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Biomedical subjects

L A Douglas

Publications and source records attributed to L A Douglas.

4 recordsLinked to original sources

Adrenoleukodystrophy: a nursing challenge.

Adrenoleukodystrophy has only recently been recognized as a disorder unique to children. Its debilitating sequelae have a profound impact on the physical, psychosocial, and cognitive development of children. Superimposed on coping with the crisis of illness is the stressor of hospitalization, a common experience for children with adrenoleukodystrophy. This article focuses on nursing's contribution to facilitating children's adaptation to the stressors of a progressive disorder, adrenoleukodystrophy, and hospitalization. Utilizing a developmental approach, the psychosocial needs of these children are addressed in a format based on the nursing process.

Adrenoleukodystrophy↗

Cocaine and development: a retrospective perspective.

Neurobehavioral alterations evident in offspring of Sprague-Dawley rat dams exposed to 40 mg/kg/day cocaine subcutaneously from gestational days 8-20 are reviewed. Consequences for offspring are often age dependent: for instance, reliable deficits in classical conditioning are evident during the early postnatal period, whereas cognitive effects are less pervasive in adulthood, although apparent in tasks such as reversal training. Gender of offspring is another variable of importance, particularly when testing animals in adulthood, with adult male offspring being more likely than their female counterparts to exhibit alterations following the prenatal exposure regimen. Characteristics of the test situation likewise influence detection of outcome effects, with effects particularly likely to emerge under stressful testing conditions or other challenges to the organism. Under these circumstances, alterations in responsiveness to stressors also sometimes emerged in offspring of pair-fed (PF) dams (whose food intake was restricted to match that of cocaine-exposed [COC] dams); these findings perhaps should not be surprising given that pair feeding is a stressor and prenatal stress is known to alter later stressor responsiveness. Although several approaches to equate food intake or avoid pair feeding have yielded disappointing findings, one promising approach is to initiate cocaine administration prior to mating followed by exposure throughout gestation. Premating exposure to cocaine was sufficient to eliminate anorexic effects of drug delivery during pregnancy, although it remains to be seen how similar the pattern of neurobehavioral alterations that emerge with this extended exposure regimen will be to effects seen following more restricted gestational exposure.

Animals↗

Sorption and degradation characteristics of phosmet in two contrasting Australian soils.

The organophosphate insecticide phosmet [phosphorodithioic acid, s-((1,3-dihydro-1,3-dioxo-2H-isoindol-2yl)methyl), o,o-dimethyl ester] is used to control red-legged earth mites (Halotydeus destructor), lucerne flea (Sminthurus viridis), and Oriental fruit moth (Cydia molesta) in horticulture and vegetable growing. This study was undertaken with two soils of contrasting properties to determine the extent to which sorption and degradation of the insecticide might influence its potential to leach from soil into receiving waters. Two soils were used: a highly organic, oxidic clay soil (Ferrosol) and a sandy soil low in organic matter (Podosol), sampled to 0.3 m depth. The extent of sorption and decomposition rate of a phosmet commercial formulation were measured in laboratory experiments. Sorption followed a Freundlich isotherm at all depths. The Freundlich coefficient K was significantly correlated (p = 0.005) with organic C content in the Podosol, and significantly correlated (p = 0.005) with organic C and clay content in the Ferrosol. K was highest (48.8 L kg-1) in the 0- to 0.05-m depth of the Ferrosol, but lowest (1.0 L kg-1) at this depth in the Podosol. Degradation followed first-order kinetics, with the phosmet half-life ranging from 14 h (0-0.05 m depth) to 187 h (0.2-0.3 m depth) in the Ferrosol. The half-life was much longer in the sandy Podosol, ranging from 462 to 866 h, and did not change significantly with depth. Soil organic C and to a lesser degree clay content influenced phosmet sorption and degradation, but the interaction was complex and possibly affected by co-solvents present in the commercial formulation.

Adsorption↗