G Jones

University of Tasmania, Hobart Town, Tasmania, Australia

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Publications (135)550.68 Total impact

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    ABSTRACT: Osteoporosis is a highly heritable disease, with estimates of genetic contribution to variance of BMD up to 80%. Genetic studies aiming to identify loci influencing BMD variation have had little success to date, largely due to inadequate power to detect the genes of small to moderate effect size likely to be involved. Adequately powered genome-wide association studies [GWAS] have successfully identified disease-associated genes in complex polygenic disorders. We performed a GWAS to search for BMD loci.
    01/2008;
  • T. Winzenberg, G. Jones
    IBMS BoneKEy 01/2008; 5(2):59-68.
  • C. Ding, F. Cicuttini, G. Jones
    Osteoarthritis and Cartilage 01/2008; 16. · 4.26 Impact Factor
  • G Jones, F M Cicuttini
    Internal Medicine Journal 10/2007; 37(9):587-8. · 1.82 Impact Factor
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    ABSTRACT: We studied the association between osteoporotic fractures and prior non-melanoma skin cancer (NMSC, a biomarker for cumulative sun exposure). The risk of prior NMSC in our fracture cohort was significantly reduced (standardised incidence ratio 0.69, 95% CI 0.61, 0.78). Adequate lifetime sun exposure may be necessary to protect against osteoporotic fractures in later life. The relationship between cumulative sun exposure and osteoporotic fractures is uncertain. We aimed to study the association between non-melanoma skin cancer (NMSC), a marker of cumulative sun exposure, and osteoporotic fractures in an older cohort. A retrospective cohort study in southern Tasmania in people aged at least 50 years with incident radiographic fracture (n = 2,283) was carried out. By record linkage to the Tasmanian Cancer Registry the cohort was followed backwards through time until the occurrence of NMSC or end-of follow-up. Relative risk was estimated by the standardised incidence ratio (SIR) using sex-, age- and calendar year-specific cancer incidence rates in southern Tasmania as reference. The incidence of prior NMSC in the fracture cohort was 31% lower than for the general population (SIR 0.69, 95% CI 0.61, 0.78). This effect was significant for most fracture subtypes except pelvic and wrist fractures and observed for both NMSC subtypes, squamous cell carcinoma and basal cell carcinoma. Older people with osteoporotic fractures may have had lifestyles linked to lower cumulative sunlight exposure. Achieving a balance between adequate lifetime sun exposure and protection against its adverse effects (such as fractures and skin cancer) may require assessment of individual risks.
    Osteoporosis International 06/2007; 18(5):687-92. · 4.04 Impact Factor
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    C Ding, F Cicuttini, G Jones
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    ABSTRACT: Unlike knee plain radiography which can only detect joint space narrowing and osteophytes, magnetic resonance imaging can directly visualize and analyse the whole knee structure, including bone size, cartilage defects and loss of cartilage volume. Tibial subchondral bone area expansion may be primary and is associated with risk factors such as age, body mass index (BMI), genetics and/or limb malalignment. It can lead to the development of knee defects, which may also be caused by demographic, anthropometric and environmental factors such as age, female sex, BMI and smoking as well as structural changes such as osteophytes, bone marrow lesions, meniscal tears, meniscal extrusion and ligament abnormalities. Once knee cartilage defects develop, they have a variable natural history but are associated with subsequent cartilage loss in a dose-response manner. Both tibial subchondral bone area and knee cartilage defects are quantitatively related to the severity of knee osteoarthritis (OA), and predictive of the need for knee joint replacement in subjects with knee OA independent of radiographic change. Taken as a whole, these studies suggest that tibial subchondral bone expansion and cartilage defect development represent important targets for the prevention of cartilage loss and joint replacement.
    Osteoarthritis and Cartilage 06/2007; 15(5):479-86. · 4.26 Impact Factor
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    ABSTRACT: Synovial haemangioma is a rare but important cause of knee symptoms, which, when undiagnosed, can lead to significant morbidity. Diagnosis is frequently difficult and delayed. We report on a case of synovial haemangioma, which demonstrates the difficulties inherent in diagnosis and the morbidity associated with diagnostic delay, in a young woman. Magnetic resonance imaging (MRI) is a useful tool for diagnosis, but detection on MRI can also be problematic, as shown by this case, demonstrating the need for greater awareness of this condition by both clinicians and radiologists. Arthroscopy is important in both the diagnosis and treatment of these lesions.
    Clinical Rheumatology 10/2006; 25(5):753-5. · 2.04 Impact Factor
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    ABSTRACT: To describe the association between knee and hip radiographic osteoarthritis (ROA), a measure of knee pain, stiffness and functional ability and objectively measured physiological falls risk predictors. Cross-sectional, population-based study of 850 randomly selected men and women aged 50-80 years (mean 62.5, SD 7.4). Falls risk (Z score) was determined objectively with the short form Physiological Profile Assessment (PPA). Two observers assessed knee and hip ROA using the Altman atlas. Pain, stiffness and functional ability were assessed using the Western Ontario McMasters Osteoarthritis index (WOMAC). Overall, the study population was at a mild risk of falling. In multivariable analysis, the WOMAC function and pain score were significantly associated with reaction time, balance, proprioception, knee extension strength, and edge contrast sensitivity. Stiffness was associated with knee extension strength and edge contrast sensitivity. Males had a dose response association between the global WOMAC score and falls risk (r=0.17, P<0.001). Those who reported a global WOMAC score of 50 and above had a higher risk of falling compared to those with a score below 50 (Z score: 0.53 vs 0.14, P<0.001). Hip joint space narrowing (JSN) was significantly associated with knee extension strength (r=-0.10, P=0.003), however, no other significant associations were observed between ROA and falls risk predictors. Self-reported functional ability and pain, and to a lesser extent, stiffness (but not knee and hip ROA), have a modest but independent association with physiological predictors of falls risk.
    Osteoarthritis and Cartilage 06/2006; 14(6):533-9. · 4.26 Impact Factor
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    ABSTRACT: To assess whether a lifestyle intervention delivered to mothers might impact on osteoporosis preventive behaviors in their children. We performed a 2-year randomized controlled trial of individualized bone mineral density feedback with either an osteoporosis information leaflet, or small group education, in a population-based sample of 354 mothers from Southern Tasmania, Australia in 2000-02. Main outcomes were maternal report of calcium intake and physical activity change in their children. Receiving small group education was associated with mothers' report of increasing children's calcium intake (odds ratio 2.3, 95% confidence interval 1.4, 3.8), as was low t-score feedback (odds ratio 2.0, 95% confidence interval 1.2, 3.3). Mothers who increased their own physical activity were more often reported increasing both physical activity (odds ratio 2.7, 95% confidence interval 1.5, 5.0) and calcium intake in their children (odds ratio 2.2, 95% confidence interval 1.3, 3.7). Mothers who commenced calcium supplements more often reported increasing children's calcium intake (odds ratio 2.6, 95% confidence interval 1.0, 6.7) but not physical activity. Both bone mineral density feedback and small group education delivered to mothers are effective at inducing maternally reported osteoporosis preventive behavior change in their children. These results require confirmation by studies with objective outcome measures.
    Preventive Medicine 02/2006; 42(1):21-6. · 3.50 Impact Factor
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    ABSTRACT: Clinical trials have shown that calcium supplementation in children can increase bone mineral density (BMD) although this effect may not be maintained. There has been no quantitative systematic review of this intervention. . To determine the effectiveness of calcium supplementation for improving BMD in children. . To determine if any effect varies by sex, pubertal stage, ethnicity or level of physical activity, and if any effect persists after supplementation is ceased. We searched CENTRAL, (Cochrane Central Register of Controlled Trials) (Issue 3, 2005), MEDLINE (1966 to 1 April 2005), EMBASE (1980 to 1 April 2005), CINAHL (1982 to 1 April 2005), AMED (1985 to 1 April 2005), MANTIS (1880 to 1 April 2005) ISI Web of Science (1945 to 1 April 2005), Food Science and Technology Abstracts (1969 to 1 April 2005) and Human Nutrition (1982 to 1 April 2005). Conference abstract books (Osteoporosis International, Journal of Bone and Mineral Research) were hand-searched. Randomised controlled trials of calcium supplementation (including by food sources) compared with placebo, with a treatment period of at least 3 months in children without co-existent medical conditions affecting bone metabolism. Outcomes had to include areal or volumetric BMD, bone mineral content (BMC), or in the case of studies using quantitative ultrasound, broadband ultrasound attenuation and ultrasonic speed of sound, measured after at least 6 months of follow-up. Two authors independently assessed trial quality and extracted data including adverse events. We contacted study authors for additional information. The 19 trials included 2859 participants, of which 1367 were randomised to supplementation and 1426 to placebo. There was no heterogeneity in the results of the main effects analyses to suggest that the studies were not comparable. There was no effect of calcium supplementation on femoral neck or lumbar spine BMD. There was a small effect on total body BMC (standardised mean difference (SMD) +0.14, 95% CI+0.01, +0.27) and upper limb BMD (SMD +0.14, 95%CI +0.04, +0.24). Only the effect in the upper limb persisted after supplementation ceased (SMD+0.14, 95%CI+0.01, +0.28). This effect is approximately equivalent to a 1.7% greater increase in supplemented groups, which at best would reduce absolute fracture risk in children by 0.1-0.2%per annum. There was no evidence of effect modification by baseline calcium intake, sex, ethnicity, physical activity or pubertal stage. Adverse events were reported infrequently and were minor. While there is a small effect of calcium supplementation in the upper limb, the increase in BMD which results is unlikely to result in a clinically significant decrease in fracture risk. The results do not support the use of calcium supplementation in healthy children as a public health intervention. These results cannot be extrapolated to children with medical conditions affecting bone metabolism.
    Cochrane database of systematic reviews (Online) 02/2006; · 5.70 Impact Factor
  • Osteoarthritis and Cartilage 01/2006; 14. · 4.26 Impact Factor
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    ABSTRACT: Cartilage defects are present in subjects with knee osteoarthritis (OA). Although they are often present in healthy subjects, there is little data on the natural history of cartilage defects. The aim of this study was to examine the change in cartilage defects over 2 yr and to identify factors associated with this change. One hundred and twenty-four healthy subjects underwent magnetic resonance imaging of their dominant knee at baseline and follow-up. Cartilage defects were scored (0-4) at five sites. Bone size was determined at medial and lateral tibial plateau and patella. Height, weight, body mass index and physical activity were measured by standard protocols. Eighty-six subjects completed the study. The mean cartilage defect score of each tibiofemoral compartment increased over time. However, medial and lateral tibiofemoral defect score decreased in 5% of the subjects. Cartilage defects were more likely to progress in males than females in each individual compartment (P<0.001 for medial tibiofemoral, P=0.005 for lateral tibiofemoral and P=0.01 for patellar cartilage). Baseline cartilage defect score was negatively associated with the progression of cartilage defects in each compartment (all P<0.001). Although knee cartilage defects progressed over time in the majority of normal subjects, those of the highest severity tended to regress. Male gender and baseline cartilage defect score were the main factors associated with the progression of cartilage defects. Larger studies will be required to identify factors associated with the progression and regression of lesions.
    Rheumatology 01/2006; 45(1):79-84. · 4.21 Impact Factor
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    ABSTRACT: To determine whether articular cartilage defects are associated with cartilage loss and joint replacement in subjects with symptomatic knee osteoarthritis (OA). One hundred and seventeen subjects with symptomatic knee OA underwent magnetic resonance imaging of their dominant knee at baseline and 2 yr later. Cartilage defects were identified as prevalent (defect score > or =2) in each knee compartment. Occurrence of joint replacement by 4 yr was documented. Cartilage defects were present in 81% of medial, 64% of lateral tibiofemoral compartments and 55% of patellar cartilages. Annual patellar cartilage loss was highest in those with defects compared with no defects (5.5% vs 3.2%, P = 0.01). Tibial cartilage loss was not associated with defects in the medial (4.6% vs 5.8%, P = 0.42) or lateral (4.7% vs 6.5%, P = 0.21) tibial cartilages. Higher total cartilage defect scores (8-15) were associated with a 6.0-fold increased risk of joint replacement over 4 yr compared with those with lower scores (2-7) (95% confidence interval 1.6, 22.3), independently of potential confounders. Articular cartilage defects are associated with disease severity in knee OA and predict patellar cartilage loss and knee replacement.
    Rheumatology 10/2005; 44(10):1311-6. · 4.21 Impact Factor
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    ABSTRACT: Although the current recommendation is to measure radiographic joint space width (JSW) to assess structural change in osteoarthritis (OA), there is increasing interest in direct measurement of cartilage volume from magnetic resonance imaging (MRI). We performed a longitudinal study to compare change in both JSW and articular cartilage volume in subjects with symptomatic knee OA. JSW was measured in 28 subjects with knee OA (57% females, mean age 62.8+/-9.8 years) who had standing radiographs in full extension, where both radiographs had satisfactory alignment. Each subject had femoral, tibial and combined femoral and tibial cartilage volumes determined from T1-weighted fat saturated sagittal knee MRI. All subjects had a repeat of the knee radiograph and MRI 1.96+/-0.4 years later. At baseline there was a moderate, but statistically significant, correlation between JSW and femoral and tibial cartilage volumes in the medial tibiofemoral joint, which was strengthened by adjusting for medial tibial bone size (R=0.58-0.66, P=0.001). Although we observed a reduction in JSW and femoral and tibial cartilage volumes over the study period, there was no significant association between reduction in JSW and cartilage volume (R<0.13). There was a trend towards a significant association between change in medial tibiofemoral cartilage volume and joint replacement at 4 years (OR=9.0, P=0.07) but not change in medial tibiofemoral JSW (OR=1.1, P=0.92). Although there was a modest correlation between cartilage volume and JSW in the medial tibiofemoral compartment, there was no correlation between longitudinal change in these measures. Change in cartilage volume appears to be a better predictor of joint replacement. Further work in larger samples over a longer period of time will be needed to confirm these findings.
    Osteoarthritis and Cartilage 08/2005; 13(8):722-7. · 4.26 Impact Factor
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    ABSTRACT: To describe the associations between age, knee cartilage morphology, and bone size in adults. A cross sectional convenience sample of 372 male and female subjects (mean age 45 years, range 26-61) was studied. Knee measures included a cartilage defect five site score (0-4 respectively) and prevalence (defect score of > or =2 at any site), cartilage volume and thickness, and bone surface area and/or volume. These were determined at the patellar, medial, and lateral tibial and femoral sites using T(1)weighted fat saturation MRI. Height, weight, and radiographic osteoarthritis (ROA) were measured by standard protocols. In multivariate analysis, age was significantly associated with knee cartilage defect scores (beta = +0.016 to +0.073/year, all p<0.01) and prevalence (OR = 1.05-1.10/year, all p<0.05) in all compartments. Additionally, age was negatively associated with knee cartilage thickness at all sites (beta = -0.013 to -0.035 mm/year, all p<0.05), and with patellar (beta = -11.5 microl/year, p<0.01) but not tibial cartilage volume. Lastly, age was significantly positively associated with medial and lateral tibial surface bone area (beta = +3.0 to +4.7 mm(2)/year, all p<0.05) and patellar bone volume (beta = +34.4 microl/year, p<0.05). Associations between age and tibiofemoral cartilage defect score, cartilage thickness, and bone size decreased in magnitude after adjustment for ROA, suggesting these changes are directly relevant to OA. The most consistent knee structural changes with increasing age are increase in cartilage defect severity and prevalence, cartilage thinning, and increase in bone size with inconsistent change in cartilage volume. Longitudinal studies are needed to determine which of these changes are primary and confirm their relevance to knee OA.
    Annals of the Rheumatic Diseases 05/2005; 64(4):549-55. · 9.11 Impact Factor
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    ABSTRACT: During February 2003 Comet C/2002 V1 (NEAT) passed through the field-of-view (FOV) of the LASCO C3 coronagraph onboard SOHO. The comet passed within 0.1 AU (about 20 solar radii) of the Sun and displayed complex dust and ion tails. Observations of the comet's ion tail orientation have been used to estimate the solar wind speed while in the C3 FOV. We have used the Wang-Sheeley model to estimate the solar wind speed in the vicinity of the comet for comparison with the ion-tail results. The comet's orbit combined with solar rotation produced a comet track along the source surface at nearly constant Carrington longitude and heliographic latitudes ranging from 70 North to 40 South. Photospheric magnetic field maps from Carrington Rotation 1999 measured at three observatories (Wilcox, Kitt Peak, and Mt. Wilson) were used as inputs to the Wang-Sheeley model and each gave different placements of the current sheet. Two of the model results (Wilcox and Kitt Peak) placed the current sheet at similar latitudes (40-45 degrees North) while the third (Mt. Wilson) placed the current sheet at lower latitudes (20 degrees) and appeared to agreed with the current sheet placement implied by the ion-tail results. In this presentation we will discuss the methods of solar wind speed determination from ion-tail observations, present the comparison of solar wind speeds derived from the ion tail measurements with values derived from magnetic field observations, and discuss differences in photospheric magnetic field maps that could affect the location of the current sheet.
    AGU Spring Meeting Abstracts. 05/2005;
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    ABSTRACT: To describe associations between sociodemographic factors and calcium intake in premenopausal women. Cross-sectional study. Population-based. A total of 467 randomly selected, predominantly Caucasian Tasmanian women aged 25-44 y, response rate 63%. calcium intake, sociodemographic factors, anthropometrics, osteoporosis knowledge and self-efficacy. Education level, calcium-specific osteoporosis knowledge and self-efficacy were all independently associated with calcium intake (P<0.05). The odds of achieving the recommended dietary intake for calcium increased with higher levels of calcium-specific self-efficacy and knowledge, and decreased in smokers or if the household's main financial provider was unemployed (P<0.05). Women who have lower levels of education, who are in households where the main financial provider is unemployed, who are smokers, and those with low levels of calcium-specific self-efficacy and knowledge are at risk of not achieving adequate calcium intake. This information will assist targeting of public health strategies aimed at improving the calcium intake of premenopausal women.
    European Journal of Clinical Nutrition 04/2005; 59(3):463-6. · 2.76 Impact Factor
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    ABSTRACT: In this 2-yr randomized controlled trial, we examined the effect of bone mineral density feedback and two different educational interventions (an osteoporosis information leaflet and group-based behavioral education [OPSMC]) on osteoporosis knowledge and self-efficacy in 470 women aged 25-44 yr. Osteoporosis knowledge increased across all intervention groups. Women receiving the OPSMC had a greater increase in both short (beta = +1.33, 95% confidence interval [CI] = 0.72-1.94) and long-term (beta = +0.64, 95% CI = 0.0034-1.25) osteoporosis knowledge, compared to those receiving the leaflet. In contrast, a low T-score was associated with a significant increase in long-term (beta = +0.66, 95% CI = 0.0034-1.25) but not short-term (beta = +0.57, 95% CI = -0.036 to 1.17) osteoporosis knowledge, compared to a normal T-score. Changes in osteoporosis self-efficacy were not associated with either low bone mineral density or receiving the OPSMC but were negatively associated with number of children (beta = -0.9, 95% CI = - 1.4 to -0.3) and working more than 20 h per week (beta = -2.7, 95% CI = -4.6 to -0.8). In conclusion, both the OPSMC and bone density feedback increased osteoporosis knowledge but not self-efficacy over 2 yr. Women with children or who worked full time have decreased osteoporosis self-efficacy, suggesting that this group should be a specific target for future interventional strategies.
    Journal of Clinical Densitometry 02/2005; 8(1):95-103. · 1.71 Impact Factor
  • D Ma, G Jones
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    ABSTRACT: Carbonated beverages have been reported to increase fracture risk in children but the mechanism is unclear. The aim of this population-based case-control study was to investigate the association between soft drink and milk consumption, physical activity, bone mass, and upper limb fractures in children aged 9-16 years. A total of 206 fracture cases and 206 randomly selected individually matched controls were studied. There were 47 hand fractures; 128 wrist and forearm fractures, and 31 upper arm fractures. An interviewer-administered questionnaire was utilized to retrospectively assess last-year physical activity (including television, computer, and video watching) and to recall the average weekly consumption of milk, colas, and total carbonated drinks. Bone mass at the spine, hip, and total body was assessed by dual-energy X-ray absorptiometry (DXA) and metacarpal morphometry. For total fractures, none of the above drink types was significantly different between cases and controls. For wrist and forearm fractures, there was a positive association between cola drink consumption and fracture risk (OR 1.39/unit, 95% CI: 1.01, 1.91). Cola consumption was significantly correlated with television, computer, and video watching (r = 0.20, P = 0.001) but not bone mineral density or milk drinks. After adjustment for television, computer, and video watching and bone mineral density, the association between cola drinks and fracture risk became nonsignificant (OR 1.31/unit, 95% CI: 0.94, 1.83). No association with other fracture sites was observed. In conclusion, cola, but not total carbonated beverage consumption, is associated with increased wrist and forearm fracture risk in children. However, this association is not independent of other factors and appears to be mediated by television watching and bone mineral density but not by decreased milk intake.
    Calcified Tissue International 11/2004; 75(4):286-91. · 2.75 Impact Factor
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    ABSTRACT: To compare subjects who had at least one parent with a total knee replacement for severe primary knee osteoarthritis with age and sex matched controls who had no family history of knee osteoarthritis Population based case-control study of 188 matched pairs (mean age 45 years, range 26 to 60). Articular cartilage volume and bone size were determined at the patella and at the medial tibial and lateral tibial compartments by processing images acquired using T1 weighted, fat saturated magnetic resonance imaging. Radiographic osteoarthritis (ROA) was assessed from a standing semiflexed radiograph scored for joint space narrowing and osteophytosis. Knee pain was assessed by questionnaire. Height, weight, body mass index (BMI), lower limb muscle strength, and endurance fitness were measured by standard protocols. Compared with the controls, index offspring had higher BMI (27.8 v 26.0 kg/m(2), p = 0.02), weaker lower limb muscles (127 v 135 kg, p = 0.006), more knee pain (47% v 22%, p<0.001), and greater medial tibial bone area (17.6 v 17.1 cm(2), p = 0.01). With the exception of BMI, these differences persisted in multivariate analysis. There was a non-significant trend to higher cartilage volume at tibial sites and increased ROA in the offspring in the total and subgroup analyses, but no difference in height and endurance fitness. BMI, muscle strength, knee pain, and medial tibial bone area, but not cartilage volume, appear to play a role in the genetic regulation and development of knee osteoarthritis.
    Annals of the Rheumatic Diseases 11/2004; 63(10):1255-9. · 9.11 Impact Factor

Publication Stats

4k Citations
550.68 Total Impact Points

Institutions

  • 1999–2014
    • University of Tasmania
      • Menzies Research Institute
      Hobart Town, Tasmania, Australia
  • 2013
    • University of Melbourne
      • Northwest Academy Centre
      Melbourne, Victoria, Australia
  • 2012
    • Sunshine Hospital
      Bhaganagar, Andhra Pradesh, India
  • 2004–2012
    • Menzies Research Institute
      Hobart Town, Tasmania, Australia
  • 2011
    • Children's Hospital at Westmead
      Sydney, New South Wales, Australia
  • 2010
    • Keele University
      • Department of Chemistry
      Newcastle-under-Lyme, England, United Kingdom
  • 2008
    • Alfred Hospital
      • Department of Department of Epidemiology and Preventive Medicine (DEPM)
      Melbourne, Victoria, Australia
  • 2005–2008
    • Monash University (Australia)
      • Department of Epidemiology and Preventive Medicine
      Melbourne, Victoria, Australia
  • 2001
    • University of Saskatchewan
      • College of Pharmacy and Nutrition
      Saskatoon, Saskatchewan, Canada
  • 1997–2000
    • Menzies Centre for Health Policy
      Sydney, New South Wales, Australia
  • 1993–1996
    • Garvan Institute of Medical Research
      • Cancer Research Program
      Darlinghurst, New South Wales, Australia
  • 1995
    • St. Vincent's Hospital Sydney
      Sydney, New South Wales, Australia
    • St. Vincent Hospital
      Green Bay, Wisconsin, United States