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Biomedical subjects

J M Riley

Publications and source records attributed to J M Riley.

At least 19 recordsLinked to original sources
PubMed1998

Molecular characterization of an Arabidopsis gene encoding hydroperoxide lyase, a cytochrome P-450 that is wound inducible.

Hydroperoxide lyase (HPL) cleaves lipid hydroperoxides to produce volatile flavor molecules and also potential signal molecules. We have characterized a gene from Arabidopsis that is homologous to a recently cloned HPL from green pepper (Capsicum annuum). The deduced protein sequence indicates that this gene encodes a cytochrome P-450 with a structure similar to that of allene oxide synthase. The gene was cloned into an expression vector and expressed in Escherichia coli to demonstrate HPL activity. Significant HPL activity was evident when 13S-hydroperoxy-9(Z),11(E),15(Z)-octadecatrienoic acid was used as the substrate, whereas activity with 13S-hydroperoxy-9(Z),11(E)-octadecadienoic acid was approximately 10-fold lower. Analysis of headspace volatiles by gas chromatography-mass spectrometry, after addition of the substrate to E. coli extracts expressing the protein, confirmed enzyme-activity data, since cis-3-hexenal was produced by the enzymatic activity of the encoded protein, whereas hexanal production was limited. Molecular characterization of this gene indicates that it is expressed at high levels in floral tissue and is wound inducible but, unlike allene oxide synthase, it is not induced by treatment with methyl jasmonate.

Aldehyde-Lyases↗
PubMed1998

Wired on ethics.

Explore the source record for details and available documents.

Ethics, Nursing↗
PubMed1997

Transplantation of adenovirally transduced allogeneic chondrocytes into articular cartilage defects in vivo.

Gene transfer to chondrocytes followed by intra-articular transplantation may allow for functional modulation of chondrocyte biology and enhanced repair of damaged articular cartilage. We chose to examine the loss of chondrocytes transduced with a recombinant adenovirus containing the gene for Escherichia coli beta-galactosidase (Ad.RSVntlacZ), followed by transplantation into deep and shallow articular cartilage defects using New Zealand White rabbits as an animal model. A type I collagen matrix was used as a carrier for the growth of the transduced chondrocytes and to retain the cells within the surgically created articular defects. Histochemical analysis of matrices recovered from the animals 1, 3 and 10 days after implantation showed the continued loss of lacZ positive chondrocytes. The number of cells recovered from the matrices was also compared with the initial innoculum of transduced cells present within the matrices at the time of implantation. The greatest loss of transduced cells was observed in the first 24 h after implantation. The numbers of transduced cells present within the matrices were relatively constant between 1 and 3 days postimplantation, but had progressively declined by 10 days postimplantation. These results suggest that transduction of chondrocytes followed by intra-articular transplantation in this rabbit model may enable us to examine the biological effects of focal transgenic overexpression of proteins involved in cartilage homeostasis and repair.

Adenoviridae↗
PubMed1996

The scholarship of a practice discipline.

The article proposes that all nurses, as members of a discipline that is embedded in practice, share in the obligation to take part, in different capacities, in the generation of nursing scholarship. A model of scholarly inquiry that connects knowledge development and professional values to gather wisdom that benefits the health and well-being of society is advanced. Opportunity for all nurses to engage in a dialogue to create ownership of their scholarship is pivotal to its revisioning.

Humans↗
PubMed1995

Short-term evaluation of a foraging device for non-human primates.

In the USA, any institution involved in using non-human primates for research has had, for regulatory reasons, to address the psychological needs of these animals. Enriching the environment through the use of foraging devices has been one method and a study was designed to evaluate the short-term effect of a new foraging device on singly-housed cynomolgus monkeys. The study was divided into 3 one-week periods of observation: baseline, device filled with normal ration, and device filled with a novel food. Four behaviours were recorded: foraging, self-directed, hopper feeding, and other behaviours. During the observation periods the device was accepted in preference to the standard hopper style feeder and self-directed behaviours were significantly reduced compared with the baseline period. Changing to a novel food re-kindled interest in the device and reduced the extinguishing effect: i.e. decrease in interest or use of the device. Based on this study, the feeder has been included with several other devices in a rotation programme.

Animal Feed↗
PubMed1991

Living wills: making life and death decisions.

Each day, health care providers and families across the United States struggle with decisions regarding life-sustaining treatments for patients in irreversible vegetative states. And each day, these decisionmakers must face the potential for lawsuits for agreeing or refusing to carry out directives that may have been the "wish" of the patient, but were never put in writing.

Advance Directives↗
PubMed1987

Adult norms for the Kaufman Hand Movements Test and a single-subject design for acute brain injury rehabilitation.

Systematic administration of Luria's (1980) fist-edge-palm test in a series of increasingly complex patterns (Kaufman & Kaufman, 1983) is presented as the basis for an intervention strategy with acute brain injury rehabilitation patients. A normative sample of 80 adults was drawn from the community, and results are reported by age and gender. A therapeutic technique for improving focused attention is then described in terms of a multiple baseline, single-subject experimental paradigm. Verbal mediation of the hand movements is systematically introduced as a coping skill and the patient's ability to internalize the skill is evaluated as treatment conditions are varied. The immediate therapeutic goal is transfer of control of the strategy from therapist to patient. Statistical analysis suggests a significant treatment effect apart from improvement attributable to natural recovery. Incidental therapeutic gains are noted.

Adult↗
PubMed1967

Effect of virus input multiplicity and tissue cell concentration on growth of Rift Valley fever virus.

The effects of virus input multiplicity and of tissue cell concentration upon the growth of Rift Valley fever virus in L cells (Earle) were determined. The titers obtained in suspension cultures with cells obtained from two separate laboratories were significantly different. With both monolayer culture and suspension culture systems, a virus input multiplicity of 2.5 resulted in the greatest proliferation of virus. Optimal viral yields were obtained in suspension cultures containing 4 x 10(5) tissue cells per ml of suspension.

Arboviruses↗
PubMed1967

Application of the single-dose assay technique to psittacosis.

When suspensions of psittacosis organisms were injected intracerebrally into groups of mice, a nearly linear relationship was observed between the concentration of the organisms injected and the mean time to death of the mice. Thirty-four psittacosis preparations were assayed and, by plotting the relationship between the reciprocal time to death for mice given the 10(-3) dilution of agent against the number of mouse intracerebral median lethal doses (MICLD(50)), a reference curve was established. By use of this reference curve, it was possible to estimate directly the LD(50) value of a psittacosis suspension of unknown concentration from the mean reciprocal time to death of a group of mice injected with a single dilution. By this procedure, the number of mice used was reduced by 62.5%, the titrations were completed in 3 to 5 days as compared with the usual 12 days, three to four times as many assays could be done in 1 day, and no assays had to be repeated. In addition, the precision of the single-dilution assay compared favorably with that of the LD(50) titration.

Animals↗