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D Purdie

Publications and source records attributed to D Purdie.

At least 19 recordsLinked to original sources
PubMed2006

The properties of the International Classification of the External Cause of Injury when used as an instrument for injury prevention research.

OBJECTIVE: To demonstrate properties of the International Classification of the External Cause of Injury (ICECI) as a tool for use in injury prevention research. METHODS: The Childhood Injury Prevention Study (CHIPS) is a prospective longitudinal follow up study of a cohort of 871 children 5-12 years of age, with a nested case crossover component. The ICECI is the latest tool in the International Classification of Diseases (ICD) family and has been designed to improve the precision of coding injury events. The details of all injury events recorded in the study, as well as all measured injury related exposures, were coded using the ICECI. This paper reports a substudy on the utility and practicability of using the ICECI in the CHIPS to record exposures. Interrater reliability was quantified for a sample of injured participants using the Kappa statistic to measure concordance between codes independently coded by two research staff. RESULTS: There were 767 diaries collected at baseline and event details from 563 injuries and exposure details from injury crossover periods. There were no event, location, or activity details which could not be coded using the ICECI. Kappa statistics for concordance between raters within each of the dimensions ranged from 0.31 to 0.93 for the injury events and 0.94 and 0.97 for activity and location in the control periods. DISCUSSION: This study represents the first detailed account of the properties of the ICECI revealed by its use in a primary analytic epidemiological study of injury prevention. The results of this study provide considerable support for the ICECI and its further use.

Child↗
PubMed2004

Indices to quantify changes in intracranial and cerebral perfusion pressure by assessing agreement between hourly and semi-continuous recordings.

OBJECTIVES: Little published data exists on whether nurse-recorded end-hour values of intracranial pressure (ICP) and cerebral perfusion pressure (CPP) are representative of continuous monitoring during the hour. There is also no standard method of quantifying the observed perturbations in cerebral hemodynamics. This study compared the level of agreement between end-hour values and computer downloaded observations of ICP and CPP at 15-min intervals. We also developed the intracranial hypertension index and the cerebral hypoperfusion index to quantify perturbations in cerebral hemodynamics. Each of these indices relates the number of abnormal observations to the total number of observations taken. METHODS: Prospective, non-interventional study. RESULTS: The bias and precision between the two methods for ICP and CPP were -0.002+/-2.6 mmHg and -1.1+/-6.2 mmHg, respectively. A strong correlation existed between the hourly mean calculated from the 15-min and the end-hour values for both ICP ( r(2)=0.95, p<0.0001) and CPP ( r(2)=0.78, p<0.001). The intracranial hypertension index was 40% from the 15-min measurements and 41% from the hourly observations ( p= NS). The cerebral hypoperfusion indices were 13.4% and 13.1% with the 15-min and end-hour values, respectively ( p= NS). CONCLUSIONS: The end-hour values of ICP and CPP are as accurate as more frequent measurements during the hour and are adequate for purposes of epidemiological research and medico-legal audit. The intracranial hypertension and cerebral hypoperfusion indices may be useful in describing cerebral hemodynamics for future interventional studies and for assessing quality in the delivery of neuro-critical care.

Brain Injuries↗
PubMed2002

Winter intervention against Aedes aegypti (Diptera: Culicidae) larvae in subterranean habitats slows surface recolonization in summer.

At semiarid Charters Towers, north Queensland, Australia, the importance of Aedes aegypti (L.) in wells was assessed in relation to the colonization of surface habitats during the wet season. From April to July 1999, 10 wells (five positive for Ae. aegypti) were monitored to assess their status and larvae population numbers therein. All surface containers located within a 100 m radius of each well were removed, treated with s-methoprene or sealed to prevent the utilization of these containers by mosquitoes. These inner cores were surrounded by outer zones for a further 100 m in which surface containers were left untreated but all subterranean habitats were treated. Ovitraps were monitored monthly in the inner cores for 36 wk from August 1999 to April 2000 and differences in the proportions of ovitraps positive for Ae. aegypti and Ochlerotatus notoscriptus (Skuse) were analyzed by logistic regression. Analysis of the proportions of ovitraps positive for Ae. aegypti near positive wells indicated significantly greater colonization from November to March (the wet season), compared with those situated near Ae. aegypti negative wells. As Oc. notoscriptus were not produced from subterranean sites, comparisons of the proportions of ovitraps positive for Oc. notoscriptus in positive and negative inner cores provided an indication of the relative productivity of the uncontrolled surface containers in the outer zones. Differences in the utililization of ovitraps by Oc. notoscriptus among positive and negative cores were observed during only one month (March), when oviposition was greater in ovitraps in the negative cores, compared with the positive cores. Best subsets linear regression analysis of the proportion of ovitraps positive forAe. aegypti against meteorological variables (rainfall, mean wind speed, mean relative humidity, mean minimum, and maximum temperature) during the week of ovitrapping indicated that minimum temperature and wind speed accounted for 63.4% of the variability. This study confirms that for semiarid towns such as Charters Towers, the practice of treating a relatively small number of key subterranean habitats during winter will significantly affect Ae. aegypti recolonization of surface container habitats during summer, the period of greatest risk for dengue.

Aedes↗
PubMed2001

Reduced expression of intercellular adhesion molecule-1 in ovarian adenocarcinomas.

Ovarian adenocarcinomas develop as the result of multiple genetic and epigenetic changes in the precursor ovarian surface epithelial (OSE) cells which result in a malignant phenotype. We investigated changes in gene expression in ovarian adenocarcinoma using a cDNA array containing 588 known human genes. We found that intercellular adhesion molecule-1 (ICAM-1) was expressed at lower levels in the ovarian tumour cell lines OAW42, PEO1 and JAM than in the immortalised human ovarian surface epithelial cell line HOSE 17.1. Further investigation revealed ICAM-1 was expressed in the surface epithelium of normal ovaries and both mRNA and protein expression levels were reduced in the majority of ovarian adenocarcinoma cell lines and primary tumours. ICAM-1 expression was increased in 8/8 cell lines treated with the de novo methyltransferase inhibitor 5-aza-2'-deoxycytidine, indicating that methylation of CpG islands may play a role in the down-regulation of its expression in primary tumours. There was a significant association between patients whose tumours expressed ICAM-1 and survival (P = 0.03), suggesting that expression levels of ICAM-1 may have clinical relevance.

Adenocarcinoma↗
PubMed2001

Decreased expression of the Id3 gene at 1p36.1 in ovarian adenocarcinomas.

The molecular events that drive the initiation and progression of ovarian adenocarcinoma are not well defined. We have investigated changes in gene expression in ovarian cancer cell lines compared to an immortalized human ovarian surface epithelial cell line (HOSE) using a cDNA array. We identified 17 genes that were under-expressed and 10 genes that were over-expressed in the cell lines compared to the HOSE cells. One of the genes under-expressed in the ovarian cancer cell lines, Id3, a transcriptional inactivator, was selected for further investigation. Id3 mRNA was expressed at reduced levels in 6 out of 9 ovarian cancer cell lines compared to the HOSE cells while at the protein level, all 7 ovarian cancer cell lines examined expressed the Id3 protein at greatly reduced levels. Expression of Id3 mRNA was also examined in primary ovarian tumours and was found in only 12/38 (32%) cases. A search was conducted for mutations of Id3 in primary ovarian cancers using single stranded conformation polymorphism (SSCP) analysis. Only one nucleotide substitution, present also in the corresponding constitutional DNA, was found in 94 ovarian tumours. Furthermore no association was found between LOH at 1p36 and lack of expression of Id3. These data suggest that Id3 is not the target of LOH at 1p36.

Adenocarcinoma↗
PubMed2001

Incidence of distal forearm fracture in British men and women.

Fracture of the distal forearm is one of the most frequent osteoporotic fractures. However, there are few data concerning its incidence in Britain. The aim of this study was to determine the incidence of distal forearm fracture in adult British men and women. Six centers took part in the study: Aberdeen, Hull, Nottingham, Portsmouth, Southampton and Truro. At each center, men and women aged 35 years and over with an incident distal forearm fracture and who resided in the catchment area of the main hospital at that center, were identified during a 12 month period. Incident fractures were identified from all possible point-of-contact sources in each locality, including accident and emergency records, fracture clinics, ward listings and plaster room registers. The population at risk was defined geographically according to postcode and the denominator obtained from 1991 census data mapped to these postcodes. During the 12 month study period, 3161 individuals with distal forearm fracture were identified. The age-adjusted incidence, age 35 years and over, was 36.8/10,000 person-years in women and 9.0/10,000 person-years in men. In women, the incidence of fracture increased progressively with age from the perimenopausal period, while in men the incidence remained low until later life. Fractures were more frequently left-sided (55.6%) and 19.4% of subjects required hospitalization. On the basis of these data we estimate that 71,000 adult men and women sustain a distal forearm fracture in Britain each year. Compared with previous British surveys the pattern of incidence with age appears to have changed in women, the reason for this is unclear.

Adult↗
PubMed2001

Cigarette smoking and risk of epithelial ovarian cancer (Australia).

OBJECTIVES: We studied the association between cigarette smoking and ovarian cancer in a population-based case control study. METHODS: A total of 794 women with histologically confirmed epithelial ovarian cancer who were aged 18-79 years and resident in one of three Australian states were interviewed, together with 855 controls aged 18-79 years selected at random from the electoral roll from the same states. Information was obtained about cigarette smoking and other factors including age, parity, oral contraceptive use, and reproductive factors. We estimated the relative risk of ovarian cancer associated with cigarette smoking, accounting for histologic type, using multivariable logistic regression to adjust for confounding factors. RESULTS: Women who had ever smoked cigarettes were more likely to develop ovarian cancer than women who had never smoked (adjusted odds ratio (OR) = 1.5; 95% confidence interval (CI) = 1.2-1.9). Risk was greater for ovarian cancers of borderline malignancy (OR = 2.4; 95% CI = 1.4-4.1) than for invasive tumors (OR = 1.7; 95% CI = 1.2-2.4) and the histologic subtype most strongly associated overall was the mucinous subtype among both current smokers (OR = 3.2; 95% CI = 1.8-5.7) and past smokers (OR = 2.3; 95% CI = 1.3-3.9). CONCLUSIONS: These data extend recent findings and suggest that cigarette smoking is a risk factor for ovarian cancer, especially mucinous and borderline mucinous types. From a public health viewpoint, this is one of the few reports of a potentially avoidable risk factor for ovarian cancer.

Adenocarcinoma, Mucinous↗
PubMed2001

A study of infertility treatment and melanoma.

This study examined the possible association between melanoma and exposure to fertility drugs, specifically clomiphene citrate, human menopausal gonadotrophin (HMG) and human chorionic gonadotrophin (HCG). A cohort of 3186 women who attended a fertility clinic between 1 January 1980 and 31 December 1990 was studied; by January 1996, 14 women had been diagnosed with primary melanoma. Details of fertility treatment were extracted from the clinical records. The incidence of melanoma in the cohort resembled that of the female Queensland population (standardized incidence ratio = 0.89, 95% confidence interval [CI] = 0.54-1.48). Exposure to clomiphene citrate, HMG or HCG did not affect the incidence of melanoma. Women with infertile partners who were treated with fertility drugs were at increased risk of melanoma (odds ratio [OR] = 3.17, 95% CI = 1.01-9.98). Compared with women exposed only to clomiphene citrate and HMG, a lower incidence of melanoma was observed among those who received HCG as well (OR = 0.10, 95% CI = 0.02-0.42). Women exposed to two or more cycles of either clomiphene citrate (OR = 0.27, 95% CI = 0.08-0.94) or HMG (OR = 0.23, 95% CI = 0.07-0.84) had a significant reduction in melanoma risk compared with women exposed to no or one cycle. In summary, a woman's infertility per se was not found to be associated with melanoma, while exposure to fertility drugs was positively associated with melanoma in women with infertile partners and negatively associated in women with low doses of fertility drugs.

Adult↗
PubMed2001

Intravenous ketamine plus midazolam is superior to intranasal midazolam for emergency paediatric procedural sedation.

OBJECTIVES: This study compared intranasal midazolam (INM) with a combination of intravenous ketamine and intravenous midazolam (IVKM) for sedation of children requiring minor procedures in the emergency department. METHOD: A single blinded randomised clinical trial was conducted in the emergency department of a major urban paediatric hospital. Subjects requiring sedation for minor procedures were randomised to receive either INM (0.4 mg/kg) or intravenous ketamine (1 mg/kg) plus intravenous midazolam (0.1 mg/kg). Physiological variables and two independent measures of sedation (Sedation Score and Visual Analogue Sedation Scale) were recorded before sedation and at regular intervals during the procedure and recovery period. Times to adequate level of sedation and to discharge were compared. RESULTS: Fifty three patients were enrolled over a 10 month period. Sedation was sufficient to complete the procedures in all children receiving IVKM and in 24 of the 26 receiving INM. Onset of sedation was an average of 5.3 minutes quicker with IVKM than with INM (95%CI 3.2, 7.4 minutes, p<0.001). Children given INM were discharged an average of 19 minutes earlier than those given IVKM (95%CI 4, 33 minutes, p=0.02). Mean Sedation Scores and Visual Analogue Sedation Scale scores for the 30 minutes after drug administration were significantly better in children given IVKM compared with INM (2.4 and 1.8 versus 3.5 and 3.8, respectively). Both doctors and parents were more satisfied with sedation by intravenous ketamine and midazolam. CONCLUSIONS: Intravenous ketamine plus midazolam used in an appropriate setting by experienced personnel provides an excellent means of achieving sedation suitable for most non-painful minor procedures for children in the emergency department. This combination is superior to INM in terms of speed of onset and consistency of effect. INM delivered via aerosol spray has a more variable effect but may still be adequate for the completion of many of these procedures.

Administration, Intranasal↗
PubMed2000

A comparison of the effects of dialysis and renal transplantation on the survival of older uremic patients.

BACKGROUND: Patients over age 60 constitute half of all new patients accepted into the renal replacement therapy programs in Australia. However, the optimal treatment of their end-stage renal disease remains controversial. The aim of the present study was to compare survival for dialysis and renal transplantation in older patients who were rigorously screened and considered eligible for transplantation. METHODS: The study cohort consisted of 174 consecutive patients over 60 who were accepted on to the Queensland cadaveric renal transplant waiting list between January 1, 1993 and December 31, 1997. Follow-up was terminated on October 1, 1998. Data were analyzed on an intention-to-transplant basis using a Cox regression model with time-varying explanatory variables. An alternative survival analysis was also performed, in which patients no longer considered suitable for transplantation were censored at the time of their removal from the waiting list. RESULTS: There were 67 patients receiving a renal transplant, whereas the other 107 continued to undergo dialysis. These two groups were well matched at baseline with respect to age, gender, body mass index, renal disease etiology, comorbid illnesses, and dialysis duration and modality. The overall mortality rate was 0.096 per patient-year (0.131 for dialysis and 0.029 for transplant, P<0.001). Respective 1-, 3- and 5-year survivals were 92%, 62%, and 27% for the dialysis group and 98%, 95%, and 90% (P<0.01) for the transplant group. Patients in the transplant group had an adjusted hazard ratio 0.16 times that of the dialysis group (95% confidence interval 0.06-0.42). If patients were censored at the time of their withdrawal from the transplant waiting list, the adjusted hazard ratio was 0.24 (95% confidence interval 0.09-0.69). CONCLUSIONS: Renal transplantation seems to confer a substantial survival advantage over dialysis in patients with end-stage renal failure who are rigorously screened and considered suitable for renal transplantation.

Aged↗
PubMed2000

Effect of pre-existing cytotoxic T lymphocytes on therapeutic vaccines.

Therapeutic vaccines which aim to induce CD8(+) cytotoxic T lymphocyte (CTL) responses will often be required to perform in the presence of pre-existing CTL which recognize epitopes within the vaccine. Here we explore the ability of a viral vaccine vector presenting several co-dominant CTL epitopes to prime CTL responses in animals that have a pre-existing CTL response to one of the epitopes in the vaccine. The vaccine was usually capable of inducing multiple new responses, suggesting that immunodomination effects of pre-existing CTL may generally be minimal following vaccination. However, when large numbers of pre-existing CTL were present, a novel type of immune modulation was observed whereby (1) the vaccine failed to prime efficiently new CTL responses that were restricted by the same MHC gene as the pre-existing responses, and (2) vaccine-induced CTL responses restricted by other MHC genes were enhanced. These results may have implications for therapeutic multi-epitope vaccines for diseases like HIV and melanoma, which aim to broaden CTL responses.

Adoptive Transfer↗
PubMed2000

Increasing chromosome 1 copy number parallels histological progression in breast carcinogenesis.

Chromosome 1 copy number in the benign breast lesions hyperplasia and atypical duct hyperplasia (ADH) was investigated using fluorescence in situ hybridization on paraffin sections. Progression of chromosome 1 changes occurring in parallel with histological progression from normal through hyperplasia and ADH to ductal carcinoma in situ (DCIS) and invasive carcinoma was also assessed, both overall and within individual patients. The mean signal number for normal cells was 1.14, while that for hyperplasia was 1.56 and ADH was 1.5, while values for DCIS of 1.95 and invasive duct carcinoma of 1.79, were higher (P < 0.001). Six of the seven cases also showed a significant trend towards an increasing proportion of cells with greater than 2 signals per nucleus occurring with histological progression (P < 0.001). These results support the concept that benign proliferative breast disease is a biological precursor of in-situ and invasive ductal carcinoma, the early histological changes possibly indicating a field effect with further genetic changes required for the development of a malignant phenotype.

Breast Neoplasms↗
PubMed2000

Beyond ovulation: oral contraceptives and epithelial ovarian cancer.

In a case-control study in three Australian states that included 794 women with epithelial ovarian cancer and 853 community controls for whom we had adequate contraceptive and reproductive histories, we examined the effects of oral contraceptive use after controlling for estimated number of ovulatory cycles. Other covariates included in the multiple logistic regression analysis were parity, smoking, and history of pelvic surgery. The protective effect of duration of oral contraceptive use appeared to be multiplicative, with a 7% decrease in relative risk per year [95% confidence interval (CI) = 4-9%], persisting beyond 15 years of exposure. Use for up to 1 year may have a greater effect than predicted (odds ratio = 0.57; 95% CI = 0.40-0.82), whereas use before the first pregnancy may be additionally beneficial (odds ratio = 0.95; 95% CI = 0.87-1.03, adjusted for overall duration of use). Better control for ovulatory life might attenuate these estimates somewhat. There was little evidence of waning protection with time since last exposure or of extra benefit with early commencement of oral contraceptive use. We found no convincing evidence of effect modification in any factor examined or differences in effect among the three main histologic cancer types or between borderline and malignant tumors. Oral contraceptives may act by both suppressing ovulation and altering the tumor-promoting milieu.

Adult↗
PubMed2000

Toxicity of insecticides for control of freshwater Culex annulirostris (Diptera: Culicidae) to the nontarget shrimp, Caradina indistincta (Decapoda: Atyidae).

Laboratory evaluations were conducted in southeastern Queensland, Australia, to determine the toxicities of two organophosphate compounds (temephos and pirimiphos-methyl), an insect growth regulator (s-methoprene), and an entomopathogenic bacterium (Bacillus thuringiensis variety israelensis de Barjac [B.t.i.]) to Culex annulirostris (Skuse), an Australian freshwater mosquito vector of arboviruses, and to Caradina indistincta Calman, a co-habiting nontarget shrimp species. S-methoprene and B.t.i. were safest for Cx. annulirostris control with lethal dose ratios (LC95 nontarget/LC95 target) of 3,300 and 846,000, respectively. In contrast, lethal dose ratios for temephos and pirimiphos-methyl were 0.05 and 0.00005, respectively, suggesting that they are environmentally unsuitable. Based on their high lethal dose ratios, s-methoprene and B.t.i. are recommended for control of larval Cx. annulirostris in Australian freshwater habitats.

Animals↗
PubMed1999

Apolipoprotein E polymorphism in indigenous Australians: allelic frequencies and relationship with dyslipidaemia.

OBJECTIVES: To determine the apolipoprotein E (apoE) allelic frequencies and the effect of apoE genotype on lipid concentrations in indigenous Australian subjects. DESIGN: Cross-sectional study. SUBJECTS AND SETTING: 155 indigenous Australians (92 women and 63 men) of mean (+/- standard deviation) age 45 +/- 17 years (SD +/- 50) were recruited without regard to history of atherosclerotic disease, in collaboration with community-based health centres in five indigenous communities in south-east Queensland. For comparison, 113 subjects of European descent and similar age distribution from the Brisbane and Gold Coast regions were also studied. MAIN OUTCOME MEASURES: ApoE allelic frequency; apoE genotype; sex; age; diabetes status; body mass index; history of atherosclerotic vascular disease; and concentrations of total cholesterol, triglyceride, HDL-cholesterol and LDL-cholesterol. RESULTS: The frequency of the apoE4 allele was found to be significantly higher in the indigenous subjects than in the subjects of European descent (P < 0.001). Among indigenous subjects, those with the apoE4 allele tended to have higher triglyceride concentrations and had significantly lower HDL-cholesterol concentrations than those with the apoE3/3 and 3/2 genotypes. CONCLUSIONS: ApoE allelic frequency is likely to be one of the cluster of factors contributing to the high cardiovascular mortality of indigenous Australians.

Adult↗
PubMed1999

Plasma homocysteine levels in indigenous Australians.

OBJECTIVES: To determine plasma homocysteine levels in indigenous Australians living in urban areas, and the relationship of these levels with other risk factors in this population. DESIGN: Cross-sectional study. SUBJECTS AND SETTING: 365 urban indigenous Australian subjects, 153 men and 212 women, mean (SE) age 42 (1) years, ascertained without regard to history of atherosclerotic disease, in collaboration with community-based health centres in five indigenous communities in south-east Queensland, 1997-1998. MAIN OUTCOME MEASURES: Plasma homocysteine levels, age, sex, smoking history, metformin therapy, history of atherosclerotic vascular disease, serum creatinine level, red cell folate and serum vitamin B12 levels. RESULTS: 89 subjects (24%) had plasma homocysteine levels 15 mumol/L or above. Homocysteine levels were higher in men than in women (men: 14.4 mumol/L; 95% confidence interval [CI], 13.6-15.2; women: 11.9 mumol/L; 95% CI, 11.4-12.5) (P < 0.001); correlated with age (P < 0.001); higher in current smokers (P = 0.02); higher in subjects taking metformin therapy (P = 0.007); and higher in subjects with a history of atherosclerotic vascular disease (P < 0.001). Homocysteine levels were also correlated with serum levels of creatinine (P < 0.001), red cell folate (P < 0.001), and vitamin B12 (P < 0.001). CONCLUSIONS: These data indicate that the high plasma levels of homocysteine of Australian indigenous subjects are associated with a history of vascular disease, and correlated with, among other things, smoking, and folate and vitamin B12 nutritional deficiency. These are potentially reversible risk factors, and our data suggest that focusing public health initiatives on these issues may reduce the high prevalence of cardiovascular disease in the Australian indigenous population.

Adult↗