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Biomedical subjects

D R Harris

Publications and source records attributed to D R Harris.

At least 19 recordsLinked to original sources
PubMed1992

Changes in mammography use: economic, need, and service factors.

OBJECTIVES: The purpose of this study was to document changes in mammography use between 1987 and 1990 and assess the relationship of use to selected economic, need, and health system factors. METHODS: Independent random-digit-dialed telephone surveys of women between 52 and 75 years of age were conducted. RESULTS: Between 1987 and 1990, the proportion of women who had had a mammogram in the past year increased from 31% to 51%. Though income was significantly related to overall patterns of use, it was not associated with recent mammogram use in 1990. Women with a family history of breast cancer reported greater use at both times, as did women who reported having a regular physician (particularly a gynecologist or internist). When all other variables were controlled for, women were over nine times more likely to have had multiple and recent mammograms in 1990 than in 1987. CONCLUSIONS: Mammography use dramatically increased between 1987 and 1990. There were strong relationships between the type of regular physician and mammography screening and between economic and personal history and repeated and recent mammography use.

Aged↗
PubMed1992

Work-site nutrition intervention and employees' dietary habits: the Treatwell program.

In a randomized, controlled study of the Treatwell work-site nutrition intervention program, which focused on promoting eating patterns low in fat and high in fiber, 16 work sites from Massachusetts and Rhode Island were recruited to participate and randomly assigned to either an intervention or a control condition. The intervention included direct education and environmental programming tailored to each work site; control work sites received no intervention. A cohort of workers randomly sampled from each site was surveyed both prior to and following the intervention. Dietary patterns were assessed using a semiquantitative food frequency questionnaire. Adjusting for work site, the decrease in mean dietary fat intake was 1.1% of total calories more in intervention sites than in control sites (P less than .005). Mean changes in dietary fiber intake between intervention and control sites did not differ. This study provides evidence that a work-site nutrition intervention program can effectively influence the dietary habits of workers.

Adolescent↗
PubMed1991

Acute thyroid hormone promotes slow inactivation of sodium current in neonatal cardiac myocytes.

Sodium current (INa) inactivation kinetics in neonatal cardiac myocytes were analyzed using whole cell voltage clamp before and after acute treatments with thyroid hormone (3,5,3'-triiodo-L-thyronine, T3). In untreated neonatal myocytes, INa inactivation was predominantly mono-exponential, with 93 +/- 3% (S.D.; n = 9) of the peak amplitude decaying with a time constant, tau h1, of 1.8 +/- 0.5 ms at -30 mV. The remaining 7% of control INa decayed more slowly, with a time constant, tau h2, of 9.3 +/- 3.0 ms at -30 mV. The contribution of slowly-inactivating channels to peak current was increased from 7% to 43 +/- 27% within 5 min of exposure to 5-20 nM T3 (nine cells; P less than 0.005). The time constants for both the fast- and slow-inactivating components of peak current (tau h1 and tau h2) were not significantly changed by acute T3 treatment, nor was steady-state INa inactivation (h infinity) affected. Thyroid hormone action on sodium inactivation was partially reversible by lidocaine. These findings indicate that T3 acts at the neonatal cardiac cell membrane to promote slow inactivation kinetics in sodium channels.

Animals↗
PubMed1991

Evaluation of a standardized survey design proposed for use in epidemiological research on AIDS.

A Monte Carlo model simulating actual populations was employed to evaluate the precision in estimation of a standardized sampling method proposed by the Global Programme on AIDS of the World Health Organization, for general use in collecting population-based data on HIV seroprevalence. It appears that in real populations, where there is likely to be 'pocketing' of infection, the proposed methodology will generally fail to provide estimates accurate to within 1% of the true population value. However, if the primary objective of a particular survey is to construct confidence intervals that include the true population HIV seroprevalence rate, then this survey method appears to be a reasonable choice. This study also suggests that selection of only one adult per household improves the precision of resulting estimates. However, since selection of only one adult per household would require that more households be visited, any gain in precision would need to be weighed against the likely increase in cost of household visits.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Evaluation of the EPI survey methodology for estimating relative risk.

Precision in estimation of relative risks using a standardized sampling method proposed by the WHO Global Programme on AIDS was evaluated using a Monte Carlo model simulating actual populations; the proposed survey design represents a modification of the methodology used by the WHO Expanded Programme on Immunization (EPI) to estimate immunization coverage among children. This study suggests that in actual populations the proposed survey strategy is a reasonable alternative to the use of simple random sampling (SRS) at the second stage of cluster sampling. Although varying such population characteristics as the seroprevalence rate, nonresponse rate, and rate of misclassification of exposure failed to demonstrate a clear advantage of one method over the other, the added cost and difficulty of implementing SRS under field conditions warrant further consideration of the EPI-like methodology for use in estimating relative risks.

Adult↗
PubMed1990

Acute effects of thyroid hormone on sodium currents in neonatal myocytes.

Sodium currents and action potentials were recorded from myocytes of neonatal rats during acute exposure to thyroid hormone (5-20 nM). One to 5 minutes after addition of thyroid hormone to the bath, decay from peak Na current was slowed, with the fractional current flowing 20 ms after onset (relative to peak current) increasing from 6 +/- 5% to 17 +/- 13% (p less than 0.01, n = 12). Action potential durations were increased from 55 +/- 14 to 86 +/- 36 msec (p less than 0.05, n = 6). The effects of thyroid hormone were partially reversed by lidocaine (60 microM, n = 5), a specific blocker of a slow sub-population of Na channels. Thus thyroid hormone interacts directly with myocyte membrane, probably by slowing of inactivation of Na channels.

Action Potentials↗
PubMed1986

Prostate cancer.

Explore the source record for details and available documents.

Aged↗
PubMed1985

Non-invasive measurements of cell surface receptors.

None of the current methods for assessing the effects of subtle changes in drug structure on tissue is entirely satisfactory. The observation that 3H-drug molecules emit photons of light when they bind to membrane proteins (called Condensed Phase Radioluminescence) probably represents a significant advance in measuring non-invasively kinetic effects of drugs on beating monolayers of cardiac myocytes. The potential utility of CPR is great.

Animals↗
PubMed1976

Differential bone scanning.

This is a preliminary report of eleven patients with painful total joint arthroplasties. In their evaluation the difficulty in the differential diagnosis between the loose and the infected total joint becomes apparent. We have found the use of differential bone scans an accurate method to identify the infected total joint. Further study along these lines is indicated with a larger series and generalization to other types of implants.

Aged↗
PubMed1975

An evaluation of cryosurgery for basal cell carcinoma.

Fifteen histologically proven basal cell carcinomas were treated by conventional cryosurgery. Three to 6 months following healing, the entire treated area was excised and serially sectioned. There was clinical and microscopic evidence of residual tumor in two of the 15 cases and microscopic evidence of recurrence in one additional patient (20 percent recurrence).

Adult↗