Giant Left Ventricular Aneurysm With Dynamic Right Ventricular Compression and Subsequent End-Stage Heart Failure

We report a case of a patient with a missed anterior myocardial infarction and associated ischemic cardiomyopathy. The patient had a massive true left ventricular aneurysm causing dynamic right ventricular compression, with associated cardiogenic shock, for which a heart transplantation was ultimately performed.

Addressing challenges related to the professional practice of abortion post-Roe

The landmark Roe vs Wade Supreme Court decision in 1973 established a constitutional right to abortion. In June 2022, the Dobbs vs Jackson Women's Health Organization Supreme Court decision brought an end to the established professional practice of abortion throughout the United States. Rights-based reductionism and zealotry threaten the professional practice of abortion. Rights-based reductionism is generally the view that moral or ethical issues can be reduced exclusively to matters of rights. In relation to abortion, there are 2 opposing forms of rights-based reductionism, namely fetal rights reductionism, which emphasizes the rights for the fetus while disregarding the rights and autonomy of the pregnant patient, and pregnant patient rights reductionism, which supports unlimited abortion without regards for the fetus. The 2 positions are irreconcilable. This article provides historical examples of the destructive nature of zealotry, which is characterized by extreme devotion to one's beliefs and an intolerant stance to opposing viewpoints, and of the importance of enlightenment to limit zealotry. This article then explores the professional responsibility model as a clinically ethically sound approach to overcome the clashing forms of rights-based reductionism and zealotry and to address the professional practice of abortion. The professional responsibility model refers to the ethical and professional obligations that obstetricians and other healthcare providers have toward pregnant patients, fetuses, and the society at large. It provides a more balanced and nuanced approach to the abortion debate, avoiding the pitfalls of reductionism and zealotry, and allows both the rights of the woman and the obligations to pregnant and fetal patients to be considered alongside broader ethical, medical, and societal implications. Constructive and respectful dialogue is crucial in addressing diverse perspectives and finding common ground. Embracing the professional responsibility model enables professionals to manage abortion responsibly, thereby prioritizing patients' interests and navigating between absolutist viewpoints to find balanced ethical solutions.

The importance of professional responsibility and fetal viability in the management of abortion

In June 2022, the Dobbs v. Jackson Women's Health Organization Supreme Court decision ended the constitutional right to the professional practice of abortion throughout the United States. The removal of the constitutional right to abortion has significantly altered the practice of obstetricians and gynecologists across the US. It potentially increases risks to pregnant patients, leads to profound changes in how physicians can provide care, especially in states with strict bans or gestational limits to abortion, and has introduced personal challenges, including moral distress and injury as well as legal risks for patients and clinicians alike. The professional responsibility model is based on the ethical concept of medicine as a profession and has been influential in shaping medical ethics in the field of obstetrics and gynecology. It provides the framework for the importance of ethical and professional conduct in obstetrics and gynecology. Viability marks a stage where the fetus is a patient with a claim to access to medical care. By allowing unrestricted abortions past this stage without adequate justifications, such as those concerning the life and health of the pregnant individual, or in instances of serious fetal anomalies, the states may not be upholding the equitable ethical consideration owed to the fetus as a patient. Using the professional responsibility model, we emphasize the need for nuanced, evidence-based policies that allow abortion management prior to viability without restrictions and allow abortion after viability to protect the pregnant patient's life and health, as well as permitting abortion for serious fetal anomalies.

A Reinterpretation of the Relationship Between Persistent and Resurgent Sodium Currents

The resurgent sodium current (INaR) activates on membrane repolarization, such as during the downstroke of neuronal action potentials. Due to its unique activation properties, INaR is thought to drive high rates of repetitive neuronal firing. However, INaR is often studied in combination with the persistent or non-inactivating portion of sodium currents (INaP). We used dynamic clamp to test how INaR and INaP individually affect repetitive firing in adult cerebellar Purkinje neurons. We learned INaR does not scale repetitive firing rates due to its rapid decay at subthreshold voltages, and that subthreshold INaP is critical in regulating neuronal firing rate. Adjustments to the Nav conductance model used in these studies revealed INaP and INaR can be inversely scaled by adjusting occupancy in the slow inactivated kinetic state. Together with additional dynamic clamp experiments, these data suggest the regulation of sodium channel slow inactivation can fine-tune INaP and Purkinje neuron repetitive firing rates.

Mechanical Resistance to Micro-Heart Tissue Contractility unveils early Structural and Functional Pathology in iPSC Models of Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy is the most common cause of sudden death in the young. Because the disease exhibits variable penetrance, there are likely nongenetic factors that contribute to the manifestation of the disease phenotype. Clinically, hypertension is a major cause of morbidity and mortality in patients with HCM, suggesting a potential synergistic role for the sarcomeric mutations associated with HCM and mechanical stress on the heart. We developed an in vitro physiological model to investigate how the afterload that the heart muscle works against during contraction acts together with HCM-linked MYBPC3 mutations to trigger a disease phenotype. Micro-heart muscle arrays (μHM) were engineered from iPSC-derived cardiomyocytes bearing MYBPC3 loss-of-function mutations and challenged to contract against mechanical resistance with substrates stiffnesses ranging from the of embryonic hearts (0.4 kPa) up to the stiffness of fibrotic adult hearts (114 kPa). Whereas MYBPC3 +/- iPSC-cardiomyocytes showed little signs of disease pathology in standard 2D culture, μHMs that included components of afterload revealed several hallmarks of HCM, including cellular hypertrophy, impaired contractile energetics, and maladaptive calcium handling. Remarkably, we discovered changes in troponin C and T localization in the MYBPC3 +/- μHM that were entirely absent in 2D culture. Pharmacologic studies suggested that excessive Ca 2+ intake through membrane-embedded channels, rather than sarcoplasmic reticulum Ca 2+ ATPase (SERCA) dysfunction or Ca 2+ buffering at myofilaments underlie the observed electrophysiological abnormalities. These results illustrate the power of physiologically relevant engineered tissue models to study inherited disease mechanisms with iPSC technology.

Counseling for the option of termination of pregnancy for severe fetal anomalies in light of the recent Supreme Court ruling to remove the constitutional right to an abortion

A birth defect is a structural or chromosomal change present at birth that can affect almost any part or parts of the body. Birth defects can vary from mild to severe. On June 24, 2022, with its Dobbs v Jackson Women's Health Organization decision the Supreme Court of the United States overturned Roe v. Wade, removing the longstanding landmark 1973 ruling that secured a person's constitutional right to an abortion. With this decision individual states can now decide their own abortion laws. In about one-half of the states that continue the legality of pregnancy termination, the process of offering, discussing, and performing terminations of pregnancy remain the same as previously. In states where abortions are not legal, there will be conflicts between the law and the ethical responsibility of physicians to offer and discuss termination of pregnancy for severe anomalies.

Emerging methods to model cardiac ion channel and myocyte electrophysiology

In the field of cardiac electrophysiology, modeling has played a central role for many decades. However, even though the effort is well-established, it has recently seen a rapid and sustained evolution in the complexity and predictive power of the models being created. In particular, new approaches to modeling have allowed the tracking of parallel and interconnected processes that span from the nanometers and femtoseconds that determine ion channel gating to the centimeters and minutes needed to describe an arrhythmia. The connection between scales has brought unprecedented insight into cardiac arrhythmia mechanisms and drug therapies. This review focuses on the generation of these models from first principles, generation of detailed models to describe ion channel kinetics, algorithms to create and numerically solve kinetic models, and new approaches toward data gathering that parameterize these models. While we focus on application of these models for cardiac arrhythmia, these concepts are widely applicable to model the physiology and pathophysiology of any excitable cell.

Is Russia's Research Ethics Culture Reliable?

The Russian invasion of Ukraine has led to the imposition of economic sanctions intended to isolate Russia from much of global commerce, which implicitly includes the medical research enterprise. The prospect of ongoing isolation of Russia's substantial research enterprise raises issues related to but distinct from the more familiar problem of corruption. In this paper, we identify reasons that the culture of research ethics in Russia may have been weak even before the war, contributing to hard questions about its future role in the global clinical research community.

Robust, Automated Analysis of Electrophysiology in Induced Pluripotent Stem Cell-Derived Micro-Heart Muscle for Drug Toxicity

Drugs are often removed from clinical trials or market progression owing to their unforeseen effects on cardiac action potential and calcium handling. Induced pluripotent stem cell-derived cardiomyocytes and tissues fabricated from these cells are promising as screening tools for early identification of these potential cardiac liabilities. In this study, we describe an automated, open-source MATLAB-based analysis software for calculating cardiac action potentials and calcium transients from fluorescent reporters. We first identified the most robust manner in which to automatically identify the initiation point for action potentials and calcium transients in a user-independent manner, and used this approach to quantify the duration and morphology of these signals. We then demonstrate the software by assessing changes to action potentials and calcium transients in our micro-heart muscles after exposure to hydroxychloroquine, an antimalarial drug with known cardiac liability. Consistent with clinical observations, our system predicted mild action potential prolongation. However, we also observed marked calcium transient suppression, highlighting the advantage of testing multiple physiologic readouts in cardiomyocytes rather than relying on heterologous overexpression of single channels such as the human ether-a-go-go-related gene channel. This open-source software can serve as a useful, high-throughput tool for analyzing cardiomyocyte physiology from fluorescence imaging.

John Stuart Mill is relevant to COVID-19 vaccination in pregnancy today

The scientific evidence about COVID-19 and pregnancy is conclusive: COVID-19 infections increase the risk of stillbirths and preterm births, and pregnant and postpartum patients are more likely to get severely ill with COVID-19 and die when compared with people who are not pregnant. Getting a COVID-19 vaccine protects from severe illness from COVID-19 and risk of death. COVID-19 vaccination is recommended for pregnant patients, those trying to conceive, and who are breastfeeding, or might become pregnant in the future. The justification for government involvement in public health measures that restrict personal liberty that we are so familiar with today emanated from a philosophical source at the same time as the progress in managing infectious disease. John Stuart Mill (1806-1873), an empiricist and a utilitarian, was not specifically addressing the ethics of public health in his classic On Liberty (1859), but his arguments have become the reference point for liberal democracies and public health measures. Mill was in search of a philosophical principle that could justify constraints on personal freedom. John Stuart Mill gives direct guidance to our approach supporting not only strong recommendations for pregnant patients to accept vaccinations against COVID-19 but also for those working in healthcare setting to be required to be vaccinated. This approach is respectful to our patient's liberty while doing all that's reasonable to protect them from harm. Based on our professional experience we recognize that some physicians and patients have fixed false beliefs. Physicians espousing fixed false beliefs against COVID-19 vaccines should be censured.

Creating Ion Channel Kinetic Models Using Cloud Computing

Computational modeling of ion channels provides key insight into experimental electrophysiology results and can be used to connect channel dynamics to emergent phenomena observed at the tissue and organ levels. However, creation of these models requires substantial mathematical and computational background. This tutorial seeks to lower the barrier to creating these models by providing an automated pipeline for creating Markov models of an ion channel kinetics dataset. We start by detailing how to encode sample voltage-clamp protocols and experimental data into the program and its implementation in a cloud computing environment. We guide the reader on how to build a containerized instance, push the machine image, and finally run the routine on cluster nodes. While providing open-source code has become more standard in computational studies, this tutorial provides unprecedented detail on the use of the program and the creation of channel models, starting from inputting the raw experimental data. © 2022 Wiley Periodicals LLC. Basic Protocol: Creation of ion channel kinetic models with a cloud computing environment Alternate Protocol: Instructions for use in a standard high-performance compute cluster.

Angiotensin II Type 1 Receptor Antibody-mediated Rejection Following Orthotopic Heart Transplant: A Single-center Experience

BACKGROUND

Antibody-mediated rejection (AMR) following orthotopic heart transplant (OHT) causes significant morbidity and mortality. There are limited data on antibodies to the angiotensin II type 1 receptor antibody (AT1R-Ab) causing rejection following OHT.

METHODS

This is a retrospective, single-center study that presents our 2-y experience with a series of 11 patients with evidence of nonspecific graft dysfunction and pathologic levels of AT1R-Ab. The clinical outcomes and treatments were compared to a group of 10 patients, also with evidence of nonspecific graft dysfunction, but who had nonsignificant AT1R-Ab titers.

RESULTS

The mean age of the AT1R-Ab cohort was 52% and 73% were bridged to transplant with an left ventricular assist device. The average left ventricular ejection fraction at presentation was 45%, and most were not on an angiotensin receptor blocker (ARB). Endomyocardial biopsies in those with elevated AT1R-Ab levels frequently showed reactive endothelium/endocardium without C4d or intravascular CD68 staining. Ten patients (91%) were started on an ARB. Other therapies included plasmapheresis and IVIg (64%), with 4 patients also receiving rituximab. Most patients had symptom improvement, but minimal change in graft function at an average 6 mo of follow-up.

CONCLUSIONS

The role of AT1R-Ab-mediated rejection in OHT recipients remains poorly understood. More than half of patients at our center who presented with graft dysfunction in the absence of acute cellular rejection or AMR were found to have elevated AT1R-Ab titers. Empiric AMR treatment in conjunction with ARB therapy may improve patient outcomes. Future studies are needed to better define the optimal treatment modalities for ATR1-Ab-mediated AMR.

Intrinsic mechanisms in the gating of resurgent Na+ currents

The resurgent component of the voltage-gated sodium current (I_NaR) is a depolarizing conductance, revealed on membrane hyperpolarizations following brief depolarizing voltage steps, which has been shown to contribute to regulating the firing properties of numerous neuronal cell types throughout the central and peripheral nervous systems. Although mediated by the same voltage-gated sodium (Nav) channels that underlie the transient and persistent Nav current components, the gating mechanisms that contribute to the generation of I_NaR remain unclear. Here, we characterized Nav currents in mouse cerebellar Purkinje neurons, and used tailored voltage-clamp protocols to define how the voltage and the duration of the initial membrane depolarization affect the amplitudes and kinetics of I_NaR. Using the acquired voltage-clamp data, we developed a novel Markov kinetic state model with parallel (fast and slow) inactivation pathways and, we show that this model reproduces the properties of the resurgent, as well as the transient and persistent, Nav currents recorded in (mouse) cerebellar Purkinje neurons. Based on the acquired experimental data and the simulations, we propose that resurgent Na⁺ influx occurs as a result of fast inactivating Nav channels transitioning into an open/conducting state on membrane hyperpolarization, and that the decay of I_NaR reflects the slow accumulation of recovered/opened Nav channels into a second, alternative and more slowly populated, inactivated state. Additional simulations reveal that extrinsic factors that affect the kinetics of fast or slow Nav channel inactivation and/or impact the relative distribution of Nav channels in the fast- and slow-inactivated states, such as the accessory Navβ4 channel subunit, can modulate the amplitude of I_NaR.

Autonomy and Social Responsibility: The Post-Pandemic Challenge

Over the last 80 years, a series of critical events has led to reconsideration of the basic premises of medical ethics. One of these events was the recognition of horrific medical experiments performed by German medical scientists in World War II concentration camps, resulting in intensified emphasis on a consent requirement, later understood as grounded in the bioethical principle of respect for autonomy, as well as on the moral accountability of the experimenter. Another important event that is forcing a reconsideration of respect for autonomy in medicine and health care is the COVID-19 pandemic. But this time the matter pulls in a different direction, from respect for autonomy to social responsibility, represented in problems as disparate as the wearing of masks, vaccination requirements, and equity in vaccine access and distribution. How can modern bioethics, in part a creature of the response to Nazi crimes, accommodate the intensified sensitivity about public health needs that has accompanied the shock of the pandemic? The responses of European medical ethics to the Nazi era provide tools for bioethics as it faces the challenge now at hand. This article uses historical context from postwar Europe to argue that, in light of the pandemic experience, respect for autonomy must systematically incorporate a commitment to social responsibility.

The Vaccination Cold War

Surveying the early responses to the Covid‐19 pandemic among nation states, one finds a veritable babel of responses, some predictable and some not. Would these results have been different half a century or more ago, when smallpox was eradicated and hopes were high that international cooperation would yield similar results for other infectious diseases? Is this a story about the stability provided by the bipolar postwar world, juxtaposed with the complex geopolitical repositioning that finally followed the collapse of the Soviet Union, or is that too rich an irony? A multipolar world may indeed be less prepared to cope with an international health crisis than a bipolar one. In any case, the patterns of global response are not only reminiscent of the Cold War era itself but also suggestive of a new vaccination cold war.

Identification of structures for ion channel kinetic models

Markov models of ion channel dynamics have evolved as experimental advances have improved our understanding of channel function. Past studies have examined limited sets of various topologies for Markov models of channel dynamics. We present a systematic method for identification of all possible Markov model topologies using experimental data for two types of native voltage-gated ion channel currents: mouse atrial sodium currents and human left ventricular fast transient outward potassium currents. Successful models identified with this approach have certain characteristics in common, suggesting that aspects of the model topology are determined by the experimental data. Incorporating these channel models into cell and tissue simulations to assess model performance within protocols that were not used for training provided validation and further narrowing of the number of acceptable models. The success of this approach suggests a channel model creation pipeline may be feasible where the structure of the model is not specified a priori.

Markov models of ion channel dynamics have evolved as experimental advances have improved our understanding of channel function. Past studies have examined limited sets of various structures for Markov models of channel dynamics. Here, we present a computational routine designed to thoroughly search for Markov model topologies for simulating whole-cell currents. We tested this method on two distinct types of voltage-gated cardiac ion channels and found the number of states and connectivity required to recapitulate experimentally observed kinetics. Successful models identified with this approach have certain characteristics in common, suggesting that model structures are determined by the experimental data. Incorporation of these models into higher scale action potential and cable (an approximation of one-dimensional action potential propagation) simulations, identified key channel phenomena that were required for proper function. These methods provide a route to create functional channel models that can be used for action potential simulation without pre-defining their structure ahead of time.

Human Infection Challenge Experiments: Then and Now

In the midst of the Covid-19 pandemic, ethicists, researchers, and journalists have recommended studies that deliberately infect healthy volunteers with the coronavirus as a scientific means of expediting vaccine development. In this essay, we trace the history of infection challenge experiments and reflect on the Nuremberg Code of 1947, issued in response to brutal human experiments conducted by Nazi investigators in concentration camps. We argue that the Code continues to offer valuable guidance for assessing the ethics of this controversial form of research, with respect particularly to the acceptable limits to research risks and the social value of research necessary to justify exposing human participants to these risks.

Heritable Human Genome Editing: The Public Engagement Imperative

In the view of many, heritable human genome editing (HHGE) harbors the remedial potential of ridding the world of deadly genetic diseases. A Hippocratic obligation, if there ever was one, HHGE is widely viewed as a life-sustaining proposition. The national go/no-go decision regarding the implementation of HHGE, however, must not, in the collective view of the authors, proceed absent thorough public engagement. A comparable call for an "extensive societal dialogue" was recently issued by the International Commission on the Clinical Use of Human Germline Genome Editing. In this communication, the authors lay out the foundational principles undergirding the formation, modification, and evaluation of public opinion. It is against this backdrop that the societal decision to warrant or enjoin the clinical conduct of HHGE will doubtlessly transpire.

Belmont in Context

Given its outsized influence as a core document in bioethics, it is worth reminding ourselves of the historical context in which the Belmont Report came to be. This article examines the societal forces that helped bring about the Belmont Report and that shaped its conception of ethical research. A product of a public investigation that included many nonscientists and espoused philosophical principles, the Report internalized a growing call in the late 1960s for oversight over the research enterprise, which had long been the private realm of physician-investigators. Belmont helped bring about a regulatory and oversight apparatus to the research enterprise, as well as a language and discipline of bioethics that added a multidisciplinary set of voices and decision-makers to discussions of what constitutes ethical research. Because it reflected the spirit of protectionism engendered by events of the 1960s and 1970s, Belmont also helped emphasize the importance of informed consent and the protection of vulnerable populations. But because the Report was a product of its time, contingent on historical developments and highly publicized events, it is not necessarily responsive to new factors that now condition the research enterprise.

Predicting Patient Response to the Antiarrhythmic Mexiletine Based on Genetic Variation

RATIONALE

Mutations in the SCN5A gene, encoding the α subunit of the Nav1.5 channel, cause a life-threatening form of cardiac arrhythmia, long QT syndrome type 3 (LQT3). Mexiletine, which is structurally related to the Na⁺ channel-blocking anesthetic lidocaine, is used to treat LQT3 patients. However, the patient response is variable, depending on the genetic mutation in SCN5A.

OBJECTIVE

The goal of this study is to understand the molecular basis of patients' variable responses and build a predictive statistical model that can be used to personalize mexiletine treatment based on patient's genetic variant.

METHODS AND RESULTS

We monitored the cardiac Na⁺ channel voltage-sensing domain (VSD) conformational dynamics simultaneously with other gating properties for the LQT3 variants. To systematically identify the relationship between mexiletine block and channel biophysical properties, we used a system-based statistical modeling approach to connect the multivariate properties to patient phenotype. We found that mexiletine altered the conformation of the Domain III VSD, which is the same VSD that many tested LQT3 mutations affect. Analysis of 15 LQT3 variants showed a strong correlation between the activation of the Domain III-VSD and the strength of the inhibition of the channel by mexiletine. Based on this improved molecular-level understanding, we generated a systems-based model based on a dataset of 32 LQT3 patients, which then successfully predicted the response of 7 out of 8 patients to mexiletine in a blinded, retrospective trial.

CONCLUSIONS

Our results imply that the modulated receptor theory of local anesthetic action, which confines local anesthetic binding effects to the channel pore, should be revised to include drug interaction with the Domain III-VSD. Using an algorithm that incorporates this mode of action, we can predict patient-specific responses to mexiletine, improving therapeutic decision making.

A Molecularly Detailed NaV1.5 Model Reveals a New Class I Antiarrhythmic Target

•

Antiarrhythmic therapies remain suboptimal due to our inability to predict how drug interactions with ion channels will affect the ability of the tissue to initiate and sustain an arrhythmia.

•

We built a computational framework that allows for in silico design of precision-targeted therapeutic agents that simultaneously assesses antiarrhythmic markers of success and failure at multiple spatial and time scales. Using this framework, a novel in silico mexiletine “booster” was designed that may dramatically improve the efficacy of mexiletine in suppression of arrhythmia triggers.

•

These results provide a roadmap for the design of novel molecular-based therapy to treat myriad arrhythmia syndromes, including ventricular tachycardia, heart failure arrhythmias, and inherited arrhythmia syndromes.

•

In summary, computational modeling approaches to drug discovery represent a novel tool to design and test precision-targeted therapeutic agents. By exploiting nontraditional ion channel drug targets, an entirely new dimension can be added to the wide parameter space of traditional antiarrhythmic drugs to develop more precision-targeted and potent Class I therapeutic agents.

Antiarrhythmic treatment strategies remain suboptimal due to our inability to predict how drug interactions with ion channels will affect the ability of the tissues to initiate and sustain an arrhythmia. We built a multiscale molecular model of the Na⁺ channel domain III (domain III voltage-sensing domain) to highlight the molecular underpinnings responsible for mexiletine drug efficacy. This model predicts that a hyperpolarizing shift in the domain III voltage-sensing domain is critical for drug efficacy and may be leveraged to design more potent Class I molecules. The model was therefore used to design, in silico, a theoretical mexiletine booster that can dramatically rescue a mutant resistant to the potent antiarrhythmic effects of mexiletine. Our framework provides a strategy for in silico design of precision-targeted therapeutic agents that simultaneously assesses antiarrhythmic markers of success and failure at multiple spatial and time scales. This approach provides a roadmap for the design of novel molecular-based therapy to treat myriad arrhythmia syndromes, including ventricular tachycardia, heart failure arrhythmias, and inherited arrhythmia syndromes.

Transplantation of Human Brain Organoids: Revisiting the Science and Ethics of Brain Chimeras

Recent demonstrations of human brain organoid transplantation in rodents have accentuated ethical concerns associated with these entities, especially as they relate to potential "humanization" of host animals. Consideration of established scientific principles can help define the realistic range of expected outcomes in such transplantation studies. This practical approach suggests that augmentation of discrete brain functions in transplant hosts is a more relevant ethical question in the near term than the possibility of "conscious" chimeric animals. We hope that this framework contributes to a balanced approach for proceeding with studies involving brain organoid transplantation and other forms of human-animal brain chimeras.

Mapping Bioethics in Latin America: History, Theoretical Models, and Scientific Output

OBJECTIVE

To present a narrative review of the history of bioethics in Latin America and of scientific output in this interdisciplinary field.

METHODS

This was a mixed-methods study.

RESULTS

A total of 1458 records were retrieved, of which 1167 met the inclusion criteria. According to the Web of Science classification, the predominant topics of study were medical ethics (n= 488), social sciences and medicine (n= 354), and environmental and public health topics (n= 279). Four themes of bioethics output in the Latin American literature have emerged: (a) issues involving the beginning and end of life, (b) ethics in human research, (c) patient-provider relationships, and (d) ethics training for health professionals.

CONCLUSION

Although bioethics is a growing interdisciplinary field in Latin America, its academic impact is still very low, and programmes are highly concentrated in large urban centres in a few countries. Challenges includes the regional and international impact of local scientific output.

Beecher Reconsidered

In 1962, Harvard professor of anesthesiology Henry Beecher wrote to Senator Estes Kefauver about certain additions to the federal Food and Drug Act then being considered. According to The Antibiotic Era, the Maryland congressman Samuel Friedel had introduced language that would require informed consent in clinical research. Beecher joined a number of other distinguished medical scientists warning that such a requirement would "cripple" American medical research. A year before, Beecher had protested the U.S. Army's inclusion of the Nuremberg Code in its contracts. Beecher's commitment to a medical ethics of virtue rather than one of oversight suggests that he was a far more interesting person than the cardboard cutout so often vaguely referenced in bioethics as an icon of the rights of human subjects. His thinking about research ethics was rooted in his post-World War II laboratory work with LSD.

Ethical considerations on the complicity of psychologists and scientists in torture

INTRODUCTION

The long-standing debate on medical complicity in torture has overlooked the complicity of cognitive scientists-psychologists, psychiatrists and neuroscientists-in the practice of torture as a distinct phenomenon. In this paper, we identify the risk of the re-emergence of torture as a practice in the USA, and the complicity of cognitive scientists in these practices.

METHODS

We review arguments for physician complicity in torture. We argue that these defences fail to defend the complicity of cognitive scientists. We address objections to our account, and then provide recommendations for professional associations in resisting complicity in torture.

RESULTS

Arguments for cognitive scientist complicity in torture fail when those actions stem from the same reasons as physician complicity. Cognitive scientist involvement in the torture programme has, from the outset, been focused on the outcomes of interrogation rather than supportive care. Any possibility of a therapeutic relationship between cognitive therapists and detainees is fatally undermined by therapists' complicity with torture.

CONCLUSION

Professional associations ought to strengthen their commitment to refraining from engaging in any aspect of torture. They should also move to protect whistle-blowers against torture programmes who are members of their association. If the political institutions that are supposed to prevent the practice of torture are not strengthened, cognitive scientists should take collective action to compel intelligence agencies to refrain from torture.

Mechanisms and models of cardiac sodium channel inactivation

Shortly after cardiac Na+ channels activate and initiate the action potential, inactivation ensues within milliseconds, attenuating the peak Na+ current, INa, and allowing the cell membrane to repolarize. A very limited number of Na+ channels that do not inactivate carry a persistent INa, or late INa. While late INa is only a small fraction of peak magnitude, it significantly prolongs ventricular action potential duration, which predisposes patients to arrhythmia. Here, we review our current understanding of inactivation mechanisms, their regulation, and how they have been modeled computationally. Based on this body of work, we conclude that inactivation and its connection to late INa would be best modeled with a "feet-on-the-door" approach where multiple channel components participate in determining inactivation and late INa. This model reflects experimental findings showing that perturbation of many channel locations can destabilize inactivation and cause pathological late INa.

The First Neuroethics Meeting: Then and Now

It wasn't until 2002 that more than 150 neuroscientists, bioethicists, doctors of psychiatry and psychology, philosophers, and professors of law and public policy came together to chart the boundaries, define the issues, and raise some of the ethical implications tied to advances in brain research. On the 15^thanniversary of the Neuroethics: Mapping the Field conference in San Francisco, we asked three of the original speakers to reflect on how far the neuroethics field has come in 15 years-and where the field may be going in the next 15.

History, Morals, and Medicine

This essay provides a rational reconstruction of the author's genetically inscribed inclination to do normative ethics with an historical bent and offers some reflections on the value of historical thinking for bioethics.

Parameterization for In-Silico Modeling of Ion Channel Interactions with Drugs

Since the first Hodgkin and Huxley ion channel model was described in the 1950s, there has been an explosion in mathematical models to describe ion channel function. As experimental data has become richer, models have concomitantly been improved to better represent ion channel kinetic processes, although these improvements have generally resulted in more model complexity and an increase in the number of parameters necessary to populate the models. Models have also been developed to explicitly model drug interactions with ion channels. Recent models of drug-channel interactions account for the discrete kinetics of drug interaction with distinct ion channel state conformations, as it has become clear that such interactions underlie complex emergent kinetics such as use-dependent block. Here, we describe an approach for developing a model for ion channel drug interactions. The method describes the process of extracting rate constants from experimental electrophysiological function data to use as initial conditions for the model parameters. We then describe implementation of a parameter optimization method to refine the model rate constants describing ion channel drug kinetics. The algorithm takes advantage of readily available parallel computing tools to speed up the optimization. Finally, we describe some potential applications of the platform including the potential for gaining fundamental mechanistic insights into ion channel function and applications to in silico drug screening and development.

Acid Brothers: Henry Beecher, Timothy Leary, and the psychedelic of the century

Henry Knowles Beecher, an icon of human research ethics, and Timothy Francis Leary, a guru of the counterculture, are bound together in history by the synthetic hallucinogen lysergic acid diethylamide (LSD). Both were associated with Harvard University during a critical period in their careers and of drastic social change. To all appearances the first was a paragon of the establishment and a constructive if complex hero, the second a rebel and a criminal, a rogue and a scoundrel. Although there is no evidence they ever met, Beecher's indirect struggle with Leary over control of the 20th century's most celebrated psychedelic was at the very heart of his views about the legitimate, responsible investigator. That struggle also proves to be a revealing bellwether of the increasingly formalized scrutiny of human experiments that was then taking shape.

In silico prediction of drug therapy in catecholaminergic polymorphic ventricular tachycardia

Key points

The mechanism of therapeutic efficacy of flecainide for catecholaminergic polymorphic ventricular tachycardia (CPVT) is unclear.

Model predictions suggest that Na⁺ channel effects are insufficient to explain flecainide efficacy in CPVT.

This study represents a first step toward predicting therapeutic mechanisms of drug efficacy in the setting of CPVT and then using these mechanisms to guide modelling and simulation to predict alternative drug therapies.

Abstract

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia syndrome characterized by fatal ventricular arrhythmias in structurally normal hearts during β‐adrenergic stimulation. Current treatment strategies include β‐blockade, flecainide and ICD implementation – none of which is fully effective and each comes with associated risk. Recently, flecainide has gained considerable interest in CPVT treatment, but its mechanism of action for therapeutic efficacy is unclear. In this study, we performed in silico mutagenesis to construct a CPVT model and then used a computational modelling and simulation approach to make predictions of drug mechanisms and efficacy in the setting of CPVT. Experiments were carried out to validate model results. Our simulations revealed that Na⁺ channel effects are insufficient to explain flecainide efficacy in CPVT. The pure Na⁺ channel blocker lidocaine and the antianginal ranolazine were additionally tested and also found to be ineffective. When we tested lower dose combination therapy with flecainide, β‐blockade and CaMKII inhibition, our model predicted superior therapeutic efficacy than with flecainide monotherapy. Simulations indicate a polytherapeutic approach may mitigate side‐effects and proarrhythmic potential plaguing CPVT pharmacological management today. Importantly, our prediction of a novel polytherapy for CPVT was confirmed experimentally. Our simulations suggest that flecainide therapeutic efficacy in CPVT is unlikely to derive from primary interactions with the Na⁺ channel, and benefit may be gained from an alternative multi‐drug regimen.

The mechanism of therapeutic efficacy of flecainide for catecholaminergic polymorphic ventricular tachycardia (CPVT) is unclear.

Model predictions suggest that Na⁺ channel effects are insufficient to explain flecainide efficacy in CPVT.

This study represents a first step toward predicting therapeutic mechanisms of drug efficacy in the setting of CPVT and then using these mechanisms to guide modelling and simulation to predict alternative drug therapies.

Yesterday's war; tomorrow's technology: peer commentary on 'Ethical, legal, social and policy issues in the use of genomic technologies by the US military'

A recent article by Maxwell J. Mehlman and Tracy Yeheng Li, in the Journal of Law and the Biosciences, sought to examine the ethical, legal, social, and policy issues associated with the use of genetic screening and germ-line therapies ('genomic technologies') by the US Military. In this commentary, we will elaborate several related matters: the relationship between genetic and non-genetic screening methods, the history of selection processes and force strength, and the consequences and ethics of, as Mehlman and Li suggest, engineering enhanced soldiers. We contend, first, that the strengths of genomic testing as a method of determining enrollment in the armed forces has limited appeal, given the state of current selection methods in the US armed forces. Second, that the vagaries of genetic selection, much like other forms of selection that do not bear causally or reliably on soldier performance (such as race, gender, and sexuality), pose a systematic threat to force strength by limiting the (valuable) diversity of combat units. Third, that the idea of enhancing warfighters through germ-line interventions poses serious ethical issues in terms of the control and ownership of 'enhancements' when members separate from service.