NobleBlocks

VA Pacific Islands Health Care System

Hospital / health systemHonolulu, United States

Research output, citation impact, and the most-cited recent papers from VA Pacific Islands Health Care System (United States). Aggregated across the NobleBlocks index of 300M+ scholarly works.

Total works
426
Citations
32.2K
h-index
90
i10-index
365
Also known as
VA Pacific Islands Health Care System

Top-cited papers from VA Pacific Islands Health Care System

Rotenone, Paraquat, and Parkinson’s Disease
Caroline M. Tanner, Freya Kamel, G. Webster Ross, Jane A. Hoppin +4 more
2011· Environmental Health Perspectives1.4Kdoi:10.1289/ehp.1002839

BACKGROUND: Mitochondrial dysfunction and oxidative stress are pathophysiologic mechanisms implicated in experimental models and genetic forms of Parkinson's disease (PD). Certain pesticides may affect these mechanisms, but no pesticide has been definitively associated with PD in humans. OBJECTIVES: Our goal was to determine whether pesticides that cause mitochondrial dysfunction or oxidative stress are associated with PD or clinical features of parkinsonism in humans. METHODS: We assessed lifetime use of pesticides selected by mechanism in a case-control study nested in the Agricultural Health Study (AHS). PD was diagnosed by movement disorders specialists. Controls were a stratified random sample of all AHS participants frequency-matched to cases by age, sex, and state at approximately three controls:one case. RESULTS: In 110 PD cases and 358 controls, PD was associated with use of a group of pesticides that inhibit mitochondrial complex I [odds ratio (OR)=1.7; 95% confidence interval (CI), 1.0-2.8] including rotenone (OR=2.5; 95% CI, 1.3-4.7) and with use of a group of pesticides that cause oxidative stress (OR = 2.0; 95% CI, 1.2-3.6), including paraquat (OR=2.5; 95% CI, 1.4-4.7). CONCLUSIONS: PD was positively associated with two groups of pesticides defined by mechanisms implicated experimentally-those that impair mitochondrial function and those that increase oxidative stress-supporting a role for these mechanisms in PD pathophysiology.

Prevalence of Parkinson’s disease across North America
Connie Marras, James C. Beck, James H. Bower, Eric Roberts +4 more
2018· npj Parkinson s Disease1.0Kdoi:10.1038/s41531-018-0058-0

Estimates of the prevalence of Parkinson's disease in North America have varied widely and many estimates are based on small numbers of cases and from small regional subpopulations. We sought to estimate the prevalence of Parkinson's disease in North America by combining data from a multi-study sampling strategy in diverse geographic regions and/or data sources. Five separate cohort studies in California (2), Minnesota (1), Hawaii USA (1), and Ontario, Canada (1) estimated the prevalence of PD from health-care records (3), active ascertainment through facilities, large group, and neurology practices (1), and longitudinal follow-up of a population cohort (1). US Medicare program data provided complementary estimates for the corresponding regions. Using our age- and sex-specific meta-estimates from California, Minnesota, and Ontario and the US population structure from 2010, we estimate the overall prevalence of PD among those aged ≥45 years to be 572 per 100,000 (95% confidence interval 537-614) that there were 680,000 individuals in the US aged ≥45 years with PD in 2010 and that that number will rise to approximately 930,000 in 2020 and 1,238,000 in 2030 based on the US Census Bureau population projections. Regional variations in prevalence were also observed in both the project results and the Medicare-based calculations with which they were compared. The estimates generated by the Hawaiian study were lower across age categories. These estimates can guide health-care planning but should be considered minimum estimates. Some heterogeneity exists that remains to be understood.

Past, present, and future of Parkinson's disease: A special essay on the 200th Anniversary of the Shaking Palsy
José Á. Obeso, María Stamelou, Christopher G. Goetz, Werner Poewe +4 more
2017· Movement Disorders838doi:10.1002/mds.27115

This article reviews and summarizes 200 years of Parkinson's disease. It comprises a relevant history of Dr. James Parkinson's himself and what he described accurately and what he missed from today's perspective. Parkinson's disease today is understood as a multietiological condition with uncertain etiopathogenesis. Many advances have occurred regarding pathophysiology and symptomatic treatments, but critically important issues are still pending resolution. Among the latter, the need to modify disease progression is undoubtedly a priority. In sum, this multiple-author article, prepared to commemorate the bicentenary of the shaking palsy, provides a historical state-of-the-art account of what has been achieved, the current situation, and how to progress toward resolving Parkinson's disease. © 2017 International Parkinson and Movement Disorder Society.

Association of Coffee and Caffeine Intake With the Risk of Parkinson Disease
G. Webster Ross
2000· JAMA793doi:10.1001/jama.283.20.2674

CONTEXT: The projected expansion in the next several decades of the elderly population at highest risk for Parkinson disease (PD) makes identification of factors that promote or prevent the disease an important goal. OBJECTIVE: To explore the association of coffee and dietary caffeine intake with risk of PD. DESIGN, SETTING, AND PARTICIPANTS: Data were analyzed from 30 years of follow-up of 8004 Japanese-American men (aged 45-68 years) enrolled in the prospective longitudinal Honolulu Heart Program between 1965 and 1968. MAIN OUTCOME MEASURE: Incident PD, by amount of coffee intake (measured at study enrollment and 6-year follow-up) and by total dietary caffeine intake (measured at enrollment). RESULTS: During follow-up, 102 men were identified as having PD. Age-adjusted incidence of PD declined consistently with increased amounts of coffee intake, from 10.4 per 10,000 person-years in men who drank no coffee to 1.9 per 10,000 person-years in men who drank at least 28 oz/d (P<.001 for trend). Similar relationships were observed with total caffeine intake (P<.001 for trend) and caffeine from non-coffee sources (P=.03 for trend). Consumption of increasing amounts of coffee was also associated with lower risk of PD in men who were never, past, and current smokers at baseline (P=.049, P=.22, and P=.02, respectively, for trend). Other nutrients in coffee, including niacin, were unrelated to PD incidence. The relationship between caffeine and PD was unaltered by intake of milk and sugar. CONCLUSIONS: Our findings indicate that higher coffee and caffeine intake is associated with a significantly lower incidence of PD. This effect appears to be independent of smoking. The data suggest that the mechanism is related to caffeine intake and not to other nutrients contained in coffee. JAMA. 2000;283:2674-2679.

Association of olfactory dysfunction with risk for future Parkinson's disease
G. Webster Ross, Helen Petrovitch, Robert D. Abbott, Caroline M. Tanner +4 more
2007· Annals of Neurology738doi:10.1002/ana.21291

OBJECTIVE: Although olfactory dysfunction is commonly associated with Parkinson's disease (PD), it is not known whether such dysfunction can predate the onset of clinical PD in a community-based population. This study examines the association of olfactory dysfunction with future development of PD in Honolulu-Asia Aging Study cohort members METHODS: Olfaction was assessed from 1991 to 1996 in 2,267 men in the Honolulu-Asia Aging Study aged 71 to 95 years who were free of clinical PD and dementia at the time of olfaction testing. Participants were followed for up to 8 years for incident PD RESULTS: In the course of follow-up, 35 men were diagnosed with PD (24.6/10,000 person-years). The average age at the time of diagnosis was 82.9 +/- 3.8 (range, 76-93) years, and the average time to a diagnosis was 4.0 +/- 1.9 (range, 1-8) years. During the first 4 years of follow-up, age-adjusted incidence of PD declined from 54.5/10,000 person-years in the lowest quartile of odor identification to 26.6, 8.2, and 8.4/10,000 person-years in the second, third, and fourth quartiles, respectively (p < 0.001 for trend). After adjustment for age and other potential confounders, the odds ratios for PD in the lowest quartile was 5.2 (95% confidence interval, 1.5-25.6) compared with the top two quartiles. This relation was not evident beyond 4 years of follow-up. INTERPRETATION: Impaired olfaction can predate clinical PD in men by at least 4 years and may be a useful screening tool to detect those at high risk for development of PD in later life.

Freeze, Flight, Fight, Fright, Faint: Adaptationist Perspectives on the Acute Stress Response Spectrum
H. Stefan Bracha
2004· CNS Spectrums462doi:10.1017/s1092852900001954

This article reviews the existing evolutionary perspectives on the acute stress response habitual faintness and blood-injection-injury type-specific phobia (BIITS phobia). In this article, an alternative evolutionary perspective, based on recent advances in evolutionary psychology, is proposed. Specifically, that fear-induced faintness (eg, fainting following the sight of a syringe, blood, or following a trivial skin injury) is a distinct Homo sapiens-specific extreme-stress survival response to an inescapable threat. The article suggests that faintness evolved in response to middle paleolithic intra-group and inter-group violence (of con-specifics) rather than as a pan-mammalian defense response, as is presently assumed. Based on recent literature, freeze, flight, fight, fright, faint provides a more complete description of the human acute stress response sequence than current descriptions. Faintness, one of three primary physiological reactions involved in BIITS phobia, is extremely rare in other phobias. Since heritability estimates are higher for faintness than for fears or phobias, the author suggests that trait-faintness may be a useful complement to trait-anxiety as an endophenotype in research on the human fear circuitry. Some implications for the forthcoming Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition as well as for clinical, health services, and transcriptomic research are briefly discussed.

Pesticide Exposure and Self-reported Parkinson's Disease in the Agricultural Health Study
Freya Kamel, Caroline M. Tanner, David M. Umbach, Jane A. Hoppin +4 more
2006· American Journal of Epidemiology342doi:10.1093/aje/kwk024

Previous studies based on limited exposure assessment have suggested that Parkinson's disease (PD) is associated with pesticide exposure. The authors used data obtained from licensed private pesticide applicators and spouses participating in the Agricultural Health Study to evaluate the relation of self-reported PD to pesticide exposure. Cohort members, who were enrolled in 1993-1997, provided detailed information on lifetime pesticide use. At follow-up in 1999-2003, 68% of the cohort was interviewed. Cases were defined as participants who reported physician-diagnosed PD at enrollment (prevalent cases, n = 83) or follow-up (incident cases, n = 78). Cases were compared with cohort members who did not report PD (n = 79,557 at enrollment and n = 55,931 at follow-up). Incident PD was associated with cumulative days of pesticide use at enrollment (for highest quartile vs. lowest, odds ratio (OR) = 2.3, 95% confidence interval: 1.2, 4.5; p-trend = 0.009), with personally applying pesticides more than half the time (OR = 1.9, 95% confidence interval: 0.7, 4.7), and with some specific pesticides (ORs > or = 1.4). Prevalent PD was not associated with overall pesticide use. This study suggests that exposure to certain pesticides may increase PD risk. Findings for specific chemicals may provide fruitful leads for further investigation.

Brief treatment for elementary school children with disaster‐related posttraumatic stress disorder: A field study
Claude M. Chemtob, Joanne P. Nakashima, John G. Carlson
2001· Journal of Clinical Psychology299doi:10.1002/jclp.1131

Effective psychological intervention is needed to help children recover from disaster-related posttraumatic stress disorder (PTSD). This controlled study evaluated the effectiveness of a brief intervention for disaster-related PTSD. At one-year follow-up of a prior intervention for disaster-related symptoms, some previously treated children were still suffering significant trauma symptoms. Using a randomized lagged-groups design, we provided three sessions of Eye Movement Desensitization and Reprocessing (EMDR) treatment to 32 of these children who met clinical criteria for PTSD. The Children's Reaction Inventory (CRI) was the primary measure of the treatment's effect on PTSD symptoms. Associated symptoms were measured using the Revised Children's Manifest Anxiety Scale (RCMAS) and the Children's Depression Inventory (CDI). Treatment resulted in substantial reductions in both groups' CRI scores and in significant, though more modest, reductions in RCMAS and CDI scores. Gains were maintained at six-month follow-up. Health visits to the school nurse were significantly reduced following treatment. Psychosocial intervention appears useful for children suffering disaster-related PTSD. Conducting controlled studies of children's treatment in the postdisaster environment appears feasible.

Telemedicine for Anger Management Therapy in a Rural Population of Combat Veterans With Posttraumatic Stress Disorder
Leslie A. Morland, Carolyn J. Greene, Craig S. Rosen, David W. Foy +4 more
2010· The Journal of Clinical Psychiatry278doi:10.4088/jcp.09m05604blu

Article AbstractObjective: To demonstrate the noninferiority of a telemedicine modality, videoteleconferencing, compared to traditional in-person service delivery of a group psychotherapy intervention for rural combat veterans with posttraumatic stress disorder (PTSD).Method: A randomized controlled noninferiority trial of 125 male veterans with PTSD (according to DSM criteria on the Clinician-Administered PTSD Scale) and anger difficulties was conducted at 3 Veterans Affairs outpatient clinics. Participants were randomly assigned to receive anger management therapy delivered in a group setting with the therapist either in-person (n†‰=†‰64) or via videoteleconferencing (n†‰=†‰61). Participants were assessed at baseline, midtreatment (3 weeks), posttreatment (6 weeks), and 3 and 6 months posttreatment. The primary clinical outcome was reduction of anger difficulties, as measured by the anger expression and trait anger subscales of the State-Trait Anger Expression Inventory-2 (STAXI-2) and by the Novaco Anger Scale total score (NAS-T). Data were collected from August 2005 to October 2008.Results: Participants in both groups showed significant and clinically meaningful reductions in anger symptoms, with posttreatment and 3 and 6 months posttreatment effect sizes ranging from .12 to .63. Using a noninferiority margin of 2 points for STAXI-2 subscales anger expression and trait anger and 4 points for NAS-T outcomes, participants in the videoteleconferencing condition demonstrated a reduction in anger symptoms similar ("non-inferior") to symptom reductions in the in-person groups. Additionally, no significant between-group differences were found on process variables, including attrition, adherence, satisfaction, and treatment expectancy. Participants in the in-person condition reported significantly higher group therapy alliance.Conclusions: Clinical and process outcomes indicate delivering cognitive-behavioral group treatment for PTSD-related anger problems via videoteleconferencing is an effective and feasible way to increase access to evidence-based care for veterans residing in rural or remote locations.Trial Registration: clinicaltrials.gov Identifier: NCT00122109J Clin Psychiatry 2010;71(7):855-863Submitted: August 11, 2009; accepted September 28, 2009.Online ahead of print: January 26, 2010 (doi:10.4088/JCP.09m05604blu).Corresponding author: Leslie A. Morland, PsyD, National Center for PTSD-Pacific Islands Division, Department of Veterans Affairs Pacific Islands Healthcare System, 3375 Koapaka St, Suite I-560, Honolulu, HI 96819 (Leslie.Morland@va.gov).

Midlife Blood Pressure, Plasma β-Amyloid, and the Risk for Alzheimer Disease
Nilay S. Shah, Jean‐Sébastien Vidal, Kamal Masaki, Helen Petrovitch +4 more
2012· Hypertension216doi:10.1161/hypertensionaha.111.178962

β-Amyloid (Aβ), a vasoactive protein, and elevated blood pressure (BP) levels are associated with Alzheimer disease (AD) and possibly vascular dementia. We investigated the joint association of midlife BP and Aβ peptide levels with the risk for late-life AD and vascular dementia. Subjects were 667 Japanese-American men (including 73 with a brain autopsy), from the prospective Honolulu Heart Program/Honolulu Asia Aging Study (1965-2000). Midlife BP was measured starting in 1971 in participants with a mean age of 58 years; Aβ was measured in specimens collected in 1980-1982, and assessment of dementia and autopsy collection started in 1991-1993. The outcome measures were prevalent (present in 1991-1993) and incident AD (n=53, including 38 with no contributing cardiovascular disease) and vascular dementia (n=24). Cerebral amyloid angiopathy, β-amyloid neuritic plaques, and neurofibrillary tangles were evaluated in postmortem tissue. The risk for AD significantly increased with lower levels of plasma Aβ (Aβ1-40 hazard ratio: 2.1 [95% CI: 1.4 to 3.1]; Aβ1-42 hazard ratio: 1.6 [95% CI: 1.1 to 2.3]). Evidence of interaction between diastolic BP and plasma Aβ (1-40 P(interaction)<0.05; 1-42 P(interaction)<0.07) levels indicated that the Aβ-related risk for AD was higher when BP was higher. Low plasma Aβ was associated with the presence of cerebral amyloid angiopathy (P(trend)<0.05) but not the other neuropathologies. Aβ plasma levels start decreasing ≥15 years before AD is diagnosed, and the association of Aβ to AD is modulated by midlife diastolic BP. Elevated BP may compromise vascular integrity leading to cerebral amyloid angiopathy and impaired Aβ clearance from the brain.

Bowel movement frequency in late‐life and incidental Lewy bodies
Robert D. Abbott, G. Webster Ross, Helen Petrovitch, Caroline M. Tanner +4 more
2007· Movement Disorders202doi:10.1002/mds.21560

It is not known if constipation is associated with the preclinical phase of Parkinson's disease (PD), often characterized by the presence of incidental Lewy bodies (ILB). Such an association could provide evidence that constipation is an early symptom of PD. The purpose of this report is to examine the association between late-life bowel movement frequency and ILB. Bowel movement frequency was assessed from 1991 to 1993 in 245 men aged 71 to 93 years in the Honolulu-Asia Aging Study who later received postmortem examinations. All were without clinical PD and dementia. Brains were examined for ILB in the substantia nigra and locus ceruleus. Among the decedents, 30 men had ILB (12.2%). After age-adjustment, the percent of brains with ILB declined with increasing bowel movement frequency (P=0.013). For men with <1, 1, and >1 bowel movement/day, corresponding percents were 24.1, 13.5, and 6.5%. Findings persisted after additional adjustment for time to death, mid-life pack-years of smoking and coffee intake, physical activity, and cognitive function. Infrequent bowel movements are associated with ILB. Findings provide evidence that constipation can predate the extrapyramidal signs of PD. Constipation could be one of the earliest markers of the beginning of PD processes.

Association of olfactory dysfunction with incidental Lewy bodies
G. Webster Ross, Robert D. Abbott, Helen Petrovitch, Caroline M. Tanner +4 more
2006· Movement Disorders195doi:10.1002/mds.21076

Olfactory dysfunction is found in early Parkinson's disease (PD) and in asymptomatic relatives of PD patients. Incidental Lewy bodies (ILB), the presence of Lewy bodies in the brains of deceased individuals without a history of PD or dementia during life, are thought to represent a presymptomatic stage of PD. If olfactory dysfunction were associated with the presence of ILB, this would suggest that olfactory deficits may precede clinical PD. The purpose of this study was to determine the association of olfactory dysfunction during late life with ILB in the substantia nigra or locus ceruleus. Olfaction was assessed during the 1991-1994 and 1994-1996 examinations of elderly Japanese-American men participating in the longitudinal Honolulu-Asia Aging Study. Among those who later died and underwent a standardized postmortem examination, brains were examined for Lewy bodies in the substantia nigra and the locus ceruleus with hematoxylin and eosin stain. Lewy bodies in the brains of individuals without clinical PD or dementia were classified as ILB. There were 164 autopsied men without clinical PD or dementia who had olfaction testing during one of the examinations. Seventeen had ILB. The age-adjusted percent of brains with ILB increased from 1.8% in the highest tertile of odor identification to 11.9% in the mid-tertile to 17.4% in the lowest tertile (P = 0.019 in test for trend). Age-adjusted relative odds of ILB for the lowest versus the highest tertile was 11.0 (P = 0.02). Olfactory dysfunction is associated with ILB. If incidental Lewy bodies represent presymptomatic stage of PD, olfactory testing may be a useful screening tool to identify those at high risk for developing PD.

Cognitive-behavioral treatment for severe anger in posttraumatic stress disorder.
Claude M. Chemtob, Raymond W. Novaco, Roger S. Hamada, Douglas M. Gross
1997· Journal of Consulting and Clinical Psychology190doi:10.1037//0022-006x.65.1.184

With a randomized group design, a 12-session anger treatment was evaluated with severely angry Vietnam War veterans suffering combat-related posttraumatic stress disorder (PTSD). Eight participants in anger treatment and 7 in a routine clinical care control condition completed multiple measures of anger control, anger reaction, and anger disposition, as well as measures of anxiety, depression, and PTSD at pre- and posttreatment. Controlling for pretreatment scores, significant effects were found on anger reaction and anger control measures but not on anger disposition or physiological measures. Eighteen-months follow-up (for both completers and dropouts) supported the posttreatment anger control findings. The challenges of treatment research with this refractory population are discussed.

Solvent exposures and parkinson disease risk in twins
Samuel M. Goldman, Patricia Quinlan, G. Webster Ross, Connie Marras +4 more
2011· Annals of Neurology183doi:10.1002/ana.22629

OBJECTIVE: Several case reports have linked solvent exposure to Parkinson disease (PD), but few studies have assessed associations with specific agents using an analytic epidemiologic design. We tested the hypothesis that exposure to specific solvents is associated with PD risk using a discordant twin pair design. METHODS: Ninety-nine twin pairs discordant for PD ascertained from the National Academy of Sciences/National Research Council World War II Veteran Twins Cohort were interviewed regarding lifetime occupations and hobbies using detailed job task-specific questionnaires. Exposures to 6 specific solvents selected a priori were estimated by expert raters unaware of case status. RESULTS: Ever exposure to trichloroethylene (TCE) was associated with significantly increased risk of PD (odds ratio [OR], 6.1; 95% confidence interval [CI] 1.2-33; p = 0.034), and exposure to perchloroethylene (PERC) and carbon tetrachloride (CCl(4) ) tended toward significance (respectively: OR, 10.5; 95% CI, 0.97-113; p = 0.053; OR, 2.3; 95% CI, 0.9-6.1; p = 0.088). Results were similar for estimates of exposure duration and cumulative lifetime exposure. INTERPRETATION: Exposure to specific solvents may increase risk of PD. TCE is the most common organic contaminant in groundwater, and PERC and CCl(4) are also ubiquitous in the environment. Our findings require replication in other populations with well-characterized exposures, but the potential public health implications are substantial.

Noninferiority and equivalence designs: Issues and implications for mental health research
Carolyn J. Greene, Leslie A. Morland, Valerie Durkalski, B. Christopher Frueh
2008· Journal of Traumatic Stress182doi:10.1002/jts.20367

The terms noninferiority and equivalence are often used interchangeably to refer to trials in which the primary objective is to show that a novel intervention is as effective as the standard intervention. The use of these designs is becoming increasingly relevant to mental health research. Despite the fundamental importance of these designs, they are often poorly understood, improperly applied, and subsequently misinterpreted. In this article, the authors explain noninferiority and equivalence designs and key methodological and statistical considerations. Decision points in using these designs are discussed, such as choice of control condition, determination of the noninferiority margin, and calculation of sample size and power. With increasing utilization of these designs, it is critical that researchers understand the methodological issues, advantages, disadvantages, and related challenges.

TELEMEDICINE VERSUS IN-PERSON DELIVERY OF COGNITIVE PROCESSING THERAPY FOR WOMEN WITH POSTTRAUMATIC STRESS DISORDER: A RANDOMIZED NONINFERIORITY TRIAL
Leslie A. Morland, Margaret‐Anne Mackintosh, Craig S. Rosen, Emy Willis +3 more
2015· Depression and Anxiety177doi:10.1002/da.22397

BACKGROUND: This study examined the effectiveness of telemedicine to provide psychotherapy to women with posttraumatic stress disorder (PTSD) who might be unable to access treatment. Objectives were to compare clinical and process outcomes of PTSD treatment delivered via videoteleconferencing (VTC) and in-person (NP) in an ethnically diverse sample of veteran and civilian women with PTSD. METHODS: A randomized controlled trial of Cognitive Processing Therapy, an evidence-based intervention for PTSD, was conducted through a noninferiority design to compare delivery modalities on difference in posttreatment PTSD symptoms. Women with PTSD, including 21 veterans and 105 civilians, were assigned to receive psychotherapy delivered via VTC or NP. Primary treatment outcomes were changes in PTSD symptoms in the completer sample. RESULTS: Improvements in PTSD symptoms in the VTC condition (n = 63) were noninferior to outcomes in the NP condition (n = 63). Clinical outcomes obtained when both conditions were pooled together (N = 126) demonstrated that PTSD symptoms declined substantially posttreatment (mean = -20.5, 95% CI -29.6 to -11.4) and gains were maintained at 3- (mean = -20.8, 95% CI -30.1 to -11.5) and 6-month followup (mean = -22.0, 95% CI -33.1 to -10.9. Veterans demonstrated smaller symptom reductions posttreatment (mean = -9.4, 95% CI -22.5 to 3.7) than civilian women (mean = -22.7, 95% CI -29.9 to -15.5. CONCLUSIONS: Providing psychotherapy to women with PTSD via VTC produced outcomes comparable to NP treatment. VTC can increase access to specialty mental health care for women in rural or remote areas.

Cross-Language Intrusion Errors in Aging Bilinguals Reveal the Link Between Executive Control and Language Selection
Tamar H. Gollan, Tiffany C. Sandoval, David P. Salmon
2011· Psychological Science174doi:10.1177/0956797611417002

Bilinguals outperform monolinguals on measures of executive control, but it is not known how bilingualism introduces these advantages. To address this question, we investigated whether language-control failures increase with aging-related declines in executive control. Eighteen younger and 18 older Spanish-English bilinguals completed a verbal-fluency task, in which they produced words in 18 categories (9 in each language), and a flanker task. Performance on both tasks exhibited robust effects of aging, but cross-language and within-language errors on the verbal-fluency task differed in a number of ways. Within-language errors occurred relatively often and decreased with higher levels of education in both younger and older bilinguals. In contrast, cross-language intrusions (e.g., inadvertently saying an English word on a Spanish-language trial) were rarely produced, were not associated with education level, and were strongly associated with flanker-task errors in older but not younger bilinguals. These results imply that executive control plays a role in maintaining language selection, but they also suggest the presence of independent forces that prevent language-selection errors.

Glutathione Peroxidase 4 is associated with Neuromelanin in Substantia Nigra and Dystrophic Axons in Putamen of Parkinson's brain
Frederick P. Bellinger, Miyoko T. Bellinger, Lucia A. Seale, Andrea S. Takemoto +4 more
2011· Molecular Neurodegeneration168doi:10.1186/1750-1326-6-8

BACKGROUND: Parkinson's disease is a neurodegenerative disorder characterized pathologically by the loss of nigrostriatal dopamine neurons that project from the substantia nigra in the midbrain to the putamen and caudate nuclei, leading to the clinical features of bradykinesia, rigidity, and rest tremor. Oxidative stress from oxidized dopamine and related compounds may contribute to the degeneration characteristic of this disease. RESULTS: To investigate a possible role of the phospholipid hydroperoxidase glutathione peroxidase 4 (GPX4) in protection from oxidative stress, we investigated GPX4 expression in postmortem human brain tissue from individuals with and without Parkinson's disease. In both control and Parkinson's samples, GPX4 was found in dopaminergic nigral neurons colocalized with neuromelanin. Overall GPX4 was significantly reduced in substantia nigra in Parkinson's vs. control subjects, but was increased relative to the cell density of surviving nigral cells. In putamen, GPX4 was concentrated within dystrophic dopaminergic axons in Parkinson's subjects, although overall levels of GPX4 were not significantly different compared to control putamen. CONCLUSIONS: This study demonstrates an up-regulation of GPX4 in neurons of substantia nigra and association of this protein with dystrophic axons in striatum of Parkinson's brain, indicating a possible neuroprotective role. Additionally, our findings suggest this enzyme may contribute to the production of neuromelanin.

Lewy pathology is not the first sign of degeneration in vulnerable neurons in Parkinson disease
Joshua Milber, Joseph V. Noorigian, James F. Morley, Helen Petrovitch +3 more
2012· Neurology158doi:10.1212/wnl.0b013e318278fe32

OBJECTIVE: To determine whether evidence of neuronal dysfunction or demise preceded deposition of Lewy pathology in vulnerable neurons in Parkinson disease (PD). METHODS: We examined the extent of nigral dysfunction and degeneration among 63 normal, incidental Lewy body disease (ILBD), and PD cases based on tyrosine hydroxylase (TH) immunoreactivity and neuron densities, respectively. The relationship between these markers and Lewy pathology (LP) burden in the substantia nigra (SN) and Braak PD stage was assessed. RESULTS: Compared with normal subjects, ILBD cases displayed a significantly higher percentage of TH-negative cells and lower neuronal densities in the SN as early as Braak PD stages 1 and 2, before LP deposition in the nigrostriatal system. ILBD nigral neuron densities were intermediate between normal subjects and PD cases, and TH-negative percentages were higher in ILBD than either normal or PD cases. Furthermore, neuron density and neuronal dysfunction levels remained relatively constant across Braak PD stages in ILBD. CONCLUSIONS: These results suggest that significant neurodegeneration and cellular dysfunction precede LP in the SN, challenging the pathogenic role of LP in PD and the assumption that ILBD always represents preclinical PD.

Neuropathologic findings in essential tremor
Elan D. Louis, Jean Paul Vonsattel, Lawrence S. Honig, G. Webster Ross +2 more
2006· Neurology155doi:10.1212/01.wnl.0000218162.80315.b9

Pathologic findings, including cerebellar changes and brainstem Lewy bodies, distinguished 10 essential tremor (ET) cases from 12 controls. Numbers of torpedoes (p = 0.009) and Bergmann glia (p = 0.046) were increased in cases. Six cases (60%) had Lewy bodies vs 2 controls (16.7%) (odds ratio 7.5, 95% CI 1.04 to 54.1; p = 0.035). Four of these six had an atypical distribution of brainstem Lewy bodies. ET may be pathologically heterogeneous.