Parkinson Disease: US Federal Service

Solomon NP. · Research Speech-Language Pathologist, Army Audiology and Speech Center, Walter Reed Army Medical Center, Washington, DC 20307, USA. · Semin Speech Lang. · Pubmed #17117353 No free full text.

Abstract: Speech-language pathologists are likely to encounter patients who report symptoms of fatigue, but there are few clinical procedures to assess this phenomenon. Furthermore, it is difficult to determine whether fatigue contributes to a patient's dysphagia or dysarthria. This article reviews orofacial muscles, including the muscles of the tongue, lips, and cheeks, highlighting in particular their role in swallowing and speaking. It provides definitions of fatigue and describes assessment procedures. The author's research has focused on assessing fatigue, especially of the tongue, and elucidating the effects of exercising the tongue on speech and nonspeech tasks. Most of this work involves people who have Parkinson's disease and neurologically normal adults; results generally support heightened fatigue in Parkinson's disease. However, the effect of fatigue on functional activities remains unclear. Literature regarding the effects of orofacial fatigue on swallowing and speaking is notably sparse, but preliminary evidence indicates that these functions are rather robust.

Rouault TA, Cooperman S. · Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA. · Semin Pediatr Neurol. · Pubmed #17101452 No free full text.

Abstract: Brain iron uptake is regulated by the expression of transferrin receptor 1 in endothelial cells of the blood-brain barrier. Transferrin-bound iron in the systemic circulation is endocytosed by brain endothelial cells, and elemental iron is released to brain interstitial fluid, likely by the iron exporter, ferroportin. Transferrin synthesized by oligodendrocytes in the brain binds much of the iron that traverses the blood-brain barrier after oxidation of the iron, most likely by a glycophosphosinositide-linked ceruloplasmin found in astrocytic foot processes that ensheathe brain endothelial cells. Neurons acquire iron from diferric transferrin, but it is less clear how glial cells acquire iron. In aging mammals, iron accumulates in the basal ganglia, and iron accumulation is believed to contribute to neurodegenerative diseases, including Parkinson and Alzheimer disease. Here we consider the possibility that iron accumulations, which are often thought to facilitate free radical generation and oxidative damage, may contain insoluble iron that is unavailable for cellular use, and the pathology associated with iron accumulations may result from functional iron deficiency in some diseases.

Hardy J, Cai H, Cookson MR, Gwinn-Hardy K, Singleton A. · Laboratory of Neurogenetics, National Institute on Aging, Porter Neuroscience Building, 35 Convent Drive, Bethesda, MD 20892, USA. · Ann Neurol. · Pubmed #17068789 No free full text.

Abstract: Until 10 years ago, conventional wisdom held that Parkinson's disease was not a genetic disorder. Since that time, there have been a plethora of genetic findings, culminating in the cloning of several genes that derive from the loci given the nomenclature PARK1-PARK12 (OMIM 168600). Recently, these research findings have begun to impact clinical practice, and this impact is likely to increase. The primary purpose of this article is to outline these genetic advances, discuss their importance for current practice in clinical and related settings, and outline briefly how they are influencing research into the causes of and possible future treatments for this prevalent disorder.

Mattson MP. · Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, Maryland 21224, USA. · Antioxid Redox Signal. · Pubmed #17034345 No free full text.

Abstract: When subjected to excessive oxidative stress, neurons may respond adaptively to overcome the stress, or they may activate a programmed cell death pathway called apoptosis. Apoptosis is characterized by alterations in mitochondria and the endoplasmic reticulum and activation of cysteine proteases called caspases. Increasing evidence suggests that apoptotic biochemical cascades are involved in the dysfunction and death of neurons in neurodegenerative disorders such as Alzheimer's, Parkinson, and Huntington's diseases. Studies of normal aging, of genetic mutations that cause disease, and of environmental factors that affect disease risk are revealing cellular and molecular alterations that may cause excessive oxidative stress and trigger neuronal apoptosis. Accumulation of self-aggregating proteins such as amyloid beta-peptide, tau, alpha-synuclein, and huntingtin may be involved in apoptosis both upstream and downstream of oxidative stress. Membrane-associated oxidative stress resulting in perturbed lipid metabolism and disruption of cellular calcium homeostasis may trigger apoptosis in several different neurodegenerative disorders. Counteracting neurodegenerative processes are an array of mechanisms including neurotrophic factor signaling, antioxidant enzymes, protein chaperones, antiapoptotic proteins, and ionostatic systems. Emerging findings suggest that the resistance of neurons to death during aging can be enhanced by modifications of diet and lifestyle.

Goldstein DS. · Clinical Neurocardiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-1620, USA. · J Neural Transm Suppl. · Pubmed #17017550 No free full text.

Abstract: This chapter provides an update about cardiovascular aspects of Parkinson disease (PD), with the following topics: (1) Orthostatic hypotension (OH) as an early finding in PD; (2) neurocirculatory abnormalities in PD + OH independent of levodopa treatment; (3) cardiac and extracardiac noradrenergic denervation in PD + OH; (4) progressive loss of cardiac sympathetic innervation in PD without OH.

Sidransky E. · Section on Molecular Neurogenetics, Clinical Genetics Branch, National Human Genome Research Institute, Bethesda, MD 20892-3708, USA. · Clin Genet. · Pubmed #16965318 No free full text.

Abstract: While genetic diseases are generally classified as being either 'simple' monogenic or 'complex' polygenic, the distinction between Mendelian and complex disorders is becoming increasingly blurred. Mendelian disorders may demonstrate qualities more typical of multifactorial diseases through shared clinical presentations, the effect of genetic modifiers, moonlighting proteins, synergistic heterozygosity, disease manifestations in heterozygotes and situations where heterozygosity for a 'simple' disorder proves to be a risk factor for seemingly unrelated complex diseases. A recent example of the last instance is the observation that mutations in glucocerebrosidase, the enzyme deficient in Gaucher disease, may be a risk factor for the development of Parkinson disease and other synucleinopathies. Insights gleaned from the study of Mendelian disorders may ultimately lead to a better understanding of factors influencing complex diseases.

Gasior M, Rogawski MA, Hartman AL. · Epilepsy Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892-3702, USA. · Behav Pharmacol. · Pubmed #16940764 links to  free full text

Abstract: The ketogenic diet has been in clinical use for over 80 years, primarily for the symptomatic treatment of epilepsy. A recent clinical study has raised the possibility that exposure to the ketogenic diet may confer long-lasting therapeutic benefits for patients with epilepsy. Moreover, there is evidence from uncontrolled clinical trials and studies in animal models that the ketogenic diet can provide symptomatic and disease-modifying activity in a broad range of neurodegenerative disorders including Alzheimer's disease and Parkinson's disease, and may also be protective in traumatic brain injury and stroke. These observations are supported by studies in animal models and isolated cells that show that ketone bodies, especially beta-hydroxybutyrate, confer neuroprotection against diverse types of cellular injury. This review summarizes the experimental, epidemiological and clinical evidence indicating that the ketogenic diet could have beneficial effects in a broad range of brain disorders characterized by the death of neurons. Although the mechanisms are not yet well defined, it is plausible that neuroprotection results from enhanced neuronal energy reserves, which improve the ability of neurons to resist metabolic challenges, and possibly through other actions including antioxidant and anti-inflammatory effects. As the underlying mechanisms become better understood, it will be possible to develop alternative strategies that produce similar or even improved therapeutic effects without the need for exposure to an unpalatable and unhealthy, high-fat diet.

Kleiner-Fisman G, Herzog J, Fisman DN, Tamma F, Lyons KE, Pahwa R, Lang AE, Deuschl G. · Parkinson's Disease Research Education and Clinical Center, Philadelphia VA Hospital, Philadelphia, Pennsylvania 19104, USA. · Mov Disord. · Pubmed #16892449 No free full text.

Abstract: Subthalamic nucleus (STN) deep brain stimulation (DBS) is currently the most common therapeutic surgical procedure for patients with Parkinson's disease (PD) who have failed medical management. However, a recent summary of clinical evidence on the effectiveness of STN DBS is lacking. We report the results of such a systematic review and meta-analysis. A comprehensive review of the literature using Medline and Ovid databases from 1993 until 2004 was conducted. Estimates of change in absolute Unified Parkinson's Disease Rating Scale (UPDRS) scores after surgery were generated using random-effects models. Sources of heterogeneity were explored with meta-regression models, and the possibility of publication bias was evaluated. Patient demographics, reduction in medication requirements, change in dyskinesia, daily offs, quality of life, and a ratio of postoperative improvement from stimulation compared to preoperative improvement by medication from each study were tabulated and average scores were calculated. Adverse effects from each study were summarized. Thirty-seven cohorts were included in the review. Twenty-two studies with estimates of standard errors were included in the meta-analysis. The estimated decreases in absolute UPDRS II (activities of daily living) and III (motor) scores after surgery in the stimulation ON/medication off state compared to preoperative medication off state were 13.35 (95% CI: 10.85-15.85; 50%) and 27.55 (95% CI: 24.23-30.87; 52%), respectively. Average reduction in L-dopa equivalents following surgery was 55.9% (95% CI: 50%-61.8%). Average reduction in dyskinesia following surgery was 69.1% (95% CI: 62.0%-76.2%). Average reduction in daily off periods was 68.2% (95% CI: 57.6%-78.9%). Average improvement in quality of life using PDQ-39 was 34.5% +/- 15.3%. Univariable regression showed improvements in UPDRS III scores were significantly greater in studies with higher baseline UPDRS III off scores, increasing disease duration prior to surgery, earlier year of publication, and higher baseline L-dopa responsiveness. Average baseline UPDRS III off scores were significantly lower (i.e., suggesting milder disease) in later than in earlier studies. In multivariable regression, L-dopa responsiveness, higher baseline motor scores, and disease duration were independent predictors of greater change in motor score. No evidence of publication bias in the available literature was found. The most common serious adverse event related to surgery was intracranial hemorrhage in 3.9% of patients. Psychiatric sequelae were common. Synthesis of the available literature indicates that STN DBS improves motor activity and activities of daily living in advanced PD. Differences between available studies likely reflect differences in patient populations and follow-up periods. These data provide an estimate of the magnitude of the treatment effects and emphasize the need for controlled and randomized studies.

Goldstein DS, Eisenhofer G, Kopin IJ. · Clinical Neurocardiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892-1620, USA. · Cell Mol Neurobiol. · Pubmed #16871444 No free full text.

Abstract: 1. Discoveries, insights, and concepts that Julius Axelrod introduced about the disposition and metabolism of catecholamines provided the scientific basis and spurred the development of clinical catecholamine neurochemistry. 2. Here, we provide examples of this aspect of Axelrod's scientific legacy.

Voon V, Kubu C, Krack P, Houeto JL, Tröster AI. · Department of Psychiatry, Toronto Western Hospital, Toronto, Canada. · Mov Disord. · Pubmed #16810676 No free full text.

Abstract: Parkinson's disease (PD) is a neurodegenerative disorder characterized by motor, cognitive, neuropsychiatric, autonomic, and other nonmotor symptoms. The efficacy of deep brain stimulation (DBS) for the motor symptoms of advanced PD is well established. However, the effects of DBS on the cognitive and neuropsychiatric symptoms are less clear. The neuropsychiatric aspects of DBS for PD have recently been of considerable clinical and pathophysiological interest. As a companion to the preoperative and postoperative sections of the DBS consensus articles, this article reviews the published literature on the cognitive and neuropsychiatric aspects of DBS for PD. The majority of the observed neuropsychiatric symptoms are transient, treatable, and potentially preventable. Outcome studies, methodological issues, pathophysiology, and preoperative and postoperative management of the cognitive and neuropsychiatric aspects and complications of DBS for PD are discussed.

McNamara P, Durso R. · Department of Neurology, Boston University School of Medicine, Boston VA Healthcare System, Boston, MA 02130, USA. · Behav Neurol. · Pubmed #16720959 No free full text.

Abstract: Many patients with Parkinson's Disease (PD) experience significant cognitive and mood impairment -even early in the course of the disease. These mental impairments are only partially responsive to levodopa treatment and are often as disabling as the motor impairment, particularly in mid and late stages of the disease. Investigators have recently begun a search for new agents that can effectively treat mental dysfunction of PD. Although there have been only a handful of properly controlled clinical trials of interventions targeted at amelioration of mental dysfunction in PD, progress has been made. Based on the available evidence, targeting catecholaminergic and cholinergic function may be an effective strategy for amelioration of cognitve, mood and psychiatric disturbances in PD.

Obering CD, Chen JJ, Swope DM. · School of Pharmacy, University of Missouri-Kansas City, and the Department of Pharmacy, Kansas City Veterans Affairs Medical Center, Kansas City, Missouri 64108, USA. · Pharmacotherapy. · Pubmed #16716137 No free full text.

Abstract: As Parkinson's disease progresses, fluctuations between akinesia, or hypomobility ("off" times), and mobility ("on" times) increase in frequency despite optimized pharmacotherapy. Motor fluctuations include predictable shortening of therapeutic effects, nocturnal or early morning akinesia, random hypomobility, and delayed mobility (variable responses to individual doses of drugs). Current oral antiparkinson drugs are inadequate for rapid and consistent relief of symptoms during hypomobility. Apomorphine, an injectable dopamine agonist recently introduced in the United States, is indicated for the management of hypomobility associated with advanced Parkinson's disease. Subcutaneous apomorphine is effective for rapid and consistent rescue from hypomobility, with a magnitude of motor improvement similar to that of levodopa. The effect begins within 20 minutes after dosing and lasts approximately 100 minutes. Therapeutic rescue doses are 2-6 mg, and patients typically require approximately three rescue doses/day. Apomorphine is associated with a clinically significant potential to cause nausea and orthostatic hypotension. These potential effects can be managed with antiemetic prophylaxis and appropriate determination of the therapeutic rescue dose.

Cropley VL, Fujita M, Innis RB, Nathan PJ. · Department of Physiology, Behavioural Neuroscience Laboratory, Monash Centre for Brain and Behaviour, Monash University, Victoria, Australia. · Biol Psychiatry. · Pubmed #16682268 No free full text.

Abstract: Molecular imaging with positron emission tomography (PET) and single photon emission computed tomography (SPECT) has recently been used to examine dopamine (DA) function and its relationship with cognition in human subjects. This article will review PET and SPECT studies that have explored the relationship between cognitive processes and components of the DA system (pre-, intra-, and postsynaptic) in healthy and patient populations such as Parkinson's disease (PD), schizophrenia, Huntington's disease, and aging. It is demonstrated that DA activity modulates a range of frontal executive-type cognitive processes such as working memory, attentional functioning, and sequential organization, and alterations of DA within the fronto-striato-thalamic circuits might contribute to the cognitive impairments observed in PD, schizophrenia, and normal aging. Although associations between DA and cognitive measures need to be considered within the context of fronto-striato-thalamic circuitry, it is suggested that striatal (especially caudate) DA activity, particularly via D2 receptors, might be important for response inhibition, temporal organization of material, and motor performance, whereas cortical DA transmission via D1 receptors might be important for maintaining and representing on-going behavior.

Piper M, Abrams GM, Marks WJ. · Parkinsons Disease Research, Education, & Clinical Center, San Francisco Veterans Affairs Medical Center, San Francisco, CA 94121, USA. · NeuroRehabilitation. · Pubmed #16340102 No free full text.

Abstract: Abnormality in gait is a cardinal feature of Parkinson's disease. Walking is characterized by relatively preserved sequencing of trunk and limb movements, but diminished velocity, shortened stride length, increased base, and diminished double stance support time. The principle problem producing the gait abnormalities is dopamine deficiency, which is hypothesized to disrupt pallido-thalamic modulation of cortical motor regions that automatically regulate walking. Deep brain stimulation currently is directed at either the globus pallidum internus (GPi) or subthalamic nucleus (STN) and improves many of the abnormal characteristics of parkinsonian gait with efficacy similar to dopamine replacement. The optimal target for stimulation remains uncertain and is currently being addressed in a large VA cooperative study. Our studies show that unilateral stimulation of GPi or STN improves gait to a similar extent. Functional and quantitative gait analyses confirm sustained improvement in gait dynamics with bilateral stimulation for periods for more than several years. Parkinsonian gait is also improved with rehabilitation training, primarily using external visual or auditory cues. The combination of deep brain stimulation, pharmacotherapy, and rehabilitation training may result in more effective comprehensive approaches to the reduced mobility associated with Parkinson's disease.

Trail M, Fox C, Ramig LO, Sapir S, Howard J, Lai EC. · Parkinson's Disease Research, Education and Clinical Center, Michael E. DeBakey VA Medical Center, Houston, TX 77030, USA. · NeuroRehabilitation. · Pubmed #16340101 No free full text.

Abstract: Researchers estimate that 89% of people with Parkinson's disease (PD) have a speech or voice disorder including disorders of laryngeal, respiratory, and articulatory function. Despite the high incidence of speech and voice impairment, studies suggest that only 3-4% of people with PD receive speech treatment. The authors review the literature on the characteristics and features of speech and voice disorders in people with PD, the types of treatment techniques available, including medical, surgical, and behavioral therapies, and provide recommendations for the current efficacy of treatment interventions and directions of future research.

Veazey C, Aki SO, Cook KF, Lai EC, Kunik ME. · Houston Center for Quality of Care and Utilization Studies, Veterans Affairs Medical Center (152), 2002 Holcombe Blvd., Houston, TX 77030, USA. · J Neuropsychiatry Clin Neurosci. · Pubmed #16179652 links to  free full text

Abstract: Parkinson's disease (PD) is a progressive neurological condition with debilitating symptoms, and depression is a common comorbid condition of this disease. The authors review existing literature on the prevalence and treatment of depression in PD. Prevalence estimates of depression vary widely, ranging from 7%-76%. This variation is due to inconsistent methodology. Treatment options for depression in PD include medication therapy, electroconvulsive therapy (ECT), and psychotherapy. There are few randomized controlled trials of these treatment options. The authors argue for more systematic and controlled research examining both the prevalence and treatment of depression in PD.

Pal PK, Netravathi M. · Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore 560029. · J Indian Med Assoc. · Pubmed #16173294 No free full text.

Abstract: Neurodegenerative disorders result from premature progressive degeneration of specific neurons, and manifest as diseases or syndromes with varied combinations of cognitive, motor, sensory and autonomic dysfunctions. The management involves pharmacotherapy as well as non-pharmacological measures and also to lessen the burden of the care-givers. The medications available for medical treatment are: Levodopa, dopamine agonists, amantadine, anticholinergics, enzyme inhibitors, etc. Advanced Parkinson's disease is concerned with management of motor complications and non-motor complications. Recently surgical treatment is a great option for managing motor complication. Orthostatic hypotension, gait distiurbances, emotional and psychiatric problems, sleep disturbances can be managed and had been discussed in brief. Currently there is no medication available for the cure of Alzheimer's disease. The specific medications claimed to improve patient's well being and cognition include cholinesterase inhibitors, N-methyl-D-aspartate receptor antagonist, anti-oxidants, and anti-amyloid therapy. While medical and surgical treatments for Parkinson's disease have revolutionised the management, still drug therapy for Alzheimer's disease is dismal.

Zheng Z, Yenari MA. · Dept. of Neurology, University of California, The San Francisco Veterans Affairs Medical Center, San Francisco, CA 94121, USA. · Front Biosci. · Pubmed #16146762 No free full text.

Abstract: The 70-kDa heat shock proteins (HSP70s) are well-studied and characterized heat shock proteins (HSPs). They constitute essential components of a quality control system of protein synthesis, and function as molecular chaperones to prevent proteins from misfolding and aggregating during both de novo synthesis and under conditions of stress. Moreover, it is now well established that HSP70s play important cytoprotective roles in various pathological settings. Recognition of molecular chaperone and cytoprotective functions of HSP70s is fostering active investigations into the potential of HSP70s as therapeutic targets at the laboratory level. Gaining insight into these recent advances may have profound implications in the development of HSP70-based clinical studies.

Romeo MJ, Espina V, Lowenthal M, Espina BH, Petricoin EF, Liotta LA. · Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA. · Expert Rev Proteomics. · Pubmed #15966853 No free full text.

Abstract: Proteomic analysis is not limited to the analysis of serum or tissues. Synovial, peritoneal, pericardial and cerebrospinal fluid represent unique proteomes for disease diagnosis and prognosis. In particular, cerebrospinal fluid serves as a rich source of putative biomarkers that are not solely limited to neurologic disorders. Peptides, proteolytic fragments and antibodies are capable of crossing the blood-brain barrier, thus providing a repository of pathologic information. Proteomic technologies such as immunoblotting, isoelectric focusing, 2D gel electrophoresis and mass spectrometry have proven useful for deciphering this unique proteome. Cerebrospinal fluid proteins are generally less abundant than their corresponding serum counterparts, necessitating the development and use of sensitive analytical techniques. This review highlights some of the promising areas of cerebrospinal fluid proteomic research and their clinical applications.

Singleton AB. · Molecular Genetics Unit, National Institute on Aging, National Institutes of Health, Porter Neuroscience Research Center, Room 1A1000, MSC3707, 35 Lincoln Drive, Bethesda, MD 20892, USA. · Trends Neurosci. · Pubmed #15955578 No free full text.

Abstract: The past decade has been a fruitful one for geneticists involved in Parkinson's disease (PD) research. The initial hurdle of identifying the first gene underlying parkinsonism was cleared with apparent ease in 1997 and four additional genes have since been found to contain mutations causing this disorder. Driving this research is the belief that these data will highlight disease mechanisms and directly implicate a pathway amenable to therapeutic intervention. This article will focus on recent genetic advances in the field, focusing on data that suggest alpha-synuclein expression is key in the etiology of PD. In addition, it will discuss the recent identification of LRRK2 mutation as a cause of PD and the potential of this finding to provide further insight into disease.

Cookson MR. · Cell Biology Section, Laboratory of Neurogenetics, National Institute on Aging, Bethesda, Maryland 20892, USA. · Annu Rev Biochem. · Pubmed #15952880 No free full text.

Abstract: Several genes have been identified for monogenic disorders that variably resemble Parkinson's disease. Dominant mutations in the gene encoding alpha-synuclein enhance the propensity of this protein to aggregate. As a consequence, these patients have a widespread disease with protein inclusion bodies in several brain areas. In contrast, mutations in several recessive genes (parkin, DJ-1, and PINK1) produce neuronal cell loss but generally without protein aggregation pathology. Progress has been made in understanding some of the mechanisms of toxicity: Parkin is an E3 ubiquitin ligase and DJ-1 and PINK1 appear to protect against mitochondrial damage. However, we have not yet fully resolved how the recessive genes relate to alpha-synuclein, or whether they represent different ways to induce a similar phenotype.

Solomon NP. · Army Audiology & Speech Center, Walter Reed Army Medical Center, Washington, DC 20307, USA. · Int J Orofacial Myology. · Pubmed #15832858 No free full text.

Abstract: Assessment of nonspeech tongue function is common in speech-language pathology. This paper reviews techniques used to determine tongue strength and endurance, and describes a constant-effort task. These techniques are intended to reveal and quantify the presence of weakness or fatigue of the tongue. The consequences of performing these tasks with and without a bite block, used to fix jaw position, are considered. Whether nonspeech tongue impairment is associated with speech dysfunction in Parkinson's disease is another topic of interest. Past studies indicated reduced tongue strength and endurance in Parkinson's disease, but these measures did not correlate with speech measures. It was hypothesized that weakness and fatigue need to be impaired to a "critical" level before speech is perceptibly affected. To examine whether experimentally induced tongue fatigue affects speech, normal speakers performed prolonged strenuous tongue exercise. Speech deteriorated following these exercises. A new investigation examines whether 1 hour of speech-like tongue exercise (rapid syllable repetitions) affects dysarthric speech. Preliminary data from 6 participants with Parkinson's disease, 1 person with bulbar ALS, and 6 neurologically normal control subjects indicate that sentences sound more precise but less natural after the exercises. Surprisingly, results did not differ significantly between the groups. Continued collection of data and refinement of tasks will contribute to our understanding of the potential relationships between weakness, fatigue, and speech.

Jezior MR, Kent SM, Atwood JE. · Captain, US Army Medical Corps, Cardiology Service, Walter Reed Army Medical Center, Washington, DC 20307, USA. · Chest. · Pubmed #15821231 links to  free full text

Abstract: ECG changes during exercise stress testing, such as false-positive ST-segment depression and disappearance of the delta wave, are reported in patients with the Wolff-Parkinson-White (WPW) pattern. We present a case of exercise testing in a 53-year-old man with WPW syndrome with ischemic-appearing ECG changes and normal nuclear stress perfusion study findings who was thought to be at clinically low risk for having significant coronary disease. A literature review is discussed. Although ST-segment depression typical for ischemia occurs in half of the patients in whom WPW syndrome is reported, exercise testing is still an important tool in their evaluation. Data other than ECG response can be interpreted in the context of clinical history and physical examination findings to stratify the risk of coronary disease. Complete and sudden disappearance of the delta wave has been seen during exercise in 20% of patients with WPW syndrome and can identify those who are at low risk for sudden arrhythmic death.

Plowman BK, Boggie DT, Morreale AP, Schaefer MG, Delattre ML, Chan H. · Veterans Affairs San Diego Healthcare System (VASDHS), San Diego, CA 92161, USA. · Am J Health Syst Pharm. · Pubmed #15745920 No free full text.

This publication has no abstract.

Mattson MP, Duan W, Wan R, Guo Z. · Laboratory of Neurosciences, National Institute on Aging Gerontology Research Center, Baltimore, Maryland 21224, USA. · NeuroRx. · Pubmed #15717011 links to  free full text

Abstract: It is well established that when most types of cells, including neurons, are exposed to a mild stress they increase their ability to resist more severe stress. This "preconditioning" phenomenon involves up-regulation of genes that encode cytoprotective proteins such as heat-shock proteins and growth factors. We found that a similar beneficial cellular stress response can be induced in neurons throughout the brain by a "meal-skipping" dietary restriction (DR) regimen in rats and mice. DR is effective in protecting neurons and improving functional outcome in models of stroke, Alzheimer's, Parkinson's and Huntington's diseases. DR induces an increase in the levels of brain-derived neurotrophic factor (BDNF) and heat-shock proteins in neurons. DR also stimulates neurogenesis in the hippocampus, and BDNF plays a role in this effect of DR. Physical exercise and environmental enrichment are two other manipulations that have been shown to induce BDNF expression in the brain, presumably because it is a mild cellular stress. When taken together with epidemiological and clinical studies in humans, the data from animal studies suggest that it may be possible to reduce the risk for age-related neurodegenerative disorders through dietary and behavioral modifications that act by promoting neuronal plasticity and survival.