Biomedical subjects

R Hiller

Publications and source records attributed to R Hiller.

At least 55 records · Page 3Linked to original sources

PubMed1984

Factors influencing the accumulation of tetraphenylphosphonium cation in HeLa cells.

Exposure of HeLa cells to tetraphenylphosphonium cation (TPP+) results in a rapid accumulation intracellularly, and a steady-state level is reached within 10 min. Accumulation of [3H]TPP+ in HeLa cells is reduced under the following conditions: (i) after preincubation of cells in buffered saline or in medium containing two- to fourfold higher concentrations of amino acids, (ii) exposure to the alkylating agent L-1-tosylamido-2-phenyl-ethylchloromethyl ketone, (iii) ouabain-mediated inhibition of the Na+, K+ ATPase, and (iv) high external K+ concentrations. In contrast, addition of serum increases the uptake of TPP+. In synchronized cells, intracellular levels of TPP+ differ at various stages of cell cycle and are lowest in mitosis.

Biological Transport, Active↗

PubMed1983

Epidemiologic associations with cataract in the 1971-1972 National Health and Nutrition Examination Survey.

Data from the 1971-1972 National Health and Nutrition Examination Survey were used to examine the associations between cataract and age, race, sex, education, diabetes, systolic blood pressure, urban vs. rural residence, and average daily ultraviolet spectrum B (UV-B) radiation counts at the site of examination. The multivariate logistic risk function was applied to data on 2225 persons, aged 45-74, who had resided for at least half their lifetime in the state where their examination was conducted. Cataracts (cortical, nuclear or posterior subcapsular opacities consistent with best corrected visual acuity of 6/9 (20/30) or worse or aphakic status) were present in 413 persons. The multivariate analysis showed that they were more common among blacks, diabetics, and rural dwellers, and were positively associated with increasing age, increasing UV-B radiation counts at the site of the examination, and decreasing number of years spent in school. The association with cataracts was also present when latitude or sunlight hours was substituted for UV-B radiation counts.

Aged↗

PubMed1983

Validity of a survey question as a measure of visual acuity impairment.

Survey questions are frequently used to collect data on the prevalence of vision difficulties. The 1971-1972 Health and Nutrition Examination Survey included both a question about "trouble with your vision even when wearing glasses or contact lenses," and clinical measurement of central distance visual acuity with usual corrective lenses. The question had low sensitivity for impairment of visual acuity, with variation by age and severity of impairment. Sensitivity analyses from other studies are reviewed. (Am J Public Health 1983; 72:93-96.)

Adult↗

PubMed1982

Pseudoexfoliation, intraocular pressure, and senile lens changes in a population-based survey.

The prevalence rate of pseudoexfoliation among persons in the Framingham Eye Study, a population-based survey, increased from 0.6% for ages 52 to 64 years to 2.6% for ages 65 to 74 years to 5.0% for ages 75 to 85 years. Age-adjusted rates showed a statistically significant 2.3 to 1.0 female to male ratio. Pseudoexfoliation was associated with higher intraocular pressure levels and more frequent senile lens changes, but the latter relationship was not statistically significant. The age-specific prevalence rates for the Framingham population are similar to those reported from a mass screening of subjects in Norway, where the condition is thought to be especially common. Some of the previously reported geographic variations in prevalence rates may be due to differences in disease definitions, subject selection, and examination conditions.

Age Factors↗

PubMed1982

Race, iris pigmentation, and intraocular pressure.

The association of intraocular pressure with age, sex, race, iris pigmentation, systemic blood pressure, and family income was evaluated using data from the Health and Nutrition Examination Survey of 1971-1972. In general, mean intraocular pressure was highest for blacks with brown irides and progressively lower for whites with brown irides, whites with neither brown nor blue irides, and whites with blue irides. Multilinear regression analysis showed positive associations of intraocular pressure with systolic blood pressure (p less than 0.0001), age (p less than 0.0001) and amount of iris pigmentation (p less than 0.0001). The association with iris pigmentation held for both a combined race/iris color variable and for iris color among white persons. When race rather than iris pigmentation was used in the regression equation, it was a weaker (p less than 0.03) but still significant risk factor for higher levels of intraocular pressure. Intraocular pressure was negatively associated with family income (p less than 0.004). Despite the significant associations, the proportion of variance in intraocular pressure that was explained by these variables was small (R2 = 0.06).

Adult↗

PubMed1981

Lens opacities and senile maculopathy.

Analysis of data from a population survey, the Framingham Eye Study, shows that when the various senile lens changes are pooled, no associations with senile maculopathy are evident. Subgroup analysis shows the relative risk of senile maculopathy to be lower than 1.00 in the presence of nuclear sclerosis for all age groups and greater than 1.00 for persons between 52 and 74 years in the presence of cortical changes. Nuclear-cortical interaction tests are highly significant, indicating that nuclear sclerosis and cortical opacities have opposite effects on the relative risk of senile maculopathy.

Age Factors↗

PubMed1981

Senile lens changes and diabetes in two population studies.

Clinical and epidemiologic studies of the association between senile cataract and diabetes have produced what initially appears to be conflicting evidence. Three studies of extracted cataract have found a positive association in persons less than 70 years old. Conversely, two studies of senile lens changes (including aphakia) reported no association with diabetes. These apparently disparate findings led to the hypothesis that the diseases are in fact not associated, but that diabetics are more likely to be referred to ophthalmologists and therefore to have cataracts removed. We tested this hypothesis with data from two population surveys, the Framingham Eye Study and the Health and Nutrition Examination Survey (HANES). Both studies showed a marked excess prevalence of senile cataract (including aphakia) in diabetics less than 65 years old (relative risks of 4.02 and 2.97, respectively). Beyond the age of 64 years, the HANES study but not the Framingham study showed an excess prevalence, although it was less marked (relative risks of 1.63 and 1.02, respectively). For senile lens changes other than cataract, both studies showed little, if any, association with diabetes. Our results for cataract (whether removed or not) were generally consistent with those of previous studies of extracted cataract for persons under the age of 70 years and for persons aged 70 years or more. The two studies that reported no association between lens changes and diabetes provided information inadequate to support or refute the foregoing findings. The various studies failed to support increased referral of diabetics to ophthalmologists as an explanation for the observed association. All these studies found the association in persons less than 70 years old, whether the cataract had been removed or not.

Age Factors↗

PubMed1979

[Automatic regeneration of capillary dialysers].

First results of an automatically working regeneration apparatus for capillary dialysators in 200 dialyses allow the on an average tenfold use of the dialysator CDAK 4. In this case a reduction of the effective surface to 70% of the initial value must be taken into bargain. Pyrogenic reactions or bacterial contamination of the regenerated dialysators were not taken into consideration. This method is recommended as transitional solution up to the industrial production of cheap dialysators for a single use.

Kidneys, Artificial↗

PubMed1979

Prognosis for life in patients with diabetes: relation to severity of retinopathy.

In a group of 709 individuals with diabetes diagnosed prior to age 50 and followed for five to thirteen years a strong inverse relationship was demonstrated between the severity of the retinopathy at the initial visit and survival. Survival in patients with no retinopathy or with microaneurysms only was little different from that of the general population (five-year rate .99, SE .01). The five-year survival rate for patients with more severe nonproliferative retinopathy, characterized by the presence of hemorrhages and/or exudates, but without new vessels or vitreous hemorrhage (B2), was .81 (SE .04), and that for patients with proliferative retinopathy (PDR) was .56 (SE .03). After adjustment for age at diagnosis of diabetes, duration of diabetes and sex, the differences in survival between these three groups were highly statistically significant. Impairment of visual acuity was also shown to be inversely related to survival. The five-year survival rate for patients with visual acuity of 20/200 or worse in each eye was .42 (SE .05). In patients with B2 retinopathy there was a weak but statistically significant trend towards decreasing survival with increasing duration of diabetes. In patients with PDR survival decreased with increasing duration up to 20 years, but then improved for patients with 20 years or more of diabetes.

Adolescent↗

PubMed1977

Sunlight and cataract: an epidemiologic investigation.

Cataract prevalence data from two large U.S. sources were divided according to small geographic areas for which average annual sunlight hours were determined from a map prepared by the U.S. Weather Bureau. Several non-cataract disease controls were chosen from the same geographic locations (separately for each data set). It was found that the cataract-to-control ratios for persons aged 65 years or older were significantly larger in locations with large amounts of sunlight compared to those in locations with small amounts (P less than .05). Discussion of some possible biases in the data leads to the conclusion that the biases, if they exist, are probably not large. The authors believe, however, that more research should be done before the association between sunshine and cataract is considered established.

Aged↗

PubMed1976

Senile cataract extraction and diabetes.

A study of hospital discharge diagnoses from both national data and data from a local medical centre indicates that diabetes substantially increases the probability of cataract extraction at age 40-49, about doubles or triples the probability for age 50-69, and has little effect on risk at age 70 and over. Strengths and weaknesses of the data are discussed. Other reports, generally estimating a much stronger association between diabetes and probability of cataract extraction, at least at age 50 and above, are critically evaluated.

Adult↗

PubMed1975

Blindness from glaucoma.

We observed an overall ratio of 8:1 for nonwhite to white primary glaucoma blindness. Our fragmentary evidence suggested that the ratio of underlying disease, that is, nonblinding glaucoma or intraocular pressure differentials, may be closer to 2:1 than 8:1 as between nonwhites and whites. The remaining four fold differential can be explained by a combination of the following: more complete reporting for nonwhites, reporting for medical care later in the disease than whites, and poorer response to treatment for nonwhites compared to whites. The trend of new blindness from glaucoma for recent years was stationary in the United States, England, and Wales.

Adolescent↗

PubMed1974