Search PubMed⌕ Search

Biomedical subjects

S Wakefield

Publications and source records attributed to S Wakefield.

14 recordsLinked to original sources
PubMed2006

The Drosophila reticulon, Rtnl-1, has multiple differentially expressed isoforms that are associated with a sub-compartment of the endoplasmic reticulum.

The reticulons are a recently discovered family of proteins that have a predominant localisation to the membrane of the endoplasmic reticulum. The precise function of the reticulons is unclear despite their presence in a wide variety of eukaryotic organisms. Here we describe the characterisation of the Drosophila reticulon, reticulon-like1 (Rtnl1), which is the only functional reticulon in Drosophila. The Rtnl1 locus produces seven predicted mRNA transcripts encoding five different protein isoforms. The different transcripts have tissue-specific expression patterns remarkably similar to their mammalian counterparts. Rtnl1 protein is associated with organelles of the secretory pathway including the endoplasmic reticulum and the Golgi apparatus. Rtnl1 function appears to be non-essential or redundant since loss of function Rtnl1 mutants are viable. However, a significant reduction in life expectancy was seen in Rtnl1 mutant flies. This may point towards a possible protective role for reticulons against conditions of environmental stress.

Animals↗
PubMed2006

The risks and benefits of being a young female adolescent standardised patient.

OBJECTIVE: To follow the progress of young female adolescents, as risk-taking standardised patients (SPs), and to monitor for adverse affects that role-playing may have on the adolescents. METHODS: A prospective design was used in which 11 female adolescents, aged 13-15 years, were recruited from 2 schools. The adolescents were trained to portray risk-taking individuals with a medical condition and were interviewed with their SP mother by final-year medical students 1-3 times a month over 6-14 months. A control group was selected from both schools (n = 6). Main outcome measures were pre- and post-interviews using standardised questionnaires [Achenbach's Youth Self-Report (YSR) and Piers Harris Children's Self Concept Scale (SCS),] and focus groups. RESULTS: The adolescent group simulated 111 interviews (mean per adolescent 10.1, SD = 6.2) each lasting 60-70 minutes. QUANTITATIVE DATA: The pre- and post-scores from the YSR and SCS demonstrated no significant differences within the SP study participants or between the control group vs. the study group. FOCUS GROUP FINDINGS: The initial focus group acted as a debriefing exercise and prompted the adolescents to request that they come out of their role when giving feedback. Subsequent focus group discussion was around the medical student performance and their family doctors. CONCLUSION: Adolescent females showed no adverse effects when used extensively to portray risk-taking SPs. The focus groups provided the adolescents with an opportunity to debrief together. The adolescent SPs reported benefiting from this study but requested unanimously that they come "out of character" when giving feedback to the medical students.

Adolescent↗
PubMed2002

Pathology of cultured paua Haliotis iris infected with a novel haplosporidian parasite, with some observations on the course of disease.

Mortalities among juvenile paua Haliotis iris Martyn 1784 in a commercial culture facility were reported in April 2000. Histology of moribund paua showed heavy systemic infections of a uni- to multi-nucleate stage of a novel organism later confirmed by transmission electron microscopy (TEM) and molecular studies to be a haplosporidian. Multinucleate plasmodia up to 25 microm diameter with up to 17 nuclei were detectable in wet preparations of hemolymph from heavily infected paua. The presence of the haplosporidian in the affected facility was associated with mortalities of slow growing 'runt' paua during the summer months. Total mortalities in affected raceways 6 mo after mortalities began were between 82.5 and 90%. Heavily infected paua exhibited behavioural abnormalities including lethargy, loss of righting reflex, and were easily detached from surfaces. Some heavily infected paua exhibited oedema and pale lesions in the foot and mantle, but no reliable gross signs of disease were noted. Light infections of the haplosporidian were also found in apparently healthy paua from the facility. Histology indicated that the early stages of infection were characterised by small numbers of plasmodia in the connective tissue surrounding the gut, amongst glial cells adjacent to nerves in the mantle and foot and within gill lamellae. In heavy infections, large numbers of small plasmodia (mean size 5.5 x 7 microm in histological sections) were present in the hemolymph, gills, heart, kidneys, mantle, foot, epipodium and connective tissue of the digestive gland. Infections were not transferred horizontally at 14 and 19 degrees C after cohabiting heavily infected paua with uninfected paua for 3 mo in aquaria, or 3 mo after injecting healthy paua with hemolymph containing haplosporidian plasmodia. This may indicate that the prepatent period for disease is longer than 3 mo, that disease is not expressed below 20 degrees C, or that an intermediate host is required for transmission. Spore formation was not observed in juvenile paua but sporocyst-like bodies containing putative spores were observed amongst haplosporidian plasmodia in the right kidney of poorly performing adult paua collected from the wild.

Animals↗
PubMed2002

Ultrastructure of a haplosporidian containing Rickettsiae, associated with mortalities among cultured paua Haliotis iris.

Uninucleate and multinucleate stages of a protozoan parasite are described from cultured abalone Haliotis iris Martyn, 1784 in New Zealand. The parasite is identified as a haplosporidian by the occurrence of multinucleate plasmodia, mitochondria with tubular cristae, lipid droplets, anastomosing endoplasmic reticulum (aER), multivesicular bodies (MVBs), haplosporogenesis by the production of haplosporosome-like bodies from nuclear membrane-bound Golgi, and their maturation to haplosporosomes. Coated pits occurred in the plasma membrane and coated vesicles were scattered in the cytoplasm, particularly in association with the Golgi face away from the nucleus, and aER. It is concluded that the outward face of the Golgi may be the trans face, and that aER is the trans-Golgi network. Coated pits and bristle-coated vesicles are reported from a haplosporidian for the first time. The vesicles in the MVBs resembled the cores and inner membranes of haplosporosomes, without the outer layer. The possible inter-relationships of these features are discussed. The abalone parasite differs from previously described haplosporidians in the apparent absence of a persistent mitotic spindle, and the presence of intracytoplasmic coccoid to rod-shaped bacteria resembling Rickettsiales-like prokaryotes. Phylogenetic analysis of the 16S rRNA gene sequence of the Rickettsiales-like prokaryotes indicated that these organisms belong to the Rickettsia cluster. The prokaryotes have a high (7%) sequence divergence from known Rickettsieae, with Rickettsia sp. and R. massiliae being the closest relatives. The lack of non-molecular evidence prevents us from proposing a new rickettsial genus at this time.

Alphaproteobacteria↗
PubMed2000

Environmental risk perception and well-being: effects of the landfill siting process in two southern Ontario communities.

In the context of siting (environmentally) noxious land uses, recent research suggests that the well-being of individuals and communities is impacted as much by the decision-making process as the outcome itself. The study results presented in this paper stem from an ongoing, two-stage quantitative/qualitative investigation of impacts on individual and community well-being associated with the environmental assessment process in Ontario, Canada. This research uses a parallel case-study design to investigate two proposed landfill sites in southern Ontario. Qualitative in-depth interviews (n = 36), conducted across a variety of stakeholder groups, were used to address the following objectives: to explore the nature of concerns experienced by individuals faced with a local landfill site proposal; to explore the effects of the siting process on individuals and communities; and to examine the coping strategies employed by individuals in response to impacts experienced. The work attempts to apply theories of risk society (as conceptualised by Beck and Giddens) at a community scale. In so doing, we build on the work of health geographers attempting to link the social and contextual with the medical. Overall, substantial impacts on individual and community well-being were reported across all stakeholder groups interviewed: these included stress, disempowerment, hostility and divisions within the community. The experience of psychosocial impacts and effectiveness of coping strategies is shaped by certain factors associated with the site and the siting process (including uncertainty and the perceived lack of meaningful participation). The links between risk, process and impacts are theorized using a conceptual framework which incorporates site and process factors, effects on daily life (e.g. feelings of losing control, mistrust), and Gidden's conception of 'ontological security'. These findings have implications for environmental decision-making, as they suggest a need to locate the delicate balance point between community involvement and an expedient decision-making process within variable community contexts.

Adaptation, Psychological↗
PubMed1999

The power of perception: health risk attributed to air pollution in an urban industrial neighbourhood.

This paper describes a multi-stakeholder process designed to assess the potential health risks associated with adverse air quality in an urban industrial neighborhood. The paper briefly describes the quantitative health risk assessment conducted by scientific experts, with input by a grassroots community group concerned about the impacts of adverse air quality on their health and quality of life. In this case, rather than accept the views of the scientific experts, the community used their powers of perception to advantage by successfully advocating for a professionally conducted community health survey. This survey was designed to document, systematically and rigorously, the health risk perceptions community members associated with exposure to adverse air quality in their neighborhood. This paper describes the institutional and community contexts within which the research is situated as well as the design, administration, analysis, and results of the community health survey administered to 402 households living in an urban industrial neighborhood in Hamilton, Ontario, Canada. These survey results served to legitimate the community's concerns about air quality and to help broaden operational definitions of 'health.' In addition, the results of both health risk assessment exercises served to keep issues of air quality on the local political agenda. Implications of these findings for our understanding of the environmental justice process as well as the ability of communities to influence environmental health policy are discussed.

Air Pollution↗
PubMed1999

Shared governance: time to consider the cons as well as the pros.

AIMS: This paper aims to provide a critical appraisal of an approach to the management and organization of nursing work known as shared governance (SG). BACKGROUND: This approach has its origins in the USA, where, during the past 20 years it has become increasingly influential. The advocates of SG claim that it can, inter alia, improve recruitment and retention rates, boost morale, and help raise clinical skills. Little wonder that SG in now beginning to make significant inroads into the NHS. ORIGIN OF INFORMATION: However, a trawl through the extensive US literature, using printed and online (e.g. BIDS, CINHAL, MEDLINE, etc.) bibliographical sources, suggests that the claimed benefits of SG should be treated with caution. KEY ISSUES: Much of the existing published research appears to be both methodologically flawed and lacking in any critical edge. While many researchers and commentators appear only too willing to highlight what they see as the promise of SG, they shy away from exploring any potential pitfalls. One consequence of this is that many of the putative benefits SG is said to confer, may in fact be more apparent than real. CONCLUSIONS: Nurses and nurse managers need to be apprised of and consider seriously, the possible cons as well as the potential pros of SG, if any promise it may have is to be realized.

Clinical Competence↗
PubMed1996

Pancreaticopleural fistula: a rare complication of chronic pancreatitis.

Pancreaticopleural fistula is an uncommon sequelae of pancreatitis. The condition is often elusive, as respiratory rather than abdominal symptoms usually predominate and the fistula can be difficult to demonstrate radiologically. Confirmation is by demonstrating a high amylase content in the pleural aspirate relative to the serum. About half the fistulae will close with conservative treatment but persistent or recurrent effusions, often associated with stenosis or disruption of the main pancreatic duct, are an indication for surgery. The long-term outcome is good in 80-95% of cases. We report five patients with pleural effusion of pancreatic origin due to pancreaticopleural fistula.

Adult↗
PubMed1994

A comparative trial of didanosine or zalcitabine after treatment with zidovudine in patients with human immunodeficiency virus infection. The Terry Beirn Community Programs for Clinical Research on AIDS.

BACKGROUND: Both didanosine and zalcitabine are commonly used to treat patients with human immunodeficiency virus (HIV) infection who cannot tolerate zidovudine treatment or who have had disease progression despite it. The relative efficacy and safety of these second-line therapies are not well defined. METHODS: In this multicenter, open-label trial we randomly assigned 467 patients who previously received zidovudine and had 300 or fewer CD4 cells per cubic millimeter or a diagnosis of the acquired immunodeficiency syndrome (AIDS) to treatment with either didanosine (500 mg per day) or zalcitabine (2.25 mg per day). RESULTS: After a median follow-up of 16 months, disease progression or death occurred in 157 of 230 patients assigned to didanosine and 152 of 237 patients assigned to zalcitabine, for a relative risk of 0.93 for the zalcitabine group as compared with the didanosine group (P = 0.56), which decreased to 0.84 (P = 0.15) after adjustment for the CD4 count, Karnofsky score, and presence of AIDS at base line. There were 100 deaths in the didanosine group and 88 in the zalcitabine group, for a relative risk of 0.78 (P = 0.09) and an adjusted relative risk of 0.63 (P = 0.003). A majority of patients in each group (66 percent) had at least one adverse event during treatment (153 patients taking didanosine and 157 taking zalcitabine). Peripheral neuropathy and stomatitis occurred more often with zalcitabine and diarrhea and abdominal pain more frequently with didanosine. CONCLUSIONS: For patients with HIV infection who have not responded to treatment with zidovudine, zalcitabine is at least as efficacious as didanosine in delaying disease progression and death.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Report of a case and further delineation of the SHORT syndrome.

We describe a boy with the manifestations of the SHORT syndrome: lipoatrophy, delayed speech development, minor facial anomalies, clinodactyly, and short stature. In addition, this boy had deafness, which was not previously reported in the SHORT syndrome.

Abnormalities, Multiple↗
PubMed1980

Abnormal cilia in Polynesians with bronchiectasis.

Bronchial or nasal ciliated epithelium from 13 patients with bronchiectasis (12 Polynesians and 1 European) was examined by electron microscopy. All cilia examined lacked dynein arams. In 2 patients, this was the only abnormality observed, but in the others, various ciliary abnormalities were present, including cilia with missing tubules, extra tubules, and misplaced tubules, as well as compound cilia, intracytoplasmic cilia, vesiculated cilia, and cilia with long winglike folds. In all of these patients pulmonary mucociliary transport rates were either absent or markedly reduced. It is suggested that these abnormalities were due to a mutation or group of mutations, which was the underlying cause of the bronchiectasis.

Adult↗