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Dive into the research topics where G. Webster Ross is active.

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Featured researches published by G. Webster Ross.


Neurobiology of Aging | 2000

Midlife blood pressure and dementia: the Honolulu–Asia aging study☆ ☆

Lenore J. Launer; G. Webster Ross; Helen Petrovitch; Kamal Masaki; Dan Foley; Lon R. White; Richard J. Havlik

We studied the association of mid-life blood pressure to late age dementia, specifically Alzheimers disease and vascular dementia. Data are from the cohort of 3703 Japanese-American men who were followed in the Honolulu Heart Program (HHP;1965-1971), and subsequently re-examined in 1991 for dementia. We assessed the risk (odds ratio (95% CI)) for dementia associated with categories of systolic (SBP) and diastolic blood pressure (DBP), stratified by never/ever treatment with anti-hypertensive medications, and adjusting for age, education, apolipoprotein epsilon allele, smoking and alcohol intake. Among those never treated (57% sample), the risk for dementia was OR 95% CI 3.8 (1.6-8.7) for DBP of 90-94 mm Hg, and 4. 3 (1.7-10.8) for DBP of 95 mmHg and over compared to those with DBP of 80 to 89 mm Hg. Compared to those with SBP of 110 to 139 mm Hg, the risk for dementia was 4.8 (2.0-11.0) in those with SBP 160 mm Hg and higher. Blood pressure was not associated with the risk for dementia in treated men. These results were consistent for Alzheimers disease and vascular dementia. This study suggests elevated levels of blood pressure in middle age can increase the risk for late age dementia in men never treated with anti-hypertensive medication.


Environmental Health Perspectives | 2011

Rotenone, Paraquat, and Parkinson’s Disease

Caroline M. Tanner; Freya Kamel; G. Webster Ross; Jane A. Hoppin; Samuel M. Goldman; Monica Korell; Connie Marras; Grace S. Bhudhikanok; Meike Kasten; Anabel Chade; Kathleen Comyns; Marie Richards; Cheryl Meng; Benjamin Priestley; Hubert H. Fernandez; Franca Cambi; David M. Umbach; Aaron Blair; Dale P. Sandler; J. William Langston

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.


Annals of Neurology | 2008

Association of olfactory dysfunction with risk for future Parkinson's disease

G. Webster Ross; Helen Petrovitch; Robert D. Abbott; Caroline M. Tanner; Jordan S. Popper; Kamal Masaki; Lenore J. Launer; Lon R. White

Although olfactory dysfunction is commonly associated with Parkinsons 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


Annals of the New York Academy of Sciences | 2002

Cerebrovascular Pathology and Dementia in Autopsied Honolulu‐Asia Aging Study Participants

Lon R. White; Helen Petrovitch; John Hardman; James Nelson; Daron G. Davis; G. Webster Ross; Kamal Masaki; Lenore J. Launer; William R. Markesbery

Abstract: Clinicopathologic data from 285 autopsies were analyzed. The decedents were long‐standing participants in the Honolulu‐Asia Aging Study, a prospective epidemiologic investigation of stroke, neurodegenerative diseases, and aging. We assessed the prevalence at death of four primary neuropathologic processes using specific microscopic lesions as indicators. An algorithm was developed to assign each decedent to one of six subsets, corresponding to pathologic dominance by microvascular lesions (14% of decedents), Alzheimer lesions (12%), hippocampal sclerosis (5%), cortical Lewy bodies (5%), codominance by two or more primary processes (9%), or without a dominant pathologic process recognized (55%). Definite or probable dementia had been identified in 118 of the decedents. The proportions of men in each subset identified as demented were (in the same order) 57%, 53%, 79%, 57%, 76%, and 25%. In this autopsied panel of older Japanese‐American men, the importance of microvascular lesions as a likely explanation for dementia was nearly equal to that of Alzheimer lesions. The cerebrovascular lesion type most essentially and inclusively related to dementia was multiple microinfarction.


Circulation | 1999

Effects of Walking on Coronary Heart Disease in Elderly Men: The Honolulu Heart Program

Amy A. Hakim; J. David Curb; Helen Petrovitch; Beatriz L. Rodriguez; Katsuhiko Yano; G. Webster Ross; Lon R. White; Robert D. Abbott

BACKGROUND Effects of walking on the risk of coronary heart disease morbidity and mortality have not been identified in the elderly. The purpose of this study was to determine whether walking is associated with a reduced risk of coronary heart disease in a sample of elderly men. METHODS AND RESULTS For this study, distance walked (mile/d) was examined at a baseline examination that occurred from 1991 to 1993 in the Honolulu Heart Program. Incident coronary heart disease from all causes was observed over a 2- to 4-year follow-up period. Subjects followed up were 2678 physically capable elderly men aged 71 to 93 years. During the course of follow-up, 109 men developed coronary heart disease. Men who walked <0.25 mile/d had a 2-fold increased risk of coronary heart disease versus those who walked >1. 5 mile/d (5.1% versus 2.5%; P<0.01). Men who walked 0.25 to 1.5 mile/d were also at a significantly higher risk of coronary heart disease than men who walked longer distances (4.5% versus 2.5%; P<0. 05). Adjustment for age and other risk factors failed to alter these findings. CONCLUSIONS Findings from the Honolulu Heart Program, which targeted physically capable elderly men, suggest that the risk of coronary heart disease is reduced with increases in distance walked. Combined with evidence that suggests that an active lifestyle reduces the risk of cardiovascular disease in younger and more diverse groups, this suggests that important health benefits could be derived by encouraging the elderly to walk.


Stroke | 2001

β 2-glycoprotein 1-dependent anticardiolipin antibodies and risk of ischemic stroke and myocardial infarction: The Honolulu Heart Program

Robin L. Brey; Robert D. Abbott; J. David Curb; Dan S. Sharp; G. Webster Ross; Christian L. Stallworth; Steven J. Kittner

Background— It has been hypothesized that immunoreactivity to &bgr;2-glycoprotein 1 (&bgr;2GP1)-dependent anticardiolipin antibody (aCL), but not &bgr;2GP1-independent aCL, is associated with increased risk of ischemic stroke and myocardial infarction (MI). Methods— We performed a nested case-control study examining aCL as a risk factor for ischemic stroke and MI by using stored frozen sera obtained from subjects enrolled in the Honolulu Heart Program and followed for up for 20 years. We measured &bgr;2GP1-dependent and &bgr;2GP1-independent aCL and anti-&bgr;2GP1 immunoreactivity in 259 men who developed an ischemic stroke, in 374 men who developed an MI, and in a control group of 1360 men who remained free of both conditions. Results— Only &bgr;2GP1-dependent aCL of the IgG class was significantly associated with both incident ischemic stroke and MI. This association was attenuated in the last 5 years of the 20-year follow-up. For stroke, the risk factor–adjusted relative odds for men with a positive versus a negative &bgr;2GP1-dependent aCL of the IgG class were 2.2 (95% CI 1.5 to 3.4) at 15 years and 1.5 (95% CI 1.0 to 2.3) at 20 years. For MI, the adjusted relative odds were 1.8 (95% CI 1.2 to 2.6) at 15 years and 1.5 (95% CI 1.1 to 2.1) at 20 years. Conclusions— These data suggest that aCL IgG, particularly the &bgr;2GP1-dependent variety, is an important predictor of future stroke and MI in men.


Annals of Neurology | 2005

AD lesions and infarcts in demented and non-demented Japanese-American men

Helen Petrovitch; G. Webster Ross; Sandra C. Steinhorn; Robert D. Abbott; William R. Markesbery; Daron G. Davis; James Nelson; John Hardman; Kamal Masaki; Margaret R. Vogt; Lenore J. Launer; Lon R. White

Neocortical neuritic plaques and neurofibrillary tangles are hallmark neuropathological lesions of dementia. Concomitant cerebrovascular lesions increase dementia severity in patients meeting neuropathological criteria for Alzheimers disease and contribute to cognitive impairment in persons with mild entorhinal Alzheimer lesions. This study investigates whether individuals with sparse neocortical neuritic plaques experience increased odds of crossing the threshold to clinical dementia when they have coexistent cerebrovascular lesions. Dementia examinations were given to 3,734 men during the 1991–1993 Honolulu‐Asia Aging Study examination and to 2,603 men during the 1994–1996 examination. Lesion quantification was done without clinical data. Among 333 autopsied men, 120 had dementia, 115 had marginal results, and 98 had normal cognition. In men with neurofibrillary tangles, dementia frequency increased with increasing neuritic plaque density, and increased further in the presence of cerebrovascular lesions. The association was strongest in men with sparse neuritic plaques (1–3/mm2) where dementia frequency more than doubled with coexistent cerebrovascular lesions (45 vs 20%). Among all dementia cases, 24% were linked to cerebrovascular lesions. Findings suggest cerebrovascular lesions are associated with a marked excess of dementia in cases with low neuritic plaque frequency. Prevention of cerebrovascular lesions may be critically important in preserving late‐life cognitive function. Ann Neurol 2005


Neurobiology of Aging | 2003

Mid-life smoking and late-life dementia : the Honolulu-Asia Aging Study

Suzanne L. Tyas; Lon R. White; Helen Petrovitch; G. Webster Ross; Daniel J. Foley; Harley K. Heimovitz; Lenore J. Launer

We studied the association between mid-life smoking and late-life dementia in the Honolulu Heart Program (1965-1971) and follow-up assessment for dementia (1991-1996) of 3734 Japanese-American men (80% of survivors). Neuropathologic data were available for 218 men. Adjusting for age, education and apolipoprotein E (APOE) genotype, the risk of Alzheimers disease (AD) in smokers increased with pack-years of smoking at medium (odds ratio (OR)=2.18, 95% confidence interval (CI)=1.07-4.69) and heavy (OR=2.40; 95% CI=1.16-5.17) smoking levels. Very heavy smoking was not associated with AD (OR=1.08; 95% CI=0.43-2.63). Findings were similar when AD cases included those with cerebrovascular disease and for all dementias combined. Adjustment for cardiovascular and respiratory factors or stratification by apolipoprotein E genotype did not change these associations. In an autopsied subsample, the number of neuritic plaques increased with amount smoked. This study suggests that amount smoked is associated with an increasing risk of AD and Alzheimer-type neuropathology up to heavy smoking levels. The lack of association in very heavy smokers may be due to a hardy survivor effect.


Movement Disorders | 2007

Bowel movement frequency in late-life and incidental Lewy bodies

Robert D. Abbott; G. Webster Ross; Helen Petrovitch; Caroline M. Tanner; Daron G. Davis; Kamal Masaki; Lenore J. Launer; J. David Curb; Lon R. White

It is not known if constipation is associated with the preclinical phase of Parkinsons 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.


JAMA Neurology | 2009

Occupation and Risk of Parkinsonism: A Multicenter Case-Control Study

Caroline M. Tanner; G. Webster Ross; Sarah A. Jewell; Robert A. Hauser; Joseph Jankovic; Stewart A. Factor; Susan Bressman; Amanda Deligtisch; Connie Marras; Kelly E. Lyons; Grace S. Bhudhikanok; Diana F. Roucoux; Cheryl Meng; Robert D. Abbott; J. William Langston

BACKGROUND We examined risk of parkinsonism in occupations (agriculture, education, health care, welding, and mining) and toxicant exposures (solvents and pesticides) putatively associated with parkinsonism. OBJECTIVE To investigate occupations, specific job tasks, or exposures and risk of parkinsonism and clinical subtypes. DESIGN Case-control. SETTING Eight movement disorders centers in North America. PARTICIPANTS Inclusion criteria were parkinsonism (>or=2 cardinal signs), diagnosis within 8 years of recruitment (to minimize survival bias), and ability to participate in detailed telephone interviews. Control subjects were primarily nonblood relatives or acquaintances of patients. MAIN OUTCOME MEASURES This multicenter case-control study compared lifelong occupational and job task histories to determine associations with parkinsonism and certain clinical subtypes (postural instability and gait difficulty and age at diagnosis <or=50 years). RESULTS Findings in 519 cases and 511 controls were analyzed. Work in agriculture, education, health care, or welding was not associated with increased risk of parkinsonism. Unexpected increased risks associated with legal, construction and extraction, or religious occupations were not maintained after adjustment for duration. Risk of parkinsonism increased with pesticide use (odds ratio, 1.90; 95% confidence interval, 1.12-3.21), use of any of 8 pesticides mechanistically associated with experimental parkinsonism (2.20; 1.02-4.75), and use of 2,4-dichlorophenoxyacetic acid (2.59; 1.03-6.48). None of the specific occupations, job tasks, or task-related exposures were associated with younger age at diagnosis (<or=50 years). Ever working in business and finance, legal occupations, construction and extraction, or transportation and material moving was associated with postural instability and gait difficulty subtype of parkinsonism. Tobacco use was inversely associated with parkinsonism risk. CONCLUSION The association of disease risk with pesticides support a toxicant-induced cause of parkinsonism.

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Helen Petrovitch

University of Hawaii at Manoa

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Kamal Masaki

University of Hawaii at Manoa

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Lenore J. Launer

National Institutes of Health

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J. David Curb

University of Hawaii at Manoa

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Beatriz L. Rodriguez

University of Hawaii at Manoa

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J. William Langston

Santa Clara Valley Medical Center

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