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K Sharp

Publications and source records attributed to K Sharp.

26 records · Page 2Linked to original sources
PubMed1986

Electrokinetic and electrostatic properties of bilayers containing gangliosides GM1, GD1a, or GT1. Comparison with a nonlinear theory.

We formed vesicles from mixtures of egg phosphatidylcholine (PC) and the gangliosides GM1, GD1a, or GT1 to model the electrokinetic properties of biological membranes. The electrophoretic mobilities of the vesicles are similar in NaCl, CsCl, and TMACl solutions, suggesting that monovalent cations do not bind significantly to these gangliosides. If we assume the sialic acid groups on the gangliosides are located some distance from the surface of the vesicle and the sugar moieties exert hydrodynamic drag, we can describe the mobility data in 1, 10, and 100 mM monovalent salt solutions with a combination of the Navier-Stokes and nonlinear Poisson-Boltzmann equations. The values we assume for the thickness of the ganglioside head group and the location of the charge affect the theoretical predictions markedly, but the Stokes radius of each sugar and the location of the hydrodynamic shear plane do not. We obtain a reasonable fit to the mobility data by assuming that all ganglioside head groups project 2.5 nm from the bilayer and all fixed charges are in a plane 1 nm from the bilayer surface. We tested the latter assumption by estimating the surface potentials of PC/ganglioside bilayers using four techniques: we made 31P nuclear magnetic resonance, fluorescence, electron spin resonance, and conductance measurements. The results are qualitatively consistent with our assumption.

Egg Yolk↗
PubMed1986

Control by H-2 genes of murine antibody responses to protein antigens of Mycobacterium tuberculosis.

The genetic control of antibody responses after immunization with Mycobacterium tuberculosis soluble antigens was examined in inbred and H-2 congenic mouse strains. Antibody levels to five distinct epitopes were determined by a competitive inhibition test using radiolabelled murine monoclonal probes. High or low responder antibody levels were associated with either the H-2b (TB23, TB71 and TB72 specificities) or the H-2k (TB68) allele on both B10 and BALB backgrounds. The high response of TB78 specificity associated with the H-2k on the BALB but with H-2b haplotype on B10 background. The phenotype of (C57BL/6 X CBA)F1 hybrids reflected the high response for four and the low or intermediary response for one (TB68) of the tested paratopes. This is the first demonstration of immune response gene control in respect of defined mycobacterial protein epitopes. The implications towards the analysis of pathogenic or protective mechanisms during mycobacterial infection are briefly outlined.

Animals↗
PubMed1983

Aging and perceived health status.

Using a probability sample of 660 adults in Illinois, this study focuses on the relationship between age and perceived health status. According to age stratification theory, age groups need to be analyzed as age-specific entities that exist in relation to other sets of age groups. Following this perspective these data examine differences across the spectrum of adult age groups in this sample in regard to self-assessments of health. Number of symptoms was the strongest predictor of perceived health status employed in this analysis, followed by age, education, and race. It was found that those persons belonging to age groups over the age of 60 tend to perceive their own health in a significantly more positive fashion than members of younger adult age groups. The more educated elderly persons and those with the fewest symptoms, however, were most likely to hold this perception. One important area in which people appear to adjust their perception in later life is in their evaluation of personal health status.

Adolescent↗
PubMed1968

Ribonucleic acid synthesis in T2-infected Escherichia coli during "stringent" control.

The leucine auxotroph Escherichia coli 2961 exhibited stringent control of net ribonucleic acid (RNA) synthesis during amino acid starvation. After leucine was exhausted from the medium, the rate of uracil incorporation into RNA rapidly decreased to 2 to 4% of the prestarvation value. Infection of the starved cells with T2 phage stimulated uracil incorporation to a level equivalent to that of unstarved, T2-infected cells. The RNA synthesized during leucine starvation of the T2-infected cells consisted of T2 and E. coli messenger RNA, but stable ribosomal RNA (23S and 16S) did not appear to be synthesized. It is concluded that one or more T2-specific proteins are required to shut off host messenger RNA synthesis. Furthermore, transcription of E. coli and T2 deoxyribonucleic acid is not necessarily coupled to the translation of messenger RNA during stringent control of net RNA synthesis.

Amino Acids↗
PubMedDate not supplied

Sociology in nurse education: help or hindrance?

Recent years have seen a dramatic increase in the role of the social and behavioural sciences in nurse education. In part this follows the UKCC's recommendations for Project 2000 curricula, but it can also be seen as a wider reaction to the domination of nursing knowledge by the so-called 'biomedical' model. Indeed, not only do pre-registration courses in nursing and midwifery now incorporate significant elements of sociology and psychology, but so, especially, do post-registration diploma and degree courses. Although this development is often regarded by nurse educators (many of whom either possess, or are in the process of acquiring degrees or post-graduate qualifications in the social sciences) as a positive step towards greater professionalism and autonomy within the nursing profession, there are a number of reasons why such assumptions should be regarded with caution. This paper explores some of the most important of these, and argues that the keenness with which nurse educators have embraced the discipline of sociology into the nursing curriculum, could in fact be seriously misplaced.

Curriculum↗