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In JoVE (1)
Other Publications (15)
- Memory & Cognition
- Seishin Shinkeigaku Zasshi = Psychiatria Et Neurologia Japonica
- Cancer
- Clinics in Sports Medicine
- Theoretical Medicine and Bioethics
- Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology
- Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology
- Philosophy, Ethics, and Humanities in Medicine : PEHM
- American Journal of Health Promotion : AJHP
- Journal of Biomolecular Screening
- Philosophy, Ethics, and Humanities in Medicine : PEHM
- Disability and Health Journal
- Journal of Laboratory Automation
- Biotechnology and Bioengineering
- Philosophy, Ethics, and Humanities in Medicine : PEHM
Articles by Michael A. Schwartz in JoVE
JoVE General
Platelet Adhesion and Aggregation Under Flow using Microfluidic Flow Cells
The platelet adhesion cascade takes place in the presence of shear flow, a factor not accounted for in conventional (static) well-plate assays. This article reports on a platelet-aggregation assay utilizing a microfluidic well-plate format to emulate physiological shear flow conditions.
Other articles by Michael A. Schwartz on PubMed
Are False Memories More Difficult to Forget Than Accurate Memories? The Effect of Retention Interval on Recall and Recognition
What is the effect of retention interval on accurate and false recollection in the Deese, Roediger, and McDermott (DRM) procedure? Previous research has suggested that false recall is more persistent than accurate recall but the recognition results have been inconsistent. In two parametric studies, we tested recall and recognition for the same DRM lists, over retention intervals that ranged from no delay to a 2-month delay. We found that accurate and false memory were diminished by increases in retention interval, false memory persistence was present for recall and recognition, greater persistence for false memory than for accurate memory was more readily observed for recall than recognition, and the high-threshold (Pr), signal detection (d'), and nonparametric (A') recognition measures differed in their sensitivity for detecting change. The effect of retention interval on accurate and false memory is consistent with expectations from fuzzy trace theory. In the DRM procedure, truth is not more memorable than fiction.
Rebuilding Reality: a Phenomenology of Aspects of Chronic Schizophrenia
Schizophrenia, like other "pathological" conditions, has not been systematically included in the general study of consciousness. By focusing on aspects of chronic schizophrenia, we attempt to survey one way of remedying this omission. Some basic components of Edmund Husserl's phenomenology of human experience (intentionality, constitution, and unbuilding) are explicated in detail, and these components are then employed in an account of exemplary aspects of chronic schizophrenia. We maintain that in schizophrenic experience some very basic constituents of reality--constituents so basic we call them "ontological"--are lost so that the patient must try to explicitly re-constitute those ontological features of the world. Using Husserl's concepts such experiences are described as a weakening of "automatic mental life" so that much of the world that is normally taken-for-granted cannot continue to be so. This requires the patient to actively busy him or herself with re-laying the ontological foundations of reality.
Phase II Study of High-dose Fish Oil Capsules for Patients with Cancer-related Cachexia
The authors undertook a multiinstitutional Phase II cooperative group study to examine the potential of oral fish oil fatty acid supplements administered at high doses to slow weight loss and to improve quality of life in patients with malignancy-related cachexia.
Diagnosis and Treatment of Medial Epicondylitis of the Elbow
Although limited literature exists on medial epicondylitis of the elbow, this disorder is an injury affecting many athletes at every level, especially throwing athletes. Care must be taken in diagnosing medial epicondylitis to distinguish it from other possible pathologies of the medial elbow, which may exist concurrently. The large majority of patients diagnosed with medial epicondylitis will respond to a well-structured, nonsurgical program; however, patients with persistent or recurring symptoms can be treated surgically, which yields high patient satisfaction and ultimately a reliable return to preinjury levels of activity.
Richard Zaner's Phenomenology of the Clinical Encounter
The "clinical ethics" propounded by Richard Zaner is unique. Partly because of his phenomenological orientation and partly because of his own daily practice as a clinical ethicist in a large university hospital, Zaner focuses on the particular concrete situations in which patients and their families confront illness and injury and struggle toward workable ways for dealing with them. He locates ethical reality in the "clinical encounter." This encounter encompasses not only patient and physician but also the patient's family and friends and indeed the entire "lifeworld" in which the patient is still striving to live. In order to illuminate the central moral constituents of such human predicaments, Zaner discusses the often-overlooked features of disruption and crisis, the changed self, the patient's dependence and the physician's power, the violation of personal boundaries and their necessary reconfiguring, and the art of listening.
American Society of Clinical Oncology Clinical Practice Guideline for the Use of Larynx-preservation Strategies in the Treatment of Laryngeal Cancer
To develop a clinical practice guideline for treatment of laryngeal cancer with the intent of preserving the larynx (either the organ itself or its function). This guideline is intended for use by oncologists in the care of patients outside of clinical trials.
Bevacizumab in Combination with Oxaliplatin, Fluorouracil, and Leucovorin (FOLFOX4) for Previously Treated Metastatic Colorectal Cancer: Results from the Eastern Cooperative Oncology Group Study E3200
Colorectal cancer is the second leading cause of cancer mortality in the United States. Antiangiogenic therapy with bevacizumab combined with chemotherapy improves survival in previously untreated metastatic colorectal cancer. This study was conducted to determine the effect of bevacizumab (at 10 mg/kg) on survival duration for oxaliplatin-based chemotherapy in patients with previously treated metastatic colorectal cancer.
Death, Organ Transplantation and Medical Practice
A series of papers in Philosophy, Ethics and Humanities in Medicine (PEHM) have recently disputed whether non-heart beating organ donors are alive and whether non-heart beating organ donation (NHBD) contravenes the dead donor rule. Several authors who argue that NHBD involves harvesting organs from live patients appeal to "strong irreversibility" (death beyond the reach of resuscitative efforts to restore life) as a necessary criterion that patients must meet before physicians can declare them to be dead. Sam Shemie, who defends our current practice of NHBD, holds that in fact physicians consider patients to be dead or not according to physician intention to resuscitate or not. We suggest that criteria for a concept are not necessarily truth conditions for assertions involving the concept. Hence, non-heart beating donors may be declared dead without meeting the criterion of strong irreversibility even though strong irreversibility is implied by the concept of death. Our perception that a concept applies in a given case is determined not by the concept itself but by our necessary skill and judgment when using it. In the case of deciding that a patient is dead, such judgment is learned by physicians as they learn the practice of medicine and may vary according to circumstances. Current practice of NHBD can therefore be defended without abandoning death as an empirical concept, as Shemie appears to do. We conclude that the dead donor rule continues to be viable and ought to be retained so as to guarantee what the public most cares about as regards organ donation: that physicians can be trusted to make determinations of eligibility for organ donation in the interests of patients and not for other purposes such as increasing the availability of organs.
Are Perceptions About Worksite Neighborhoods and Policies Associated with Walking?
To examine associations of the built environment surrounding worksites and of work policies with walking behaviors.
Well Plate-coupled Microfluidic Devices Designed for Facile Image-based Cell Adhesion and Transmigration Assays
Microfluidic devices have become invaluable tools in recent years to model biological phenomena. Here, the authors present a well plate microfluidic (WPM) device for conducting cell biology assays under shear flow. Physiological shear flow conditions of cell-cell and cell-ligand adhesion within this device produce results with higher biological significance than conventional well plates. The WPM format also produced significant work flow advantages such as faster liquid handling compared to static well plate assays. The authors used the VLA-4-VCAM-1 cell adhesion model as the basis for a rapid, higher throughput adhesion inhibition screen of monoclonal antibodies against VLA-4. Using the WPM device, they generated IC(50) dose-response curves 96 times faster than conventional flow cells. The WPM device was also used to study transmigration of mononuclear cells through endothelial cell monolayers. Twenty-four channels of transmigration data were generated in a single experiment.
Psychosomatic Medicine and the Philosophy of Life
Basing ourselves on the writings of Hans Jonas, we offer to psychosomatic medicine a philosophy of life that surmounts the mind-body dualism which has plagued Western thought since the origins of modern science in seventeenth century Europe. Any present-day account of reality must draw upon everything we know about the living and the non-living. Since we are living beings ourselves, we know what it means to be alive from our own first-hand experience. Therefore, our philosophy of life, in addition to starting with what empirical science tells us about inorganic and organic reality, must also begin from our own direct experience of life in ourselves and in others; it can then show how the two meet in the living being. Since life is ultimately one reality, our theory must reintegrate psyche with soma such that no component of the whole is short-changed, neither the objective nor the subjective. In this essay, we lay out the foundational components of such a theory by clarifying the defining features of living beings as polarities. We describe three such polarities: 1) Being vs. non-being: Always threatened by non-being, the organism must constantly re-assert its being through its own activity. 2) World-relatedness vs. self-enclosure: Living beings are both enclosed with themselves, defined by the boundaries that separate them from their environment, while they are also ceaselessly reaching out to their environment and engaging in transactions with it. 3) Dependence vs. independence: Living beings are both dependent on the material components that constitute them at any given moment and independent of any particular groupings of these components over time.We then discuss important features of the polarities of life: Metabolism; organic structure; enclosure by a semi-permeable membrane; distinction between "self" and "other"; autonomy; neediness; teleology; sensitivity; values. Moral needs and values already arise at the most basic levels of life, even if only human beings can recognize such values as moral requirements and develop responses to them.
Health Care Under the ADA: a Vision or a Mirage?
Problems in health care access are identified using recent studies documenting the health disparities experienced by people with disabilities. Some of these health care access barriers qualify as discrimination prohibited under the Americans with Disabilities Act. Focusing on the past decade of ADA enforcement, issues reported in the U.S. Department of Justice listing of resolved ADA complaints and settlements are compared to the profile of access problems. Key court case outcomes of the past decade also are presented. These sources indicate that the majority of resolved complaints and settlements involved failure to provide effective communication (often sign language interpretation). A smaller percentage of complaints and settlements addressed issues of refusal to provide treatment, physical access, equipment access, and provider procedures. Most of the key settlements involved hospitals and larger provider organizations, while many complaints also focused on individual physicians. Although the record indicates that the ADA can be, and has been, effectively used to increase access in many instances, other types of access problems have been lightly addressed through application of the ADA. This likely stems from enforcement choices made by the Department of Justice and the dynamics of the patient-doctor relationship. The broad challenge for the coming decade is to develop means to achieve effective communication and eliminate physical and programmatic barriers in more health care provider settings more consistently. The ADA can be a vigorous force in this effort as part of a multipronged strategy.
Using Well-plate Microfluidic Devices to Conduct Shear-based Thrombosis Assays
Shear stress plays a critical role in regulating platelet adhesion and thrombus formation at the site of vascular injury. As such, platelets are often examined in vitro under controlled shear flow conditions for their hemostatic and thrombotic functions. Common shear-based platelet analyses include the evaluation of genetic mutants, inhibitory or experimental compounds, matrix substrates, and the effects of different physiological and pathological shear forces. There are several laboratory instruments widely used for studying shear flow, including cone and plate viscometers and parallel plate perfusion chambers. These technologies vary widely in the types of samples, substrates, blood volumes, and throughput that are involved. Here, we describe a microfluidic system for platelet analysis under shear flow. We used the devices to study thrombus formation on collagen I and von Willebrand factor. The system was also used to investigate dose response to the antiplatelet compound, Abciximab, under shear flow conditions with an emphasis on maximizing the number of data points per single patient sample. The presented method confers multiple advantages over conventional approaches. These include the ability to assess up to 24 conditions simultaneously in real time, maintain identical physical conditions across experiments, and use extremely low donor volumes.
Well Plate Microfluidic System for Investigation of Dynamic Platelet Behavior Under Variable Shear Loads
The study of platelet behavior in real-time under controlled shear stress offers insights into the underlying mechanisms of many vascular diseases and enables evaluation of platelet-focused therapeutics. The two most common methods used to study platelet behavior at the vessel wall under uniform shear flow are parallel plate flow chambers and cone-plate viscometers. Typically, these methods are difficult to use, lack experimental flexibility, provide low data content, are low in throughput, and require large reagent volumes. Here, we report a well plate microfluidic (WPM)-based system that offers high throughput, low reagent consumption, and high experimental flexibility in an easy to use well plate format. The system consists of well plates with an integrated array of microfluidic channels, a pneumatic interface, an automated microscope, and software. This WPM system was used to investigate dynamic platelet behavior under shear stress. Multiple channel designs are presented and tested for shear loads with whole blood to determine their applicability to study thrombus formation. Normal physiological shear (0.1-20 dyn/cm(2) ) and pathological shear (20-200 dyn/cm(2) ) devices were used to study platelet behavior in vitro under various shear, matrix coating, and monolayer conditions. The high physiological relevance, low blood consumption, and increased throughput create a valuable technique available to vascular biology researchers. The approach also has extensibility to other research areas including inflammation, cancer biology, and developmental/stem cell research.
The Six Most Essential Questions in Psychiatric Diagnosis: A Pluralogue. Part 1: Conceptual and Definitional Issues in Psychiatric Diagnosis
ABSTRACT: In face of the multiple controversies surrounding the DSM process in general and the development of DSM-5 in particular, we have organized a discussion around what we consider six essential questions in further work on the DSM. The six questions involve: 1) the nature of a mental disorder; 2) the definition of mental disorder; 3) the issue of whether, in the current state of psychiatric science, DSM-5 should assume a cautious, conservative posture or an assertive, transformative posture; 4) the role of pragmatic considerations in the construction of DSM-5; 5) the issue of utility of the DSM - whether DSM-III and IV have been designed more for clinicians or researchers, and how this conflict should be dealt with in the new manual; and 6) the possibility and advisability, given all the problems with DSM-III and IV, of designing a different diagnostic system. Part I of this article will take up the first two questions. With the first question, invited commentators express a range of opinion regarding the nature of psychiatric disorders, loosely divided into a realist position that the diagnostic categories represent real diseases that we can accurately name and know with our perceptual abilities, a middle, nominalist position that psychiatric disorders do exist in the real world but that our diagnostic categories are constructs that may or may not accurately represent the disorders out there, and finally a purely constructivist position that the diagnostic categories are simply constructs with no evidence of psychiatric disorders in the real world. The second question again offers a range of opinion as to how we should define a mental or psychiatric disorder, including the possibility that we should not try to formulate a definition. The general introduction, as well as the introductions and conclusions for the specific questions, are written by James Phillips, and the responses to commentaries are written by Allen Frances.
