Preimplantation genetic diagnosis for retinoblastoma survivors: a cost-effectiveness study.

This study aimed to investigate the cost-effectiveness of preimplantation genetic diagnosis (PGD) for the reproductive choices of patients with heritable retinoblastoma. The study modelled the costs of three cycles of in-vitro fertilization (IVF) and PGD across all uptake rates of PGD, number of children affected with retinoblastoma at each uptake rate and the estimated quality-adjusted life years (QALYs) gained. Cost-effectiveness analysis was conducted from the Australian public healthcare perspective. The intervention was the use of three cycles (one fresh and two frozen) of IVF and PGD with the aim of live births unaffected by the retinoblastoma phenotype. Compared with the standard care pathway (i.e. natural pregnancy), IVF and PGD resulted in a cost-saving to 18 years of age of AUD$2,747,294 for a base case of 100 couples with an uptake rate of 50%. IVF and PGD resulted in fewer affected (n = 56) and unaffected (n = 78) live births compared with standard care (71 affected and 83 unaffected live births), and an additional 0.03 QALYs per live birth. This modelling suggests that the use of IVF and PGD to achieve an unaffected child for patients with heritable retinoblastoma resulted in an overall cost-saving. There was an increase in QALYs per baby across all uptake rates. However, in total, fewer babies were born following the IVF and PGD pathway.

Correction to: Effectiveness of a new model of primary care management on knee pain and function in patients with knee osteoarthritis: Protocol for THE PARTNER STUDY.

After the publication of this protocol [1], our collaborator Prima Health solutions advised us of their intent to withdraw from the study.

Application of next-generation sequencing to improve cancer management: A review of the clinical effectiveness and cost-effectiveness.

Uptake of next-generation sequencing (NGS) has increased dramatically due to significant cost reductions and broader community acceptance of NGS. To systematically review the evidence on both the clinical effectiveness and the cost-effectiveness of applying NGS to cancer care. A systematic search for full-length original research articles on the clinical effectiveness and cost-effectiveness of NGS in MEDLINE and EMBASE. Articles that focussed on cancer care and involved the application of NGS were included for the review of clinical effectiveness. For the cost-effectiveness review, we only included the articles with economic evaluations of NGS in cancer care. We report the rate of successfully detecting mutations from the clinical studies. The incremental cost-effectiveness ratio and sensitivity analysis outcomes are reported for the cost-effectiveness articles. Fifty-six articles reported that sequencing patient samples using targeted gene panels, and 83% of the successfully sequenced patients harboured at least 1 mutation. Only 6 studies reported on the cost-effectiveness of the application of NGS in cancer care. NGS is an effective tool for identifying mutation in cancer patients. However, more rigorous cost-effectiveness studies of NGS applied to cancer management are needed to determine whether NGS can improve patient outcomes cost-effectively.

Detection of Bacillus anthracis spores from environmental water using bioluminescent reporter phage.

AIMS: We investigated the ability of a temperate Bacillus anthracis reporter phage (Wß::luxAB-2), which transduces bioluminescence to infected cells, to detect viable spores from deliberately contaminated environmental water samples. METHODS AND RESULTS: Environmental water was inoculated with spores and assayed with Wß::luxAB-2. Bioluminescent signals directly correlated with input phage and spore concentrations. A limit of detection of 101 and 102 CFU per ml within 8 h was achieved from pond and lake water, respectively. Detection was greatly simplified by minimizing sample processing steps without spore extraction. The complex endogenous microbial flora and salt content of brackish water challenged the assay, extending the detection time to 12 h for a sensitivity of 102 CFU per ml. Phage-mediated bioluminescence was strictly dependent on bacterial physiology, being significantly reduced in mid/late log phase cells. This was shown to be due to an inability of the phage to adsorb. CONCLUSIONS: The reporter phage Wß::luxAB-2 displays potential for simplified detection of viable spores from contaminated water samples within 12 h. SIGNIFICANCE AND IMPACT OF THE STUDY: A deliberate aerosol release of spores could lead to widespread contamination, leaving large areas uninhabitable until remediation. An essential requirement of this restoration process is the development of simplified detection assays in different environmental matrices.

Tectonic and climatic considerations for deep geological disposal of radioactive waste: A UK perspective.

Identifying and evaluating the factors that might impact on the long-term integrity of a deep Geological Disposal Facility (GDF) and its surrounding geological and surface environment is central to developing a safety case for underground disposal of radioactive waste. The geological environment should be relatively stable and its behaviour adequately predictable so that scientifically sound evaluations of the long-term radiological safety of a GDF can be made. In considering this, it is necessary to take into account natural processes that could affect a GDF or modify its geological environment up to 1millionyears into the future. Key processes considered in this paper include those which result from plate tectonics, such as seismicity and volcanism, as well as climate-related processes, such as erosion, uplift and the effects of glaciation. Understanding the inherent variability of process rates, critical thresholds and likely potential influence of unpredictable perturbations represent significant challenges to predicting the natural environment. From a plate-tectonic perspective, a one million year time frame represents a very short segment of geological time and is largely below the current resolution of observation of past processes. Similarly, predicting climate system evolution on such time-scales, particularly beyond 200ka AP is highly uncertain, relying on estimating the extremes within which climate and related processes may vary with reasonable confidence. The paper highlights some of the challenges facing a deep geological disposal program in the UK to review understanding of the natural changes that may affect siting and design of a GDF.

The impact of poverty on self-efficacy: an Australian longitudinal study.

BACKGROUND: People with strong feelings of 'self-efficacy', i.e. how much a person feels they have control over their life, perform better in the workplace. However, little is known about negative influences on feelings of self-efficacy. In view of the increasing number of people whose income places them below the poverty line despite being in employment, poverty may negatively influence feelings of self-efficacy and hence workplace productivity. AIMS: To assess whether falling into poverty lowers self-efficacy. METHODS: Longitudinal analysis of waves 7 to 11 of the nationally representative Household, Income and Labour Dynamics in Australia (HILDA) survey, using linear regression models. RESULTS: Those who fell into multidimensional poverty (income poverty plus poor health or insufficient level of education attainment) had significantly lower self-efficacy scores (up to 18% lower (95% CI -31% to -1%, P < 0.05)) than those never in poverty, after accounting for initial self-efficacy score and other confounding factors. Income uniquely accounted for 3% of the variance in self-efficacy scores, physical health for 10%, mental health for 78% and education for 1%. CONCLUSIONS: Given the known links between self-efficacy and workplace productivity, workers who are below the poverty line may be at risk of poor productivity due to the experience of poverty. In addition to the poor outcomes from the employer's perceptive, this may also lead to a negative spiral for the employee.

Isolation and development of bioluminescent reporter phages for bacterial dysentery.

Shigellosis is a significant cause of morbidity and mortality worldwide, most notably amongst children. Moreover, there is a global increase in the occurrence of multidrug-resistant isolates, including the epidemic and pandemic Shigella dysenteriae type 1 strain. We developed a bioluminescent reporter phage assay to facilitate detection and simultaneously determine antibiotic susceptibility. A Shigella flexneri phage (Shfl25875) was isolated from environmental wastewater and characterized by DNA sequencing. Shfl25875 is T4-like, harbors a 169,062-bp genome, and grows on most (28/29) S. flexneri strains and all 12 S. dysenteriae type 1 strains tested. The genes encoding bacterial luciferase were integrated into the Shfl25875 genome to create a "light-tagged" phage capable of transducing a bioluminescent phenotype to infected cells. Shfl25875::luxAB rapidly detects cultured isolates with high sensitivity. Specificity experiments indicate that the reporter does not respond to Shigella boydii, non-type 1 S. dysenteriae strains, and most non-Shigella Enterobacteriaceae. Shfl25875::luxAB generates ampicillin and ciprofloxacin susceptibility profiles that are similar to the standard Clinical and Laboratory Standards Institute (CLSI) growth microdilution method, but in a significantly shorter time. In addition, the reporter phage detects Shigella in mock-infected stool. This new reporter phage shows promise as a tool for the detection of cultured isolates or complex clinical samples.

Rapid detection and simultaneous antibiotic susceptibility analysis of Yersinia pestis directly from clinical specimens by use of reporter phage.

Yersinia pestis is a tier 1 agent due to its contagious pneumopathogenicity, extremely rapid progression, and high mortality rate. As the disease is usually fatal without appropriate therapy, rapid detection from clinical matrices is critical to patient outcomes. We previously engineered the diagnostic phage ΦA1122 with luxAB to create a "light-tagged" reporter phage. ΦA1122::luxAB rapidly detects Y. pestis in pure culture and human serum by transducing a bioluminescent signal response. In this report, we assessed the analytical specificity of the reporter phage and investigated diagnostic utility (detection and antibiotic susceptibility analysis) directly from spiked whole blood. The bioreporter displayed 100% (n = 59) inclusivity for Y. pestis and consistent intraspecific signal transduction levels. False positives were not obtained from species typically associated with bacteremia or those relevant to plague diagnosis. However, some non-pestis Yersinia strains and Enterobacteriaceae did elicit signals, albeit at highly attenuated transduction levels. Diagnostic performance was assayed in simple broth-enriched blood samples and standard aerobic culture bottles. In blood, <10(2) CFU/ml was detected within 5 h. In addition, Y. pestis was identified directly from positive blood cultures within 20 to 45 min without further processing. Importantly, coincubation of blood samples with antibiotics facilitated simultaneous antimicrobial susceptibility profiling. Consequently, the reporter phage demonstrated rapid detection and antibiotic susceptibility profiling directly from clinical samples, features that may improve patient prognosis during plague outbreaks.

Rising cost of anticancer drugs in Australia.

BACKGROUND: Anticancer drugs are often expensive and are contributing to the growing cost of cancer care. Concerns have been raised about the effect rising costs may have on availability of new anticancer drugs. AIM: This study aims to determine the recent changes in the costs of anticancer drugs in Australia. METHODS: Publicly available expenditure and prices paid by the Australian Pharmaceutical Benefits Scheme (PBS) for anticancer drugs from 2000 to 2012 were reviewed. The measures used to determine changes in cost were total PBS expenditure and average price paid by the PBS per prescription for anticancer drugs and for all PBS listed drugs. An estimated monthly price paid for newly listed anticancer drugs was also calculated. RESULTS: Annual PBS expenditure on anticancer drugs rose from A$65 million in 1999-2000 to A$466 million in 2011-2012; an average increase of 19% per annum. The average price paid by the PBS per anticancer drug prescription, adjusted for inflation, increased 133% from A$337 to A$786. The real average annual increase in the price per anticancer drug prescription was more than double that for all other PBS drugs combined (7.6% vs 2.8%, difference 4.8%, 95% confidence interval -0.4% to 10.1%, P = 0.07). The median price for a month's treatment of the new anticancer drugs listed was A$4919 (range A$1003 to A$12 578, 2012 prices). CONCLUSIONS: PBS expenditure and the price of anticancer drugs in Australia rose substantially from 2000 to 2012. Dealing with these burgeoning costs will be a major challenge for our health system and for those affected by cancer.

Cost effectiveness of primary care referral to a commercial provider for weight loss treatment, relative to standard care: a modelled lifetime analysis.

BACKGROUND: Because of the high prevalence of overweight and obesity, there is a need to identify cost-effective approaches for weight loss in primary care and community settings. OBJECTIVE: To evaluate the long-term cost effectiveness of a commercial weight loss programme (Weight Watchers) (CP) compared with standard care (SC), as defined by national guidelines. METHODS: A Markov model was developed to calculate the incremental cost-effectiveness ratio (ICER), expressed as the cost per quality-adjusted life year (QALY) over the lifetime. The probabilities and quality-of-life utilities of outcomes were extrapolated from trial data using estimates from the published literature. A health sector perspective was adopted. RESULTS: Over a patient's lifetime, the CP resulted in an incremental cost saving of AUD 70 per patient, and an incremental 0.03 QALYs gained per patient. As such, the CP was found to be the dominant treatment, being more effective and less costly than SC (95% confidence interval: dominant to 6225 per QALY). Despite the CP delaying the onset of diabetes by ∼10 months, there was no significant difference in the incidence of type 2 diabetes, with the CP achieving <0.1% fewer cases than SC over the lifetime. CONCLUSION: The modelled results suggest that referral to community-based interventions may provide a highly cost-effective approach for those at high risk of weight-related comorbidities.

First Report of Bacterial Leaf Blight on Mustard Greens (Brassica juncea) Caused by Pseudomonas cannabina pv. alisalensis in Mississippi.

In 2010, a brassica leafy greens grower in Sunflower County, MS, observed scattered outbreaks of a leaf blight on mustard greens (Brassica juncea) in a 180-ha field. A severe outbreak of leaf blight occurred on mustard greens and turnip greens (B. rapa) in the same field in 2011 with more than 80 ha affected. The affected field, established in 2010, had no prior history of being cropped to brassica leafy greens. Symptoms appeared on the 6-week-old transplants as brown to tan necrotic spots with faint chlorotic borders and associated water-soaking. Lesions varied from 4 mm to 3 cm in diameter and often coalesced to cover >90% of older leaves. Whole plants of the mustard greens cv. Florida Broadleaf were collected in 2011 from the symptomatic field. Leaves were surface-disinfested with 0.5% NaOCl for 5 min, rinsed twice in sterilized distilled water [(sd)H2O], macerated in sdH2O, then streaked onto nutrient agar (NA), pseudomonas agar F (PAF), and potato dextrose agar (PDA). Little or no bacterial growth was observed on PDA, while on NA and PAF the majority of bacterial growth appeared to be a single colony type. All strains collected (25 total, one per plant) were gram-negative and fluoresced blue-green under UV light after 48 h at 28°C on PAF. All 25 strains were identified as belonging to Pseudomonas group 1a using Lelliot's determinative assay (2). Ten of the 25 strains were tested for pathogenicity on Florida Broadleaf, and turnip greens cv. Alamo. Bacteria were grown on PAF for 48 h, and a bacterial suspension was prepared and adjusted to an optical density of 0.1 at 600 nm. Three-week-old plants (three plants per cultivar) were sprayed with the appropriate bacterial suspension to runoff, placed at 100% relative humidity for 48 h, and then put in a growth chamber at 28°C with a 16-h diurnal light cycle for 14 days. Additionally, three plants each of Florida Broadleaf and Alamo were either sprayed with H2O or inoculated with Pseudomonas cannabina pv. alisalensis (Pca) pathotype strain BS91 (1). All 10 strains, as well as the Pca pathotype strain, were pathogenic on both cultivars and caused symptoms similar to those observed in the field. Symptoms were not observed on H2O-sprayed plants. Comparative rep-PCR analysis using the BOXA1R primer showed the 10 strains had identical DNA-banding profiles and were identical to that of Pca BS91 (5). Five strains tested using a Pca-specific, 'light-tagged' reporter bacteriophage gave a strong positive reaction, while a negative control strain, P. syringae pv. maculicola, gave no signal (3). From these tests, the isolated bacteria were determined to be Pca. Bacteria re-isolated on PAF from the inoculated Florida Broadleaf plants had identical rep-PCR profiles with those of the strains used for inoculations. Over the past 10 years, Pca has been found in numerous states in the United States, as well as in Europe, Australia, and Japan (4). As brassica leafy greens production expands to new fields and new states, leaf blight caused by Pca appears to become a problem rapidly. Since resistant cultivars and highly effective bactericides are lacking, growers are extremely concerned about the rapid spread of this disease into existing and new brassica leafy greens regions. References: (1) N. A. Cintas et al. Plant Dis. 86:992, 2002. (2) R. Lelliott. J. Appl. Bacteriol. 29:470, 1066. (3) D. Schofield et al. Appl. Environ. Microbiol. 78:3592, 2012. (4) F. Takahashi et al. J. Gen. Plant Pathol. 79:260, 2013. (5) J. Versalovic et al. Methods Mol. Cell Biol 5:25, 1994.

Partial and complete retirement due to ill-health among mature age Australians.

OBJECTIVES: An ageing population requires governments to keep older people working longer and delay early retirement. This paper investigates the extent to which common health problems and geographical location are associated with full and partial early retirement among mature-age Australians. STUDY DESIGN: Cross sectional. METHODS: Multinomial logistic regression analysis of self-reported data of 21,719 women and 16,393 men from the 45 and Up Study. OUTCOME MEASURE: retirement status. RESULTS: Women who reported ever having been told by a doctor that they had a stroke, cancer (except melanoma and skin and breast cancer), osteoarthritis, depression, osteoporosis, thrombosis, or anxiety were more likely to be fully retired due to ill-health compared to those without these health problems. Those who reported ever having been told by a doctor that they had depression, breast cancer or osteoarthritis were more likely to be partially retired due to ill-health than those without these health problems. Men who reported ever having been told by a doctor that they had cancer, heart disease, anxiety or depression were more likely to be fullyorpartially retired due to ill-health than those without these health problems. Men who reported having had a stroke, diabetes, thyroid problems, osteoarthritis or osteoporosis were more likely to be fully retired due to ill-health compared to those without these health problems. Men and women living outside major cities were more likely to be fully retired due to ill-health. Men from outer regional areas were also more likely to be partially retired due to ill-health. CONCLUSIONS: To reduce early retirement due to ill-health, health practitioners, governments and employers should address targeted health problems, particularly in areas outside capital cities.

A within-trial cost-effectiveness analysis of primary care referral to a commercial provider for weight loss treatment, relative to standard care--an international randomised controlled trial.

BACKGROUND: Due to the high prevalence of overweight and obesity there is a need to identify cost-effective approaches for weight loss in primary care and community settings. OBJECTIVE: We evaluated the cost effectiveness of two weight loss programmes of 1-year duration, either standard care (SC) as defined by national guidelines, or a commercial provider (Weight Watchers) (CP). DESIGN: This analysis was based on a randomised controlled trial of 772 adults (87% female; age 47.4±12.9 years; body mass index 31.4±2.6 kg m(-2)) recruited by health professionals in primary care in Australia, United Kingdom and Germany. Both a health sector and societal perspective were adopted to calculate the cost per kilogram of weight loss and the ICER, expressed as the cost per quality adjusted life year (QALY). RESULTS: The cost per kilogram of weight loss was USD122, 90 and 180 for the CP in Australia, the United Kingdom and Germany, respectively. For SC the cost was USD138, 151 and 133, respectively. From a health-sector perspective, the ICER for the CP relative to SC was USD18 266, 12 100 and 40 933 for Australia, the United Kingdom and Germany, respectively. Corresponding societal ICER figures were USD31,663, 24,996 and 51,571. CONCLUSION: The CP was a cost-effective approach from a health funder and societal perspective. Despite participants in the CP group attending two to three times more meetings than the SC group, the CP was still cost effective even including these added patient travel costs. This study indicates that it is cost effective for general practitioners (GPs) to refer overweight and obese patients to a CP, which may be better value than expending public funds on GP visits to manage this problem.

Generation of a mutagenized organophosphorus hydrolase for the biodegradation of the organophosphate pesticides malathion and demeton-S.

AIMS: The bacterial organophosphorus hydrolase (OPH) enzyme hydrolyses and detoxifies a broad range of toxic organophosphate pesticides and warfare nerve agents by cleaving the various phosphorus-ester bonds (P-O, P-F, P-CN, P-S); however, OPH hydrolyses these bonds with varying efficiencies. The aim of this study was to generate a variant OPH enzyme with improved hydrolytic efficiency against the poorly hydrolysed P-S class of organophosphates. METHODS AND RESULTS: The gene encoding OPH was sequentially mutated at specific codons by saturation mutagenesis and screened for improved activity against the P-S substrates demeton-S methyl and malathion. Escherichia coli lysates harbouring the variants displayed up to 177- and 1800-fold improvement in specific activity against demeton-S methyl and malathion, respectively, compared to the wild-type lysates. The specificity constants of the purified variant proteins were improved up to 25-fold for demeton-S methyl and malathion compared to the wild-type. Activity was associated with organophosphate detoxification as the hydrolysed substrate lost the ability to inhibit acetylcholinesterase. The improved hydrolytic efficiency against demeton-S translated to the improved ability to hydrolyse the warfare agent VX. CONCLUSIONS: OPH variant enzymes were generated that displayed significantly improved ability to hydrolyse and detoxify organophosphates harbouring the P-S bond. SIGNIFICANCE AND IMPACT OF THE STUDY: The long-term goal is to generate an environmentally-friendly enzyme-mediated bioremediation approach for the removal of toxic organophosphate compounds in the environment.

Generating a panel of highly specific antibodies to 20 human SH2 domains by phage display.

To demonstrate the utility of phage display in generating highly specific antibodies, affinity selections were conducted on 20 related Src Homology 2 (SH2) domains (ABL1, ABL2, BTK, BCAR3, CRK, FYN, GRB2, GRAP2, LYN, LCK, NCK1, PTPN11 C, PIK3R1 C, PLCgamma1 C, RASA1 C, SHC1, SH2D1A, SYK N, VAV1 and the tandem domains of ZAP70). The domains were expressed in Escherichia coli, purified and used in affinity selection experiments. In total, 1292/3800 of the resultant antibodies were shown to bind the target antigen. Of the 695 further evaluated in specificity ELISAs against all 20 SH2 domains, 379 antibodies were identified with unique specificity (i.e. monospecific). Sequence analysis revealed that there were at least 150 different clones with 1-19 different antibodies/antigen. This includes antibodies that distinguish between ABL1 and ABL2, despite their 89% sequence identity. Specificity was confirmed for many on protein arrays fabricated with 432 different proteins. Thus, even though the SH2 domains share a common three-dimensional structure and 20-89% identity at the primary structure level, we were able to isolate antibodies with exquisite specificity within this family of structurally related domains.

Phage-mediated bioluminescent detection of Bacillus anthracis.

AIMS: Bacillus anthracis, the causative agent of anthrax, is a serious human pathogen. The aim of this study was to provide the proof of principle results for the development of a 'bioluminescent' reporter bacteriophage that was capable of specifically detecting B. anthracis. METHODS AND RESULTS: The reporter phage was engineered by integrating the bacterial luxA and luxB reporter genes into a nonessential region of the lysogenic Wbeta phage genome. This resulted in a phage that was capable of specifically infecting and conferring a bioluminescent phenotype to B. anthracis viable cells. No processing or cell preparation was required; the phage and cells were simply mixed, and the samples were analysed for bioluminescence. A bioluminescent signal was evident after 16 min postinfection of vegetative cells. The strength and time required to generate the signal was dependent on the number of cells present. Nevertheless, 10(3) CFU ml(-1) was detectable within 60 min. The utility of the bioluminescent phage was analysed using spores as the starting material. The Wbeta::luxAB phage was able to transduce a bioluminescent signal to germinating spores within 60 min. CONCLUSIONS: This proof of principle study demonstrates that the reporter phage displays promise as a tool for the rapid detection of B. anthracis. SIGNIFICANCE AND IMPACT OF THE STUDY: The new methodology offers the potential for the detection of viable cells from either environmental or clinical samples.

Baby boomer retirement and the future of dentistry.

BACKGROUND: The dental workforce, like the Australian population, is ageing. As the large baby boomer cohort retires dental shortages will likely increase. METHODS: Australian Bureau of Statistics census data from 1986 to 2001 were used to examine ageing of the dental workforce and attrition of dentists aged 50 years and over. The number of dentists to retire was projected over the next 20 years. RESULTS: Since 1986, the dental workforce has aged significantly (p < 0.01). About half of the current dental workforce is projected to retire by 2026. Generation X dentists are significantly less likely to work long hours than the baby boomer cohort of dentists (p < 0.01). This is partly due to an increase in the proportion of women in the dental workforce and male Generation X dentists being less likely to work long hours (>41 per week) than male baby boomer dentists (p < 0.01). CONCLUSIONS: Ageing of the workforce will have an impact on dentistry later than on some other professions due to the 35 per cent of dentists who work beyond 65 years of age. Nonetheless, existing dental shortages are likely to be exacerbated over the short term by the 22 per cent of dentists projected to retire over the next 10 years.

Ageing of the baby boomer generation: how demographic change will impact on city and rural GP and nursing workforce.

OBJECTIVE: To compare the impact of ageing on the GP and nursing rural and city workforce. METHOD: Cohort analysis of Australian Bureau of Statistics census data. The data was used to examine the age distribution of the city and rural GP and nursing workforce; patterns of attrition for those 50 years and over; and the impact of changes in working hours. RESULTS: The rural GP and nursing workforce is significantly older than their city counterparts (p<0.001) with the 'baby boomer' generation making up 52% of city GPs but 59% of rural GPs in 2001. While a large proportion of city and rural GPs continued to work past the age of 65 years, rural GPs left the workforce at a significantly younger age than city doctors (p<0.001). Rural nurses are older than their city peers (p<0.001) but retire at an older age than city nurses (p<0.001). In 1986, a significantly higher proportion of rural GPs in all age cohorts worked more than 41 hours per week compared with their city counterparts (p<0.001). By 2001, rural 'generation X' GPs were no more likely to work long hours than those in the city (p<0.001). However, significantly more rural than city 'baby boomers' continued to work long hours. CONCLUSIONS: Rural GPs are retiring faster than city GPs and strategies to attract rural GPs and nurses will be critical to ensure adequate rural health care and that current rural workforce shortage do not worsen.

Intravenous antioxidant modulation of end-organ damage in L-arginine-induced experimental acute pancreatitis.

BACKGROUND: Oxidative stress mediates acinar injury in experimental acute pancreatitis (AP) and antioxidants are depleted in human AP. This study tests the hypothesis that exogenous antioxidant supplementation ameliorates experimental AP. METHODS: Male Sprague-Dawley rats were randomly allocated to 1 of 4 groups (n = 5/group) and sacrificed at 72 h. AP was induced by 250 mg per 100 g body weight of 20% L-arginine hydrochloride in 0.15 mol/l sodium chloride. Group allocations were: group 1 (control) no intervention; group 2 AP; group 3 early multiple antioxidant (MAOX) intervention comprising 15 microg/kg selenium, 30 microg/kg ascorbate and 300 mg/kg N-acetylcysteine given at 6 and 30 h and group 4 the MAOX combination above given at 24 and 48 h. Endpoints were: serum amylase, antioxidant levels, bronchoalveolar lavage (BAL) protein and lung myeloperoxidase (MPO) activity and histological assessment of pancreatic injury. RESULTS: L-arginine induced AP characterised by oedema, neutrophil infiltration, acinar cell degranulation and elevated serum amylase. Early MAOX reduced pulmonary MPO and BAL protein and reduced acinar swelling, degranulation and pancreatic parenchymal infiltration by inflammatory cells. These features were absent when intervention was delayed. CONCLUSION: In this model, early but not late antioxidant intervention ameliorates pancreatic and pulmonary injury.

Intravenous n-acetylcysteine, ascorbic acid and selenium-based anti-oxidant therapy in severe acute pancreatitis.

BACKGROUND: To observe outcome in a cohort of patients with severe acute pancreatitis receiving multiple anti-oxidant therapy. METHODS: An observational study was carried out in 46 consecutive patients with acute pancreatitis fulfilling current Atlanta consensus criteria for severe disease. All patients received multiple anti-oxidant therapy based on intravenous selenium, N-acetylcysteine and ascorbic acid plus beta-carotene and alpha-tocopherol delivered via nasogastric tube. Principal outcomes were the effect of anti-oxidant supplementation on anti-oxidant levels, morbidity and mortality in patients on anti-oxidant therapy, case-control analysis of observed survival compared to predicted survival derived from logistic organ dysfunction score (LODS), logistic regression analysis of factors influencing outcome and side effect profile of anti-oxidant therapy. RESULTS: Paired baseline and post-supplementation data were available for 25 patients and revealed that anti-oxidant supplementation restored vitamin C (P = 0.003) and selenium (P = 0.028) toward normal. In univariate survival analysis, patient survival to discharge was best predicted by admission APACHE-II score with relative risk of death increasing 12.6% for each unit increase (95% CI 6.0% to 19.6%). The mean LODS calculated on admission to hospital was 3.7 (standard error of the mean 4.1) giving a predicted mortality for the cohort of 21%. The observed in-hospital mortality was 43%. CONCLUSIONS: Case-control analyses do not appear to demonstrate any benefit from the multiple anti-oxidant combination of selenium, N-acetylcysteine and ascorbic acid in severe acute pancreatitis.