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Biomedical subjects

L R White

Publications and source records attributed to L R White.

126 records · Page 7Linked to original sources
PubMed1978

Acetylesterase isoenzymes in rat uterus and placenta.

The occurrence of acetylesterase activity in the uterus and placenta of the rat has been investigated using a general histochemical simultaneous coupling technique after separation on polyacrylamide gradient gels. apart from a complex band associated with serum esterases which was demonstrated in all the tissues studied, several other isoenzyme bands were demonstrable in differing degrees in the yolk sac and the virgin uterus. Two of these bands were evident in metrial gland up to day 16 of pregnancy, and a third became present by day 17. Unlike the other two bands, this new band did not seem to be associated with the large granules of the granulated metrial gland cells. None of these bands were detected in trophoblast. The metrial gland isoenzymes reacted as well at acid pH as at neutral pH. The yolk sac isoenzymes reacted either as well or slightly better at acid pH, and one extra band was demonstrable under acid conditions.

Acetylesterase↗
PubMedDate not supplied

Association of coffee and caffeine intake with the risk of Parkinson disease.

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.

Aged↗
PubMedDate not supplied

Midlife blood pressure and dementia: the Honolulu-Asia aging study.

We studied the association of mid-life blood pressure to late age dementia, specifically Alzheimer's 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 Alzheimer's 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.

Age Factors↗
PubMedDate not supplied

Midlife blood pressure and neuritic plaques, neurofibrillary tangles, and brain weight at death: the HAAS. Honolulu-Asia aging Study.

Midlife hypertension is associated with later development of cognitive impairment, vascular dementia (VsD), and possibly Alzheimer's disease (AD). Neuropathic cerebrovascular lesions and brain atrophy have been associated with elevated blood pressure (BP), however, to our knowledge there have been no prospective investigations of an association of blood pressure levels measured in midlife with the microscopic lesions of AD. We investigated the relationship of BP level in midlife to development of neurofibrillary tangles (NFT), neuritic plaques (NP), and low brain weight at autopsy among Japanese-American men who were members of the Honolulu Heart Program/Honolulu-Asia aging Study (HHP/HAAS) cohort. The HHP/HAAS is a population-based, longitudinal study of cognitive function and dementia with 36 years of follow-up. Neocortical and hippocampal NFT and NP were counted per mm(2), and fixed brain weight was measured for 243 decedents. Elevated systolic BP, (> or =160 mm Hg) in midlife was associated with low brain weight and greater numbers of NP in both neocortex and hippocampus. Diastolic BP elevation, (> or =95 mm Hg) was associated with greater numbers of NFT in hippocampus. Results indicate that in addition to the accepted association of high BP with neuropathic cerebrovascular lesions, there is a direct relationship with brain atrophy, NP and NFT.

Aged↗
PubMedDate not supplied

Endothelin-1 inhibits the vasodilation induced by substance P in isolated porcine ophthalmic artery.

The vasoconstrictor effect of endothelin-1 is long-lasting and slow in onset, suggesting that this peptide may be involved with long-term vascular responses. Substance P, a quick-acting, vasodilatory tachykinin present in sensory nerves, may be released by trigeminal fibres and thereby participate in the regulation of vascular tone in the head. Given the potential role of vasoregulatory peptides in the ocular-forehead circulation in the pathophysiology of vascular headaches, the interactions between substance P and endothelin-1 over time were studied in isolated porcine ophthalmic artery. Substance P-induced relaxation of precontracted artery segments was significantly diminished by endothelin-1, despite the fact that endothelin-1 itself had no further significant contractile effect on these arteries. It is also noteworthy that the observed reduction of substance P-induced relaxation occurred much more rapidly than the onset of endothelin-1-induced contraction in relaxed porcine ophthalmic artery. The results suggest an inhibitory synergism between endothelin-1 and substance P in this vascular bed.

Animals↗
PubMedDate not supplied

Prevalence and correlates of dementia: survey of the last days of life.

OBJECTIVES: To estimate the prevalence and correlates of dementia at death and to assess the usefulness of death certificate data in the reporting of dementia. METHODS: The authors analyzed next-of-kin interviews for 599 male and 628 female decedents using data from the National Institute on Aging's Survey of the Last Days of Life. RESULTS: Death certificate data in this population show the prevalence of dementia to be less than 1%, consistent with previous reports based on death certificates but a substantial underestimate compared to the 11.9% reported in a national survey. Using a dementia index based on the informant's report of whether the decedent had been diagnosed with a dementing illness and the extent of her or his cognitive and functional limitations, this study found a prevalence of dementia of 8.5%. A high score on the dementia index was significantly associated with older age, Parkinson's disease, and incontinence. Lower relative odds for dementia at death were found for people with either a lifetime history or a death certificate report of cancer. Similarly, people with a lifetime history of coronary heart disease were found to have lower relative odds for dementia at death. CONCLUSION: These results suggest that informant interviews may be a useful source of data to examine factors associated with dementia and to estimate the prevalence of dementia in the last year of life.

Age Distribution↗