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Childhood-onset systemic lupus erythematosus (cSLE) is a multisystem disease; its severity depends on the organs involved. Monogenic diseases have been described as predisposing to the onset of cSLE. Analytical and immunological tests are used for diagnostic confirmation. The main goal of treatment is remission and flare prevention. Here we describe the clinical case of a patient with prolonged febrile syndrome, arthralgias, and anemia, positive analytical tests for antinuclear antibodies and anti-DNA antibodies and low values of complement C3, C4, and C1q; so the patient was diagnosed with cSLE associated with C1q deficiency. Patients with C1q deficiency present with early onset of disease and significant target organ damage with nephritis. An early diagnosis of cSLE is important to ensure an early and appropriate treatment. Treatment may be personalized depending on the underlying defect that generates the subtype of lupus., (Sociedad Argentina de Pediatría.)

Myocardial necrosis following the successful reperfusion of a coronary artery occluded by thrombus in a patient presenting with ST-elevation myocardial infarction (STEMI) continues to be a serious problem, despite the multiple attempts to attenuate the necrosis with agents that have shown promise in pre-clinical investigations. Possible reasons include confounding clinical risk factors, the delayed application of protective agents, poorly designed pre-clinical investigations, the possible effects of routinely administered agents that might unknowingly already have protected the myocardium or that might have blocked protection, and the biological differences of the myocardium in humans and experimental animals. A better understanding of the pathobiology of myocardial infarction is needed to stem this reperfusion injury. P2Y 12 receptor antagonists minimize platelet aggregation and are currently part of the standard treatment to prevent thrombus formation and propagation in STEMI protocols. Serendipitously, these P2Y 12 antagonists also dramatically attenuate reperfusion injury in experimental animals and are presumed to provide a similar protection in STEMI patients. However, additional protective agents are needed to further diminish reperfusion injury. It is possible to achieve additive protection if the added intervention protects by a mechanism different from that of P2Y 12 antagonists. Inflammation is now recognized to be a critical factor in the complex intracellular response to ischemia and reperfusion that leads to tissue necrosis. Interference with cardiomyocyte inflammasome assembly and activation has shown great promise in attenuating reperfusion injury in pre-clinical animal models. And the blockade of the executioner protease caspase-1, indeed, supplements the protection already seen after the administration of P2Y 12 antagonists. Importantly, protective interventions must be applied in the first minutes of reperfusion, if protection is to be achieved. The promise of such a combination of protective strategies provides hope that the successful attenuation of reperfusion injury is attainable.

Purpose: The goal of this study was to develop a fully convolutional network (FCN) tool to automatedly segment the left-ventricular (LV) myocardium in displacement encoding with stimulated echoes MRI. The segmentation results are used for LV chamber quantification and strain analyses in breast cancer patients susceptible to cancer therapy-related cardiac dysfunction (CTRCD). Approach: A DeepLabV3+ FCN with a ResNet-101 backbone was custom-designed to conduct chamber quantification on 45 female breast cancer datasets (23 training, 11 validation, and 11 test sets). LV structural parameters and LV ejection fraction (LVEF) were measured, and myocardial strains estimated with the radial point interpolation method. Myocardial classification validation was against quantization-based ground-truth with computations of accuracy, Dice score, average perpendicular distance (APD), Hausdorff-distance, and others. Additional validations were conducted with equivalence tests and Cronbach's alpha ( C - α ) intraclass correlation coefficients between the FCN and a vendor tool on chamber quantification and myocardial strain computations. Results: Myocardial classification results against ground-truth were Dice = 0.89 , APD = 2.4    mm , and accuracy = 97 % for the validation set and Dice = 0.90 , APD = 2.5    mm , and accuracy = 97 % for the test set. The confidence intervals (CI) and two one-sided t-test results of equivalence tests between the FCN and vendor-tool were CI = - 1.36 % to 2.42%, p-value < 0.001 for LVEF ( 58 ± 5 % versus 57 ± 6 % ), and CI = - 0.71 % to 0.63%, p-value < 0.001 for longitudinal strain ( - 15 ± 2 % versus - 15 ± 3 % ). Conclusions: The validation results were found equivalent to the vendor tool-based parameter estimates, which show that accurate LV chamber quantification followed by strain analysis for CTRCD investigation can be achieved with our proposed FCN methodology., (© 2024 Society of Photo-Optical Instrumentation Engineers (SPIE).)

Pylephlebitis is defined as suppurative thrombosis of the portal vein as a complication of abdominal infections. In pediatrics, the most frequent etiology is appendicitis, generally of late diagnosis, presenting as sepsis, with a high mortality rate. Imaging methods are necessary for diagnosis; the most common are the Doppler ultrasound and computed tomography angiography. Treatment is based on surgery, antibiotic therapy, and anticoagulation. The indication for the latter is controversial, but it may improve prognosis and decrease morbidity and mortality. Here we describe a clinical case of pylephlebitis secondary to Escherichia coli sepsis, which started as acute appendicitis in a pediatric patient who progressed to cavernomatous transformation of the portal vein. It is important to know the management of this disease because, once the initial symptoms are overcome, it will require close follow-up due to a potential progression to liver failure., (Sociedad Argentina de Pediatría.)

Osteomyelitis is defined as an inflammation of the bone caused by infection. Acute osteomyelitis is common in pediatrics. A Brodie abscess is a type of subacute osteomyelitis, with a historically low incidence; however, its incidence is currently increasing. Given its little clinical impact, with non-specific laboratory tests and radiological studies of difficult interpretation, diagnostic suspicion is crucial. It resembles neoplasms, either benign or malignant. An adequate diagnosis falls on the health care provider's experience. Treatment consists of antibiotics, both parenteral and oral, with potential surgical drainage. Here we describe the case of a healthy female patient with a tumor found in the topography of the left clavicle 3 months before. She was diagnosed with Brodie abscess; treatment was started with a good response. A high index of suspicion of Brodie abscess is critical to avoid invasive tests and studies or inadequate treatments, and to prevent future sequelae., (Sociedad Argentina de Pediatría.)

Pneumonia elicits the production of cytotoxic beta amyloid (Aβ) that contributes to end-organ dysfunction, yet the mechanism(s) linking infection to activation of the amyloidogenic pathway that produces cytotoxic Aβ is unknown. Here, we tested the hypothesis that gamma-secretase activating protein (GSAP), which contributes to the amyloidogenic pathway in the brain, promotes end-organ dysfunction following bacterial pneumonia. First-in-kind Gsap knockout rats were generated. Wild-type and knockout rats possessed similar body weights, organ weights, circulating blood cell counts, arterial blood gases, and cardiac indices at baseline. Intratracheal Pseudomonas aeruginosa infection caused acute lung injury and a hyperdynamic circulatory state. Whereas infection led to arterial hypoxemia in wild-type rats, the alveolar-capillary barrier integrity was preserved in Gsap knockout rats. Infection potentiated myocardial infarction following ischemia-reperfusion injury, and this potentiation was abolished in knockout rats. In the hippocampus, GSAP contributed to both pre- and postsynaptic neurotransmission, increasing the presynaptic action potential recruitment, decreasing neurotransmitter release probability, decreasing the postsynaptic response, and preventing postsynaptic hyperexcitability, resulting in greater early long-term potentiation but reduced late long-term potentiation. Infection abolished early and late long-term potentiation in wild-type rats, whereas the late long-term potentiation was partially preserved in Gsap knockout rats. Furthermore, hippocampi from knockout rats, and both the wild-type and knockout rats following infection, exhibited a GSAP-dependent increase in neurotransmitter release probability and postsynaptic hyperexcitability. These results elucidate an unappreciated role for GSAP in innate immunity and highlight the contribution of GSAP to end-organ dysfunction during infection. NEW & NOTEWORTHY Pneumonia is a common cause of end-organ dysfunction, both during and in the aftermath of infection. In particular, pneumonia is a common cause of lung injury, increased risk of myocardial infarction, and neurocognitive dysfunction, although the mechanisms responsible for such increased risk are unknown. Here, we reveal that gamma-secretase activating protein, which contributes to the amyloidogenic pathway, is important for end-organ dysfunction following infection.

Purpose: To determine if Artificial Intelligence-based computation of global longitudinal strain (GLS) from left ventricular (LV) MRI is an early prognostic factor of cancer therapy-related cardiac dysfunction (CTRCD) in breast cancer patients. The main hypothesis based on the patients receiving antineoplastic chemotherapy treatment was CTRCD risk analysis with GLS that was independent of LV ejection fraction (LVEF)., Methods: Displacement Encoding with Stimulated Echoes (DENSE) MRI was acquired on 32 breast cancer patients at baseline and 3- and 6-month follow-ups after chemotherapy. Two DeepLabV3+ Fully Convolutional Networks (FCNs) were deployed to automate image segmentation for LV chamber quantification and phase-unwrapping for 3D strains, computed with the Radial Point Interpolation Method. CTRCD risk (cardiotoxicity and adverse cardiac events) was analyzed with Cox Proportional Hazards (PH) models with clinical and contractile prognostic factors., Results: GLS worsened from baseline to the 3- and 6-month follow-ups (-19.1 ± 2.1%, -16.0 ± 3.1%, -16.1 ± 3.0%; P < 0.001). Univariable Cox regression showed the 3-month GLS significantly associated as an agonist (hazard ratio [HR]-per-SD: 2.1; 95% CI: 1.4-3.1; P < 0.001) and LVEF as a protector (HR-per-SD: 0.8; 95% CI: 0.7-0.9; P = 0.001) for CTRCD occurrence. Bivariable regression showed the 3-month GLS (HR-per-SD: 2.0; 95% CI: 1.2-3.4; P = 0.01) as a CTRCD prognostic factor independent of other covariates, including LVEF (HR-per-SD: 1.0; 95% CI: 0.9-1.2; P = 0.9)., Conclusions: The end-point analyses proved the hypothesis that GLS is an early, independent prognosticator of incident CTRCD risk. This novel GLS-guided approach to CTRCD risk analysis could improve antineoplastic treatment with further validation in a larger clinical trial., (Copyright © 2022. Published by Elsevier Inc.)

To study the relationship between caspase-1/4 and reperfusion injury, we measured infarct size (IS) in isolated mouse hearts undergoing 50 min global ischemia/2 h reperfusion. Starting VRT-043198 (VRT) at reperfusion halved IS. The pan-caspase inhibitor emricasan duplicated VRT's protection. IS in caspase-1/4-knockout hearts was similarly reduced, supporting the hypothesis that caspase-1/4 was VRT's only protective target. NLRC4 inflammasomes activate caspase-1. NLRC4 knockout hearts were not protected, eliminating NLRC4 as caspase-1/4's activator. The amount of protection that could be achieved by only suppressing caspase-1/4 activity was limited. In wild-type (WT) hearts, ischemic preconditioning (IPC) was as protective as caspase-1/4 inhibitors. Combining IPC and emricasan in these hearts or preconditioning caspase-1/4-knockout hearts produced an additive IS reduction, indicating that more protection could be achieved by combining treatments. We determined when caspase-1/4 exerted its lethal injury. Starting VRT after 10 min of reperfusion in WT hearts was no longer protective, revealing that caspase-1/4 inflicted its injury within the first 10 min of reperfusion. Ca ++ influx at reperfusion might activate caspase-1/4. We tested whether Ca ++ -dependent soluble adenylyl cyclase (AC10) could be responsible. However, IS in AC10 -/- hearts was not different from that in WT control hearts. Ca ++ -activated calpain has been implicated in reperfusion injury. Calpain could be releasing actin-bound procaspase-1 in cardiomyocytes, which would explain why caspase-1/4-related injury is confined to early reperfusion. The calpain inhibitor calpeptin duplicated emricasan's protection. Unlike IPC, adding calpain to emricasan offered no additional protection, suggesting that caspase-1/4 and calpain may share the same protective target.

This study's purpose was to develop a direct MRI-based, deep-learning semantic segmentation approach for computing global longitudinal strain (GLS), a known metric for detecting left-ventricular (LV) cardiotoxicity in breast cancer. Displacement Encoding with Stimulated Echoes cardiac image phases acquired from 30 breast cancer patients and 30 healthy females were unwrapped via a DeepLabV3 + fully convolutional network (FCN). Myocardial strains were directly computed from the unwrapped phases with the Radial Point Interpolation Method. FCN-unwrapped phases of a phantom's rotating gel were validated against quality-guided phase-unwrapping (QGPU) and robust transport of intensity equation (RTIE) phase-unwrapping. FCN performance on unwrapping human LV data was measured with F1 and Dice scores versus QGPU ground-truth. The reliability of FCN-based strains was assessed against RTIE-based strains with Cronbach's alpha (C-α) intraclass correlation coefficient. Mean squared error (MSE) of unwrapping the phantom experiment data at 0 dB signal-to-noise ratio were 1.6, 2.7 and 6.1 with FCN, QGPU and RTIE techniques. Human data classification accuracies were F1 = 0.95 (Dice = 0.96) with FCN and F1 = 0.94 (Dice = 0.95) with RTIE. GLS results from FCN and RTIE were -16 ± 3% vs. -16 ± 3% (C-α = 0.9) for patients and -20 ± 3% vs. -20 ± 3% (C-α = 0.9) for healthy subjects. The low MSE from the phantom validation demonstrates accuracy of phase-unwrapping with the FCN and comparable human subject results versus RTIE demonstrate GLS analysis accuracy. A deep-learning methodology for phase-unwrapping in medical images and GLS computation was developed and validated in a heterogeneous cohort., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

While ischemia itself can kill heart muscle, much of the infarction after a transient period of coronary artery occlusion has been found to result from injury during reperfusion. Here we review the role of inflammation and possible pyroptosis in myocardial reperfusion injury. Current evidence suggests pyroptosis's contribution to infarction may be considerable. Pyroptosis occurs when inflammasomes activate caspases that in turn cleave off an N-terminal fragment of gasdermin D. This active fragment makes large pores in the cell membrane thus killing the cell. Inhibition of inflammation enhances cardiac tolerance to ischemia and reperfusion injury. Stimulation of the purinergic P2X7 receptor and the β-adrenergic receptor and activation of nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) by toll-like receptor (TLR) agonists are all known to contribute to ischemia/reperfusion (I/R) cardiac injury through inflammation, potentially by pyroptosis. In contrast, stimulation of the cannabinoid CB2 receptor reduces I/R cardiac injury and inhibits this pathway. MicroRNAs, Akt, the phosphate and tension homology deleted on chromosome 10 protein (PTEN), pyruvate dehydrogenase and sirtuin-1 reportedly modulate inflammation in cardiomyocytes during I/R. Cryopyrin and caspase-1/4 inhibitors are reported to increase cardiac tolerance to ischemic and reperfusion cardiac injury, presumably by suppressing inflammasome-dependent inflammation. The ambiguity surrounding the role of pyroptosis in reperfusion injury arises because caspase-1 also activates cytotoxic interleukins and proteolytically degrades a surprisingly large number of cytosolic enzymes in addition to activating gasdermin D.

Background: Doxorubicin (Dox) is a first-line treatment for triple negative breast cancer (TNBC), but its use may be limited by its cardiotoxicity mediated by the production of reactive oxygen species. We evaluated whether vitamin D may prevent Dox-induced cardiotoxicity in a mouse TNBC model., Methods: Female Balb/c mice received rodent chow with vitamin D 3 (1500 IU/kg; vehicle) or chow supplemented with additional vitamin D 3 (total, 11,500 IU/kg). the mice were inoculated with TNBC tumors and treated with intraperitoneal Dox (6 or 10 mg/kg). Cardiac function was evaluated with transthoracic echocardiography. The cardiac tissue was evaluated with immunohistochemistry and immunoblot for levels of 4-hydroxynonenal, NAD(P)H quinone oxidoreductase (NQO1), C-MYC, and dynamin-related protein 1 (DRP1) phosphorylation., Results: At 15 to 18 days, the mean ejection fraction, stroke volume, and fractional shortening were similar between the mice treated with vitamin D + Dox (10 mg/kg) vs. vehicle but significantly greater in mice treated with vitamin D + Dox (10 mg/kg) vs. Dox (10 mg/kg). Dox (10 mg/kg) increased the cardiac tissue levels of 4-hydroxynonenal, NQO1, C-MYC, and DRP1 phosphorylation at serine 616, but these increases were not observed with vitamin D + Dox (10 mg/kg). A decreased tumor volume was observed with Dox (10 mg/kg) and vitamin D + Dox (10 mg/kg)., Conclusions: Vitamin D supplementation decreased Dox-induced cardiotoxicity by decreasing the reactive oxygen species and mitochondrial damage, and did not decrease the anticancer efficacy of Dox against TNBC.

Left-ventricular (LV) strain measurements with the Displacement Encoding with Stimulated Echoes (DENSE) MRI sequence provide accurate estimates of cardiotoxicity damage related to breast cancer chemotherapy. This study investigated an automated LV chamber quantification tool via segmentation with a supervised deep convolutional neural network (DCNN) before strain analysis with DENSE images. Segmentation for chamber quantification analysis was conducted with a custom DeepLabV3+ DCNN with ResNet-50 backbone on 42 female breast cancer datasets (22 training-sets, eight validation-sets and 12 independent test-sets). Parameters such as LV end-diastolic diameter (LVEDD) and ejection fraction (LVEF) were quantified, and myocardial strains analyzed with the Radial Point Interpolation Method (RPIM). Myocardial classification was validated against ground-truth with sensitivity-specificity analysis, the metrics of Dice, average perpendicular distance (APD) and Hausdorff-distance. Following segmentation, validation was conducted with the Cronbach's Alpha (C-Alpha) intraclass correlation coefficient between LV chamber quantification results with DENSE and Steady State Free Precession (SSFP) acquisitions and a vendor tool-based method to segment the DENSE data, and similarly for myocardial strain analysis in the chambers. The results of myocardial classification from segmentation of the DENSE data were accuracy = 97%, Dice = 0.89 and APD = 2.4 mm in the test-set. The C-Alpha correlations from comparing chamber quantification results between the segmented DENSE and SSFP data and vendor tool-based method were 0.97 for LVEF (56 ± 7% vs 55 ± 7% vs 55 ± 6%, p = 0.6) and 0.77 for LVEDD (4.6 ± 0.4 cm vs 4.5 ± 0.3 cm vs 4.5 ± 0.3 cm, p = 0.8). The validation metrics against ground-truth and equivalent parameters obtained from the SSFP segmentation and vendor tool-based comparisons show that the DCNN approach is applicable for automated LV chamber quantification and subsequent strain analysis in cardiotoxicity., (Copyright © 2021 Elsevier Inc. All rights reserved.)

The Society for Cardiovascular Magnetic Resonance (SCMR) is an international society focused on the research, education, and clinical application of cardiovascular magnetic resonance (CMR). The SCMR web site ( https://www.scmr.org ) hosts a case series designed to present case reports demonstrating the unique attributes of CMR in the diagnosis or management of cardiovascular disease. Each clinical presentation is followed by a brief discussion of the disease and unique role of CMR in disease diagnosis or management guidance. By nature, some of these are somewhat esoteric, but all are instructive. In this publication, we provide a digital archive of the 2019 Case of the Week series as a means of further enhancing the education of those interested in CMR and as a means of more readily identifying these cases using a PubMed or similar search engine.

DNA vaccine evaluation in small animals is hampered by low immunogenicity when the vaccines are delivered using a needle and syringe. To overcome this technical hurdle we tested the possibility that a device developed for human intradermal medicine delivery might be adapted to successfully deliver a DNA vaccine to small animals. Disposable syringe jet injection (DSJI) does not currently exist for small animals. However, a commercialized, human intradermal device used to to administer medicines to the human dermis in a 0.1 mL volume was evaluated in Syrian hamsters. Here, we found that hantavirus DNA vaccines administered to hamsters using DSJI were substantially more immunogenic than the same vaccines delivered by needle/syringe or particle mediated epidermal delivery (gene gun) vaccination. By adjusting how the device was used we could deliver vaccine to either subcutaneous tissues, or through the skin into the muscle. RNA and/or antigen expression was detected in epidermal, subepidermal and fibroblast cells. We directly compared six optimized and non-optimized hantavirus DNA vaccines in hamsters. Optimization, including codon-usage and mRNA stability, did not necessarily result in increased immunogenicity for all vaccines tested; however, optimization of the Andes virus (ANDV) DNA vaccine protected vaccinated hamsters from lethal disease. This is the first time active vaccination with an ANDV DNA vaccine has shown protective efficacy in the hamster model. The adaptation of a human intradermal jet injection device for use as a method of subcutaneous and intramuscular jet injection of DNA vaccines will advance the development of nucleic acid based medical countermeasures for diseases modeled in hamsters., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Ltd.)

Purpose: To comprehensively outline the methodology of a fully automated, MRI motion-guided, left-ventricular (LV) chamber quantification algorithm that enhances a similar, existing semi-automated approach. Additionally, to validate the motion-guided technique in comparison to chamber quantification with a vendor tool in post-chemotherapy breast cancer patients susceptible to cardiotoxicity. Approach: LV deformation data were acquired with the displacement encoding with stimulated echoes (DENSE) sequence on N = 21 post-chemotherapy female patients and N = 21 age-matched healthy females. The new chamber quantification algorithm consists of detecting LV boundary motion via a combination of image quantization and DENSE phase-encoded displacements. LV contractility was analyzed via chamber quantification and computations of 3D strains and torsion. For validation, estimates of chamber quantification with the motion-guided algorithm on DENSE and steady-state free precession (SSFP) acquisitions, and similar estimates with an existing vendor tool on DENSE acquisitions were compared via repeated measures analysis. Patient results were compared to healthy subjects for observing abnormalities. Results: Repeated measures analysis showed similar LV ejection fractions (LVEF), 59 % ± 6 % , 58 % ± 6 % , and 58 % ± 6 % , p = 0.2 , by applying the motion-guided algorithm on DENSE and SSFP and vendor tool on DENSE acquisitions, respectively. Differences found between patients and healthy subjects included enlarged basal diameters ( 5.0 ± 0.5    cm versus 4.4 ± 0.5    cm , p < 0.01 ), torsions ( p < 0.001 ), and longitudinal strains ( p < 0.001 ), but not LVEF ( p = 0.1 ). Conclusions: Measurement similarities between new and existing tools, and between DENSE and SSFP validated the motion-guided algorithm and differences found between subpopulations demonstrate the ability to detect contractile abnormalities., (© 2020 Society of Photo-Optical Instrumentation Engineers (SPIE).)

Pulmonary arterial hypertension is a fatal disease, where death is associated with right heart failure and reduced cardiorespiratory reserve. The Sugen 5416, hypoxia and normoxia Fischer rat model mimics human pulmonary arterial hypertension, although the cause(s) of death remains incompletely understood. Here, we hypothesized that these animals develop biventricular diastolic dysfunction that contributes to tissue hypoperfusion coincident with severe pulmonary arterial hypertension. We performed comprehensive echocardiographic and hematologic assessments. Serial echocardiogram at 3-5 weeks was performed followed by blood sampling via aortic or cardiac puncture. Echocardiogram revealed pulmonary arterial hypertension in pulmonary artery Doppler waves, including notched wave envelopes, and decreased pulmonary artery acceleration time/pulmonary artery ejection time ratio and right ventricular outflow tract velocity time integral. Impaired right ventricular systolic function, assessed by decreased tricuspid annular plane systolic excursion and tricuspid tissue Doppler systolic positive wave velocity, was observed in pulmonary arterial hypertension. Tricuspid and mitral pulsed wave and tissue Doppler findings suggested biventricular diastolic dysfunction, with dynamic changes in early and late diastolic filling waves, their fusion patterns, and a decrease in e' velocity. Heart rate and ejection fraction did not change, but cardiac output, stroke volume, and end-diastolic volume were decreased, and inferior vena cava respiratory variation was decreased. Blood electrolyte values were suggestive of intravascular volume expansion early in the disease followed by volume contraction and tissue hypoperfusion in the latter stages of disease. Complete blood count showed thrombocytopenia and non-anemic macrocytosis with reticulocytosis and an increase in red blood cell distribution width. Thus, pulmonary, cardiac, and hematological findings in Fischer animals with pulmonary arterial hypertension are characteristic of humans and provide an insightful experimental platform to resolve mechanisms of disease progression., (© The Author(s) 2020.)

We explored an emerging technology to produce anti-Hantaan virus (HTNV) and anti-Puumala virus (PUUV) neutralizing antibodies for use as pre- or post-exposure prophylactics. The technology involves hyperimmunization of transchomosomic bovines (TcB) engineered to express human polyclonal IgG antibodies with HTNV and PUUV DNA vaccines encoding G n G c glycoproteins. For the anti-HTNV product, TcB was hyperimmunized with HTNV DNA plus adjuvant or HTNV DNA formulated using lipid nanoparticles (LNP). The LNP-formulated vaccine yielded fivefold higher neutralizing antibody titers using 10-fold less DNA. Human IgG purified from the LNP-formulated animal (SAB-159), had anti-HTNV neutralizing antibody titers >100,000. SAB-159 was capable of neutralizing pseudovirions with monoclonal antibody escape mutations in G n and G c demonstrating neutralization escape resistance. SAB-159 protected hamsters from HTNV infection when administered pre- or post-exposure, and limited HTNV infection in a marmoset model. An LNP-formulated PUUV DNA vaccine generated purified anti-PUUV IgG, SAB-159P, with a neutralizing antibody titer >600,000. As little as 0.33 mg/kg of SAB-159P protected hamsters against PUUV infection for pre-exposure and 10 mg/kg SAB-159P protected PUUV-infected hamsters post-exposure. These data demonstrate that DNA vaccines combined with the TcB-based manufacturing platform can be used to rapidly produce potent, human, polyclonal, escape-resistant anti-HTNV, and anti-PUUV neutralizing antibodies that are protective in animal models., (Copyright © 2020 Perley, Brocato, Wu, Bausch, Karmali, Vega, Cohen, Somerville, Kwilas, Principe, Shamblin, Chivukula, Sullivan and Hooper.)

Guidelines recommend treatment with a P2Y 12 platelet adenosine diphosphate receptor inhibitor in patients undergoing elective or urgent percutaneous coronary intervention (PCI), but the optimal agent or timing of administration is still not clearly specified. The P2Y 12 inhibitor was initially used for its platelet anti-aggregatory action to block thrombosis of the recanalized coronary artery or deployed stent. It is now recognized that these agents also offer potent cardioprotection against a reperfusion injury that occurs in the first minutes of reperfusion if platelet aggregation is blocked at the time of reperfusion. But this is difficult to achieve with oral agents which are slowly absorbed and often require time-consuming metabolic activation. Patients with ST-segment elevation myocardial infarction who usually have a large mass of myocardium at risk of infarction seldom have sufficient time for upstream-administered oral agents to achieve a therapeutic P2Y 12 level of inhibition by the time of balloon inflation. However, optimal treatment could be assured by initiating an IV cangrelor infusion shortly prior to stenting followed by subsequent post-PCI transition to an oral agent, that is, ticagrelor, once success of the recanalization and absence of need for surgical intervention are confirmed. Not only should this sequence provide optimal protection against infarction, it should also negate bleeding if coronary artery bypass grafting should be required since stopping the cangrelor infusion at any time will quickly restore platelet reactivity. It is anticipated that cangrelor-induced myocardial salvage will help preserve myocardial function and significantly diminish postinfarction heart failure.

Objective: This study investigated the occurrence of cardiotoxicity-related left-ventricular (LV) contractile dysfunction in breast cancer patients following treatment with antineoplastic chemotherapy agents., Methods: A validated and automated MRI-based LV contractility analysis tool consisting of quantization-based boundary detection, unwrapping of image phases and the meshfree Radial Point Interpolation Method was used toward measuring LV chamber quantifications (LVCQ), three-dimensional strains and torsions in patients and healthy subjects. Data were acquired with the Displacement Encoding with Stimulated Echoes (DENSE) sequence on 21 female patients and 21 age-matched healthy females. Estimates of patient LVCQs from DENSE acquisitions were validated in comparison to similar steady-state free precession measurements and their strain results validated via Bland-Altman interobserver agreements. The occurrence of LV abnormalities was investigated via significant differences in contractility measurements (LVCQs, strains and torsions) between patients and healthy subjects., Results: Repeated measures analysis showed similarities between LVCQ measurements from DENSE and steady-state free precession, including cardiac output (4.7 ± 0.4 L, 4.6 ± 0.4 L, p = 0.8), and LV ejection fractions (59±6%, 58±5%, p = 0.2). Differences found between patients and healthy subjects included enlarged basal diameter (5.0 ± 0.5 cm vs 4.4 ± 0.5 cm, p < 0.01), apical torsion (6.0 ± 1.1° vs 9.7 ± 1.4°, p < 0.001) and global longitudinal strain (-0.15 ± 0.02 vs. -0.21 ± 0.04, p < 0.001), but not LV ejection fraction (59±6% vs. 63±6%, p = 0.1)., Conclusion: The results from the statistical analysis reveal the possibility of LV abnormalities in the post-chemotherapy patients via enlarged basal diameter and reduced longitudinal strain and torsion, in comparison to healthy subjects., Advances in Knowledge: This study shows that subclinical LV abnormalities in post-chemotherapy breast cancer patients can be detected with an automated technique for the comprehensive analysis of contractile parameters.

Purpose: This study applied a novel and automated contractility analysis tool to investigate possible cardiotoxicity-related left-ventricular (LV) dysfunction in breast cancer patients following treatment with anti-neoplastic chemotherapy agents (CTA). Subclinical dysfunction otherwise undetected via LV ejection fraction (LVEF) was determined., Methods: Deformation data were acquired with the Displacement Encoding with Stimulated Echoes (DENSE) MRI sequence on 16 female patients who had CTA-based treatment. The contractility analysis tool consisting of image quantization-based boundary detection and the meshfree Radial Point Interpolation Method was used to compare chamber quantifications, 3D regional strains and torsion between patients and healthy subjects (N = 26 females with N = 14 age-matched). Quantifications of patient LVEFs from DENSE and Steady-State Free Precession (SSFP) acquisitions were compared, Bland-Altman interobserver agreements measured on their strain results and differences in contractile parameters with healthy subjects determined via Student's t-tests., Results: A significant difference was not found between DENSE and SSFP-based patient LVEFs at 58 ± 7% vs 57 ± 9%, p = 0.6. Bland-Altman agreements were - 0.01 ± 0.05 for longitudinal strain and 0.1 ± 1.3° for torsion. Differences in basal diameter indicating enlargement, 5.2 ± 0.5 cm vs 4.5 ± 0.5 cm, p < 0.01, and torsion, 4.7 ± 1.0° vs 8.1 ± 1.1°, p < 0.001 in the mid-ventricle and 5.9 ± 1.2° vs 10.2 ± 0.9°, p < 0.001 apically, were seen between patients and age-matched healthy subjects and similarly in longitudinal strain, but not in LVEF., Conclusions: Results from the statistical analysis reveal the likelihood of LV remodeling in this patient subpopulation otherwise not indicated by LVEF measurements., (Published by Elsevier Inc.)

P2Y 12 receptor-blocking drugs given at reperfusion offer protection against myocardial infarction in animal models of transient coronary occlusion. Two recent reports concluded that ticagrelor was more cardioprotective than clopidogrel and attributed this to ticagrelor's unique ability to raise tissue adenosine by blocking the equilibrative nucleoside transporter 1. Indeed, an adenosine receptor blocker attenuated ticagrelor's protection. The related P2Y 12 inhibitor cangrelor, which does not block the transporter, protects hearts only when platelets are in the perfusate, while adenosine is known to protect equally in situ blood-perfused and crystalloid-perfused isolated hearts. We, therefore, tested whether ticagrelor liberates a sufficient amount of adenosine to protect a Krebs buffer-perfused isolated rat heart subjected to 40 minutes of global ischemia followed by 2 hours of reperfusion. In untreated hearts, 77.6% ± 4.0% of the ventricle was infarcted as measured by triphenyltetrazolium staining. Ischemically preconditioned hearts had only 32.7% ± 3.6% infarction ( P < .001 vs untreated), indicating that our model could be protected by preconditioning which is known to involve adenosine. Strikingly, hearts treated with 10 μmol/L ticagrelor in the buffer throughout the reperfusion period had 77.5% ± 2.4% infarction comparable to unprotected controls ( P = NS vs untreated). These data strongly suggest that ticagrelor was unable to release sufficient adenosine from the crystalloid-perfused rat heart to protect it against infarction. Our previous studies have found no difference in the anti-infarct potency among clopidogrel, cangrelor, and ticagrelor in open-chest rats and rabbits, and surprisingly adenosine receptor antagonists block protection from all 3 drugs. We have no explanation why ticagrelor is more protective in the pig than clopidogrel but suspect a species or perhaps a treatment schedule difference that may or may not involve adenosine.

Acute obstruction of a coronary artery causes myocardial ischaemia and if prolonged, may result in an ST-segment elevation myocardial infarction (STEMI). First-line treatment involves rapid reperfusion. However, a highly dynamic and co-ordinated inflammatory response is rapidly mounted to repair and remove the injured cells which, paradoxically, can further exacerbate myocardial injury. Furthermore, although cardiac remodelling may initially preserve some function to the heart, it can lead over time to adverse remodelling and eventually heart failure. Since the size of the infarct corresponds to the subsequent risk of developing heart failure, it is important to find ways to limit initial infarct development. In this review, we focus on the role of the innate immune system in the acute response to ischaemia-reperfusion (IR) and specifically its contribution to cell death and myocardial infarction. Numerous danger-associated molecular patterns are released from dying cells in the myocardium, which can stimulate pattern recognition receptors including toll like receptors and NOD-like receptors (NLRs) in resident cardiac and immune cells. Activation of the NLRP3 inflammasome, caspase 1, and pyroptosis may ensue, particularly when the myocardium has been previously aggravated by the presence of comorbidities. Evidence will be discussed that suggests agents targeting innate immunity may be a promising means of protecting the hearts of STEMI patients against acute IR injury. However, the dosing and timing of such agents should be carefully determined because innate immunity pathways may also be involved in cardioprotection. This article is part of a Cardiovascular Research Spotlight Issue entitled 'Cardioprotection Beyond the Cardiomyocyte', and emerged as part of the discussions of the European Union (EU)-CARDIOPROTECTION Cooperation in Science and Technology (COST) Action, CA16225., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: journals.permissions@oup.com.)

During an ST-elevation myocardial infarction (STEMI), the myocardium undergoes a prolonged period of ischaemia. Reperfusion therapy is essential to minimize cardiac injury but can paradoxically cause further damage. Experimental procedures to limit ischaemia and reperfusion (IR) injury have tended to focus on the cardiomyocytes since they are crucial for cardiac function. However, there is increasing evidence that non-cardiomyocyte resident cells in the heart (as discussed in a separate review in this Spotlight series) as well as circulating cells and factors play important roles in this pathology. For example, erythrocytes, in addition to their main oxygen-ferrying role, can protect the heart from IR injury via the export of nitric oxide bioactivity. Platelets are well-known to be involved in haemostasis and thrombosis, but beyond these roles, they secrete numerous factors including sphingosine-1 phosphate (S1P), platelet activating factor, and cytokines that can all strongly influence the development of IR injury. This is particularly relevant given that most STEMI patients receive at least one type of platelet inhibitor. Moreover, there are large numbers of circulating vesicles in the blood, including microvesicles and exosomes, which can exert both beneficial and detrimental effects on IR injury. Some of these effects are mediated by the transfer of microRNA (miRNA) to the heart. Synthetic miRNA molecules may offer an alternative approach to limiting the response to IR injury. We discuss these and other circulating factors, focussing on potential therapeutic targets relevant to IR injury. Given the prevalence of comorbidities such as diabetes in the target patient population, their influence will also be discussed. This article is part of a Cardiovascular Research Spotlight Issue entitled 'Cardioprotection Beyond the Cardiomyocyte', and emerged as part of the discussions of the European Union (EU)-CARDIOPROTECTION Cooperation in Science and Technology (COST) Action, CA16225., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: journals.permissions@oup.com.)

Despite the development of ventricular assist devices, cardiac transplantation remains an important procedure for patients with advanced heart failure. The number of transplants done annually has remained stable because of lack of of donors. Left ventricular systolic dysfunction remains one of the most important reasons for seeking a donor heart. Myocardial stunning is an important cause of reversible systolic dysfunction. Electrical injury is a recognized cause of myocardial stunning with variable duration ranging from days to weeks. Repeating the transthoracic echocardiogram to look for reversibility of left ventricular dysfunction can be a cost-effective method to improve the selection of heart donors. This can significantly help to decrease critical organ shortage. We present a case of myocardial stunning after electrocution which was completely reversible within a few hours, thus meeting cardiac transplant donor criteria., Competing Interests: None.

Patients with acute myocardial infarction receive a P2Y 12 receptor antagonist prior to reperfusion, a treatment that has reduced, but not eliminated, mortality, or heart failure. We tested whether the caspase-1 inhibitor VX-765 given at reperfusion (a requirement for clinical use) can provide sustained reduction of infarction and long-term preservation of ventricular function in a pre-clinical model of ischemia/reperfusion that had been treated with a P2Y 12 receptor antagonist. To address, the hypothesis open-chest rats were subjected to 60-min left coronary artery branch occlusion/120-min reperfusion. Vehicle or inhibitors were administered intravenously immediately before reperfusion. With vehicle only, 60.3 ± 3.8% of the risk zone suffered infarction. Ticagrelor, a P2Y 12 antagonist, and VX-765 decreased infarct size to 42.8 ± 3.3 and 29.2 ± 4.9%, respectively. Combining ticagrelor with VX-765 further decreased infarction to 17.5 ± 2.3%. Similar to recent clinical trials, combining ticagrelor and ischemic postconditioning did not result in additional cardioprotection. VX-765 plus another P2Y 12 antagonist, cangrelor, also decreased infarction and preserved ventricular function when reperfusion was increased to 3 days. In addition, VX-765 reduced infarction in blood-free, isolated rat hearts indicating at least a portion of injurious caspase-1 activation originates in cardiac tissue. While the pro-drug VX-765 only protected isolated hearts when started prior to ischemia, its active derivative VRT-043198 provided the same amount of protection when started at reperfusion, indicating that even in blood-free hearts, caspase-1 appears to exert its injury only at reperfusion. Moreover, VX-765 decreased circulating IL-1β, prevented loss of cardiac glycolytic enzymes, preserved mitochondrial complex I activity, and decreased release of lactate dehydrogenase, a marker of pyroptosis. Our results are the first demonstration of a clinical-grade drug given at reperfusion providing additional, sustained infarct size reduction when added to a P2Y 12 receptor antagonist.

Objective: Displacement ENcoding with Stimulated Echoes (DENSE) is an MRI technique developed to encode phase related to myocardial tissue displacements, and the displacement information directly applied towards detecting left-ventricular (LV) myocardial motion during the cardiac cycle. The purpose of this study is to present a novel, three-dimensional (3D) DENSE displacement-based and magnitude image quantization-based, semi-automated detection technique for myocardial wall motion, whose boundaries are used for rapid and automated computation of 3D myocardial strain., Methods: The architecture of this boundary detection algorithm is primarily based on pixelwise spatiotemporal increments in LV tissue displacements during the cardiac cycle and further reinforced by radially searching for pixel-based image gradients in multithreshold quantized magnitude images. This spatiotemporal edge detection methodology was applied to all LV partitions and their subsequent timeframes that lead to full 3D LV reconstructions. It was followed by quantifications of 3D chamber dimensions and myocardial strains, whose rapid computation was the primary motivation behind developing this algorithm. A pre-existing two-dimensional (2D) semi-automated contouring technique was used in parallel to validate the accuracy of the algorithm and both methods tested on DENSE data acquired in (N = 14) healthy subjects. Chamber quantifications between methods were compared using paired t-tests and Bland-Altman analysis established regional strain agreements., Results: There were no significant differences in the results of chamber quantifications between the 3D semi-automated and existing 2D boundary detection techniques. This included comparisons of ejection fractions, which were 0.62 ± 0.04 vs 0.60 ± 0.06 (p = 0.23) for apical, 0.60 ± 0.04 vs 0.59 ± 0.05 (p = 0.76) for midventricular and 0.56 ± 0.04 vs 0.58 ± 0.05 (p = 0.07) for basal segments, that were quantified using the 3D semi-automated and 2D pre-existing methodologies, respectively. Bland-Altman agreement between regional strains generated biases of 0.01 ± 0.06, -0.01 ± 0.01 and 0.0 ± 0.06 for the radial, circumferential and longitudinal directions, respectively., Conclusion: A new, 3D semi-automated methodology for contouring the entire LV and rapidly generating chamber quantifications and regional strains is presented that was validated in relation to an existing 2D contouring technique. Advances in knowledge: This study introduced a scientific tool for rapid, semi-automated generation of clinical information regarding shape and function in the 3D LV.

Use of ischemic postconditioning and other related cardioprotective interventions to treat patients with acute myocardial infarction (AMI) has failed to improve outcomes in clinical trials. Because P2Y 12 inhibitors are themselves postconditioning mimetics, it has been postulated that the loading dose of platelet inhibitors routinely given to patients treated for AMI masks the anti-infarct effect of other intended cardioprotective interventions. To further improve outcomes of patients with AMI, an intervention must be able to provide additive protection in the presence of a P2Y 12 platelet inhibitor. Previous studies reported an anti-infarct effect using a peptide inhibitor of the pro-inflammatory caspase-1 in animal models of AMI. Herein we tested whether a pharmacologic caspase-1 inhibitor can further limit infarct size in open-chest, anesthetized rats treated with a P2Y 12 inhibitor. One hour occlusion of a coronary branch followed by 2 hours of reperfusion was used to simulate clinical AMI and reflow. One group of rats received an intravenous bolus of 16 mg/kg of the highly selective caspase-1 inhibitor VX-765 30 minutes prior to onset of ischemia. A second group received a 60 µg/kg intravenous bolus of the P2Y 12 inhibitor cangrelor 10 minutes prior to reperfusion followed by 6 µg/kg/min continuous infusion. A third group received treatment with both inhibitors as above. Control animals received no treatment. Infarct size was measured by tetrazolium stain and volume of muscle at risk by fluorescent microspheres. In untreated hearts, 73.7% ± 4.1% of the ischemic zone infarcted. Treatment with either cangrelor or VX-765 alone reduced infarct size to 43.8% ± 2.4% and 39.6% ± 3.6% of the ischemic zone, respectively. Combining cangrelor and VX-765 was highly protective, resulting in only 14.0% ± 2.9% infarction. The ability of VX-765 to provide protection beyond that of a platelet inhibitor alone positions it as an attractive candidate therapy to further improve outcomes in today's patients with AMI.

Scientists and clinicians have been concerned by the lack of a clinically suitable strategy for cardioprotection in patients with acute myocardial infarction despite decades of intensive pre-clinical investigations and a surprising number of clinical trials based on those observations which have uniformly been disappointing. However, it would be a mistake to abandon this search. Rather it would be useful to examine these past efforts and determine reasons for the multiple failures. It appears that earlier clinical trials were often based on results from a single experimental laboratory, thus minimizing the importance of establishing reproducibility in multiple laboratories by multiple scientists and in multiple models. Clinical trials should be discouraged unless robust protection is demonstrated in pre-clinical testing. After approximately 2005 a loading dose of a platelet P2Y 12 receptor antagonist became increasingly widespread in patients with acute myocardial infarction prior to revascularization and quickly became standard-of-care. These agents are now thought to be a cause of failure of recent clinical trials since these pleiotropic drugs also happen to be potent postconditioning mimetics. Thus, introduction of an additional cardioprotective strategy such as ischemic postconditioning which uses the same signaling pathway as these P2Y 12 antagonists would be redundant and doomed to failure. Additive cardioprotection could be achieved only if the second intervention had a different mechanism of cardioprotection. This concept has been demonstrated in experimental animals. So lack of reproducibility of earlier studies and failure to examine interventions in experimental animals also treated with anti-platelet agents could well explain past failures. These realizations should clear the way for development of interventions which can be translated into successful clinical treatments.

In animal models platelet P2Y12 receptor antagonists put the heart into a protected state, not as a result of suppressed thrombosis but rather through protective signaling, similar to that for ischemic postconditioning. While both ischemic postconditioning and the P2Y12 blocker cangrelor protect blood-perfused hearts, only the former protects buffer-perfused hearts indicating that the blocker requires a blood-borne constituent or factor to protect. We used an anti-platelet antibody to make thrombocytopenic rats to test if that factor resides within the platelet. Infarct size was measured in open-chest rats subjected to 30-min ischemia/2-h reperfusion. Infarct size was not different in thrombocytopenic rats showing that preventing aggregation alone is not protective. While ischemic preconditioning could reduce infarct size in thrombocytopenic rats, the P2Y12 inhibitor cangrelor could not, indicating that it protects by interacting with some factor in the platelet. Ischemic preconditioning is known to require phosphorylation of sphingosine. In rats treated with dimethylsphingosine to block sphingosine kinase, cangrelor was no longer protective. Thus cangrelor's protective mechanism appears to also involve sphingosine kinase revealing yet another similarity to conditioning's mechanism.

Recovery from severe immunosuppression requires hematopoietic stem cell reconstitution and effective thymopoiesis to restore a functional immune cell repertoire. Herein, a model of immune cell reconstitution consequent to potentially lethal doses of irradiation is described, which may be valuable in evaluating potential medical countermeasures. Male rhesus macaques were total body irradiated by exposure to 6.00 Gy 250 kVp x-radiation (midline tissue dose, 0.13 Gy min), resulting in an approximate LD10/60 (n = 5/59). Animals received medical management, and hematopoietic and immune cell recovery was assessed (n ≤ 14) through 370 d post exposure. A subset of animals (n ≤ 8) was examined through 700 d. Myeloid recovery was assessed by neutrophil and platelet-related parameters. Lymphoid recovery was assessed by the absolute lymphocyte count and FACS-based phenotyping of B- and T-cell subsets. Recent thymic emigrants were identified by T cell receptor excision circle quantification. Severe neutropenia, lymphopenia, and thrombocytopenia resolved within 30 d. Total CD3+ cells μL required 60 d to reach values 60% of normal, followed by subsequent slow recovery to approximately normal by 180 d post irradiation. Recovery of CD3+4+ and CD3+8+ cell memory and naïve subsets were markedly different. Memory populations were ≥ 100% of normal by day 60, whereas naïve populations were only 57% normal at 180 d and never fully recovered to baseline post irradiation. Total (CD20+) B cells μL were within normal levels by 77 d post exposure. This animal model elucidates the variable T- and B-cell subset recovery kinetics after a potentially lethal dose of total-body irradiation that are dependent on marrow-derived stem and progenitor cell recovery, peripheral homeostatic expansion, and thymopoiesis.

Early recanalization of the occluded culprit coronary artery clearly reduces infarct size in both animal models and patients and improves clinical outcomes. Unfortunately, reperfusion can seldom be accomplished before some myocardium infarcts. As a result there has been an intensive search for interventions that will make the heart resistant to infarction so that reperfusion could salvage more myocardium. A number of interventions have been identified in animal models, foremost being ischemic preconditioning. It protects by activating signaling pathways that prevent lethal permeability transition pores from forming in the heart's mitochondria at reperfusion. Such conditioning can be accomplished in a clinically relevant manner either by staccato reperfusion (ischemic postconditioning) or by pharmacological activation of the conditioning signaling pathways prior to reperfusion. Unfortunately, clinical trials of ischemic postconditioning and pharmacologic conditioning have been largely disappointing. We suggest that this may be caused by inappropriate use as models intended to mimic the clinical scenario of young healthy animals that receive none of the many drugs currently given to our patients. Patients may be resistant to some forms of conditioning because of comorbidities, for example, diabetes, or they may already be conditioned by adjunct medications, for example, P2Y12 inhibitors or opioids. Incremental technological improvements in patient care may render some approaches to cardioprotection redundant, and thus the clinical target may be continually changing, while our animal models have not kept pace. In remote conditioning, a limb is subjected to ischemia/reperfusion prior to or during coronary reperfusion. Its mechanism is not as well understood as that of ischemic preconditioning, but the results have been very encouraging. In the present article, we will review ischemic, remote, and pharmacologic conditioning and possible confounders that could interfere with their efficacy in clinical trials in 2 settings of myocardial ischemia: (1) primary angioplasty in acute myocardial infarction and (2) elective angioplasty., (© The Author(s) 2015.)

Ischaemic pre- and postconditioning are potent cardioprotective interventions that spare ischaemic myocardium and decrease infarct size after periods of myocardial ischaemia/reperfusion. They are dependent on complex signalling pathways involving ligands released from ischaemic myocardium, G-protein-linked receptors, membrane growth factor receptors, phospholipids, signalling kinases, NO, PKC and PKG, mitochondrial ATP-sensitive potassium channels, reactive oxygen species, TNF-α and sphingosine-1-phosphate. The final effector is probably the mitochondrial permeability transition pore and the signalling produces protection by preventing pore formation. Many investigators have worked to produce a roadmap of this signalling with the hope that it would reveal where one could intervene to therapeutically protect patients with acute myocardial infarction whose hearts are being reperfused. However, attempts to date to show efficacy of such an intervention in large clinical trials have been unsuccessful. Reasons for this inability to translate successes in the experimental laboratory to the clinical arena are evaluated in this review. It is suggested that all patients with acute coronary syndromes currently presenting to the hospital and being treated with platelet P2Y12 receptor antagonists, the current standard of care, are indeed already benefiting from protection from the conditioning pathways outlined earlier. If that proves to be the case, then future attempts to further decrease infarction will have to rely on interventions which protect by a different mechanism., (© 2014 The British Pharmacological Society.)

Recent reports indicate that elevating DNA glycosylase/AP lyase repair enzyme activity offers marked cytoprotection in cultured cells and a variety of injury models. In this study, we measured the effect of EndoIII, a fusion protein construct that traffics Endonuclease III, a DNA glycosylase/AP lyase, to the mitochondria, on infarct size in a rat model of myocardial ischemia/reperfusion. Open-chest, anesthetized rats were subjected to 30 min of occlusion of a coronary artery followed by 2 h of reperfusion. An intravenous bolus of EndoIII, 8 mg/kg, just prior to reperfusion reduced infarct size from 43.8 ± 1.4% of the risk zone in control animals to 24.0 ± 1.3% with no detectable hemodynamic effect. Neither EndoIII's vehicle nor an enzymatically inactive EndoIII mutant (K120Q) offered any protection. The magnitude of EndoIII's protection was comparable to that seen with the platelet aggregation inhibitor cangrelor (25.0 ± 1.8% infarction of risk zone). Because loading with a P2Y12 receptor blocker to inhibit platelets is currently the standard of care for treatment of acute myocardial infarction, we tested whether EndoIII could further reduce infarct size in rats treated with a maximally protective dose of cangrelor. The combination reduced infarct size to 15.1 ± 0.9% which was significantly smaller than that seen with either cangrelor or EndoIII alone. Protection from cangrelor but not EndoIII was abrogated by pharmacologic blockade of phosphatidylinositol-3 kinase or adenosine receptors indicating differing cellular mechanisms. We hypothesized that EndoIII protected the heart from spreading necrosis by preventing the release of proinflammatory fragments of mitochondrial DNA (mtDNA) into the heart tissue. In support of this hypothesis, an intravenous bolus at reperfusion of deoxyribonuclease I (DNase I) which should degrade any DNA fragments escaping into the extracellular space was as protective as EndoIII. Furthermore, the combination of EndoIII and DNase I produced additive protection. While EndoIII would maintain mitochondrial integrity in many of the ischemic cardiomyocytes, DNase I would further prevent mtDNA released from those cells that EndoIII could not save from propagating further necrosis. Thus, our mtDNA hypothesis would predict additive protection. Finally to demonstrate the toxicity of mtDNA, isolated hearts were subjected to 15 min of global ischemia. Infarct size doubled when the coronary vasculature was filled with mtDNA fragments during the period of global ischemia. To our knowledge, EndoIII and DNase are the first agents that can both be given at reperfusion and add to the protection of a P2Y12 blocker, and thus should be effective in today's patient with acute myocardial infarction.

Since the P2Y12 receptor antagonists were first introduced, they have been extensively tested in patients with acute coronary syndrome and are now standard of care. These antiplatelet drugs are very effective in reducing subsequent cardiovascular events, stent thromboses, and mortality in patients with acute myocardial infarction undergoing reperfusion therapy. Although the prevailing view is that their benefit derives from their antithrombotic properties, other unrelated pleiotropic effects appear to be equally beneficial. Accumulating clinical and animal evidence indicates that, if present at the time of reperfusion, these drugs have a direct anti-infarct effect similar to that of ischemic postconditioning. Four oral antagonists have been developed in rapid succession: ticlopidine, clopidogrel, prasugrel, and ticagrelor. Each agent had a more consistent and rapid onset of action than the previous one, and this has correlated with improved clinical outcomes when given early in treatment. Unfortunately, gut absorption causes an appreciable delay in the onset of effect, especially when morphine is used, and the constant push to minimize the door-to-balloon time has made it difficult to achieve adequate platelet inhibition at the time of percutaneous coronary intervention with an oral agent. An intravenous P2Y12 antagonist such as cangrelor may optimize treatment because it produces nearly maximal inhibition of platelet aggregation within minutes. If antiplatelet agents do protect through postconditioning's mechanism, then they would render any other intervention that protects through that mechanism redundant. Indeed, animals treated with cangrelor cannot be further protected by pre- or postconditioning. However, interventions that use a different mechanism such as mild hypothermia or cariporide, a Na(+)-H(+) exchange blocker, do add to cangrelor's protection. Future research should be directed toward identifying interventions that can augment the protection from antiplatelet therapy and finding a way to optimize P2Y12 inhibition at reperfusion in all patients.

Background: Cangrelor, a P2Y12 receptor blocker, administered just prior to reperfusion reduced but did not eliminate myocardial infarction in rabbits. Combining cangrelor with ischemic postconditioning offered no additional protection suggesting they protected by a similar mechanism. To determine if cangrelor's protection might be additive to other cardioprotective interventions we tested cangrelor in combination with ischemic preconditioning, cariporide, a sodium-hydrogen exchange blocker, and mild hypothermia., Methods: Open-chest rats underwent 30-min coronary occlusion/2-h reperfusion., Results: Cangrelor, administered as a bolus (60 μg/kg) 10 min before reperfusion and continued as an infusion (6 μg/kg/min) for the duration of the experiment, decreased infarction from 45.3 % of risk zone in control hearts to 25.0 %. Combining cangrelor and ischemic preconditioning offered no additional protection. Mild hypothermia (32-33 °C) instituted by peritoneal lavage with cold saline just prior to coronary occlusion resulted in 25.2 % infarction, and combining cangrelor and hypothermia nearly halved infarction to 14.1 % of risk zone. Cariporide (0.5 mg/kg) just prior to occlusion resulted in 27.2 % infarction and 15.8 % when combined with cangrelor. Combining cangrelor, hypothermia and cariporide further halved infarction to only 6.3 %. We also tested another P2Y12 inhibitor ticagrelor which is chemically similar to cangrelor. Ticagrelor (20 mg/kg) fed 1 h prior to surgery reduced infarct size by an amount similar to that obtained with cangrelor (25.6 % infarction), and this protective effect was abolished by chelerythrine and wortmannin, thus implicating participation of PKC and PI3-kinase, resp., in signaling., Conclusions: Cardioprotection from a P2Y12 receptor antagonist can be combined with at least 2 other strategies to magnify the protection. Combining multiple interventions that use different cardioprotective mechanisms could provide powerful protection against infarction in patients with acute coronary thrombosis.

Autoimmune thyroid diseases (AITD) are the main causes of thyroid dysfunction and the most common autoimmune diseases in the world. An association between AITD and infections with the human immunodeficiency virus (HIV), in combination with the effects of highly active anti-retroviral therapy (HAART), has been suggested by several research groups. The aim of the present study was to evaluate the frequency of thyroid dysfunction and AITD in women > 35 years of age infected with HIV, and to identify factors associated with the emergence of these thyroid abnormalities. HIV-infected women (n = 153) selected from the infectious disease outpatient clinic at a University Hospital in Rio de Janeiro were characterized based on their circulating CD4+ lymphocytes levels, viral loads, serum TSH levels, and the presence of FT4 and anti-thyroperoxidase antibodies (TPO-Ab). A total of 129 participants were on HAART and 24 were not. The frequency of thyroid disorders was 7.8% (12/153 patients) and all were on HAART at the time of diagnosis, yielding a prevalence of 9.3% in patients receiving HAART compared with 0% in patients not on HAART. AITD, hyper, and hypothyroidism were detected in 4.6%, 3.1%, and 4.1% of HAART patients. It was not detected any thyroid dysfunction or autoimmunity in HIV-infected women not on HAART. This study demonstrated an association between HAART and the development of AITD. In addition AITD only developed in HAART patients also presenting with undetectable viral loads and slightly elevated CD4+ T cell counts.