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Biomedical subjects

A Fullerton

Publications and source records attributed to A Fullerton.

25 records · Page 2Linked to original sources
PubMed1989

Patch testing with nickel chloride in a hydrogel.

Various concentrations of NiCl2 in a hydrogel were evaluated as a possible alternative to the standard patch test material of 5% NiSO4 pet. Patch test responses were recorded on a total of 430 patients with known or suspected contact allergy. A NiCl2 concentration of 1% or less in the hydrogel failed to elicit a response in some patients who reacted to 5% NiSO4 pet. The 2% NiCl2 hydrogel produced a small increase in response frequency and may reduce false-negative reactions. Along with the ability of the material to improve the topical bioavailability of nickel ions, more irritant reactions were observed. However, in cases with a positive history and a negative patch test with petrolatum, the hydrogel prepared from Methocel-E-4M seems to be a useful alternative vehicle for water-soluble allergens.

Dermatitis, Contact↗
PubMed1988

Permeation of nickel through human skin in vitro--effect of vehicles.

The effect of the vehicle on the permeation rate of nickel ions through excised human skin was evaluated. Different hydrogels were compared with the standard patch test in petrolatum. A hydroxypropyl methylcellulose gel seemed to be the most promising alternative to petrolatum. It gave high bioavailability of the nickel and had good film forming properties leaving the nickel spread across the skin surface as a thin film without microscopically detectable crystals. The content of nickel in the various skin layers after cutaneous application was determined, and nickel was found to accumulate in the epidermis, probably due to epidermal binding. A significant amount of nickel was found also in the dermis. Occlusion and application of higher nickel concentrations increased the transport rate and must be considered in patch testing using this hydrogel. We conclude that nickel permeation is highly dependent of the choice of vehicle and the vehicle should, therefore, be an important consideration in patch testing with nickel.

Humans↗
PubMed1988

Binding of nickel to human epidermis in vitro.

Human epidermis was homogenized, dried and incubated with nickel chloride solutions in the concentration range 0.008-3.4 mM/50 mg epidermis. Nickel uptake was found to occur according to the Freundlich adsorption isotherm, giving a slope of 0.55, indicating that nickel is associatively bound to constituents of the epidermis. The binding characteristics of cobalt were very similar to those of nickel, but the two metals were not found to compete significantly for binding sites in the epidermis. The metal-chelating agents, ethylenediamine tetra-acetic acid disodium, (Na-EDTA) L-histidine and D-penicillamine were tested for ability to remove nickel from its binding sites. Na-EDTA was found to be the most efficient, removing 70-90% of the nickel bound to the tissue. The possible clinical significance of these in vitro observations are discussed in relation to percutaneous absorption and allergic contact dermatitis.

Binding Sites↗
PubMed1986

Permeation of nickel salts through human skin in vitro.

The impact of occlusion and the rôle of the counter ion on the permeation of nickel ions through skin have been examined using excised human skin. A highly sensitive electrochemical method was used to quantify the amount of nickel permeating the skin. The investigations show that nickel ions are capable of permeating the skin barrier when applied under occlusion. The process is slow, having a lag time of approximately 50 h. The permeation rate, and thus the physical amount being bioavailable, is considerably increased when aqueous nickel chloride is used in comparison with aqueous nickel sulphate. With respect to nickel permeation of the skin, we conclude that the choice of salt is an important consideration in patch testing.

Female↗
PubMedDate not supplied

A reliability study of measures assessing the impact of deinstitutionalization.

This study examined the reliability of several scales and indices used to measure outcome variables (independence, integration, productivity, and satisfaction) among people with developmental disabilities. A stratified random sample of 112 people was interviewed twice in a two-week period and included equal numbers of verbal and nonverbal consumers, of parent versus other caregivers, and consumers with diagnosed level of retardation being dichotomized into high and low. In addition, half of the interviews were test-retest and half were interrater. After stratifying on these four variables, the sample was chosen randomly within subgroups from the total database of 3,700 individuals who receive services through the Developmental Disabilities Services Division of the Oklahoma Department of Human Services. Correlation and proportion agreement analyses were performed on the pre- and post-tests and comparisons made on each scale for each stratification to examine variations in reliability. Acceptable correlations and matched agreements of at least 0.70 for all measures were found, with the Adaptive Development Scale having particularly strong correlations. In addition, responses from people with developmental disabilities on items of the Consumer Satisfaction scale were acceptably reliable.

Activities of Daily Living↗