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K Dewar

Publications and source records attributed to K Dewar.

28 records · Page 2Linked to original sources

Opening up the options: making the inflexible into a flexible framework.

The post-registration framework for registered nurses and midwives was set up to provide flexible continuing education programmes for registered nurses. For those students who already have the basic professional qualification specific to their area of practice, professional development programmes are intended as a vehicle for improving their own personal professional competence. However, for those individuals who wish to gain further qualification or to change from one practice context to another, it is argued that the framework does not adequately address their needs. At present, pre-registration diplomates emerge from the Project 2000 programme with a qualification which enables them to work in one specific area of practice only. This early specialization is not in line with current and projected USA and European thinking (Castledine 1995) and may lead to a reduction in the broad base of nursing knowledge. It is further argued that pre-registration programmes should provide a generic base of nursing theory and practice, whereas specialist knowledge and practice should be the main thrust of post-registration work. The authors argue that initial development of nurses in specialist areas at pre-registration level restricts their ability to respond to rapidly changing health care needs later in their careers. The post-registration framework should be a flexible vehicle by which individuals can gain expanded knowledge in a particular field of practice or can change professional direction if they wish. Thus, nurses would have the freedom to develop in a way that is most appropriate to their changing individual needs.

Education, Nursing, Baccalaureate↗

Orientation to higher education: the challenges and rewards.

A new 'starter' course for qualified nurses entering higher education is discussed in this article. The background and aims of this course, which enables traditionally trained nurses to enter a pathway of professional and academic development, are presented. Learning outcomes of the course, identified through a formal evaluation procedure, were categorized into product and process components. Course teachers anticipated that the product outcomes would be evaluated most highly but the participants reported that the process outcomes were more important to them. They believed these process outcomes would empower them not only to undertake further academic studies but also to take a greater part in clinical decision-making. The results of this evaluation demonstrate that for many nurses, who seek to launch themselves into higher education, a 'bridging' programme is necessary to support this transition.

Career Mobility↗

Inheritance of chromosome-length polymorphisms in Ophiostoma ulmi (sensu lato).

We have investigated the mitotic and meiotic transmission of chromosome-length polymorphisms in Ophiostoma ulmi s.l., the causal agent of Dutch elm disease. The North-American aggressive (NAN) strain CESS16K has an atypical electrophoretic karyotype, carrying two chromosome-sized DNAs (chDNAs) that have not been observed in other members of the NAN biotype. Independent CESS16K chDNA preparations, even after repeated inoculation and recovery from the elm host, and analysis of 16 progeny strains after a cross between the NAN strains FG245Br-O and CESS16K, demonstrated that these unique chDNAs are integral components of the CESS16K genome. Analysis of the progeny, by electrophoretic karyotyping and hybridizations with probes specific to individual chDNAs, presented evidence that genome rearrangements can occur as a consequence of meiosis. Even though novel electrophoretic karyotypes and a novel-sized chromosome were observed in the karyotypes of the progeny strains, the low level of reassortment between the chromosomes carrying length polymorphisms presented evidence that there are constraints to genome plasticity for this fungus.

Ascomycota↗

Immunogenetic analysis of HLA-DR10 homozygous individuals.

Molecular, cellular and serological analysis of Major Histocompatibility Complex alleles was performed on three individuals who appeared to be HLA-DR10 homozygous by DNA restriction fragment analysis. Each donor was of different ethnic origin: Caucasoid, Asian Indian and African Negroid. The results of our studies show that the Caucasoid and Asian donors are indeed homozygous for the HLA-DR10 allele, while the African donor also possesses the DRB1*0103 allele. Homozygosity for the HLA-A1-B37-Cw6-DR10-DQ5 haplotype in the Caucasoid donor was confirmed by familial segregation analysis. The B-lymphoblastoid cell line produced from this donor should prove useful in studies of HLA immunogenetics.

Alleles↗

Electrophoretic karyotypes of the elm tree pathogen Ophiostoma ulmi (sensu lato).

Pulsed field gel electrophoresis using OFAGE, TAFE, and CHEF systems has been used to more fully characterize karyotypic variation within the two closely related fungal species of Ophiostoma ulmi sensu lato. Twelve wild-type and laboratory strains, representing the less aggressive species O. ulmi and both of the biotypes of the more aggressive species O. novo-ulmi were studied and their karyotypes determined. Depending on the strain, a minimum of four to a minimum of eight chromosomal DNA bands were present that fall into three distinct size classes, with one exception. Strain CESS16K (O. novo-ulmi, North American aggressive subgroup) contains a unique chromosomal DNA band which comigrated near a Saccharomyces cerevisiae chromosome of 0.95 Mb. This unique band was the smallest O. ulmi s. l. chromosomal DNA observed. Seven of the twelve strains shared a common chromosomal DNA banding pattern, whereas each of the other five had a unique karyotype. There was no correlation between chromosome profile and species, as some O. novo-ulmi and O. ulmi strains shared common electrophoretic karyotypes.

Chromosomes, Fungal↗

Analysis of a high frequency transformation system for Ophiostoma ulmi, the causal agent of Dutch elm disease.

A transformation system for Ophiostoma ulmi (Buism.) Nannf. was developed and analyzed. Protoplasts were generated from actively budding yeastlike cells by digestion with NovoZym 234 in MgSO4 after pretreatment with 2-mercaptoethanol. Protoplast regeneration was most efficient when 0.6 M sucrose was used as the osmoticum. Several plasmids containing fusions between fungal promoters and a bacterial gene for hygromycin phosphotransferase successfully transformed O. ulmi to hygromycin resistance. One of these vectors, pPS57, which contains a promoter for isopenicillin N synthetase from Penicillium chrysogenum, consistently conferred the greatest resistance to hygromycin. Linearization of the vector and inclusion of 2-mercaptoethanol in the transformation reaction resulted in enhanced transformation efficiency. Approximately 4 x 10(3) transformants/micrograms DNA per 10(7) protoplasts were obtained using the optimized procedure. Southern hybridization after alternating field and standard electrophoresis suggested random insertion of tandem repeats (some greater than 250 kb) into the fungal chromosomes. Antibiotic resistance was stable through mitosis. However, expression of the transforming DNA after meiosis was highly variable.

Ascomycota↗

Distinct adenosine deaminase-containing inputs to the substantia nigra from the striatum and tuberomammillary nucleus.

Immunohistochemical, neuroanatomical and lesion methods were used to investigate the projections of adenosine deaminase immunoreactive (ADA-IR) neurons in the striatum (caudate/putamen) and hypothalamus to the substantia nigra (SN). Striatal ADA-IR neurons were distributed within two zones; anteriorly in the medial and ventromedial extreme of the head and body of the striatum, and posteriorly in the tail of the striatum. The posterior hypothalamus contained ADA-positive neurons which were confined to the tuberomammillary nucleus (TM). The SN was devoid of ADA-positive neurons, but contained two distinct types of ADA-IR fiber terminations. One type was confined to bands located at the ventrolateral and dorsomedial borders of the pars reticulata and consisted of fine puncta. The other type was distributed throughout the SN and consisted of long, beaded fibers. Injections of the retrograde tracer Fluoro-gold (FG) into the SN gave rise to FG-labelling of significant numbers of ADA-IR neurons in both the striatum and TM. Medial SN injections preferentially labelled ADA-IR neurons in the anterior striatum and lateral SN injections labelled posterior ADA-IR striatal neurons. Kainic acid lesions of the anterior medial striatum selectively abolished the punctate ADA-IR band in the medial SN and left the long, ADA-IR nigral fibers in an apparently hypertrophied state. Despite depletion of ADA-IR neurons in the striatum by kainic acid, ADA activity increased significantly at striatal lesion sites. The results suggest that the SN receives two topographically segregated fine terminal fields from striatal ADA-IR neurons, and a substantial innervation from ADA-IR neurons in the TM as well. These findings add to the heterogeneous chemical composition of nigral afferents and are discussed in the context of adenosine neuromodulatory mechanisms in the striatonigral system.

Adenosine Deaminase↗

Adenosine deaminase-'like' immunoreactivity in cerebellar Purkinje cells of rat.

The localization of adenosine deaminase (ADA) throughout the rat CNS was investigated immunohistochemically with 5 different affinity purified polyclonal antibody preparations against ADA. Except in the cerebellum, identical immunostaining patterns of ADA-immunoreactivity were observed with all 5 antibodies. In the cerebellum, Purkinje cells and presumptive swellings on their axons were immunostained by only one of the 5 antibodies. Preabsorption with purified ADA abolished immunostaining with all 5 antibodies. Biochemical tests showed that the Km for substrate, the specific activity of immunoprecipitable enzyme and the isozymic characteristics of cerebellar ADA was not different from ADA in whole brain or several other brain regions examined. The atypical immunohistochemical behavior of cerebellar ADA, despite its biochemical similarity to ADA elsewhere in the brain, suggests that the enzyme in the cerebellum has some unique features which must be taken into account when considering its possible role in regulating the neuromodulatory actions of adenosine in the cerebellar cortex.

Adenosine Deaminase↗