Blood lead levels in children in Perth,Western Australia

Abstract: This study reports on an analysis of the lead concentrations in 123 venous blood samples collected from Perth children aged between two months and 17 years attending Princess Margaret Hospital. The overall geometric mean was 6.9 μg lead per 100 ml whole blood, with 95 per cent of results lying between 3.2 and 14.8 μg/100 ml. Among children under five years of age, those aged between 18 months and two years had the highest geometric mean blood lead (11.1 μg/100 ml). There were no consistent associations between geometric mean blood lead and area of residence, age group or sex. In this sample of Perth children, the mean blood lead concentration was lower than those reported in other studies. Less than 0.1 per cent of children of the age range studied would have been expected to have lead levels exceeding the NHMRC ‘level of concern’ (25 μg/100 ml) current at the time of the study. However, the recent adoption of goal of less than 10 μg/100 ml could mean that lead levels in up to 21 per cent of Perth children would now be regarded as excessive.     

Sunglasses and clothing—an unhealthy correlation?

Abstract: Increasing awareness of health effects of solar ultraviolet radiation has focused attention on protection measures, including sunglasses. Sunglasses, or fashion glasses with tinted lenses, may be associated with some risks, and quality is not evident from casual inspection. This study investigates one possible ‘hazard’ of sunglasses—that they may induce behavioural changes which reduce the wearer's tendency to use adequate sun protection for the rest of the body. Findings consistent with such a proposition were shown in a photographic survey of 373 people in the summer of 1991 in Perth, Western Australia. This revealed maladaptive associations between the wearing of sunglasses and a high degree of leg or arm exposure as recorded by length of sleeves or trouser legs. This was significant for the arms and the legs in males (P < 0.05), but approached significance only for the arms in females (P < 0.10). There was no significant association between degrees of arm and leg exposure in either sex. The health implications of these maladaptive behaviours, and some advantages and disadvantages of the survey technique, are discussed. The results suggest that promotion of sun-protective behaviour should encourage the use of both sunglasses and protective clothing, as subjects' behaviours with respect to these do not appear to be correlated in a rational manner. If public awareness of links between skin cancer and eye disease could be increased, promotion of sunglasses might lead to a reduction in the incidence of skin cancers in general, not just those in the periorbital area.     

Perforated colorectal neoplasms: correlation of clinical, contrast enema, and CT examinations

Results of clinical, contrast enema (CE), and computed tomographic (CT) examinations in 39 patients with perforated colorectal neoplasms were retrospectively reviewed. Twenty patients were toxemic at initial presentation, but in only four patients was the diagnosis of perforated colorectal neoplasm initially suspected clinically. CE study was performed in 22 patients and enabled the diagnosis of perforated neoplasm in 11 cases, neoplasm alone in eight, and neither neoplasm nor perforation in three. CT was performed in 38 patients and enabled the diagnosis of perforated neoplasm in 36; pericolic phlegmon but no mass lesion was evident in two. In 16 patients, CT also demonstrated metastatic disease. Because of its reliability in establishing the diagnosis and staging the extent of the inflammatory and neoplastic disease, CT is indicated in cases of suspected or proved perforated colorectal neoplasm and in cases in which CE study findings are indeterminate or suggestive of perforated neoplasm.     

Frequent ongoing T-cell receptor rearrangements in childhood B- precursor acute lymphoblastic leukemia: implications for monitoring minimal residual disease

Crosslineage T-cell receptor delta (TCR delta) rearrangements are widely used as tumor markers for the follow up of minimal residual disease in childhood B-precursor acute lymphoblastic leukemia (ALL) by polymerase chain reaction (PCR). The major drawback of this approach is the risk of false-negative results due to clonal evolution. We investigated the stability of V delta 2D delta 3 rearrangements in a group of 56 childhood B-precursor ALL patients by PCR and Southern blot analysis. At the PCR level, V delta 2D delta 3-to-J alpha rearranged subclones (one pathway for secondary TCR delta recombination) were demonstrated in 85.2% of V delta 2D delta 3-positive patients tested, which showed that small subclones are present in the large majority of patients despite apparently monoclonal TCR delta Southern blot patterns. Sequence analysis of V delta 2D delta 3J alpha rearrangements showed a biased J alpha gene usage, with HAPO5 and J alpha F in 26 of 32 and 6 of 32 clones, respectively. Comparison of V delta 2D delta 3 rearrangement status between diagnosis and first relapse showed differences in seven of eight patients studied. In contrast, from first relapse onward, no clonal changes were observed in six patients studied. To investigate the occurrence of crosslineage TCR delta rearrangements in normal B and T cells, fluorescence-activated cell sorter-sorted peripheral blood CD19+/CD3- and CD19-/CD3+ cell populations from three healthy donors were analyzed. V delta 2D delta 3 rearrangements were detected at low frequencies in both B and T cells, which suggests that V delta 2-to-D delta 3 joining also occurs during normal B-cell differentiation. A model for crosslineage TCR delta rearrangements in B-precursor ALL is deduced that explains the observed clonal changes between diagnosis and relapse and is compatible with multistep leukemogenesis of B-precursor ALL.     

Symptoms and time to presentation and treatment in ocular melanoma: the Western Canada Melanoma Study

Reports on all ocular melanomas newly diagnosed between Apr. 1, 1979, and Mar. 31, 1981, were obtained from the cancer registries of British Columbia, Alberta, Saskatchewan and Manitoba. Of the 90 cases, 87 were in patients aged 20 to 79 years, 64 of whom were interviewed about their initial symptoms. Three symptoms--loss of part of the visual field (in 33% of patients), photopsia (in 20%) and blurred vision (in 20%)--emerged as the main indicators of disease. In 17% of cases the tumour was discovered as an incidental finding on ocular examination. The length of delay before consulting a physician was generally short in symptomatic patients, with 85% reporting that they saw a physician within 3 months of onset of the first symptom. Of the 30 patients who received definitive treatment 4 months or more after initial presentation, 13 were seen by general practitioners who delayed before referring the patient to an ophthalmologist. Continuing medical education is needed to ensure earlier referral to ophthalmologists by general practitioners of patients with ocular melanoma.     

Mortality among female registered nurses and school teachers in British Columbia

The mortality profile of female nurses and teachers in British Columbia (BC) was examined using age-standardized proportional mortality ratios (PMRs) calculated for the period 1950–1984. Lowered overall mortality among nurses was seen for degenerative heart disease and for cerebrovascular accidents. Significantly elevated PMR values were observed for cancer of the breast and ovary in nurses of age 20–65 years. PMRs were significantly elevated for cancer of the pancreas and leukemia among those age 20 years and older. Elevated values were also observed for motor vehicle accidents and suicide among nurses in both age groups. Lower than expected mortality from degenerative heart disease and cerebrovascular accidents was seen in working age teachers (age 20–65 years). However, elevated PMRs were detected for carcinoma of the colon, breast, endometrium, brain, and melanoma. Among those 20 years and over, significantly elevated PMRs were also observed for cancers of the ovary and other digestive organs. Elevated PMRs were found for motor vehicle and aircraft accidents. Mortality from cirrhosis of the liver was lower than anticipated in both teachers and nurses. A number of significant PMRs declined when deaths of “homemakers” were withdrawn from the comparison group used to generate PMR values, suggesting that risk of death from various causes among women working outside the home differ from those seen in women who are predominantly in the home.     

Correlation of change in phage type with pulsed field profile and 16S rrn profile in Salmonella enteritidis phage types 4, 7 and 9a.

Using pulsed-field gel electrophoresis (PFGE) and 16S rRNA (rrn) analysis (ribotyping), the in vivo derivation of strains of Salmonella enteritidis PTs 9a and 7 from a strain of S. enteritidis PT 4 has been demonstrated. All strains were isolated from a single patient over a 6-week period. Further studies have demonstrated that in terms of pulsed-field profile and ribotype, the genotypes of the patient-derived strains differed from those of the reference strains of the respective phage types. It is concluded that when used in combination, these methods can provide evidence of phylogenetic relationships in apparently unrelated S. enteritidis phage types isolated during pathogenesis of disease.