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Biomedical subjects

J Wlodarczyk

Publications and source records attributed to J Wlodarczyk.

At least 19 recordsLinked to original sources
PubMed2002

Lead dust in broken hill homes--a potential hazard for young children?

OBJECTIVE: To determine the potential hazard posed by indoor lead dust to young children in Broken Hill, a silver-lead-zinc mining town in outback Australia, and the degree to which lead flux is influenced by factors such as geographical location, house construction type and condition. METHODS: 116 homes were selected and 93 (80%) studied from 10 localities in Broken Hill during the spring of 1995. Lead flux was measured using 85 mm diameter polystyrene petri dishes. Dishes were placed in four rooms of each house to collect dust over a six-to-eight-week period. Data on the location, condition and construction type of each house were recorded. Multiple linear regression was used to determine predictors of lead flux. Flux data were log transformed for the analysis. RESULTS: Average household lead flux varied nearly seven-fold across districts from a low of 166 (distant from the mines), to a high of 1,104 microg/m2/30-day period (adjacent to the mines). Houses that were 'adequately sealed' had 2.9 times the lead flux, and 'poorly sealed' houses 4.3 times the flux, of 'very well sealed' houses. Construction material did not significantly affect these flux levels, and no statistically significant interactions were found between house condition and location or house type. CONCLUSIONS: Many Broken Hill homes have high levels of lead flux that pose a potential risk to young children. Quantification of this hazard provides useful information for the community that can help focus efforts on actions required to minimise lead dust in the home. IMPLICATIONS: Household dust is a potential source of lead for young children in at-risk communities. Information on lead flux in homes can assist these communities and public health agencies to better understand and deal more effectively with the problem.

Air Pollution, Indoor↗
PubMed2001

A comparative study of E-cadherin and stromelysin-3 expression in de novo and ex adenoma carcinoma of the colorectum.

An apparent exception to the colorectal adenoma-carcinoma carcinogenetic pathway is the so-called "de novo" carcinoma which has no evidence of adenoma in its vicinity. Despite the fact that they are often quite small, these lesions appear to be more aggressive (i.e., greater likelihood of lymph-node metastases) than carcinomas that clearly arise from surrounding adenomas exadenoma carcinoma. The purpose of the present comparative immunohistochemical study was to compare rates of cell adhesion molecule (E-cadherin) and protease [stromelysin-3 (ST-3)] expression in groups of de novo (n=64) and ex adenoma (n=42) lesions in order to see whether their more aggressive behavior is associated with decreased cell adhesion and increased protease expression. The rates of extensive ST-3 expression and decreased E-cadherin expression were significantly higher in the de novo group (P=0.014 and 0.005, respectively). Histopathologically, the de novo group also had a significantly higher percentage of cases with an infiltrative invasion pattern. These differences highlight the more aggressive phenotype of the de novo colorectal carcinoma and fit with their greater invasive potential.

Adenoma↗
PubMed2001

Pterygium in Australia: a cost of illness study.

PURPOSE: The aim of this report was to describe the number of Australians affected by pterygium in recent years, treatment options, number of treatment encounters and costs of treatment. METHOD: A review of published literature was conducted to identify the prevalence of pterygium in Australian populations. Costs of primary care were based on national general practitioner (GP) survey data. Costs of surgical intervention were based on Health Insurance Commission claims data and Australian Institute of Health and Welfare National Hospital Morbidity Data. RESULTS: Pterygium occurs in 1.1% of Australians. It is more prevalent in populations with higher exposure to ultraviolet radiation, and older men (occurring in 12% of males over 60 years). The estimated annual number of GP contacts was 58,900. Forty per cent of primary care contacts for pterygium were referred to an ophthalmologist and topical medication was prescribed by GPs in 32% of contacts. The estimated annual cost of GP visits, specialist visits and topical medication was AUD$3.2 m. There were 6997 claims for pterygium removal in 1999/2000 with 3192 conjunctival autografts. Rates of pterygium removal were highest in Queensland with 56 per 100,000 population. The annual costs of surgical intervention were estimated at AUD$4.8 m. CONCLUSIONS: The direct medical costs of pterygium in Australia are AUD$8.3 m annually. This is likely to be an underestimate of total cost because indirect costs such as loss of work time could not be measured. More data are needed on the long-term benefits of pterygium intervention.

Adult↗
PubMed2000

Serological evidence of infection with Chlamydia pneumoniae is related to the severity of asthma.

There is evidence that infection with Chlamydia pneumoniae is associated with asthma of recent onset and that it can influence the severity of asthma. This has led to the suggestion that macrolide antibiotics may be useful in the treatment of asthma in subjects infected with C. pneumoniae. This study examined the association between immunoglobulin (Ig)G and IgA titres to C. pneumoniae and the severity of asthma. IgG and IgA antibodies to C. pneumoniae were measured in 619 subjects with asthma (18-60 yrs), using the microimmunofluoresence method. Subjects were asked about their use of asthma medicines, symptoms, previous hospitalization for asthma, smoking status and age of onset of asthma. In subjects with IgG titres of > or =1:64 and/or IgA titres > or =1:16 (n=212), spirometry was performed and peak expiratory flow rate (PEFR) and symptoms were recorded twice daily for 4 weeks on a diary card. The use of high dose inhaled steroids was associated with an increase of 74.1% in the titre of IgG antibodies (p=0.04) and an increase of 70.6% in the titre of IgA antibodies (p=0.0001) when compared with the use of low dose inhaled steroids. There was an inverse association between IgG antibodies and forced expiratory volume in one second (FEV1) as a percentage of predicted in those subjects with elevated IgG and/or IgA (p=0.04). In this group IgA antibodies were also associated with a higher daytime symptom score (p=0.04). Higher titres of antibodies to Chlamydia pneumoniae appears to be associated with markers of asthma severity. This raises the possibility that chronic infection with Chlamydia pneumoniae leads to an increase in the severity of asthma. Studies aimed at eradicating chronic infection with Chlamydia pneumoniae are necessary to determine whether or not this is the case.

Administration, Inhalation↗
PubMed1999

Comparison of family history measures used to identify high risk of coronary heart disease.

We examined 15 published continuous family history measures (scores) as well as two new formulations in terms of several desirable properties. We applied the scores to sample pedigrees and found that some systematically increase with family size. In contrast to aggregate scores, non-aggregate scores are sensitive to the age, sex, and covariate status of individual relatives but are unstable when the families are small. We also applied these scores to our own population case-control data, characterised by a high proportion of missing and false-negative responses. In these small families, all scores provided significant discrimination between CHD cases and controls beyond the usual categorical definition of positive family history, but appeared no better than detailed categorical definitions or even simple counts. Our new formulations offer no solution to the problems of few data; most scores apply asymptotic approximations to differences between observed and expected number of affected relatives and are not suited to small families. All scores would be improved by ruling out families with only one affected relative, as is being done in the NHLBI Family Heart Study. We recommend that researchers, when using a family history measure, consider the number of informative families and other characteristics of their data prior to choosing any particular formulation.

Age Factors↗
PubMed1998

Outdoor air pollution and children's respiratory symptoms in the steel cities of New South Wales.

OBJECTIVE: To investigate the relationship between outdoor air pollution and the respiratory health of children aged 8 to 10 years. DESIGN: A cross-sectional survey (between October 1993 and December 1993) of children's health and home environment. Summary measures of particulate pollution (levels of particles with an aerodynamic diameter less than 10 microns [PM10] each 6th day) and SO2 (daily mean and maximum hourly values) were estimated for each area (using air quality monitoring station data from July 1993 to June 1994). SETTING AND SURVEY PARTICIPANTS: Parents of 3023 primary school children (Years 3, 4 and 5) from industrial and non-industrial areas with air quality monitoring stations in the Hunter and Illawarra regions of New South Wales. MAIN OUTCOME MEASURES: Reported occurrence of four or more chest colds, four or more attacks of wheezing, and night-time cough without a cold for more than two weeks, all within the previous 12 months. RESULTS: 77% response rate, ranging by area from 66% to 88%. The average annual outdoor air pollution for the nine areas was 18.6-43.7 micrograms/m3 for PM10 and 0.16-0.90 parts per hundred million for SO2. The proportion of children reported to have the main outcome symptoms were: chest colds, 3.0%-9.7%; night cough, 12.3%-30.5%; and wheeze, 3.4%-11.3%. There was no significant association with SO2, but a significant increase in the odds of symptoms per 10 micrograms/m3 increase in PM10 on chest colds (odds ratio [OR], 1.43; 95% confidence interval [CI], 1.12-1.82) and night-time cough (OR, 1.34; 95% CI, 1.19-1.53), but not wheeze. Passive smoking was significantly associated with chest colds but not with the other symptoms. Maternal allergy was associated with all three respiratory symptoms, most strongly with wheeze. CONCLUSION: These results provide evidence of health effects at lower than expected levels of outdoor air pollution in the Australian setting. They also suggest differences in contributions of environmental and hereditary factors to cough and chest colds compared with wheeze.

Air Pollution↗
PubMed1998

Correction for biases in a population-based study of family history and coronary heart disease. The Newcastle Family History Study I.

In this paper, the authors report on the design of a population-based case-control study of family history as a risk factor for coronary heart disease (CHD). They studied the characteristics of subjects who completed a detailed family history questionnaire in 1992-1994 as well as the accuracy of recall of family history in order to quantify both selection and recall biases. Coronary disease cases were enrolled through the Newcastle MONICA Project (Monitoring Trends and Determinants in Cardiovascular Disease), which registered all suspected heart attacks and sudden cardiac deaths in the Lower Hunter region of New South Wales, Australia, between August 1984 and March 1994. Controls were selected at random from the New South Wales electoral roll. The response rate was 76% in cases and 62% in controls; the major factor associated with participation in the study was perceived family history of CHD, more so in the control series than in the case series. Accuracy was determined by comparing information obtained from the proband with that recorded on death certificates. In first-degree relatives, sensitivity of CHD recall was 85% (95% confidence interval (CI) 74-92%) in cases and 95% (95% CI 84-99%) in controls, while specificity was 59% (95% CI 49-69%) and 74% (95% CI 65-82%), respectively. The net bias in both selection and recall is toward the null and hence the comparisons provide a conservative estimate of risk of CHD associated with a positive family history.

Aged↗
PubMed1998

Risk associated with various definitions of family history of coronary heart disease. The Newcastle Family History Study II.

The authors carried out a population-based case-control study to estimate the risk of an acute coronary disease event associated with various definitions of a family history of coronary heart disease (CHD). A detailed family history questionnaire was completed by 403 cases and 236 controls in Newcastle, New South Wales, Australia from 1992 to 1994. Odds ratios of an acute coronary disease event adjusted for proband age and sex ranged from 2.7 (95% confidence interval (CI) 1.8-4.1) for the simplest definition (one or more first-degree relatives with CHD at any age) to 5.4 (95% CI 1.7-16.8) for the most stringent definition (two or more first-degree relatives with CHD before age 55 years). In a series of nested models, the authors examined the improvement in model fit as each component of the detailed family history was added. Additional information was provided by accounting for "don't know" responses, the number of affected relatives, the age of the affected relative, and whether the first-degree relative was a sibling rather than a parent. The results were similar when the data were analyzed as a cohort design with proband disease status as the exposure variable. The authors suggest that, to facilitate preventive efforts in a population, more detailed family history definitions should be used to better target high risk subjects.

Age of Onset↗
PubMed1998

A double-blind randomized clinical trial on the effectiveness of a daily glycolic acid 5% formulation in the treatment of photoaging.

BACKGROUND: Low-strength daily formulations of glycolic acid are widely promoted for the treatment of photoaging. However, there are few clinical studies that objectively confirm the benefits of such formulations. OBJECTIVE: The purpose of this study was to determine the effectiveness of a 5% unneutralized formulation of glycolic acid in the treatment of facial and neck photoaging. METHODS: Seventy-five volunteers were recruited to take part in this double-blind randomized placebo-controlled clinical study. Participants applied either the 5% glycolic acid cream or the placebo cream to the face and neck for a period of 3 months. Pre- and posttreatment clinical assessments of photoaging effects were made by the same physician and were analyzed for statistical significance. RESULTS: Overall there were trends towards greater improvement or less worsening in the glycolic acid group for all clinical assessments for photoaging. There was statistically significant improvement favoring the active-cream in general skin texture and discoloration. There was a trend favoring glycolic acid in reduction of wrinkles, but this did not achieve statistical significance. CONCLUSION: Unneutralized 5% glycolic acid topical cream when used on a regular daily basis can improve some photoaging effects.

Administration, Topical↗
PubMed1998

Air pollution and hospital admissions in Sydney, Australia, 1990 to 1994.

OBJECTIVES: This study examined the effects of outdoor air pollutants on daily hospital admissions in Sydney, Australia. METHODS: A time-series analysis of counts of daily hospital admissions and outdoor air pollutants (1990 to 1994) was performed, by means of Poisson regression that allowed for overdispersion and autocorrelation. RESULTS: An increase in daily maximum 1-hour concentration of nitrogen dioxide from the 10th to the 90th percentile was associated with an increase of 5.29% (95% confidence interval = 1.07, 9.68) in childhood asthma admissions and 4.60%(-0.17,9.61) in chronic obstructive pulmonary disease (COPD) admissions. A similar increase in daily maximum 1-hour particulate concentration was associated with an increase of 3.01% (-0.38, 6.52) in COPD admissions. An increase from the 10th to the 90th percentile in daily maximum 1-hour nitrogen dioxide, daily maximum 1-hour ozone, and daily mean particulate was associated with an increase in heart disease admissions among those 65 years and older of 6.71% (4.25, 9.23), 2.45% (-0.37, 5.35), and 2.82% (0.90, 4.77), respectively. Heart disease and childhood asthma were primarily associated with nitrogen dioxide; COPD was associated with both nitrogen dioxide and particulates. CONCLUSIONS: Current levels of air pollution in Sydney are associated with increased hospitalization for respiratory and heart disease.

Adolescent↗
PubMed1998

Air pollution and daily mortality in Sydney, Australia, 1989 through 1993.

OBJECTIVES: This study examined the effects of outdoor air pollutants in Sydney, Australia, on daily mortality. METHODS: Time-series analysis was performed on counts of daily mortality and major outdoor air pollutants (particulates, ozone, and nitrogen dioxide) in Sydney (1989 to 1993) with adjustment for seasonal and cyclical factors. Poisson regression was calculated with allowance for overdispersion and autocorrelation. The effects of lagging exposure by 0 to 2 days were assessed with single- and multiple-pollutant models. RESULTS: An increase in daily mean particulate concentration from the 10th to the 90th centile was associated with an increase of 2.63% (95% confidence interval 0.87 to 4.41) in all-cause mortality and 2.68% (0.25 to 5.16) in cardiovascular mortality. An increase in daily maximum 1-hour ozone concentration from the 10th to the 90th centile was associated with an increase of 2.04% (0.37 to 3.73) in all-cause mortality and 2.52% (-0.25 to 5.38) in cardiovascular mortality. An increase in the daily mean nitrogen dioxide concentration from the 10th to the 90th centile was associated with an increase of 7.71% (-0.34 to 16.40) in respiratory mortality. Multiple-pollutant models suggest that the effects of particulates and ozone on all-cause and cardiovascular mortality, and of nitrogen dioxide on respiratory mortality, are independent of the effects of the other pollutants. CONCLUSIONS: Current levels of air pollution in Sydney are associated with daily mortality.

Air Pollutants↗
PubMed1997

Gender differences and other determinants of the rise in plasma homocysteine after L-methionine loading.

The methionine load test is widely used to identify subjects with mild homocysteinemia. We studied factors influencing the rise in plasma homocysteine (tHcy) levels following oral methionine loading, after taking into account determinants of the basal level. The study population comprised 522 persons (mean age 53, range 17 to 95; 63% male; 60% with coronary disease). tHcy was measured fasting and 4 h after administration of L-methionine (dose 4 g/m2). The percentage rise in tHcy was greater in females, at younger ages, and with lower serum creatinine. Basal tHcy was lower in those with high levels of serum folate, red cell folate and serum B12; they also showed a greater percentage rise with loading. After adjustment for age, creatinine and serum vitamins the percent rise was greater in females (mean 230%, S.D. 92) than in males (mean 172%, S.D. 71, P < 0.0001). About 1/4 of this effect was explained by the methionine dose, but important independent gender effects remained. When the results of the loading test were compared with an overall reference range, females were systematically labelled as 'high' but comparison with age and gender-specific reference ranges normalised the sex distribution. Our data show that a single L-methionine loading protocol for both sexes is not appropriate. Gender-specific reference ranges should be used to define post-load homocysteinemia and previous studies which have identified a high proportion of females with this trait probably reflect the need for gender specific reference ranges.

Adolescent↗
PubMed1997

Fasting and post-methionine homocyst(e)ine levels in a healthy Australian population.

BACKGROUND: Plasma homocyst(e)ine (H[e]) is frequently measured in patients with occlusive vascular disease, but levels vary between populations and between laboratories. AIMS: We sought to derive reference values for an Australian population over a wide age range. METHODS: We measured plasma H(e) in the fasting state and after methionine loading in 116 volunteers selected at random from the Hunter districts of the New South Wales electoral roll and in 49 apparently healthy, active subjects recruited from the region's lawn bowling clubs. Reference ranges were derived for both sexes, in three age strata. We collaborated with two international laboratories in standardising our results. RESULTS: Mean fasting H(e) levels were approximately 2.7 mumol/L higher in men than women, at all ages (95% CI for the difference, 1.2 to 4.1 mumol/L). Levels increased with age (approximately 1.0 mumol/L/decade, 95% CI 0.5 to 1.5) and were correlated with serum creatine (r = 0.48), serum folate (r = -0.30), red cell folate (r = -0.25) and serum B12 (r = -0.31) (all p < 0.001). These results are similar to those reported in other populations. CONCLUSIONS: We have defined reference ranges for a typical Australian population, following careful laboratory standardisation. H(e) levels must be interpreted with regard to age, sex, renal function and vitamin B12 and folate status.

Adult↗
PubMed1997

Reproducibility of brachial ultrasonography and flow-mediated dilatation (FMD) for assessing endothelial function.

BACKGROUND: High-resolution brachial artery ultrasonography is used to study vasodilator response induced by physiologic reactive hyperaemia. We examined the reproducibility of measuring flow-mediated dilatation (FMD) on two occasions. AIMS: To determine the degree of variability of this technique in our vascular laboratory for the design of clinical research studies. METHODS: Nineteen subjects were studied on two separate occasions using an Acuson 128 ultrasound device and a 7.0 MHz linear array transducer. Reactive hyperaemia was induced in the brachial artery by inflation and release of a blood pressure cuff. Nitrate-induced dilatation was assessed in 11 of the 19 subjects. Measurements were made by two observers blinded to subject details. RESULTS: The 11 subjects given sublingual GTN during the first ultrasound study had a mean nitrate-induced dilatation of 20.7% (sd 9.6). The mean vessel diameter of 3.78 mm (sd 0.7) at rest and 3.89 mm (sd 0.7) during reactive hyperaemia yielded a mean FMD of only 3.0% (sd 2.7). The mean difference in FMD within-observers was 0.13% (sd 2.07), between-observers 0.06% (sd 2.17) and between-studies was 0.57% (sd 6.83). CONCLUSIONS: The reproducibility of FMD measured by brachial artery ultrasound was poor and likely to render the measurements inaccurate for clinical research in our hands. Between-study variation contributed the largest proportion of total study variability. We suggest that investigators using this technique conduct their own careful reproducibility studies in order to avoid the misinterpretation of 'negative' studies.

Adult↗
PubMed1997

Opportunistic blood lead testing in a paediatric inpatient population.

We report a simple protocol which has potential to estimate community paediatric blood lead levels using opportunistic testing. Permission to use leftover blood for a lead assay was sought from parents or guardians of 397 children one month to 13 years of age who were admitted to general paediatric wards of John Hunter Hospital, Newcastle, between May and August 1993 and who had blood for a full blood count taken for any reason. Results were reviewed by a medical officer and returned to parents. Where a child's blood lead level was of concern according to National Health and Medical Research Council guidelines, the child was referred to a specialist paediatrician for clinical assessment. Written consent was received from the parents or guardians of 95.5 per cent of eligible children (n = 379); 93.4 per cent of responders (354 of 379) had blood suitable for testing, giving an overall result rate of 89.2 per cent (354 of 397). The mean blood lead level for the whole group was 5.3 micrograms/dL. The highest blood lead level for any age group was 6.4 micrograms/dL in the 36 to < 60 month age group. Stratification by geographical area showed a trend in increasing blood lead with increasing population density and areas where lead polluting industries exist. The approximate cost per result achieved was $40. This opportunistic survey method provides a promising technique for obtaining data on community blood lead levels. It may be a practical and resource-efficient alternative to large-scale community surveys. Further studies are under way to validate the method as a community surveillance tool.

Adolescent↗
PubMed1997

Presence of granulomas is associated with recurrence after surgery for Crohn's disease: experience of a surgical unit.

BACKGROUND: The determinants for recurrence of Crohn's disease remain controversial. Eight factors that might predict recurrence were studied in 130 patients operated on for Crohn's disease over a 24-year period. METHODS: Separate survival curves were estimated for each variable. A multivariate analysis was then carried out in which several selected explanatory variables were included simultaneously in a proportional hazards regression model. RESULTS: Operation for recurrent disease was necessary in 36 patients. Univariate analysis revealed a highly significant relationship between the presence of granulomas and subsequent recurrence (P = 0.003). There was a trend towards increased recurrence in patients with ileocolonic disease and segmental colectomy (P = 0.11 and P = 0.1 respectively). Age, sex, length of history, indication for operation and affected lines of transection were not associated with recurrence. After multivariate analysis, the association of granulomas with recurrence remained significant (P = 0.03). This association persisted when death was regarded as a treatment failure (P = 0.02). CONCLUSION: The presence of granulomas in patients with Crohn's disease is significantly associated with recurrence.

Adolescent↗
PubMed1996

Nasal inflammation and chronic ear disease in Australian Aboriginal children.

OBJECTIVE: Chronic middle ear disease is common in Aboriginal children, and may be linked to nasal inflammation and Eustachian tube dysfunction. The pattern of nasal inflammation is unknown. The study reported here was performed to define the role of allergy and infection in causing nasal inflammation in Aboriginal children with chronic middle ear disease. METHODOLOGY: Thirty-one Aboriginal children aged between 3 and 7 years underwent clinical assessment, audiometry and allergy skin tests. Nasal swabs for bacterial culture and cytology were performed during the winter and again in spring to identify any seasonal variation. A randomized trial of nasal beclomethasone for 8 weeks was conducted in children with abnormal tympanometry to identify the effect of therapy upon nasal cytology. RESULTS: Twenty-six of the 31 children had abnormal tympanograms. Average hearing levels were reduced in nine children. Pathogenic organisms were isolated from most children: Streptococcus pneumoniae (82%), Haemophilus influenzae (79%), Moraxella catarrhalis (39%) and Staphylococcus aureus (29%). Eight of the 31 children (26%) were atopic. Nasal cytology disclosed a marked neutrophil infiltrate (80% of cells) during the winter, which fell significantly in spring to 52% of cells. Only two subjects had nasal eosinophilia of >10%. There was no effect of beclomethasone on nasal cytology. CONCLUSIONS: Chronic ear disease in Aboriginal children is associated with nasal inflammation, neutrophil infiltration and the presence of bacteria. These features suggest respiratory infection as the main cause of chronic nasal inflammation in Aboriginal children with middle ear disease. There is a seasonal variation in the severity of the nasal infiltrate, consistent with increased infections during winter. Despite a high prevalence of atopy, allergic nasal disease was uncommon.

Anti-Inflammatory Agents↗