There is a need for the development of alternative therapeutic treatments for amoebic gill disease (AGD) in Atlantic salmon Salmo salar L. to maintain the sustainability of the Tasmanian Atlantic salmon aquaculture industry. This study aimed to assess the effects of the mucolytic drug L-cysteine ethyl ester (LCEE) on marine Atlantic salmon mucus and whether or not it may have a therapeutic advantage for the alleviation of AGD when administered orally. We also aimed to document any physiological consequences of LCEE. Results showed that LCEE significantly decreased the viscosity of marine Atlantic salmon mucus both in vitro, where LCEE concentration showed a negative relationship to mucus viscosity (R2 = 0.95 at 11.5 s(-1)), and in vivo. Oral administration of LCEE at 52.7 mg LCEE kg(-1) fish d(-1) over 2 wk significantly delayed the progression of AGD-associated pathology during an aggressive, cohabitation induced, laboratory infection. Medicated fish had approximately 50% less gill filaments affected by AGD than control fed fish at 3 d post-infection when assessed using histology. Palatability of medicated feed was shown to be approximately 65% of control feed. No osmoregulatory disturbance was seen in medicated fish, although blood and whole body flux data indicated a slight acidosis coinciding with an increased plasma total ammonia concentration. However, both variables were within a tolerable physiological range and returned to control levels 3 d post-cessation of medicated feed. LCEE holds potential as an in-feed additive when administered over 2 wk prior to infection to delay the progression of AGD associated pathology. From the parameters measured, LCEE seems to have minimal physiological consequences after 2 wk of administration. (+info)
Recruiting undergraduates to rural practice: what the students can tell us.
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INTRODUCTION: There are still large gaps in the evidence base for the effectiveness of Australian undergraduate rural coursework and placements programs designed to increase the numbers of health graduates choosing rural practice. This article reports on an online survey conducted in 2004 of health science students at the University of Tasmania, Australia, designed as a part of a long-term study to test coursework interventions by tracking students' attitudes to, and experience of, rural practice from course entry to eventual practice. METHOD: All first and final year students in medicine, nursing and pharmacy in the Faculty of Health Science were invited to complete an online survey exploring the undergraduate experience of rural health. RESULTS: The survey was completed by 148 first year and 87 final year students, a response rate of 32.4% and 23.1% respectively. Over one-third (38.5%) of first years and 56.3% of final years indicated a general preference for rural life and practice and almost 90% expected to spend at least some of their career in rural practice. There was a statistically significant relationship between rural practice orientation and rural origin among first years, although this relationship was weaker among final years. Of first years, 82.4%, and 82.7% of final years appear to have made at least some commitment to a particular career path, and two-thirds to a particular practice environment. Rurally oriented first year students were significantly more committed to a career path than those without that orientation, although this did not hold for final years. When asked how much of their careers they expected to spend in capital city, rural, remote and/or overseas practice, both first and final year students' responses were notable for their spread. Few ruled rural or urban practice in or out entirely with most opting for middle range responses of 'most', 'about half' or 'part' of their career. Over half of both years expected to spend some time in remote practice and 75.1% of first years and 66.6% of final years some time in overseas practice. The factors rated most important in relation to career choice were those related directly to the realities of day-to-day professional practice--professional and peer support, work conditions and variety of work. Approximately three-quarters of those entering undergraduate education felt themselves to be at least 'somewhat informed' about rural practice but, apart from medical students, were little better informed by final year. The only perception of rural practice very widely shared (by more than 80% of respondents) was the possibility of developing better patient relations. Many of the other factors frequently identified as major issues in the rural practice literature--locality, flexibility, opportunities for further study, and spouse/partner and children's needs - while recognised by some, do not appear to loom large with undergraduates either in terms of career choice or perceptions of rural practice. Most final year students recalled receiving specific rural health training through rural placements and/or rural curriculum content. Overall recall of coursework was patchy, although placements were well-remembered and there was good support for increases in both. None of those who recalled undertaking rural coursework felt that it had influenced them towards a rural career and over two-thirds (n = 37, 69.8%) felt that this exposure had actually influenced them away from such a career. Three students reported that undertaking a rural placement influenced them towards, and 35 away from, a rural/remote career. CONCLUSION: The ultimate measure of the success of undergraduate interventions will be workforce changes over time. In the meantime more research is needed into undergraduate experience of rural health to provide the data needed for the careful design of coursework, detailed planning of the placement experience and long-term strategies to address those aspects of rural practice that are of most concern to these emerging health professionals. (+info)
Cultured gill-derived Neoparamoeba pemaquidensis fails to elicit amoebic gill disease (AGD) in Atlantic salmon Salmo salar.
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Amoebic gill disease (AGD) affects the culture of Atlantic salmon Salmo salar in the southeast of Tasmania. The disease is characterised by the presence of epizoic Neoparamoeba spp. in association with hyperplastic gill tissue. Gill-associated amoebae trophozoites were positively selected by plastic adherence for culture in seawater, where they proliferated using heat-killed E. coli as a nutrient source. One isolate of gill-harvested amoebae designated NP251002 was morphologically consistent to N. pemaquidensis under light, fluorescence and transmission electron microscopy. Rabbit anti-N. pemaquidensis antiserum bound to NP251002, and N. pemaquidensis small subunit (SSU) ribosomal DNA (18S rDNA) was detected in NP251002 genomic DNA preparations using PCR. A high degree of similarity in the alignment of the NP251002 18S rDNA PCR amplicon sequence with reference isolates of N. pemaquidensis suggested conspecificity. While short-term culture (72 h) of gill-harvested amoebae does not affect the capacity of amoebae to induce AGD, Atlantic salmon challenged with NP251002 after the trophozoites had been 34 and 98 d in culture exhibited neither gross nor histological evidence of AGD. It is not known if NP251002 were avirulent at the time of isolation, had down-regulated putative virulence factors or virulence was inhibited by the culture conditions. Therefore, the time in culture could be a limiting factor in maintaining virulence using the culture technique described here. (+info)
Australian rural midwives: perspectives on Continuing Professional Development.
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INTRODUCTION: Continuing Professional Development (CPD) provides an important counter to workforce pressures affecting rural midwives; however, there is a lack of information about how rural midwives understand and perceive CPD and how this is situated in the practising and social context. This research aimed to explore rural midwives' experiences and perceptions of CPD in context. METHODS: A qualitative approach gathered focus group data on the beliefs, opinions and perceptions of a total of 52 rural midwives (nine focus groups), across three Australian states: Western Australia, Victoria and Tasmania. The focus groups were taped and transcribed verbatim and data was analysed thematically using an inductive approach, with the aid of an NVivo (QSR Software, Durham, UK) computer program. RESULTS: Four key themes emerged from the data: midwives' views of CPD; their motivations for undertaking CPD; the choices they make around CPD; and how context factors facilitate their involvement in CPD. Congruence with issues evident in the literature were: the difficulties associated with role diversity, the need for acquiring key skills before engaging in CPD, and the importance of a culture supportive of ongoing learning. CONCLUSIONS: CPD can be considered an important strategy for the retention and professionalism of midwives. The study findings helped fill a gap in the literature about rural and regional Australian midwives' perspectives on CPD. (+info)
Infant sleeping environment and asthma at 7 years: a prospective cohort study.
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OBJECTIVES: We investigated the role of infant bedding items, as part of a composite bedding environment, in the development of childhood wheezing. METHODS: This prospective cohort investigation involved 863 children who participated in an infant survey in 1988 and an asthma study in Tasmania, Australia, in 1995. The derived 3 composite infant bedding categories corresponded to increasing numbers of house dust mite (HDM)-rich bedding items used. Outcomes measured included recent and frequent wheezing. RESULTS: Composite infant bedding used was associated with recent wheezing. Effects increased at increasing levels of HDM-rich bedding items used. Effects were further enhanced by home environmental factors of bedroom heating, recent bedroom painting, and absence of bedroom carpeting. When any 2 or more of these environmental factors were present, a strong dose-response relationship was evident. CONCLUSIONS: Our results show that bedding exposures in infancy are prospectively associated with childhood wheezing and that home environmental conditions may modify this association. (+info)
Genetic mechanisms of knee osteoarthritis: a population-based longitudinal study.
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To describe the differences in knee structure and non-knee structural factors between offspring having at least one parent with a total knee replacement for severe primary knee osteoarthritis and age- and sex-matched controls with no family history of knee osteoarthritis, a population-based longitudinal study of 163 matched pairs (mean age 45 years, range 26 to 61) was performed at baseline and about 2 years later. Knee cartilage defect score (0 to 4), cartilage volume and bone size were determined with T1-weighted fat saturation magnetic resonance imaging. Body mass index (BMI), lower-limb muscle strength, knee pain, physical work capacity at 170 beats/minute (PWC170) and radiographic osteoarthritis were measured by standard protocols. In comparison with controls, offspring had higher annual knee cartilage loss (-3.1% versus -2.0% at medial tibial site, -1.9% versus -1.1% at lateral tibial site and -4.7% versus -3.7% at patellar site, all P < 0.05), a greater increase in medial cartilage defect score (+0.15 versus -0.01, P < 0.05) and a greater decline in PWC170 (-0.7 watts/kg versus -0.4 watts/kg, P < 0.01). There were no significant differences in change in BMI, lower-limb muscle strength, knee pain or tibial bone area between these two groups; however, the differences in knee cartilage loss and cartilage defect change decreased in magnitude and became non-significant after adjustment for baseline cartilage volume, tibial bone area, BMI and knee pain. This longitudinal study suggests that knee cartilage loss, change in cartilage defects and decrease in physical fitness all have roles in the development of knee osteoarthritis, which is most probably polygenic but may reflect a shared environment. Importantly, the cartilage changes are largely dependent on baseline differences in cartilage volume, tibial bone area, BMI and knee pain, suggesting that these factors might have a role in their initiation. (+info)
Distribution of Neoparamoeba sp. in sediments around marine finfish farming sites in Tasmania.
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Marine sediment samples collected from various sites at 2 Atlantic salmon farms in Tasmania were analysed for the presence of Neoparamoeba sp., an amoeba associated with amoebic gill disease (AGD) in farmed Atlantic salmon. Environmental variables of the sediment layer at each site, including redox potential and sulphide concentration, were measured and the general biological condition assessed by video observation. Sediments and environmental data were collected on 4 occasions at each site over a 12 mo period. Neoparamoeba sp. was detected in populations of amoebae recovered by culture from all sites and in 50% of all sediment samples taken. There was evidence of a seasonal influence on the presence of the amoeba, but this was different at each farm. No Neoparamoeba sp. was recovered from any sites at Farm 1 during the winter of 2002 whereas at Farm 2 this was the case for the summer of 2003. There appeared to be no relationship between the presence of Neoparamoeba sp., salmon farming activities and environmental parameters. (+info)
The effect on behavior and bone mineral density of individualized bone mineral density feedback and educational interventions in premenopausal women: a randomized controlled trial [NCT00273260].
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BACKGROUND: Limited information is available on ways to influence osteoporosis risk in premenopausal women. This study tested four hypotheses regarding the effects of individualized bone density (BMD) feedback and different educational interventions on osteoporosis preventive behavior and BMD in pre-menopausal women, namely: that women are more likely to change calcium intake and physical activity if their BMD is low; that group education will be more efficacious at changing behavior than an information leaflet; that BMD feedback and group education have independent effects on behavior and BMD; and, that women who improve their physical activity or calcium intake will have a change in bone mass over 2 years that is better than those who do not alter their behavior. METHODS: We performed a 2-year randomized controlled trial of BMD feedback according to T-score and either an osteoporosis information leaflet or small group education in a population-based random sample of 470 healthy women aged 25-44 years (response rate 64%). Main outcome measures were dietary calcium intake, calcium supplement use, smoking behavior, physical activity, endurance fitness, lower limb strength and BMD. We used paired t-tests, one-way ANOVA and linear regression techniques for data analysis. RESULTS: Women who had feedback of low BMD had a greater increase in femoral neck BMD than those with normal BMD (1.6% p.a. vs. 0.7% p.a., p = 0.0001), but there was no difference in lumbar spine BMD change between these groups (0.1% p.a. vs. 0.08% p.a., p = 0.9). Both educational interventions had similar increases in femoral neck BMD (Leaflet = +1.0% p.a., Osteoporosis self-management course = + 1.3% p.a., p = 0.4). Femoral neck BMD change was only significantly associated with starting calcium supplements (1.3 % p.a, 95%CI +0.49, +2.17) and persistent self-reported change in physical activity levels (0.7% p.a., 95%CI +0.22, +1.22). CONCLUSION: Individualized BMD feedback combined with a minimal educational intervention is effective at increasing hip but not spine bone density in premenopausal women. The changes in behavior through which this was mediated are potentially important in the prevention of other diseases, thus measuring BMD at a young age may have substantial public health benefits, particularly if these changes are sustained. (+info)