allow the formation of precise connectivity with specific glomeruli that receive input from sensory neurons expressing the same receptor type.

Urinary L-Type Fatty Acid-Binding Protein Predicts Oxygen Demand of COVID-19 in Initially Mild Cases.

Early detection of illness trajectory in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infected patients is crucial for patients and healthcare workers. An effective, noninvasive approach, with simple measurement for decision-making, is necessary in a pandemic to discriminate between high- and low-risk patients, even though both groups may exhibit mild symptoms in the beginning. OBJECTIVES: To predict COVID-19 disease severity within 10 days, distinguishing cases that will progress to moderate or severe versus mild, patient urinary L-type fatty acid-binding protein (L-FABP) was assayed within 4 days of receiving a diagnosis. The study also examined whether L-FABP point of care (POC) test is helpful in risk screening. DESIGN: Symptomatic subjects who tested positive for SARS-CoV-2 and were hospitalized were prospectively enrolled at the National Center for Global Health and Medicine (NCGM), Yamanashi Prefectural Central Hospital (YPCH), and Sinai Hospital in Maryland. The outcome of each case was evaluated 7 days after admission and the diagnostic performance of L-FABP was assessed. SETTING AND PARTICIPANTS: Subjects were treated for COVID-19 at public healthcare centers in Japan from January 31, 2020, to January 31, 2021, to NCGM, YPCH, and at Sinai Hospital in Baltimore, MD, during the same period. MAIN OUTCOMES AND MEASURES: The primary outcome was to determine whether urinary L-FABP within 48 hours of admission can predict the patient's severity of COVID-19 1 week later. We obtained demographic data, information on clinical symptoms, radiographic images, and laboratory data. RESULTS: Diagnostic performance was assessed using receiver operating characteristic analysis. Of the 224 participants in the study, 173 initially had a mild form of COVID-19. The area under the curve (AUC) for a severe outcome was 93.5%. L-FABP POC risk prediction of a severe outcome had an AUC of 88.9%. CONCLUSIONS AND RELEVANCE: Urinary L-FABP can predict patient risk of COVID-19 illness severity. L-FABP POC is implementable for patient management. (ClinicalTrials.gov number, NCT04681040).

Clinical Utility of a Biomarker to Detect Contrast-Induced Acute Kidney Injury during Percutaneous Cardiovascular Procedures.

INTRODUCTION: Contrast-induced acute kidney injury (CI-AKI) is a major clinical complication of percutaneous cardiovascular procedures requiring iodinated contrast. Despite its relative frequency, practicing physicians are unlikely to identify or treat this condition. METHODS: In a 2-round clinical trial of simulated patients, we examined the clinical utility of a urine-based assay that measures liver-type fatty acid-binding protein (L-FABP), a novel marker of CI-AKI. We sought to determine if interventional cardiologists' ability to diagnose and treat potential CI-AKI improved using the biomarker assay for 3 different patient types: pre-procedure, peri-procedure, and post-procedure patients. RESULTS: 154 participating cardiologists were randomly divided into either control or intervention. At baseline, we found no difference in the demographics or how they identified and treated potential complications of AKI, with both groups providing less than half the necessary care to their patients (46.4% for control vs. 47.6% for intervention, p = 0.250). The introduction of L-FABP into patient care resulted in a statistically significant improvement of 4.6% (p = 0.001). Compared to controls, physicians receiving L-FABP results were 2.9 times more likely to correctly identify their patients' risk for AKI (95% CI 2.1-4.0) and were more than twice as likely to treat for AKI by providing volume expansion and withholding nephrotoxic medications. We found the greatest clinical utility in the pre-procedure and peri-procedure settings but limited value in the post-procedure setting. CONCLUSION: This study suggests L-FABP as a clinical marker for assessing the risk of potential CI-AKI, has clinical utility, and can lead to more accurate diagnosis and treatment.

Modification of the VerifyNow® P2Y12 test BASE channel to accommodate high levels of P2Y(12) antagonism.

The VerifyNow® P2Y12 (VN-P2Y12) test reports thienopyridine-mediated platelet inhibition relative to a "BASE" channel, potentially eliminating the need for predrug patient assessment, by activating platelets through a P2Y(12)-independent pathway. The original formulation of the BASE channel used a protease activated receptor-1 (PAR-1) peptide as agonist. However, more potent P2Y(12) antagonism required more complete activation of platelet thrombin receptors for the BASE measurement in order to negate any contribution of the P2Y(12) receptor. Accordingly, the current BASE channel formulation consists of both PAR-1 and protease activated receptor-4 (PAR-4) activating peptides to facilitate a higher degree of platelet activation. The aim of this study was to compare the performance of PAR-1 versus PAR-1/PAR-4 activating peptides as the BASE channel formulation using prasugrel's active metabolite, R-138727, in vitro to achieve high-grade P2Y(12) inhibition. Blood samples from 20 healthy donors were spiked in vitro with R-138727 at concentrations that include plasma levels achieved following prasugrel administration and were incubated for 30 minutes at 37°C. All samples were run in triplicate using both the PAR-1 and the PAR-1/PAR-4 BASE formulation in the VN-P2Y12 test device. The data confirmed the sensitivity of the original BASE formulation to high-grade P2Y(12) inhibition as reflected in the concentration-dependent decrease in values. Incorporation of PAR-4 activating peptide eliminated the effect of P2Y(12) blockade at all concentrations of R-138727. Thus, the use of PAR-1/PAR-4 in the BASE channel of the VN-P2Y12 cartridge addresses the impact of high grade P2Y(12) blockade and may allow more accurate reporting of "% inhibition" in patients treated with more effective P2Y(12) antagonists.

Measuring the Variation in the Prevention and Treatment of CI-AKI Among Interventional Cardiologists.

Contrast-induced acute kidney injury (CI-AKI) occurs in up to 10% of cardiac catheterizations and coronary interventions, resulting in increased morbidity, mortality, and cost. One main reason for these complications and costs is under-recognition of CI-AKI risk and under-treatment of patients with impaired renal status. 157 interventional cardiologists each cared for three simulated patients with common conditions requiring intravascular contrast media in three typical settings: pre-procedurally, during the procedure, and post-procedure. We evaluated their ability to assess the risk of developing CI-AKI, make the diagnosis, and treat CI-AKI, including proper volume expansion and withholding nephrotoxic medications. Overall, the quality-of-care scores averaged 46.0% ± 10.5, varying between 18% to 78%. The diagnostic scores for accurately assessing risk of CI-AKI were low at 57.1% ± 21.2% and the accuracy of diagnosis pre-existing chronic kidney disease was 50.2%. Poor diagnostic accuracy led to poor treatment: proper volume expansion done in only 30.7% of cases, in-hospital repeat creatinine evaluation performed in 32.1%, and avoiding nephrotoxic medications occurred in 14.2%. While volume expansion was relatively similar across the three settings (P = 0.287), the cardiologists were less likely to discontinue nephrotoxic medications in pre-procedurally (9.7%) compared to the other settings (27.0%), and to order in-hospital creatinine testing in peri-procedurally (18.8%) compared to post-procedure (57.8%) (P < 0.05 for both). The overall care of patients at risk for contrast-induced acute kidney injury varied widely and showed room for improvement. Improving care for this condition will require greater awareness by cardiologists and better diagnostic tools to guide them.

First Experience Addressing the Prognostic Utility of Novel Urinary Biomarkers in Patients With COVID-19.

Urine 11-dehydro-thromboxane B2 (u11-dh-TxB2), 8-hydroxy-2'-deoxyguanosine (8-OHdG), and liver-type fatty acid binding protein levels (L-FABP) at the time of hospitalization were higher in coronavirus disease 2019 (COVID-19) patients with adverse events vs without events. Higher u11-dh-TxB2 and L-FABP levels were associated with longer hospitalization, more thrombotic events, and greater mortality, providing evidence for potential utility as early prognostic biomarkers for COVID-19.

Finding the clinical utility of 1,5-anhydroglucitol among primary care practitioners.

BACKGROUND: HbA1c is widely used as the standard measure to track glycemic control in patients with diabetes and pre-diabetes but measures average levels of glycated hemoglobin over two to three months, with limited utility in the presence of recent and/or short-term fluctuations in glycemic control, which are correlated with worse patient outcomes. METHODS: We examined the clinical utility of 1-5-anhydroglucitol (1,5-AG) in six different, but common, case types of diabetes patients with short-term glycemic variability. We conducted a randomized controlled trial of simulated patients to examine the clinical practice patterns of primary care physicians before and after introducing 1,5-AG. The 145 participants were randomly assigned into standard care or standard care + 1,5-AG arms. Provider care was reviewed against explicit evidence-based care standards. RESULTS: At baseline, we saw no difference between the two study arms in clinical quality of care provided (p = 0.997). After introduction of 1,5-AG, standard care + 1,5-AG providers performed 3.2% better than controls (p = 0.025. In diagnosis and treatment, there was a slight, but nonsignificant trend toward better care (+1.1%, p = 0.507) for intervention providers. Upon disaggregation by case, almost all the improvement occurred in the medication-induced hyperglycemia patients (+8.1%, p = 0.047). CONCLUSIONS: A nationally representative sample of primary care physicians demonstrated that of six different cases used in this study, 1,5-AG was found to be most effective increasing awareness of poor glucose control in medication-induced hyperglycemia. If 1,5-AG is used in this particular circumstance, the overall savings to the healthcare system is estimated to be $28 million.

New methodological approaches for assessing thrombus formation in cardiovascular disease.

Antiplatelet therapy is the mainstay preventive strategy for cardiovascular diseases, and dual antiplatelet therapy comprising aspirin and a P2Y12 inhibitor is the standard treatment for patients who underwent percutaneous coronary intervention. The Total Thrombus­Formation Analysis System (T­TAS) is a microchip flow­chamber system developed to evaluate overall thrombus formation under flow conditions, which is reportedly able to assess single and combined antithrombotic therapy. Here, we focus on this new system, T­TAS, and review its characteristics together with those of the conventional systems available for evaluation of antithrombotic therapies for cardiovascular diseases.

Variation in Diabetes Management: A National Assessment of Primary Care Providers.

BACKGROUND: Glucose control is monitored primarily through ordering HbA1c levels, which is problematic in patients with glycemic variability. Herein, we report on the management of these patients by board-certified primary care providers (PCPs) in the United States. METHODS: We measured provider practice in a representative sample of 156 PCPs. All providers cared for simulated patients with diabetes presenting with symptoms of glycemic variability. Provider responses were reviewed by trained clinicians against evidence-based care standards and accepted standard of care protocols. RESULTS: Care varied widely-overall quality of care averaged 51.3%±10.6%-with providers performing just over half the evidence-based practices necessary for their cases. More worryingly, provider identified the underlying etiology of the poor glycemic control only 36.3% of the time. HbA1c was routinely ordered in 91.3% of all cases but often (59.5%) inappropriately. Ordering other tests of glycemic control (done in 15% of cases) led to significant increases in identifying the etiology of the hyperglycemia. Correctly modifying their patient's treatment was more likely to occur if doctors first identified the underlying etiology (65.9% vs 49.0%, P<0.001). We conservatively estimated a US $65/patient/visit in unnecessary testing and US $389 annually in additional care costs when the etiology was missed, translating potentially into millions of dollars of wasteful spending. CONCLUSION: Despite established evidence that HbA1c misses short-term changes in diabetes, we found PCPs consistently ordered HbA1c, rarely using other available blood tests. However, if the factors leading to poor glycemic control were recognized, PCPs were more likely to correctly alter their patient's hypoglycemic therapy.

Total Thrombus-Formation Analysis System (T-TAS): Clinical Application of Quantitative Analysis of Thrombus Formation in Cardiovascular Disease.

Various antithrombotic agents are clinically used to inhibit the cascade of arterial or venous thrombosis in cardiovascular diseases. Dual antiplatelet therapy with aspirin and P2Y12 inhibitors is prescribed in patients with coronary artery disease (CAD) undergoing percutaneous coronary intervention (PCI). Direct oral anticoagulants (DOACs) are widely used for the prevention or treatment of thromboembolism in patients with atrial fibrillation (AF) and venous thromboembolism. However, there has been no definitive tool to simultaneously monitor the antithrombotic effects of these drugs. The Total Thrombus-Formation Analysis System (T-TAS), a microchip-based flow chamber system that mimics in vivo conditions for evaluating whole blood thrombogenicity, was developed for the quantitative analysis of thrombus formation in whole blood specimens. The utility of T-TAS has been evaluated in CAD patients treated with antiplatelet therapies. The T-TAS PL chip area under the flow pressure curve (AUC) accurately assesses primary hemostasis and is sensitive to the therapeutic effects of various antiplatelet therapies. In addition, low AUC results are a significant predictor of periprocedural bleeding events in CAD patients undergoing PCI. The T-TAS AR chip AUC result is useful for assessing the efficacy of DOACs and warfarin in AF patients undergoing catheter ablation, and it is also a potential independent predictor of periprocedural bleeding events and avoidance of thrombosis in patients having undergone total knee arthroplasty. In conclusion, T-TAS is a useful index for evaluating the total antithrombotic effects of combination antithrombotic agents in patients with various cardiovascular diseases.

Disengagement of motor cortex from movement control during long-term learning.

Motor learning involves reorganization of the primary motor cortex (M1). However, it remains unclear how the involvement of M1 in movement control changes during long-term learning. To address this, we trained mice in a forelimb-based motor task over months and performed optogenetic inactivation and two-photon calcium imaging in M1 during the long-term training. We found that M1 inactivation impaired the forelimb movements in the early and middle stages, but not in the late stage, indicating that the movements that initially required M1 became independent of M1. As previously shown, M1 population activity became more consistent across trials from the early to middle stage while task performance rapidly improved. However, from the middle to late stage, M1 population activity became again variable despite consistent expert behaviors. This later decline in activity consistency suggests dissociation between M1 and movements. These findings suggest that long-term motor learning can disengage M1 from movement control.

History-based action selection bias in posterior parietal cortex.

Making decisions based on choice-outcome history is a crucial, adaptive ability in life. However, the neural circuit mechanisms underlying history-dependent decision-making are poorly understood. In particular, history-related signals have been found in many brain areas during various decision-making tasks, but the causal involvement of these signals in guiding behavior is unclear. Here we addressed this issue utilizing behavioral modeling, two-photon calcium imaging, and optogenetic inactivation in mice. We report that a subset of neurons in the posterior parietal cortex (PPC) closely reflect the choice-outcome history and history-dependent decision biases, and PPC inactivation diminishes the history dependency of choice. Specifically, many PPC neurons show history- and bias-tuning during the inter-trial intervals (ITI), and history dependency of choice is affected by PPC inactivation during ITI and not during trial. These results indicate that PPC is a critical region mediating the subjective use of history in biasing action selection.

Morphological analysis of activity-reduced adult-born neurons in the mouse olfactory bulb.

Adult-born neurons (ABNs) are added to the olfactory bulb (OB) throughout life in rodents. While many factors have been identified as regulating the survival and integration of ABNs into existing circuitry, the understanding of how these factors affect ABN morphology and connectivity is limited. Here we compare how cell intrinsic [small interfering RNA (siRNA) knock-down of voltage gated sodium channels Na(V)1.1-1.3] and circuit level (naris occlusion) reductions in activity affect ABN morphology during integration into the OB. We found that both manipulations reduce the number of dendritic spines (and thus likely the number of reciprocal synaptic connections) formed with the surrounding circuitry and inhibited dendritic ramification of ABNs. Further, we identified regions of ABN apical dendrites where the largest and most significant decreases occur following siRNA knock-down or naris occlusion. In siRNA knock-down cells, reduction of spines is observed in proximal regions of the apical dendrite. This suggests that distal regions of the dendrite may remain active independent of Na(V)1.1-1.3 channel expression, perhaps facilitated by activation of T-type calcium channels and NMDA receptors. By contrast, circuit level reduction of activity by naris occlusion resulted in a global depression of spine number. Together, these results indicate that ABNs retain the ability to develop their typical overall morphological features regardless of experienced activity, and activity modulates the number and location of formed connections.

Early biomarkers of stroke.

BACKGROUND: The diagnosis and management of acute ischemic stroke are limited by the lack of rapid diagnostic assays for use in an emergency setting. Computed tomography (CT) scanning is used to diagnose hemorrhagic stroke but is relatively ineffective (<33% sensitive) in detecting ischemic stroke. The ability to correlate blood-borne protein biomarkers with stroke phenotypes would aid in the development of such rapid tests. METHODS: ELISAs for >50 protein biomarkers were developed for use on a high-throughput robotic workstation. These assays were used to screen plasma samples from 214 healthy donors and 223 patients diagnosed with stroke, including 82 patients diagnosed with acute ischemic stroke. Marker assay values were first compared by univariate analysis, and then the top markers were subjected to multivariate analysis to derive a marker panel algorithm for the prediction of stroke. RESULTS: The top markers from this analysis were S-100b (a marker of astrocytic activation), B-type neurotrophic growth factor, von Willebrand factor, matrix metalloproteinase-9, and monocyte chemotactic protein-1. In a panel algorithm in which three or more marker values above their respective cutoffs were scored as positive, these five markers provided a sensitivity of 92% at 93% specificity for ischemic stroke samples taken within 6 h from symptom onset. CONCLUSION: A marker panel approach to the diagnosis of stroke may provide a useful adjunct to CT scanning in the emergency setting.