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Biomedical subjects

S Blackburn

Publications and source records attributed to S Blackburn.

At least 37 records · Page 2Linked to original sources
PubMed1987

Dinoflagellate Gymnodinium catenatum as the source of paralytic shellfish toxins in Tasmanian shellfish.

Paralytic shellfish toxins in both cultured cells and natural phytoplankton blooms of the dinoflagellate Gymnodinium catenatum from inshore Tasmanian waters (Australia) were analyzed by high performance liquid chromatography, thin layer chromatography and electrophoresis techniques. The dinoflagellate toxins were dominated by low potency sulfocarbamoyl saxitoxin derivatives (98-99 mole% in total), including gonyautoxin VIII (C2) and its epimer (C1) and sulfocarbamoyl gonyautoxins I and IV (C3 and C4). Mussels and oysters contaminated by the dinoflagellate showed similar toxins, but contained larger proportions of C3 (40-57 mole%) and more potent carbamate toxins (7-23 mole% total).

Animals↗
PubMed1987

Biosynthesis of polyamines in ornithine decarboxylase, arginine decarboxylase, and agmatine ureohydrolase deletion mutants of Escherichia coli strain K-12.

Escherichia coli K-12 mutants that carry deletions in their genes for ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17) (speC), arginine decarboxylase (L-arginine carboxy-lyase, EC 4.1.1.19) (speA), and agmatine ureohydrolase (agmatinase or agmatine amidinohydrolase, EC 3.5.3.11) (speB) can still synthesize very small amounts of putrescine and spermidine. The putrescine concentration in these mutants was found to be 1/2500th that in spe+ cells. The pathway of putrescine synthesis appears to be through the biodegradative arginine decarboxylase, which converts arginine to agmatine, in combination with a low agmatine ureohydrolase activity--1/2000th that in spe+ strains. These results suggest that even such low levels of polyamines permit a low level of protein synthesis. Evidence is presented that the polyamine requirement for the growth of the polyamine-dependent speAB, speC deletion mutants, which are also streptomycin resistant, is not due to a decreased ability to synthesize polyamines.

Bacterial Proteins↗
PubMed1985

Making a case for studying the ecologic niche of the newborn.

A major focus of theory building in nursing relates to further conceptualization of human-environmental interaction and multidimensional systems that support or do not support health. There is a growing body of knowledge regarding the newborn and his skills, and the transactions and interactions between the newborn and his environment. The newborn cannot be considered in isolation from his environment for it is this interaction with the environment that provides opportunities for organization of his behavior, physiologic functions, and regulatory processes. The caregiving environment and the newborn's interactions with this environment form the ecologic niche of the newborn; one that will enhance or impede the infant's behavioral differentiation and organization, early adaptations, later development, and the infant's interactions with his parents and other caregivers.

Adult↗
PubMed1984

Assessment of change-agent expectations in reversal-to-baseline designs.

Questionnaires similar to those used in previous research to assess behavioral expectations produced by differing reversal-to-baseline rationales were presented to 160 male and female parents in rural South Dakota. Given two case histories, respondents were asked to predict, as simulated change agents, the frequency of problem behavior during reversal in an ABAB design intervention. The five rationales for reversal were: (a) withdrawal, (b) withdrawal and counter-expectancy, (c) problem switch and counter-expectancy, (d) fade and counter-expectancy and (e) inert treatment and counter-expectancy. While obtained means were close to those of a previous study, there were no significant sex or treatment effects. This fails to confirm the earlier results obtained from university undergraduates. Implications for internal validity of ABAB designs are discussed.

Adult↗
PubMedDate not supplied

Fostering behavioral development of high-risk infants.

Concerns exist regarding the impact of the early neonatal intensive care unit environment on preterm and other high-risk infants and the lack of stimulus geared to the infant's individual needs and status. The nurse, as the primary caregiver in the neonatal intensive care unit, plays a major role in determining the infant's environment and in modulating interactions between the infant and the environment. Considerations for planning and providing infant stimulation, and nursing actions to enhance and support the infant's developmental capabilities and to foster parent-infant interaction are discussed.

Adult↗
PubMedDate not supplied

Impact of an infant's premature birth on the grandparents and parents.

Although the reactions of a family to the premature birth of an infant have been studied increasingly in recent years, the family examined has been limited almost exclusively to the parents. An exploratory survey examined the feelings, perceptions and experiences of 83 grandparents and 50 parents of premature infants. Results indicated that the impact of a premature birth was intensely felt by parents and grandparents. Both groups experienced similar reactions to the initial appearance of the neonate and neonatal intensive care unit environment and to visiting policies. Parents received most of their information about premature infants directly from nurses, doctors, and the parent support group, whereas grandparents had to rely on the newborn's parents.

Adult↗