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In this issue of Alzheimer's & Dementia, Mashour et al. propose the intriguing hypothesis that some manifestations of late-stage dementia are reversible, albeit transiently. Calling this phenomenon paradoxical lucidity, their paper follows a 2018 workshop sponsored by the National Institute on Aging that assessed the state of knowledge on lucidity in dementia and identified areas ripe for further study. The National Institute on Aging has since released two funding opportunity announcements (RFA-AG-20-016 and RFA-AG-20-017) to establish the building blocks of such a research program. The potential challenges of conducting such studies are matched by the potential opportunities to open a novel window onto our understanding of dementia. Initial findings from this research may eventually lead to studies that uncover novel mechanisms underlying cognitive decline, identify potential preventive or therapeutic approaches for individuals with dementia, offer more effective strategies for caregivers, and perhaps even expand our understanding of the nature of personhood and consciousness.

The important problems facing older adults will not be solved through the methods of a single discipline. In recognition of this, the NIA funded the Research Centers Collaborative Network (RCCN) to build collaborations between scientists from the 6 NIA-sponsored center programs: Alzheimer’s Disease Research Centers, Centers on the Demography and Economics of Aging, Claude D. Pepper Older Americans Independence Centers, Nathan Shock Centers of Excellence in the Basic Biology of Aging, Resource Centers for Minority Aging Research, and Roybal Centers for Translational Research on Aging. RCCN’s central premise is that researchers from different disciplines are most likely to collaborate when they are addressing similar problems. To foster collaboration the RCCN has convened 5 workshops on: 1. achieving and sustaining behavior change in older adults; 2. sex and gender in aging research; 3. reserve and resilience; 4. life course perspectives on aging; and 5. promoting the inclusion of older adults in clinical research. After each Workshop the RCCN awards pilot funds related to the theme. This symposium will review key learnings from the workshops and present work of four RCCN pilot teams from the first two workshops which focused on changing and sustaining behavior change in older adults, and sex and gender differences in aging. Dr. Hughes will discuss the value of interdisciplinary research to maintain behavior change while Dr. Lee will discuss social incentives to improve mobility postoperatively. Dr. Stites will discuss cognition and gender trends, while Dr. Ware will discuss sex differences in genetic effects.

The NIA/NCI ASPREE (ASPirin in Reducing Events in the Elderly) Study was a landmark RCT of 19,114 healthy adults aged 70 (whites) and 65 (US minorities) in Australia and the US that demonstrated lack of effect of low dose aspirin (LDA:100 mg/d) on the novel primary end point of Disability- Free Survival (life free of disability and dementia) over a mean treatment of 4.7 years. Surprisingly, LDA was associated with a trend toward increased all cause mortality, driven by cancer deaths (results published NEJM September 2018). After the LDA intervention was halted in June 2017, ASPREE was extended as an observational cohort follow-on study, ASPREE-XT, to measure potential delayed LDA effects on ASPREE outcomes. The ASPREE study primary results will be summarized, and the rationale for and performance of the novel DFS geriatric outcome discussed. New results of the analysis of dementia as a secondary outcome will also be presented (both for overall dementia and Alzheimer’s disease). We will also examine the unexpected increased all-cause mortality attributed to cancer deaths, despite no significant difference between groups for all incident cancer, and effects of LDA on incident metastatic disease. The important implications of the ASPREE results for prescribing LDA for primary prevention in health elderly will be discussed, and the ASPREE-XT study design and progress described. Lastly, the breadth of the ASPREE sub-studies including the Biobank, Brain Imaging studies and Genomics, and opportunities to access the rich ASPREE data and collaborate with ASPREE investigators will be reviewed.

In September 2010, the Cancer and Aging Research Group, in collaboration with the National Cancer Institute and the National Institute on Aging, conducted the first of three planned conferences to discuss research methodology to generate the highest quality research in older adults with cancer and then disseminate these findings among those working in the fields of cancer and aging. Conference speakers discussed the current level of research evidence in geriatric oncology, outlined the current knowledge gaps, and put forth principles for research designs and strategies that would address these gaps within the next 10 years. It was agreed that future oncology research trials that enroll older adults should include: (1) improved standardized geriatric assessment of older oncology patients, (2) substantially enhanced biological assessment of older oncology patients, (3) specific trials for the most vulnerable and/or those older than 75 years, and (4) research infrastructure that specifically targets older adults and substantially strengthened geriatrics and oncology research collaborations. This initial conference laid the foundation for the next two meetings, which will address the research designs and collaborations needed to enhance therapeutic and intervention trials in older adults with cancer.

Objective. There has been a growing recognition of the need for better pharmacologic management of chronic pain among older adults. To address this need, the National Institutes of Health Pain Consortium sponsored an “Expert Panel Discussion on the Pharmacological Management of Chronic Pain in Older Adults” conference in September 2010 to identify research gaps and strategies to address them. Specific emphasis was placed on ascertaining gaps regarding use of opioid and nonsteroidal anti-inflammatory medications because of continued uncertainties regarding their risks and benefits. Design. Eighteen panel members provided oral presentations; each was followed by a multidisciplinary panel discussion. Meeting transcripts and panelists' slide presentations were reviewed to identify the gaps and the types of studies and research methods panelists suggested could best address them. Results. Fifteen gaps were identified in the areas of treatment (e.g., uncertainty regarding the long-term safety and efficacy of commonly prescribed analgesics), epidemiology (e.g., lack of knowledge regarding the course of common pain syndromes), and implementation (e.g., limited understanding of optimal strategies to translate evidence-based pain treatments into practice). Analyses of data from electronic health care databases, observational cohort studies, and ongoing cohort studies (augmented with pain and other relevant outcomes measures) were felt to be practical methods for building an age-appropriate evidence base to improve the pharmacologic management of pain in later life. Conclusion. Addressing the gaps presented in the current report was judged by the panel to have substantial potential to improve the health and well-being of older adults with chronic pain.

Aging kidneys undergo structural and functional changes that decrease autoregulatory capacity and increase susceptibility to acute injury. Acute kidney injury associates with duration and location of hospitalization, mortality risk, progression to chronic kidney disease, and functional status in daily living. Definition and diagnosis of acute kidney injury are based on changes in creatinine, which is an inadequate marker and might identify patients when it is too late. The incidence of acute kidney injury is rising and increases with advancing age, yet clinical studies have been slow to address geriatric issues or the heterogeneity in etiologies, outcomes, or patient preferences among the elderly. Here we examine some of the current literature, identify knowledge gaps, and suggest potential research questions regarding acute kidney injury in older adults. Answering these questions will facilitate the integration of geriatric issues into future mechanistic and clinical studies that affect management and care of acute kidney injury.

Physical resilience, defined as one’s ability to withstand or recover from functional decline following an acute or chronic health stressor, is a concept that resonates with older patients and providers. Predicting an individual’s likelihood of a successful response to a given stressor would inform medical decision-making and help target resources. In August 2015, the National Institute on Aging convened a workshop to outline research needs to improve measures to predict and assess resilience in human aging (Hadly EC et al, J Gerontol A Biol Sci Med Sci 2017. 72(7): 980–990). One need that was identified was feasible clinical tests, such as simulation tests, to predict and assess resilient responses to “real world” stressors. This session, moderated by NIA Program Officers, will present several test paradigms currently under study as predictors of physical resilience to common stressors. Each test quantifies the individual’s response to a certain perturbation (e.g., vaccine, anesthesia, change of position) for the purpose of predicting future recovery from a health stressor. First, the moderators will introduce the emerging conceptual framework of physical resilience, emphasizing the dynamic nature of physiologic responses to stressors and their role in maintaining or regaining normal homeostasis and function. Brief presentations will follow on active lines of research, linked through the NIA-funded Physical Resiliencies: Indicators and Mechanisms in the Elderly (PRIME) Collaborative. Each speaker will describe a clinical test paradigm which is employed before, during, or soon after a stressor and will present data on the test’s ability to predict physical resilience.

Aging brings an increased predisposition to critical illness. Patients older than 65 years of age account for approximately half of all intensive care unit (ICU) admissions in the United States, a proportion that is expected to increase considerably with the aging of the population. Emerging research suggests that elderly survivors of intensive care suffer significant long-term sequelae, including accelerated age-related functional decline. Existing evidence-based interventions are frequently underused and their efficacy untested in older subjects. Improving ICU outcomes in the elderly will require not only better methods for translating sound science into improved ICU practice but also an enhanced understanding of the underlying molecular, physiological, and pathophysiological interactions of critical illness with the aging process itself. Yet, significant barriers to research for critical illness in aging exist. We review the state of knowledge and identify gaps in knowledge, research opportunities, and barriers to research, with the goal of promoting an integrated research agenda for critical illness in aging.

The American Geriatrics Society, with support from the National Institute on Aging and the John A. Hartford Foundation, held its fifth Bedside-to-Bench research conference, “Idiopathic Fatigue and Aging,” to provide participants with opportunities to learn about cutting-edge research developments, draft recommendations for future research, and network with colleagues and leaders in the field. Fatigue is a symptom that older persons, especially by those with chronic diseases, frequently experience. Definitions and prevalence of fatigue may vary across studies, across diseases, and even between investigators and patients. The focus of this review is on physical fatigue, recognizing that there are other related domains of fatigue (such as cognitive fatigue). Many definitions of fatigue involve a sensation of “low” energy, suggesting that fatigue could be a disorder of energy balance. Poor energy utilization efficiency has not been considered in previous studies but is likely to be one of the most important determinants of fatigue in older individuals. Relationships between activity level, capacity for activity, a tolerable rate of activity, and a tolerable fatigue threshold or ceiling underlie a notion of fatiguability. Mechanisms probably contributing to fatigue in older adults include decline in mitochondrial function, alterations in brain neurotransmitters, oxidative stress, and inflammation. The relationships between muscle function and fatigue are complex. A number of diseases (such as cancer) are known to cause fatigue and may serve as models for how underlying impaired physiological processes contribute to fatigue, particularly those in which energy utilization may be an important factor. A further understanding of fatigue will require two key strategies: to develop and refine fatigue definitions and measurement tools and to explore underlying mechanisms using animal and human models.

This case report describes successful treatment of autoimmune autonomic ganglionopathy (AAG) in a 74-year-old woman by total plasma exchanges (PLEX) and rituximab. Two series of PLEX temporarily, but dramatically improved orthostatic intolerance and hypotension and baroreflex function, in a manner inversely related to ganglionic neuronal nicotinic receptor antibody titer. After rituximab treatment, the antibody titer was decreased modestly but persistently, and the patient had symptomatic and clinical laboratory evidence of continued benefit for at least 10 months, supporting the autoimmune pathogenesis of AAG.

Diseases characterized by neurogenic orthostatic hypotension (NOH), such as Parkinson disease (PD) and pure autonomic failure (PAF), are associated with cardiac sympathetic denervation, as reflected by low myocardial concentrations of 6-[(18)F]fluorodopamine-derived radioactivity. We studied the impact of such denervation on cardiac chronotropic and inotropic function.Cardiac inotropic function was assessed by the pre-ejection period index and the systolic time ratio index in response to the directly acting beta-adrenoceptor agonist, isoproterenol, and to the indirectly acting sympathomimetic amine, tyramine, in patients with PD+NOH or PAF (PD+NOH/PAF group, N=13). We compared the results to those in patients with multiple system atrophy, which usually entails NOH with normal cardiac sympathetic innervation (MSA, N=15), and in normal control subjects (N=5).The innervated and denervated groups did not differ in baseline mean pre-ejection period index or systolic time ratio index. Tyramine increased cardiac contractility in the MSA patients and controls but not in the PD+NOH/PAF group. For similar heart rate responses, the PD+NOH/PAF group required less isoproterenol (p0.01) and had lower plasma isoproterenol levels (p0.01) than did the MSA group.Among patients with NOH those with cardiac sympathetic denervation have an impaired inotropic response to tyramine and exaggerated responses to isoproterenol. This pattern suggests that cardiac denervation is associated with decreased ability to release endogenous norepinephrine from sympathetic nerves and with supersensitivity of cardiac beta-adrenoreceptors.

Stress is a well-known factor affecting cardiac contractility through the cardiac sympathetic nerves. A positive inotropic effect of the cardiac sympathetic nerves on the myocardium is reflected by pre-ejection period (PEP) shortening. Patients with Parkinson disease (PD) and neurogenic orthostatic hypotension (NOH) (PD + NOH) or with pure autonomic failure (PAF) have markedly decreased myocardial 6-[ 18 F]Fluorodopamine-derived radioactivity, reflecting cardiac sympathetic denervation. The functional effects of the cardiac sympathetic denervation have been unknown. We measured PEP and heart rate-corrected PEP (PEPI) responses to i.v. tyramine (1 mg/min) in 13 patients (9 PD + NOH and 4 PAF) with low 6-[ 18 F]Fluorodopamine-derived radioactivity and in subjects with normal radioactivity (15 multiple system atrophy with NOS patients (MSA + NOS). Baseline PEP and PEPI did not differ between the groups. By 10 min after initiation of tyramine infusion, PEP and PEPI were significantly lower (P < 0.01) in MSA + NOS, compared to base line, whereas PEP and PEPI remained unchanged in the PD + NOH/PAF group. The PEP and PEPI decrease was larger in the MSA + NOS group than in the PD + NOH/PAF group (P < 0.05). One of the functional consequences of cardiac sympathetic denervation is failure to increase contractility in response to stimuli that depend on endogenous norepinephrine release.

Biomarkers are increasingly important to diagnose and test treatments of neurodegenerative diseases such as Parkinson disease (PD). This study compared neuroimaging, neurochemical, and olfactory potential biomarkers to detect central dopamine (DA) deficiency and distinguish PD from multiple system atrophy (MSA).In 77 PD, 57 MSA, and 87 control subjects, radioactivity concentrations in the putamen (PUT), caudate (CAU), occipital cortex (OCC), and substantia nigra (SN) were measured 2h after 6-[18F]fluorodopa injection, septal myocardial radioactivity measured 8min after 6-[18F]fluorodopamine injection, CSF and plasma catechols assayed, or olfaction tested (University of Pennsylvania Smell Identification Test (UPSIT)). Receiver operating characteristic curves were constructed, showing test sensitivities at given specificities.PUT:OCC, CAU:OCC, and SN:OCC ratios of 6-[18F]fluorodopa-derived radioactivity were similarly low in PD and MSA (p0.0001, p0.0001, p=0.003 compared to controls), as were CSF dihydroxyphenylacetic acid (DOPAC) and DOPA concentrations (p0.0001, each). PUT:SN and PUT:CAU ratios were lower in PD than in MSA (p=0.004; p=0.005). CSF DOPAC correlated positively with PUT:OCC ratios (r=0.61, p0.0001). Myocardial 6-[18F]fluorodopamine-derived radioactivity distinguished PD from MSA (83% sensitivity at 80% specificity, 100% sensitivity among patients with neurogenic orthostatic hypotension). Only PD patients were anosmic; only MSA patients had normal olfaction (61% sensitivity at 80% specificity).PD and MSA feature low PUT:OCC ratios of 6-[18F]fluorodopa-derived radioactivity and low CSF DOPAC and DOPA concentrations, cross-validating the neuroimaging and neurochemical approaches but not distinguishing the diseases. PUT:SN and PUT:CAU ratios of 6-[18F]fluorodopa-derived radioactivity, cardiac 6-[18F]fluorodopamine-derived radioactivity, and olfactory testing separate PD from MSA.

Familial dysautonomia (FD) involves incomplete development of the sympathetic nervous system. Whether such loss extends to sympathetic innervation of the heart has been unknown. This study used 6-[(18)F]fluorodopamine neuroimaging to assess cardiac sympathetic innervation and function in FD.Six adult FD patients underwent thoracic PET scanning for 30 minutes after i.v. 6-[(18)F]fluorodopamine injection, as did healthy volunteers without (N = 21) or with (N = 10) pre-treatment by desipramine, which interferes with neuronal uptake and thereby simulates effects of noradrenergic denervation. Effective rate constants for uptake and loss were calculated using a single compartment pharmacokinetic model.FD patients had decreased uptake and accelerated loss of 6-[(18)F]fluorodopamine-derived radioactivity in the interventricular myocardial septum (P = 0.009, P = 0.05) and ventricular free wall (P = 0.007, P0.001), compared to untreated controls. Desipramine-treated subjects had decreased uptake but normal loss of 6-[(18)F]fluorodopamine-derived radioactivity.FD involves cardiac noradrenergic hypo-innervation. Since accelerated loss of 6-[(18)F]fluorodopamine-derived radioactivity cannot be explained by decreased neuronal uptake alone, FD may also involve augmented NE loss from extant terminals.

Identifying knowledge gaps and research opportunities in cancer and aging research was the focus of a three-part conference series led by the Cancer and Aging Research Group from 2010 to 2015. The third meeting, featured representatives from the NIA, NCI, ACS and PCORI each of whom discussed research priorities and funding opportunities in cancer and aging at their respective agencies. This manuscript reports on the proceedings of that conference with a specific focus on funding priorities for interventions to improve the quality of life and survivorship of older adults with cancer. Helpful tips from each funder regarding writing a scientifically strong research proposal are presented.

In patients with neurocardiogenic syncope, head-up tilt often evokes acute loss of consciousness accompanied by vasodilatation, increased plasma adrenaline and systemic hypotension. Since hypotension increases adrenaline levels and adrenaline can produce skeletal muscle vasodilatation by activating β2 receptors, adrenaline might induce a positive feedback loop precipitating circulatory collapse. We hypothesized that propranolol, a non-selective β-blocker, would prevent adrenaline-induced vasodilatation and thereby prevent syncope. Eight subjects with recurrent neurocardiogenic syncope and previously documented tilt-induced syncope with elevated plasma adrenaline levels participated in the present study. Subjects underwent tilt table testing after receiving oral propranolol or placebo in a double-blind randomized crossover fashion. Haemodynamic and neurochemical variables were measured using intra-arterial monitoring, impedance cardiography, arterial blood sampling and tracer kinetics of simultaneously infused [3H]noradrenaline and [3H]adrenaline. The occurrence of tilt-induced neurally mediated hypotension and syncope, duration of tilt tolerance, extent of the decrease in SVRI (systemic vascular resistance index) and magnitude of plasma adrenaline increases did not differ between the propranolol and placebo treatment phases. SVRI was inversely associated with fractional increase in plasma adrenaline during both phases. One subject did not faint when on propranolol; this subject's response is discussed in the context of central effects of propranolol. In this small, but tightly controlled, study, propranolol did not prevent tilt-induced vasodilatation, syncope or elevated plasma adrenaline.

Background— Chronic orthostatic intolerance (COI) occurs in postural tachycardia syndrome (POTS) and in some individuals with repeated neurocardiogenic syncope/presyncope (NCS), without POTS. This study addressed whether patients with COI and POTS or NCS have neurocirculatory abnormalities during supine rest. Methods and Results— Adult patients referred for COI who had POTS (n=90, mean±SEM age 40±1 years, 86% women) or NCS (n=36, 41±2 years old, 78% women) underwent measurements of plasma levels of catecholamines and forearm hemodynamics. Comparison data were obtained from 32 age- and gender-matched normal volunteers (39±2 years old, 81% women). The POTS group had a relatively fast mean heart rate (79±2 bpm) during supine rest compared with the NCS group (69±1.6 bpm, P =0.03) and normal volunteers (66±3 bpm, P =0.0004). The POTS group also had higher mean arterial norepinephrine (1.61±0.11 nmol/L, n=37) and epinephrine (0.39±0.03 nmol/L, n=37) concentrations than the NCS group (1.03±0.12 nmol/L, n=20, P =0.0012; 0.21±0.03 nmol/L, n=20, P =0.0005) and normal volunteers (1.13±0.11 nmol/L, n=20, P =0.006; 0.17±0.03 nmol/L, n=15, P =0.0001). The NCS group had higher mean forearm vascular resistance (52±6 U) than the POTS group (36±2 U, P =0.003). Conclusions— Overall, POTS features increased heart rate and sympathetic nervous and adrenomedullary hormonal system outflows during supine rest. Increased sympathetic outflow may contribute to the relative tachycardia in POTS. NCS features forearm vasoconstriction during supine rest but not sympathoneural or adrenomedullary activation.

Supine hypertension occurs commonly in primary chronic autonomic failure. This study explored whether supine hypertension in this setting is associated with orthostatic hypotension (OH), and if so, what mechanisms might underlie this association. Supine and upright blood pressures, hemodynamic responses to the Valsalva maneuver, baroreflex-cardiovagal gain, and plasma norepinephrine (NE) levels were measured in pure autonomic failure (PAF), multiple-system atrophy (MSA) with or without OH, and Parkinson’s disease (PD) with or without OH. Controls included age-matched, healthy volunteers and patients with essential hypertension or those referred for dysautonomia. Baroreflex-cardiovagal gain was calculated from the relation between the interbeat interval and systolic pressure during the Valsalva maneuver. PAF, MSA with OH, and PD with OH all featured supine hypertension, which was equivalent in severity to that in essential hypertension, regardless of fludrocortisone treatment. Among patients with PD or MSA, those with OH had higher mean arterial pressure during supine rest (109±3 mm Hg) than did those lacking OH (96±3 mm Hg, P =0.002). Baroreflex-cardiovagal gain and orthostatic increments in plasma NE levels were markedly decreased in all 3 groups with OH. Among patients with PD or MSA, those with OH had much lower mean baroreflex-cardiovagal gain (0.74±0.10 ms/mm Hg) than did those lacking OH (3.13±0.72 ms/mm Hg, P =0.0002). In PAF, supine hypertension is linked to both OH and low baroreflex-cardiovagal gain. The finding of lower plasma NE levels in patients with than without supine hypertension suggests involvement of pressor mechanisms independent of the sympathetic nervous system.

Caspases are a family of mammalian proteases related to the ced-3 gene of Caenorhabditis elegans. They mediate many of the morphological and biochemical features of apoptosis, including structural dismantling of cell bodies and nuclei, fragmentation of genomic DNA, destruction of regulatory proteins, and propagation of other pro-apoptotic molecules. Based on their substrate specificities and DNA sequence homologies, the 14 currently identified caspases may be divided into three groups: apoptotic initiators, apoptotic executioners, and inflammatory mediators. Caspases are activated through two principal pathways, known as the "extrinsic pathway," which is initiated by cell surface death receptor ligation, and the intrinsic pathway, which arises from mitochondria. Endogenous inhibitors, such as the inhibitors of apoptosis (IAP) family, modulate caspase activity at various points within these pathways. Upon activation, caspases appear to play an important role in sequelae of traumatic brain injury, spinal cord injury, and cerebral ischemia. In addition, they may also play a role in mediating cell death in chronic neurodegenerative conditions such as Alzheimer's disease, Huntington's disease, and amyotrophic lateral sclerosis. This article reviews the current literature on the role of caspases in acute and chronic CNS injury, and provides evidence for the potential therapeutic use of caspase inhibitors in the setting of these conditions.

An increasing number of patients older than 65 years are referred for and have access to organ transplantation, and an increasing number of older adults are donating organs. Although short-term outcomes are similar in older versus younger transplant recipients, older donor or recipient age is associated with inferior long-term outcomes. However, age is often a proxy for other factors that might predict poor outcomes more strongly and better identify patients at risk for adverse events. Approaches to transplantation in older adults vary across programs, but despite recent gains in access and the increased use of marginal organs, older patients remain less likely than other groups to receive a transplant, and those who do are highly selected. Moreover, few studies have addressed geriatric issues in transplant patient selection or management, or the implications on health span and disability when patients age to late life with a transplanted organ. This paper summarizes a recent trans-disciplinary workshop held by ASP, in collaboration with NHLBI, NIA, NIAID, NIDDK, and AGS, to address issues related to kidney, liver, lung, or heart transplantation in older adults and to propose a research agenda in these areas.

Idiopathic pulmonary fibrosis (IPF), a heterogeneous disease with respect to clinical presentation and rates of progression, disproportionately affects older adults. The diagnosis of IPF is descriptive, based on clinical, radiologic, and histopathologic examination, and definitive diagnosis is hampered by poor interobserver agreement and lack of a consensus definition. There are no effective treatments. Cellular, molecular, genetic, and environmental risk factors have been identified for IPF, but the initiating event and the characteristics of preclinical stages are not known. IPF is predominantly a disease of older adults, and the processes underlying normal aging might significantly influence the development of IPF. Yet, the biology of aging and the principles of medical care for this population have been typically ignored in basic, translational, or clinical IPF research. In August 2009, the Association of Specialty Professors, in collaboration with the American College of Chest Physicians, the American Geriatrics Society, the National Institute on Aging, and the National Heart, Lung, and Blood Institute, held a workshop, summarized herein, to review what is known, to identify research gaps at the interface of aging and IPF, and to suggest priority areas for future research. Efforts to answer the questions identified will require the integration of geriatrics, gerontology, and pulmonary research, but these efforts have great potential to improve care for patients with IPF.

The American Geriatrics Society, with support from the National Institute on Aging and the John A. Hartford Foundation, held its fifth Bedside-to-Bench research conference, "Idiopathic Fatigue and Aging," to provide participants with opportunities to learn about cutting-edge research developments, draft recommendations for future research, and network with colleagues and leaders in the field. Fatigue is a symptom that older persons, especially by those with chronic diseases, frequently experience. Definitions and prevalence of fatigue may vary across studies, across diseases, and even between investigators and patients. The focus of this review is on physical fatigue, recognizing that there are other related domains of fatigue (such as cognitive fatigue). Many definitions of fatigue involve a sensation of "low" energy, suggesting that fatigue could be a disorder of energy balance. Poor energy utilization efficiency has not been considered in previous studies but is likely to be one of the most important determinants of fatigue in older individuals. Relationships between activity level, capacity for activity, a tolerable rate of activity, and a tolerable fatigue threshold or ceiling underlie a notion of fatiguability. Mechanisms probably contributing to fatigue in older adults include decline in mitochondrial function, alterations in brain neurotransmitters, oxidative stress, and inflammation. The relationships between muscle function and fatigue are complex. A number of diseases (such as cancer) are known to cause fatigue and may serve as models for how underlying impaired physiological processes contribute to fatigue, particularly those in which energy utilization may be an important factor. A further understanding of fatigue will require two key strategies: to develop and refine fatigue definitions and measurement tools and to explore underlying mechanisms using animal and human models.

Study objective In 2003, the Institute of Medicine Committee on the Future of Emergency Care in the United States Health System convened and identified a crisis in emergency care in the United States, including a need to enhance the research base for emergency care. As a result, the National Institutes of Health (NIH) formed an NIH Task Force on Research in Emergency Medicine to enhance NIH support for emergency care research. Members of the NIH Task Force and academic leaders in emergency care participated in 3 roundtable discussions to prioritize current opportunities for enhancing and conducting emergency care research. The objectives of these discussions were to identify key research questions essential to advancing the scientific underpinnings of emergency care and to discuss the barriers and best means to advance research by exploring the role of research networks and collaboration between the NIH and the emergency care community. Methods The Medical-Surgical Research Roundtable was convened on April 30 to May 1, 2009. Before the roundtable, the emergency care domains to be discussed were selected and experts in each of the fields were invited to participate in the roundtable. Domain experts were asked to identify research priorities and challenges and separate them into mechanistic, translational, and clinical categories. After the conference, the lists were circulated among the participants and revised to reach a consensus. Results Emergency care research is characterized by focus on the timing, sequence, and time sensitivity of disease processes and treatment effects. Rapidly identifying the phenotype and genotype of patients manifesting a specific disease process and the mechanistic reasons for heterogeneity in outcome are important challenges in emergency care research. Other research priorities include the need to elucidate the timing, sequence, and duration of causal molecular and cellular events involved in time-critical illnesses and injuries, and the development of treatments capable of halting or reversing them; the need for novel animal models; and the need to understand why there are regional differences in outcome for the same disease processes. Important barriers to emergency care research include a limited number of trained investigators and experienced mentors, limited research infrastructure and support, and regulatory hurdles. The science of emergency care may be advanced by facilitating the following: (1) training emergency care investigators with research training programs; (2) developing emergency care clinical research networks; (3) integrating emergency care research into Clinical and Translational Science Awards; (4) developing emergency care–specific initiatives within the existing structure of NIH institutes and centers; (5) involving emergency specialists in grant review and research advisory processes; (6) supporting learn-phase or small, clinical trials; and (7) performing research to address ethical and regulatory issues. Conclusion Enhancing the research base supporting the care of medical and surgical emergencies will require progress in specific mechanistic, translational, and clinical domains; effective collaboration of academic investigators across traditional clinical and scientific boundaries; federal support of research in high-priority areas; and overcoming limitations in available infrastructure, research training, and access to patient populations.

Fatigue is believed to be a common complaint among older adults; however, multiple studies of self-reported fatigue across the lifespan have found this may not be the case. To explain this paradox, this article considers "fatigability"-a phenotype characterized by the relationship between an individual's perceived fatigue and the activity level with which the fatigue is associated. Fatigability may be measured by combining self-report measures of fatigue with performance of physical or cognitive activities, provided that the work of the activity is known or can be standardized. Doing so prevents self-pacing and allows meaningful comparisons across subjects and between studies. Increased fatigability with aging may arise from a variety of factors including age-related changes in energy production or utilization, and inflammatory mechanisms. A few published intervention studies have targeted fatigue in older adults, though none have examined fatigability specifically. Because fatigue may represent a physiologic warning system, future clinical studies may benefit from a focus on fatigability, where both symptoms and function are considered.

IN older adults, fatigue is a commonly reported symptom. Different definitions have sought to represent fatigue (1,2), and for use in the present study, it is conceptualized as “the awareness of a decreased capacity for physical and/or mental activity due to an imbalance in the availability, utilization, and/or restoration of resources needed to perform activity” (3). Typically, fatigue is studied in patient populations with an index condition such as cancer, HIV infection, or multiple sclerosis. Indeed, a review of symptoms associated with cancer, AIDS, heart disease, chronic obstructive pulmonary disease, and renal disease found that between 32% and 90% of patients report fatigue (4). However, although fatigue is often attributed to underlying disease, in a large study of the general population only about one third of all fatigue cases could be explained by a diagnosed medical condition (5). The prevalence of fatigue in nondisease–specific community-dwelling older adults has not been well established. General population surveys indicate that fatigue increases with advancing age (6,7), although not consistently (8). In those studies, it was difficult to identify the prevalence of fatigue specifically for older individuals. However, in a sample of 199 older ambulatory residents of a long-term care facility, 47% reported moderate and severe fatigue (9). Furthermore, in a primary care sample of 124 older adults the prevalence of fatigue was 27% (10). Although functional consequences of fatigue have not been well characterized, studies in older adults have shown that fatigue is associated with restricted activity and disability. In a study of 754 nondisabled community-dwelling older adults, Gill and colleagues (11) showed that fatigue was the leading reason for restricted activity. In fact, among 24 prespecified reasons, 65.5 episodes of fatigue per 100 person-months of restricted activity were reported, whereas “pain or stiffness in joints” was the second leading cause associated with about half the rate (35.7 episodes per 100 person-months of restricted activity) (11). In addition, Avlund and colleagues (12) found that “tiredness” predicted adverse events such as the onset of disability, future hospitalization, and use of home care help (13) in an older nondisabled population. However, tiredness in these studies was evaluated in relation to task-specific activities of daily living (ADL), and the functional consequences of nontask-specific tiredness or fatigue are unclear. The present study used a measure of general fatigue to examine its distribution in a representative sample of older adults and to investigate the association of fatigue with measures of physical function and disability. Those classified as fatigued reported feeling that they could not get going and/or that everything was an effort on 3 or more days during a week (see the Methods section). Different measures of physical function were examined to understand whether fatigue was associated with each stage of the disablement process. In the framework of the disablement process (14–16), pathology is proposed as the first step in the model leading to impairments (e.g., low strength), functional limitation (e.g., slow walking speed), and ultimately, disability (e.g., inability to perform ADL). Typically, age-associated diseases are used to measure pathology, but markers of inflammation and thyroid function were examined as well in the current study to assess the subclinical disease that might be associated with fatigue and physical function (17–20).

Power spectral analysis of heart rate variability (HRV) has been used to indicate cardiac autonomic function. High-frequency power relates to respiratory sinus arrhythmia and therefore to parasympathetic cardiovagal tone; however, the relationship of low-frequency (LF) power to cardiac sympathetic innervation and function has been controversial. Alternatively, LF power might reflect baro reflexive modulation of autonomic outflows.We studied normal volunteers and chronic autonomic failure syndrome patients with and without loss of cardiac noradrenergic nerves to examine the relationships of LF power with cardiac sympathetic innervation and baroreflex function.We compared LF power of HRV in patients with cardiac sympathetic denervation, as indicated by low myocardial concentrations of 6-[(18)F]fluorodopamine-derived radioactivity or low rates of norepinephrine entry into coronary sinus plasma (cardiac norepinephrine spillover) to values in patients with intact innervation, at baseline, during infusion of yohimbine, which increases exocytotic norepinephrine release from sympathetic nerves, or during infusion of tyramine, which increases non-exocytotic release. Baroreflex-cardiovagal slope (BRS) was calculated from the cardiac interbeat interval and systolic pressure during the Valsalva maneuver. Results. LF power was unrelated to myocardial 6-[(18)F]fluorodopamine-derived radioactivity or cardiac norepinephrine spillover. In contrast, the log of LF power correlated positively with the log of BRS (r = 0.72, P0.0001). Patients with a low BRS (/=3 msec/mm Hg) had low LF power, regardless of cardiac innervation. Tyramine and yohimbine increased LF power in subjects with normal BRS but not in those with low BRS. BRS at baseline predicted LF responses to tyramine and yohimbine.LF power reflects baroreflex function, not cardiac sympathetic innervation.

Patient groups with chronic autonomic failure and neuroimaging evidence of intact or absent cardiac sympathetic innervation had similar mean values for myocardial perfusion. Cardiac sympathetic outflow does not seem to contribute to coronary vascular resistance.

Patients with Parkinson disease often have orthostatic hypotension. Neurocirculatory abnormalities underlying orthostatic hypotension might reflect levodopa treatment. Sixty-six Parkinson disease patients (36 with orthostatic hypotension, 15 off and 21 on levodopa; 30 without orthostatic hypotension) had tests of reflexive cardiovagal gain (decrease in interbeat interval per unit decrease in systolic pressure during the Valsalva maneuver; orthostatic increase in heart rate per unit decrease in pressure); reflexive sympathoneural function (decrease in pressure during the Valsalva maneuver; orthostatic increment in plasma norepinephrine); and cardiac and extracardiac noradrenergic innervation (septal myocardial 6-[ 18 F]fluorodopamine-derived radioactivity; supine plasma norepinephrine). Severity of orthostatic hypotension did not differ between the levodopa-untreated and levodopa-treated groups with Parkinson disease and orthostatic hypotension (−52±6 [SEM] versus −49±5 mm Hg systolic). The 2 groups had similarly low reflexive cardiovagal gain (0.84±0.23 versus 1.33±0.35 ms/mm Hg during Valsalva; 0.43±0.09 versus 0.27±0.06 bpm/mm Hg during orthostasis); and had similarly attenuated reflexive sympathoneural responses (97±29 versus 71±23 pg/mL during orthostasis; −82±10 versus −73±8 mm Hg during Valsalva). In patients off levodopa, plasma norepinephrine was lower in those with (193±19 pg/mL) than without (348±46 pg/mL) orthostatic hypotension. Low values for reflexive cardiovagal gain, sympathoneural responses, and noradrenergic innervation were strongly related to orthostatic hypotension. Parkinson disease with orthostatic hypotension features reflexive cardiovagal and sympathoneural failure and cardiac and partial extracardiac sympathetic denervation, independent of levodopa treatment.

Clinical assessments of autonomic function often include tyramine (TYR) infusion. After uptake of TYR by sympathetic nerves via the cell membrane norepinephrine (NE) transporter and translocation of axoplasmic TYR into vesicles, NE exits the vesicles. Some of the NE enters the extracellular fluid and occupies adrenoceptors on cardiovascular smooth muscle cells, increasing blood pressure. A small proportion reaches the circulation, so that plasma NE concentrations increase (1)(2)(3). Jacob et al. (4) reported an ∼50-fold mean increase in plasma dopamine (DA) concentrations during intravenous TYR infusion, associated with “paradoxical” forearm vasodilation. We also noted high plasma DA concentrations in healthy volunteers during TYR infusion (5). When we assayed the catechol contents of the TYR infusate dispensed by our pharmacy [1 g/L (6.5 mmol/L)], we found that the infusate contained ∼50 μmol/L DA, corresponding to 0.7% contamination (6). Whether during TYR infusion such contamination could actually raise plasma DA concentrations was unclear, as was whether, while stored as is customary in solution at 4 °C, TYR could be converted to DA. The present study examined these possibilities. Solutions of TYR for infusion were prepared by the NIH Pharmaceutical Development Service, using TYR hydrochloride (Sigma) dissolved in sterile water, with pH ∼9. The solutions were stored either in a refrigerator at 4 °C or in an ultra-low temperature freezer at −70 °C for up to 9 months and then were assayed for catechol content, including DA. Infusate and arterial plasma concentrations of catechols were assayed (7), and hemodynamics were assessed before and during intravenous TYR infusion [6.5 μmol (1 mg)/min] in a total of 34 adults who underwent TYR infusion as part of autonomic function testing. Of the 34 participants, 6 were healthy volunteers, 13 were patients with chronic orthostatic intolerance, 9 had neurogenic orthostatic hypotension, 5 had …

Background Upper thoracic sympathectomy is used to treat several disorders. Sympathetic nerve fibers emanating from thoracic ganglia innervate the heart. Whether unilateral or bilateral upper thoracic sympathectomy affects cardiac sympathetic innervation in humans in vivo has been unclear. Objectives The purpose of this study was to assess whether thoracic sympathectomy decreases cardiac sympathetic innervation, as indicated by positron emission tomographic scanning after intravenous injection of the sympathoneural imaging agent 6-[ 18 F]fluorodopamine. Methods Nine patients with previous upper thoracic sympathectomies (four right-sided, one left-sided, four bilateral) underwent thoracic 6-[ 18 F]fluorodopamine scanning between 1 and 2 hours after injection of the imaging agent. In each case, a low rate of entry of norepinephrine into the arm venous drainage (norepinephrine spillover) verified upper limb sympathectomy. Data were compared with those from the interventricular septum of patients with cardiac sympathetic denervation associated with pure autonomic failure and from normal volunteers. Results All four patients with bilateral sympathectomy had low septal myocardial 6-[ 18 F]fluorodopamine-derived radioactivity (2,673 ± 92 nCi-kg/cc-mCi at an average of 89 minutes after injection) compared with normal volunteers (3,634 ± 311 nCi-kg/cc-mCi at 83 minutes, N=22, P = .007) and higher radioactivity than in patients with pure autonomic failure (1,320 ± 300 nCi-kg/cc-mCi at 83 minutes, N=7, P = .003). Patients with unilateral sympathectomy had normal 6-[ 18 F]fluorodopamine-derived radioactivity (3,971 ± 337 nCi-kg/cc-mCi at 87 minutes). Conclusions Bilateral upper thoracic sympathectomy partly decreases cardiac sympathetic innervation density.

Neuronal reuptake (uptake-1) constitutes the main route of inactivation of the sympathetic neurotransmitter norepinephrine in the heart and therefore contributes importantly to cardiac sympathetic neuroeffector function. In laboratory animals and in vitro preparations, half saturation of the transporter occurs at norepinephrine concentrations of 0.1 to 1 μmol/L. This study addressed whether endogenous norepinephrine can attain high enough plasma concentrations in humans to inhibit cardiac uptake-1. Patients with increased plasma norepinephrine levels due to pheochromocytoma were assessed by 6-[ 18 F]fluorodopamine positron emission tomography. Above an antecubital venous plasma concentration of 3 nmol/L (≈500 pg/mL), left ventricular myocardial 6-[ 18 F]fluorodopamine-derived radioactivity varied inversely with the logarithm of the plasma norepinephrine concentration ( r =−0.77, P 18 F]fluorodopamine-derived radioactivity. At sufficiently high plasma concentrations, endogenous norepinephrine can compete with sympathetic imaging agents for uptake-1. The results call for caution in drawing quantitative conclusions about uptake-1 in the setting of high circulating concentrations of endogenous norepinephrine.

beta-amyloid peptide (Abeta) has been implicated in the pathogenesis of Alzheimer disease and has been reported to induce apoptotic death in cell culture. Cysteine proteases, a family of enzymes known as caspases, mediate cell death in many models of apoptosis. Multiple caspases have been implicated in Abeta toxicity; these reports are conflicting. We show that treatment of cerebellar granule cells (CGC) with Abeta25-35 causes apoptosis associated with increased activity of caspases-2, -3 and -6. Selective inhibition of each of these three caspases provides significant protection against Abeta-mediated apoptosis. In contrast, no change in caspase-1 activity was seen after Abeta25-35 application, nor was inhibition of caspase-1 neuroprotective. Similar to CGC, cortical neuronal cultures treated with Abeta25-35 demonstrate increased caspase-3 activity but not caspase-1 activity. Furthermore, significant neuroprotection is elicited by selective inhibition of caspase-3 in cortical neurons administered Abeta25-35, whereas selective caspase-1 inhibition has no effect. Taken together, these findings indicate that multiple executioner caspases may be involved in neuronal apoptosis induced by Abeta.

Apoptosis is an important mechanism of physiological and pathological cell death. It is regulated by several gene products, including caspases and the bcl-2-like proteins, whose roles have been demonstrated in numerous systems. One of these is a model of cerebellar granule cells (CGCs) in which apoptosis is induced by acute removal of serum and depolarizing concentrations of potassium. Previous work by several authors showed that benzyloxycarbonyl-DEVD-fluoromethylketone, a somewhat selective caspase inhibitor, significantly protected CGCs from apoptosis; however, because this molecule targets multiple caspases, it is not known whether a single caspase is primarily responsible for effecting cell death in this model. We attempted to answer this question by cotransfecting CGCs with green fluorescent protein reporter and a hammerhead ribozyme directed against caspase-3 mRNA. Maximal protection by this ribozyme was observed after 24 hr of deprivation, at which time apoptosis was 18 ± 0.7% compared with 32 ± 2% in control cells. Significant protection was also observed with human inhibitor of apoptosis (IAP)-like protein–X-linked IAP, a specific inhibitor of caspase-3, -7, and -9, and with p35, a general caspase inhibitor. Overexpression of bcl-2 produced almost complete protection from apoptosis after 24 hr of serum–K+deprivation (5 ± 2 vs 44 ± 2% in control cells). These results confirm that caspases play an important role in CGC apoptosis and indicate that caspase-3 itself is a significant mediator of this process.

The CED-3-related cysteine proteases (CRCPs) have been implicated as mediators of apoptosis, primarily in hematogenous cell systems, but their role in neuronal apoptosis remains unclear. The present study examined the role of two CRCP families—CPP32- and interleukin-1β converting enzyme (ICE)-like cysteine proteases—in apoptosis of cerebellar granule cells (CGCs) caused by withdrawal of serum and/or potassium (K(+)). Serum deprivation potentiated apoptosis caused by K(+) withdrawal, reducing cell viability by approximately one half of control values after 12 hr as measured by calcein fluorescence. Cell death after serum/K(+) deprivation was significantly attenuated by the CPP32-like inhibitor z-DEVD-fmk; however, the ICE-like inhibitor z-YVAD-fmk had only slightly protective effects at the highest concentration used. Both inhibitors reduced CPP32-like activity directly in an in vitro fluorometric assay system, although z-DEVD-fmk showed much greater potency. K(+)and serum/K(+) deprivation each were accompanied by increased CPP32-like activity; however, ICE-like activity was absent after 12 hr of serum and/or K(+) deprivation. CPP32 mRNA levels were unchanged after K(+) deprivation but increased after serum and combined serum/K(+)withdrawal as measured by reverse transcription-PCR (RT-PCR), with peak values at 4 hr reaching 210 ± 37% and 269 ± 42% of control levels, respectively. In contrast, ICE mRNA was undetectable by RT-PCR. These results are consistent with the hypothesis that CPP32-like proteases play an important role in apoptosis of CGCs caused by deprivation of K(+) or serum/K(+).

Background: We used polymerase chain reaction to search for nucleic acid sequences of several viruses in DNA and RNA extracted from brain tissues of schizophrenic and control subjects. Methods: We extracted DNA and RNA templates from frozen brain specimens of 31 patients with schizophrenia and 23 nonschizophrenic control patients with other diseases. The extracts were subjected to polymerase chain reaction with oligonucleotide primers for 12 different viruses (cytomegalovirus, Epstein-Barr virus, herpes simplex virus type 1, human herpesvirus type 6, varicellazoster virus, measles virus, mumps virus, rubella virus, the picornavirus group, influenza A virus, human T-cell lymphotropic virus type I, and St Louis encephalitis virus), several of which have been suspected of involvement in schizophrenia. Nested primers were used to increase the sensitivity of the method. Results: No amplified nucleic acid sequences encoded by the selected viral genomes were detected in extracts of any brain specimens from either schizophrenic or control patients. Conclusions: These data agree with previous studies that failed to find sequences of a number of viruses in the cerebrospinal fluid or selected areas of the brains of schizophrenic patients. Additional efforts should be undertaken to identify other known and unknown pathogens in schizophrenia, sampling more areas of the brain from subjects with a variety of clinical types of schizophrenia.

Background Neurocardiogenic syncope with sympathoadrenal imbalance (SAI) is characterized by loss of consciousness preceded by a disproportionately greater increase in plasma epinephrine than norepinephrine. In SAI, forearm vascular resistance decreases, probably because of skeletal muscle vasodilation from beta-2 adrenoceptor activation by epinephrine. We hypothesized that a non-selective beta blocker, propranolol, would prevent syncope associated with SAI, by attenuating beta-2-receptor-mediated vasodilation. Methods Volunteer patients with recurrent neurocardiogenic syncope with SAI are participating in an ongoing randomized, double-blind, placebo-controlled, crossover trial at the NIH Clinical Center. Propranolol or placebo is administered orally every 6–8 hours for 3 days prior to tilt table testing at a dosage sufficient to reduce resting heart rate by 10%. Results Of 7 patients studied to date, all have had positive tilt tests while on placebo, and 6 have also had positive tests on propranolol. The one patient with a negative tilt test on propranolol did not develop SAI during upright tilt. Conclusions So far propranolol has not prevented tilt-induced neurocardiogenic syncope in most patients with SAI. When successful, propranolol may work through mechanisms other than blocking beta-adrenoceptors in skeletal muscle. Clinical Pharmacology & Therapeutics (2005) 77, P55–P55; doi: 10.1016/j.clpt.2004.12.100

Apoptotic cell death is often characterized by internucleosomal cleavage of genomic DNA, which exhibits a distinctive ladder upon electrophoresis. However, techniques used for the isolation and detection of DNA to demonstrate laddering may not be sufficiently sensitive, particularly when cleaved DNA is present at modest levels. We propose a new approach for isolating total cellular DNA using a silica-based resin that improves the resolution of DNA laddering. In addition, we introduce a rapid DNA labeling method that can increase the sensitivity of detecting DNA laddering. Each of these methods can be used for DNA from cell cultures or tissues.

Uptake-1, mediated by the cell membrane norepinephrine transporter (NET), constitutes the main route of inactivation of norepinephrine at sympathetic nerve terminals. In vitro, the NET can be saturated with a KM between 0.1 and 1 μmol/L. This study addressed whether endogenous norepinephrine levels can attain high enough plasma concentrations in humans to inhibit cardiac uptake-1. patients with pheochromocytoma, a catecholamine-secreting tumor, were imaged by 6-[18F]fluorodopamine positron emission tomography. Above 3 nmol/L (about 500 pg/ml) in antecubital venous plasma, left ventricular myocardial 6-[18F]fluorodopamine-derived radioactivity varied inversely with the logarithm of plasma norepinephrine concentration (R = −0.77, P