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Biomedical subjects

P J Neafsey

Publications and source records attributed to P J Neafsey.

At least 19 recordsLinked to original sources
PubMed2001

Delivering health information about self-medication to older adults: use of touchscreen-equipped notebook computers.

Preventing Drug Interactions in Active Older Adults is an educational intervention to prevent prescription and over-the-counter (OTC) drug and alcohol interactions in active, community-living older adults. The objectives of the program are to increase older adults' knowledge of potential interactions of prescription medications with OTC drugs and alcohol and to increase their confidence (self-efficacy) about how to avoid such interactions. An interactive multimedia computer software program (Personal Education Program or PEP) was designed for the learning styles and psychomotor skills of older adults. Focus groups of older adults evaluated PEP components in a formative manner during development. The program content dealing with antacids, calcium supplements, and acid reducers was pilot tested with 60 older adults recruited from local senior centers. Participants used the PEP on notebook computers equipped with infrared-sensitive touchscreens. Users of PEP had greater knowledge and self-efficacy scores than controls. Participants indicated a high degree of satisfaction with the PEP and reported their intent to make specific changes in self-medication behaviors.

Aged↗
PubMed1995

A mortality kinetics approach to characterizing the fractionated exposure-mortality response relationship of radon progeny.

The utility of mortality kinetics analysis in evaluating mortality data from fractionated exposure studies was demonstrated using radon-progeny induced extra mortality as an example. Gompertz (log-hazard) functions were used to characterize the mortality of male SPF Wistar rats exposed to radon progeny at 100 WL and 1000 WL for total exposures ranging from 20 to 10,240 WLM. There was an upward parallel displacement of the Gompertz functions following the period of radon exposure. The shape of the Gompertz functions for the exposed animals was consistent with a Gompertz model of toxicity resulting from short-term exposure, resulting in non-repaired injury that summates with natural (aging) injury. The parallel upward displacements (epsilon ss) of the Gompertz functions showed an unexpected non-monotonic pattern for rats exposed at 1000 WL. The parallel upward displacements showed a sharp upward increase from 320 to 640 WLM, fell at 1280 WLM, and thereafter increased linearly to 10,240 WLM. These data suggest that the radon progeny exposure-mortality response is non-linear. In contrast, there was no significant parallel upward displacement of the Gompertz functions for rats exposed at 100 WL for total exposures of 20-1280 WLM, but a large displacement began at 2560 WLM total exposure.

Animals↗
PubMed1994

A mortality kinetics approach to characterizing the relative biological effectiveness of short-term exposure to fission neutrons.

A Gompertz age-specific mortality rate model was developed for toxicity resulting from a short-term exposure to a toxicant resulting in nonrepaired injury that summates with natural (aging) injury. The model was applied to mortality data for male and female B6CF1 mice subjected to 60 weekly whole-body exposures to fission neutrons and gamma rays (W. F. Thomson and D. Grahn, Radiat. Res. 115, 347-360, 1988). There was no apparent increase in the age-specific mortality rate of mice during the 60-week period of fractionated exposures to fission neutrons. Cumulative toxicity was not exhibited in the Gompertz functions of mice exposed to fission neutrons until after termination of exposure. As a secondary issue, the Gompertz age-specific mortality rate model was modified to incorporate paradoxical "oversurvival" or longevity hormesis in mice exposed to fission neutrons. This modified model was compared to a model that has no allowance for oversurvival. The logarithmic-logistic function was used to relate the parallel upward displacement of the Gompertz function at steady state (i.e., the time after exposure ceased and the mortality effects of oversurvival dissipated) with dose. The data were shown to support the assumption of parallel upward displacement. The relative biological effectiveness (RBE) of fission neutrons compared to gamma rays was calculated using the steady-state displacement of the Gompertz functions. The RBE was defined as the ratio of doses D gamma/DN necessary to produce the same upward displacement by neutron radiation (DN) and gamma rays (D gamma). This definition is proposed as a useful measurement of RBE for studies of short-term exposures to fractionated radiation.

Animals↗
PubMed1993

A Gompertz age-specific mortality rate model of toxicity from short-term whole-body exposure to fission neutrons in rats.

A Gompertz age-specific mortality rate model was developed for toxicity resulting from a single dose of a toxicant resulting in nonrepaired injury that summates with natural (aging) injury. The model was applied to mortality data for male Sprague-Dawley rats subjected to short-term whole-body exposure to fission neutrons (D. Chmelevsky et al., Radiat. Res. 98, 519-535, 1984; J. LaFuma et al., Radiat. Res. 118, 230-245, 1989). The logarithmic-logistic function was used to relate the displacement of the Gompertz function with dose. Analysis of the age-specific mortality rate provides a measure of total injury over time from combined neoplastic and non-neoplastic causes and can be used to calculate the relative biological effectiveness (RBE) of different radiation sources. It is a useful adjunct to conventional risk assessment paradigms, particularly for those toxicants such as fission neutrons which result in a large number of competing causes of death other than cancer.

Age Factors↗
PubMed1990

Longevity hormesis. A review.

The phenomenon of longevity hormesis is reviewed. The life-prolonging effects of longevity hormesis are compared and contrasted with those resulting from depressed food intake. The use of age-specific mortality rate analysis as a tool to characterize the separate and distinct effects of longevity hormesis, cumulative toxicity and depressed food intake on the survival of laboratory animals is illustrated. Finally, model systems through which the mechanism(s) of longevity hormesis may be elucidated are discussed.

Animals↗
PubMed1989

A Gompertz age-specific mortality rate model of aging: modification by dietary restriction in rats.

A Gompertz age-specific mortality rate model characterizing actuarial effects of food restriction in rats was developed based on mortality data from the study of Yu et al. (J. Gerontol. 40: 657-670, 1985). Results indicated that in the presence of adequate nutrition, food restriction reduces the aging rate parameter in a consistent manner, regardless of the age at which food restriction is initiated.

Aging↗
PubMed1988

A Gompertz age-specific mortality rate model of aging, hormesis, and toxicity: fixed-dose studies.

Based on the proposition that the logarithm of age-specific mortality rate (Gompertzian) is a linear measure of the mean intensity of injury for a homogeneous mammalian population in a uniform environment, a model was developed which characterizes mortality experience resulting from both toxic and hormetic actions. The mortality-reducing component (longevity hormesis) was assumed to be reversible; toxic effects, on the other hand, were assumed to accumulate irreversibly. Following chronic low-dose administration of selected toxic substances, it was demonstrated (in certain cases) that longevity hormesis could enhance lifespan, even in the presence of concomitant toxicity. Even when toxicity was evident, hormesis could ameliorate some of the mortality. The assumption that high-dose chronic toxicity studies can generate realistic estimates of risk at low doses is challenged.

Aging↗
PubMed1988

Hormesis, Gompertz functions, and risk assessment.

A historical survey of the literature indicates that benefits derived from low doses of toxic substances have been reported over many centuries. Hippocrates, Paracelsus, Arndt, Schulz, and Hahnemann (founder of homeopathy) have all reported that low doses of toxic substances may be "stimulatory" or otherwise beneficial. Assessment of mortality data from modern-day bioassay studies indicates that low-dose animal exposure to a variety of toxic agents can, through an unknown mechanism, also induce beneficial changes which promote health and prolong life (longevity hormesis). This nonspecific and apparently reversible phenomenon has been modeled kinetically through use of age-specific mortality rate and a generalized Gompertz function; the basic assumption is that mortality in an interval is a function of the weighted sum of intensities of physiologic injury during that interval. It was assumed that longevity-enhancing hormetic reduction in population injury may be decremented from life-shortening injury produced through the aging process and concomitant toxicity. At low exposure levels, a net reduction in age-specific mortality rate can sometimes be observed. The implications for risk assessment are significant. It is tacitly assumed in generating virtually all estimates of risk that toxic manifestations observed at higher doses are the sole effects elicited at lower doses. This appears to be qualitatively incorrect.

Animals↗
PubMed1977

Serum and duodenal alkaline phosphatase levels in fed and fasted magnesium deficient rats.

Rats depleted of magnesium for 13 days were killed after 18 to 20 hours of fasting or 2 hours after consumption of a standard-sized meal. Serum and duodenal alkaline phosphatase (AP) were reduced in fasted magnesium depleted rats compared to pair-fed and ad libitum-fed controls. With refeeding, serum alkaline phosphatase levels rose significantly in all groups, but the levels in refed Mg deficient rats remained below serum levels of fasted control rats. Inhibition of AP activity with L-phenylalanine and urea suggested that the differences in AP levels of fasted and fed rats were mainly due to enzymes of intestinal origin. Intestinal AP levels increased after feeding in all groups, but were proportionately greatest in Mg depleted rats. The pattern of serum and duodenal AP in fed and fasted rats and the results of polyacrylamide disc gel electrophoresis (PADGE) in duodenal AP extracts suggest that Mg depletion alters the release of AP into the blood that normally occurs in response to feeding.

Alkaline Phosphatase↗
PubMedDate not supplied

Pre-existing variables and outcome of cardiac arrest resuscitation in hospitalized patients.

If critical care nurses and advanced practice nurses could identify patients with an increased risk of an unsuccessful outcome from cardiac arrest resuscitation in the hospital, such patients could be monitored with a heightened vigilance. This is the first nursing study to examine pre-existing variables and outcome of cardiac arrest resuscitation in hospitalized patients. The investigators found that heart rate and respiratory rate increased significantly 8 hours before the cardiac arrest in patients with an unsuccessful outcome of resuscitation.

Cardiopulmonary Resuscitation↗
PubMedDate not supplied

Self-efficacy measurements: an approach for predicting practice outcomes in continuing education?

This study assessed the usefulness of measurements of self-efficacy in evaluating practice outcomes following a continuing education course in advanced practice pharmacology. Self-efficacy, a central construct in social-cognitive theory, refers to an individual's confidence in being able to perform a specific task to successful completion. The study demonstrated that a valid and reliable measure of self-efficacy could be developed from program objectives and used in conjunction with pre- and post-knowledge measures to gain a broader perspective of learning outcomes. Measurements of self-efficacy was a useful adjunct in post-instruction evaluation and may be a cost-effective alternative to longitudinal impact evaluation.

Clinical Competence↗
PubMedDate not supplied

Computer-assisted instruction for home study: a new venture for continuing education programs in nursing.

BACKGROUND: Advanced practice nurses (APNs) tested a 5-contact hour home-study computer assisted instructional (CAI) program in pharmacokinetics developed by the author. METHOD: Twenty-seven APNs enrolled in a traditional lecture continuing education course in pharmacology participated in the study. The APNs were given a knowledge test and self-efficacy questionnaire before using the CAI program and again at the completion of program use. RESULTS: Significant gains in knowledge and self-efficacy with large effect sizes were achieved by the program users. They cited the convenience, organization and simplicity of use, graphic animations, and interactive question sequences as advantages of the program. CONCLUSION: Home study by computer may be a feasible option to printed home-study and lecture-based continuing education programs in nursing.

Computer-Assisted Instruction↗
PubMedDate not supplied

Immediate and enduring changes in knowledge and self-efficacy in APNs following computer-assisted home study of The Pharmacology of Alcohol.

BACKGROUND: 18 advanced practice nurses (APNs) evaluated a two contact hour home-study computer-assisted instructional (CAI) program on the pharmacology of alcohol developed by the author. Changes in knowledge and self-efficacy were measured immediately following program use and 5 months later. METHOD: The APNs were recruited from two seminar sections of a traditional lecture-based continuing education course for nurses enrolled in a primary care nurse practitioner program. Participants completed cognitive and self-efficacy instruments in class pre-program use and 5 months post-program use. The APNs completed immediate post-program evaluation instruments at home and returned them by mail. RESULTS: Significant gains in knowledge and self-efficacy with large effect sizes were achieved immediately following program use. Cognitive and self-efficacy scores decayed significantly 5 months post-program use but were still significantly greater than pre-program scores. CONCLUSION: These findings indicate that continuing education in substance misuse or other pharmacology content may be effectively implemented at home via CAI.

Alcohol Drinking↗