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Biomedical subjects

L Phillips

Publications and source records attributed to L Phillips.

At least 127 records · Page 7Linked to original sources

Ethical reasoning concerning the feeding of severely demented patients: an international perspective.

Structured interviews were held with 149 registered nurses in seven countries in America, Asia, Australia and Europe concerning the feeding of severely demented patients who do not accept food. The most common reasons for nurses being willing to change their decision to feed or not to feed were an order from the medical head, a request from the patient's husband and/or the staff meeting. There was a connection between the willingness to feed and the ranking of ethical principles. Nurses who were most prone to feed the patient most often gave a high rank to the ethical principle of sanctity of life, while those who primarily chose not to feed the patient gave a high rank to the ethical principle of autonomy. All nurses stressed the ethical principle of beneficence.

Adult↗

Expression and post-translational processing of a broad-spectrum organophosphorus-neurotoxin-degrading enzyme in insect tissue culture.

A recombinant baculovirus, Autographa californica nuclear polyhedrosis virus (AcNPV), has been utilized to express the opd (organophosphate-degrading) gene from Pseudomonas diminuta in insect tissue-culture cells (Sf9) of the fall armyworm (Spodoptera frugiperda). The broad-spectrum organophosphate hydrolase (EC 3.1.8.1) encoded by this gene is a member of a general class of enzymes [organophosphate (OP) anhydrolases] that include parathion hydrolases, di-isopropyl-fluorophosphatases (DFPases), somanases, and OP phosphotriesterases. This particular enzyme possesses the ability to hydrolyse paraoxon (P-O bond), DFP, sarin (P-F bond), VX (P-S bond) and tabun (P-CN bond), as well as a number of other extensively used organophosphorus pesticides. The enzyme produced in infected Sf9 cells is post-translationally processed and resembles the mature form of the enzyme expressed in various bacterial cells as identified by immunoprecipitation on Western blots. N-terminal sequence analysis of enzyme expressed in insect cells revealed Gly-29 as the terminal residue, whereas expression in Escherichia coli removes this residue, exposing Ser-30 at the N-terminus. Conditions for optimal expression of the enzyme in this system are described. Furthermore, hydrolytic efficiency of some OPs with purified enzyme from this system is discussed in relation to the in situ activity of Pseudomonas diminuta MG cells.

Animals↗

Prevalence of shigellosis and other enteric pathogens in a zoologic collection of primates.

An epidemiologic study of shigellosis was the preliminary step in the formulation of a plan for the control of devastating infectious diseases in nonhuman primates at the National Zoological Park. Data were collected from primate groups with enzootic shigellosis and included the following species: white-cheeked and siamong gibbons (Hylobates concolor and H syndactylies); lion-tailed, celebes, and Barbary macaques (Macaca silenus, M nigera, and M sylvanus); black and white colobus monkeys (Colobus guerzea); grey-cheeked mangabeys (Cerecocebus albigena); spider monkeys (Ateles susciceps robusuts); ruffed lemurs (Lemur varrigatus); lowland gorillas (Gorilla gorilla); and orangutans (pongo pygmaeus). Data included results of physical examination, proctoscopy with biopsy, fecal parasitologic and cytologic examinations, and bacteriologic culturing of swabbed specimens of rectum and gingiva. Repetitive fecal examinations were subsequently performed and included bacteriologic culturing of fecal specimens for enteropathogenic bacteria and parasites and cytologic examination of feces. Data were collected for a 1-year period from 82 primates, and 14 gibbons were studied intensively. White-cheeked and siamang gibbons shed Shigella flexneri sporadically, but persistently. All gibbons were affected with a mean point prevalence of 30.7% (range 0 to 71%). Shigella flexneri also was isolated from feces of lion-tailed macaques. Shigella sonnei was isolated from feces of grey-cheeked mangabeys, celebes macaques, and spider monkeys.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Focus on psychometrics. Development and administration of a survey instrument for cross-cultural research.

The purpose of this article is to provide a brief review of guidelines for development of culturally appropriate measures of phenomena. The principles are illustrated by citing an example of their use in developing a survey instrument to be used with a rural Mexican American and Euro American population. Discussion focuses on practical issues of implementing the approaches suggested in the literature and adds to the literature about issues in formatting and administration of survey instruments used in cross-cultural research.

Cross-Cultural Comparison↗

An international perspective of active euthanasia: attitudes of nurses in seven countries.

This exploratory study examines the ethical justification that cancer care and dementia care nurses gave for active voluntary euthanasia. A convenient sample of 319 nurses working in seven countries was interviewed using a structured interview guide. The great majority of the nurses could not ethically justify active voluntary euthanasia. Even if the law changed, only 96 of the total sample viewed active voluntary euthanasia as ethical. For those nurses who could ethically justify active voluntary euthanasia, the majority did so because of the patients' suffering.

Adult↗

Suppression of in vitro proliferative scar fibroblast contraction by interferon alfa-2b.

Increased fibroblast activity and collagen production have been observed frequently in proliferative scars. Previous studies have demonstrated that interferons suppress collagen production by means of normal, keloid, and hypertrophic scar-derived fibroblasts. The fibroblast-populated collagen lattice is an in vitro model used to study fibroblast function. We used fibroblast-populated collagen lattices to evaluate the effect of interferon on fibroblasts harvested from normal human skin, human keloid, and hypertrophic scar tissues. Human recombinant interferon alfa-2b (1000 IU/ml) was added to the culture media. The collagen gel, prepared from rat tail tendon bundles, was overlaid with 5 x 10(4) fibroblast cells. Keloid fibroblast-populated collagen lattices showed the highest contraction. Contraction in all the groups appeared suppressed by interferon alfa-2b during the first 72 hours of study (p < 0.05). The reduction in fibroblast-populated collagen lattice contraction by interferon alfa-2b was similar among the groups. The contractile properties of fibroblasts taken from normal human skin, keloids, and hypertrophic scars in this in vitro study were suppressed by interferon alfa-2b. This suggested that interferon alfa-2b may be beneficial for the treatment of proliferative scars.

Journal Article↗

Quality of attention in chronic fatigue syndrome: subjective reports of everyday attention and cognitive difficulty, and performance on tasks of focused attention.

Patients with chronic fatigue syndrome (also known as post-viral fatigue syndrome or myalgic encephalomyelitis) commonly report cognitive difficulties concerning attention, concentration and memory. In this study, patients were compared with matched controls on two questionnaires which assess subjective difficulties with attention and general cognitive functioning, and on two tasks requiring focused attention. Patients reported significantly greater difficulty with attention on the Everyday Attention Questionnaire and more cognitive symptoms on the Profile of Fatigue-Related Symptoms. The objective tests did not clearly indicate a deficit in patients' focused attention; patients tended to perform less well on the Embedded Figures Test and the Stroop Colour-Word Interference Test, but these differences were not significant. There was, however, evidence of psychomotor retardation, with patients having longer response times for word reading and colour naming in the Stroop test. Difficulties in interpreting findings for both subjective and objective cognitive measures are discussed.

Adult↗

Antifolates induce inhibition of amido phosphoribosyltransferase in leukemia cells.

The pathway for de novo biosynthesis of purine nucleotides contains two one-carbon transfer reactions catalyzed by glycinamide ribotide (GAR) and 5-aminoimidazole-4-carboxamide ribotide (AICAR) transformylases in which N10-formyltetrahydrofolate is the one-carbon donor. We have found that the antifolates methotrexate (MTX) and piritrexim (PTX) completely block the de novo purine pathway in mouse L1210 leukemia cells growing in culture but with only minor accumulations of GAR and AICAR to less than 5% of the polyphosphate derivatives of N-formylglycinamide ribotide (FGAR) which accumulate when the pathway is blocked completely by azaserine. This azaserine-induced accumulation of FGAR polyphosphates is completely abolished by MTX, indicating that inhibition of the pathway is at or before GAR transformylase (reaction 3; Lyons, S. D., and Christopherson, R. I. (1991) Biochem. Int. 24, 187-197). Three h after the addition of MTX (0.1 microM), cellular 5-phosphoribosyl-1-pyrophosphate has accumulated 3.4-fold while 6-methyl-mercaptopurine riboside (25 microM) induces a 6.3-fold accumulation. These data suggest that amido phosphoribosyltransferase catalyzing reaction 1 of the pathway is the primary site of inhibition. In support of this conclusion, we have found that dihydrofolate-Glu5, which accumulates in MTX-treated cells, is a noncompetitive inhibitor of amido phosphoribosyltransferase with a dissociation constant of 3.41 +/- 0.08 microM for interaction with the enzyme-glutamine complex in vitro. Folate-Glu5, MTX-Glu5, PTX, dihydrotriazine benzenesulfonyl fluoride, and AICAR also inhibit amido phosphoribosyltransferase.

Amidophosphoribosyltransferase↗