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Biomedical subjects

D Porter

Publications and source records attributed to D Porter.

At least 37 records · Page 2Linked to original sources

Evaluation of reproductive function of female rats exposed to radiofrequency fields (27.12 MHz) near a shortwave diathermy device.

In recent years, there has been increased concern regarding effects of operator exposure to the electromagnetic (EM) field associated with shortwave diathermy devices. The present study was designed to investigate the effects, on rats, of repeated exposure to such an EM field. Following repeated exposure for 5 wk, a reduction in fertility occurred as indicated by a reduced number of matings in exposed rats compared to sham-irradiated rats and a reduction in the number of rats that conceived after mating. The data suggest that female operators could experience reduced fertility, if they remained close to the console for prolonged periods. This has particular significant for the physiotherapy profession.

Animals

The effect of footwear mass on the gait patterns of unilateral below-knee amputees.

This study reports an investigation into the effect of shoe mass on the gait patterns of below-knee (BK) amputees. Ten established unilateral BK, patellar-tendon-bearing prosthesis wearers were assessed using a VICON system of gait analysis. Incremental masses of 50g (up to 200g) were added to the subjects' shoes and data captured as they walked along a 15m measurement field. Coefficients of symmetry of various parameters of the swing phase (knee frequency symmetry, swing time symmetry) were measured and their correlation was tested with the patient's preferred shoe mass and also their own shoe mass, all expressed as a proportion of body mass. The subjects' 'preferred' shoe mass (139-318g) showed the greatest symmetry in all the parameters examined (correlations 0.78-0.81 p less than 0.01 and less than 0.005), whereas there was no correlation between the subjects' own shoe mass (121-325g) and the symmetry coefficients measured.

Amputation, Surgical

Progressive systemic sclerosis: Part 2--Nursing management.

Multiple body systems can be affected by scleroderma. Satisfactory coping and life-style alterations will depend on numerous factors, including the nature and extent of organ involvement, individual coping style, and health professional services provided. Because of the low incidence of this disease, nurses may have little knowledge about the nursing management. Because of the nature of the disease's complications, the nephrology or dialysis nurse may care for more scleroderma patients than other hospital nurses.

Adaptation, Psychological

Federal nutrition policies: impact on dietetic practice.

Current federal nutrition policies are likely to have a major impact on dietetic practice. Several examples have been selected to explain why and how members of the American Dietetic Association and other nutrition professionals should become involved in policy development and implementation.

Cholesterol

Self-service computerized bibliographic retrieval: a comparison of Colleague and PaperChase, programs that search the MEDLINE data base.

Colleague and PaperChase are the two most widely used computer systems designed specifically for clinicians and scientists who wish to search the National Library of Medicine's MEDLINE data base of references to the biomedical literature. The present study compares the performance of these two systems. Two matched groups of second-year medical students each received 3 hr of instruction, one group in Colleague, the other in PaperChase. Each student then attempted 10 test searches. The next day the groups were reversed, and each student attempted 5 additional searches. During 3 1/2 hr allocated for searching, users of Colleague attempted 64 test searches and retrieved 326 target references; users of PaperChase attempted 78 searches and retrieved 496. Users of Colleague took a mean of 2.2 min and spent a mean of $1.20 to find each target reference; users of PaperChase took 1.6 min and spent $0.92. We conclude that after limited training, medical students find more references faster and at lower cost with PaperChase than with Colleague.

Computer User Training

Successful operation of a regional scheme for the maintenance of automatic analysers.

The main operational and financial aspects of the maintenance service provided by the West of Scotland Health Boards' Department of Clinical Physics and Bio-Engineering (DCPB) to the clinical chemistry laboratories in the region are described. The scheme, in operation since March 1976, covers all breakdown servicing and engineering preventive maintenance for Technicon Auto-Analyzer equipment valued at pounds 1 1/4 million in terms of direct replacement costs. The engineering team works closely with the laboratory staffs to ensure that the performance of the equipment is maintained to specification. The direct economies for the Health Boards through savings in maintenance contract charges total around pounds 60,000 per year. In addition, considerable sums have been saved by servicing, modifying, and constructing other instruments for the laboratories outwith the immediate remit of Technicon maintenance. Other economic and operational benefits which result from the scheme are commercially disinterested advice on equipment obsolescence and replacement, and redistribution between the laboratories of old but useful equipment to meet specific needs of the service in the region.

Autoanalysis

Daily relaxation response breaks in a working population: I. Effects on self-reported measures of health, performance, and well-being.

An experiment conducted at the corporate offices of a manufacturing firm investigated the effects of daily relaxation breaks on five self-reported measures of health, performance, and well-being. For 12 weeks, 126 volunteers filled out daily records and reported bi-weekly for additional measurements. After four weeks of baseline monitoring, they were divided randomly into three groups: Group A was taught a technique for producing the relaxation response; Group B was instructed to sit quiety; Group C received no instructions. Groups A and B were asked to take two 15-minute relaxation breaks daily. After an eight-week experimental period, the greatest mean improvements on every index occurred in Group A; the least improvements occurred in Group C; Group B was intermediate. Differences between the mean changes in Groups A vs C reached statistical significance (p < 0.05) on four of the five indices: Symptoms, Illness Days, Performance, and Sociability-Satisfaction. Improvements on the Happiness-Unhappiness Index were not significantly different among the three groups. The relationship between amount of change and rate of practicing the relaxation response was different for the different indices. While less than three practice periods per week produced little change on any index, two daily sessions appeared to be more practice than was necessary for many individuals to achieve positive changes. Somatic symptoms and performance responded with less practice of the relaxation response than did behavioral symptoms and measures of well-being. (Am. J. Public Health 67:946-953,1977)

Adult

Collection of a clean voided urine specimen: a comparison among spoken, written, and computer-based instructions.

In an effort to compare different methods of instructing patients, 99 women 18-25 years of age were given computer, spoken, weitten, or no instructions for the collection of a clean voided urine specimen. The group who received computer instructions was the most uniform in its performance (P less than 0.002, F-test) and reported the fewest procedural problems (P less than 0.02, Fisher test). In addition, this group had fewer contaminating bacteria than the group who received written instructions (P less than 0.03 , Mann-Whitney test). The group who received no instructions had more bacteria (P less than 0.0001, Mann-Whitney test) than any of the other groups. The effectiveness of the computer instruction was probably related to numerous attributes, including the individualized quality of the dialogue, self-pacing, self-testing, and privacy.

Adolescent

A computer-based dietary counseling system.

A computer-based dietary counseling system is described. Designed to interact directly with patients, the program interviews people about their dietary behavior and plans with them a weight-reducing diet of approximately 1,500 kcal. In a preliminary trial, twenty-five volunteers gave critical commentary en route through the interviews. The results provided insight into the process of dietary interviewing by computer and helped in the preparation of an experimental study (10). It is our hope that a revised and expanded version of the program will be helpful to both patients and nutritionists in the management of a variety of clinically important dietary problems.

Computers

Dietary interviewing by computer. An experimental approach to counseling.

A computer-based dietary counseling system was tested by sixty-four volunteers from the Boston area. Most of the patients seemed to benefit from their interaction with the computer, and the two participating nutritionists frequently found that the program was useful as an antecedent to their own one-to-one sessions with the patients.

Adult

Interaction of gamma-ray and neutron effects on the proliferative capacity of Chinese hamster cells.

The loss of reproductive capacity of Chinese hamster cells has been studied using 60Co gamma-rays and DT neutrons singly or combined in fixed proportions. Surviving fractions were measured down to 2 times 10-4. Interaction between the effects produced by neutrons and gamma-rays in the mixed irradiations has been demonstrated. The results are compared with those predicted by the cellular inactivation model developed by Katz and co-workers from their delta-ray theory of track structure.

Animals

The response of the ferrous sulphate dosemeter to neutrons.

A semi-empirical method of calculating G-values for the ferrous sulphate dosemeter irradiated by neutrons up to 18 MeV has been developed. It utilizes published charged particle G-values along with particle spectra calculated for mono-energetic neutron interactions with the dosemeter medium. All available G-value measurements with neutrons have been evaluated and compared with values predicted by this method. The agreement was excellent for DT generator and cyclotron neutron beams in which the neutron spectra had been accurately determined. However, the predictions could not be completely confirmed for lower energy neutrons becuase of the large experimental uncertainties in the measured G-values and the lack of detailed information on the neutron spectra.

Evaluation Studies as Topic