Adverse pregnancy outcomes around incinerators and crematoriums in Cumbria, north west England, 1956-93

STUDY OBJECTIVE

To investigate the risk of stillbirth, neonatal death, and lethal congenital anomaly among babies of mothers living close to incinerators and crematoriums in Cumbria, north west England, 1956-93.

DESIGN

Retrospective cohort study. Logistic regression was used to investigate the risk of each outcome in relation to proximity at birth to incinerators and crematoriums, adjusting for social class, year of birth, birth order, and multiple births. Continuous odds ratios for trend with proximity to sites were estimated.

SETTING

All 3234 stillbirths, 2663 neonatal deaths, and 1569 lethal congenital anomalies among the 244 758 births to mothers living in Cumbria, 1956-1993.

MAIN RESULTS

After adjustment for social class, year of birth, birth order, and multiple births, there was an increased risk of lethal congenital anomaly, in particular spina bifida (odds ratio 1.17, 95% CI: 1.07 to 1.28) and heart defects (odds ratio 1.12, 95% CI: 1.03 to 1.22) around incinerators and an increased risk of stillbirth (odds ratio 1.04, 95% CI: 1.01 to 1.07) and anencephalus (odds ratio 1.05, 95% CI: 1.00 to 1.10) around crematoriums.

CONCLUSIONS

The authors cannot infer a causal effect from the statistical associations reported in this study. However, as there are few published studies with which to compare our results, the risk of spina bifida, heart defects, stillbirth, and anencephalus in relation to proximity to incinerators and crematoriums should be investigated further, in particular because of the increased use of incineration as a method of waste disposal.

Childhood solid tumours in relation to population mixing around the time of birth

In a retrospective cohort study of 673 787 live births in the Northern Region of England, 1975-1994, we investigated whether a higher level of population mixing around birth was a risk factor for solid tumours, by diagnostic group (Hodgkin's disease, brain and spinal tumours, neuroblastoma, other solid tumours), diagnosed during 1975-2001 under age 15 years. Logistic regression was used to relate risk to population mixing, based on (i) all movers and (ii) incomers from outside the region. Both ward and county district level analyses were performed. There was a decreased risk of brain and spinal tumours with increasing population mixing based on incomers from outside the region (OR for trend across three categories=0.79, 95% CI: 0.66-0.95, P=0.01 in the ward level analysis). Although this may be because of chance, it is consistent with a role of exposure to infection and immunological response in the aetiology of these tumours. For other tumour groups, there was no consistent evidence of an association between risk and population mixing.

A lifecourse study of risk for hyperinsulinaemia, dyslipidaemia and obesity (the central metabolic syndrome) at age 49-51 years

AIMS

Suboptimal maternal nutrition and catch-up growth in early childhood predispose to insulin resistance and other components of metabolic syndrome in later life. A central metabolic syndrome (CMS) has been identified comprising obesity, dyslipidaemia and insulin resistance. This study was designed to investigate determinants of risk for CMS.

METHODS

Persons born in Newcastle in May and June 1947 (n = 358) were followed to 1996-1998. A lifecourse approach was used to estimate the proportion of variance in a summary measure of CMS at age 49-51 years accounted for by factors operating at different stages of life.

RESULTS

After adjustment for other early life variables, childhood catch-up growth in men accounted for significant variation in the CMS score independent of adult lifestyle. In adulthood, exercise level in men and smoking in both genders were independently associated with CMS. Over two-thirds of explained variation in the CMS score in women, and almost half in men, was accounted for exclusively by factors measured in adulthood.

CONCLUSIONS

While risk for CMS in men is compounded by early life disadvantage, promotion of a healthier adult lifestyle and a reduction in the number of people taking up smoking would appear to be the public health interventions most likely to reduce the prevalence of CMS in middle age.

Childhood leukaemia and non-Hodgkin's lymphoma in relation to proximity to railways

We investigated whether living close to railway lines is a risk factor for childhood leukaemia and non-Hodgkin's lymphoma in electoral wards in England and Wales, 1966-1987. The national rail network, 1966-1987, was digitised and the numbers of cases in each ward were related to two measures of environmental exposure to railways: a proximity and a density function, contributions to these functions being weighted by the frequency of use and time in use of each stretch of railway. Poisson regression was used to derive rate ratios in relation to these measures of exposure to railways, both unadjusted and adjusted for population mixing. We found no association between risk of leukaemia and railway proximity (unadjusted rate ratio for trend from the lowest to the median value=1.006, 95% CI: 0.998 - 1.013, P=0.14) and a very small association with railway density, of marginal statistical significance (rate ratio for trend=1.001, 95% CI: 1.000 - 1.003, P=0.05). This effect depended on two deprived, urban wards with high railway density and high population mixing and became nonsignificant (P=0.09) after allowing for population mixing. The very weak association between railway density and risk of childhood leukaemia is likely to be a consequence of the association between population mixing and proximity to railways in very deprived, urban wards.

Regulation of BMP and Activin Signaling in Drosophila

Cytokines of the TGF-beta superfamily act through an evolutionarily conserved signaling pathway to elicit a diverse range of biological responses in vertebrates as well as invertebrates. Drosophila has proved to be a powerful system to unravel the profound complexities underlying the regulation of this superficially simple signaling system for two reasons--the availability of sophisticated genetic tools and the restricted number of core signaling components compared to vertebrates. A BMP signaling pathway in Drosophila that regulates growth, differentiation and morphogenesis of the embryo and the larva has been extensively characterized. This work has provided major insights into how gradients of secreted proteins can be established and maintained in vivo, allowing a single ligand to induce multiple cell fates rather than function as an on-off switch. More recently, an activin signaling pathway has also been delineated that is required for growth and neuronal function during development. This review provides an overview of TGF-beta signaling in Drosophila with emphasis on the extensive modulation of signaling activity both within and outside the cell, that enables ligands to trigger specific and context-dependent effects.

Dose-response effect of walking exercise on weight loss. How much is enough?

OBJECTIVE

Exercise is the cornerstone of behavioral weight loss programs. The total volume of exercise needed to both promote weight loss and elicit health benefits has not been sufficiently investigated. The aim of this study was to examine the effects of two different volumes of walking 'metabolic fitness' exercise prescriptions, in combination with a low-fat, ad libitum diet (LFAL) on weight loss and additional modifiable health-related variables (HRV) in an ethnically diverse sample of overweight premenopausal women.

DESIGN

Clinical 12 week weight loss intervention study with a 5.0-5.8 MJ diet daily with (a). participants walking 30 min, 5 days per week (DEX1), (b). participants walking 60 min, five times per week (DEX2) or (c). a diet only control group (DO).

SUBJECTS

A mixed racial sample (predominantly Hispanic) of 56 subjects (mean BMI=34.26+/-6.61, mean age= 39.45+/-7.34) completed the 12 week program.

MEASUREMENTS

Various body weight, body composition and fat distribution variables, dietary intake and additional HRV such as blood lipids, blood pressure and an estimate of cardiorespiratory fitness at baseline and after 3 months.

RESULTS

All groups showed similar and significant (P<0.001) declines in body weight, percentage body fat, BMI, WHR, fat mass, fat-free mass and diastolic blood pressure following the program. In addition, total cholesterol, triacylglycerol and the TC:HDL ratio displayed a significant time effect (P<0.05). Significant interactions (P<0.05) were found for waist circumference, sagittal diameter, estimated VO(2max) and LDL-C, with both exercise groups showing similar and significantly greater (P<0.05) improvements than DO. Significant interactions (P<0.05) were also observed for several dietary variables.

CONCLUSION

Our study showed no dose-response effect of walking exercise on weight loss over diet alone. Both lower and higher volume metabolic fitness prescriptions resulted in similar and significant beneficial changes in several HRV. This data suggests that 30 min of walking on most days of the week may be as beneficial as 60 min (in combination with diet) in promoting numerous additional healthful outcomes over diet alone following a 12 week weight loss program.

Childhood solid tumours in relation to infections in the community in Cumbria during pregnancy and around the time of birth

In a retrospective cohort study of all 99 976 live births in Cumbria, 1975-1992, we investigated whether higher levels of community infections during the mother's pregnancy and in early life were risk factors for solid tumours (brain/spinal and other tumours), diagnosed 1975-1993 under age 15 years. Logistic regression was used to relate risk to incidence of community infections in three prenatal and two postnatal quarters. There was an increased risk of brain/spinal tumours among children exposed around or soon after birth to higher levels of community infections, in particular measles (OR for trend=2.1, 95%CI : 1.3-3.6, P=0.008) and influenza (OR for exposure=3.3, 95%CI : 1.5-7.4, P=0.005). There was some evidence of an association between exposure to infections around and soon after birth and risk of other tumours, but this may have been a chance finding. The findings are consistent with other recent epidemiological studies suggesting brain tumours may be associated with perinatal exposure to infections.

Population mixing and childhood leukaemia and non-Hodgkin's lymphoma in census wards in England and Wales, 1966-87

We found an increased risk of childhood leukaemia with higher levels of inward migration, particularly from outside the region (rate ratio=1.9, 95%CI: 1.2-2.9, P<0.01). This significant effect was observed only in urban areas, although a marked but non-significant effect was seen in affluent, rural areas.

Paternal preconceptional irradiation, population mixing and solid tumors in the children of radiation workers (England)

OBJECTIVE

To investigate whether there was an increased incidence of solid tumors among offspring of male radiation workers at the Sellafield nuclear installation in Cumbria, northwest England and whether paternal preconceptional irradiation was associated with the risk of solid tumors.

METHODS

A cohort study of 266,710 live births in Cumbria, 1950-1991, followed up to age 25 years on the end of 1991.

RESULTS

Children of radiation workers had a non-significantly increased risk of solid tumors (RR= 1.5, 95% CI: 0.9-2.4, p = 0.09), determined largely by an increased risk of cancers excluding leukemias, lymphomas, brain, spinal and gender-specific tumors (RR= 1.9, 95% CI: 1.0-3.3, p = 0.05), which was partly explained by differing patterns of parental migration (adjusted RR= 1.7, 95% Cl: 0.8-3.2, p = 0.50). Within children of radiation workers there was no evidence of an increased risk with increasing paternal preconception dose of external radiation (hazard ratio per 100 mSv for all solid tumors=0.6, 95% CI: 0.1-1.8, p = 0.52).

CONCLUSIONS

Any observed excess of solid tumors in children of radiation workers may be partly explained by population mixing. Fathers' occupational exposure to radiation before conception was not found to be risk factor for solid tumors in their children.

Rapid MR imaging detection of renal cysts: age-based standards

PURPOSE

To establish age-based standards for renal cysts depicted at magnetic resonance (MR) imaging and to compare these standards with existing standards for ultrasonography (US).

MATERIALS AND METHODS

Three radiologists reviewed subsecond T2-weighted single-shot fast spin-echo kidney MR imaging findings in 528 patients (248 men, 280 women) selected from consecutive abdominal MR studies without regard to clinical indication. Age, sex, and number and diameter of cysts were noted. Results were analyzed with nonparametric tests and were compared with published US results.

RESULTS

Men (mean, 2.0; 95% CI: 1.5, 2.5) had more renal cysts than women (mean, 1.2; 95% CI: 0.9, 1.5) (P < .001). Number and diameter of cysts increased with age (P < .001). Of 528 patients, 330 (62.5%) had at least one renal cyst, and 315 (59.7%) had cysts of 10 mm or less. MR imaging findings were comparable to published US criteria for type 1 autosomal dominant polycystic kidney disease (ADPKD) if only cysts larger than 1 cm were considered: Only one subject in the group of 18-29-year-old subjects had at least two renal cysts, and five of 493 subjects aged 30-59 years had at least two cysts in each kidney.

CONCLUSION

Compared with reported US results, MR imaging depicted an increased number of simple renal cysts in healthy individuals because of its increased sensitivity for cysts smaller than 1 cm. If only simple renal cysts larger than 1 cm are considered, US criteria for type 1 ADPKD can be applied to MR imaging.

Implications of childhood obesity for adult health: findings from thousand families cohort study

OBJECTIVE

To determine whether being overweight in childhood increases adult obesity and risk of disease.

DESIGN

Prospective cohort study.

SETTING

City of Newcastle upon Tyne.

PARTICIPANTS

932 members of thousand families 1947 birth cohort, of whom 412 attended for clinical examination age 50.

MAIN OUTCOME MEASURES

Blood pressure; carotid artery intima-media thickness; fibrinogen concentration; total, low density lipoprotein, and high density lipoprotein cholesterol concentrations; triglyceride concentration; fasting insulin and 2 hour glucose concentrations; body mass index; and percentage body fat.

RESULTS

Body mass index at age 9 years was significantly correlated with body mass index age 50 (r=0.24, P<0.001) but not with percentage body fat age 50 (r=0.10, P=0.07). After adult body mass index had been adjusted for, body mass index at age 9 showed a significant inverse association with measures of lipid and glucose metabolism in both sexes and with blood pressure in women. However, after adjustment for adult percentage fat instead of body mass index, only the inverse associations with triglycerides (regression coefficient= -0.21, P<0.01) and total cholesterol (-0.17, P<0.05) in women remained significant.

CONCLUSIONS

Little tracking from childhood overweight to adulthood obesity was found when using a measure of fatness that was independent of build. Only children who were obese at 13 showed an increased risk of obesity as adults. No excess adult health risk from childhood or teenage overweight was found. Being thin in childhood offered no protection against adult fatness, and the thinnest children tended to have the highest adult risk at every level of adult obesity.

The Peterborough Schools Nutrition Project: a multiple intervention programme to improve school-based eating in secondary schools

OBJECTIVE

To evaluate over two years the effectiveness of multiple interventions targeted at lunches in secondary schools with the aim of increasing the consumption of healthier foods by children during the school day.

DESIGN

Controlled comparison study of two intervention schools targeted with multiple interventions to increase both the availability and the number of pupils consuming healthier foods, and one control school with no interventions but with the same observations over a two-year period.

SETTING

Three secondary schools in Peterborough, England.

SUBJECTS

Secondary school children in the three schools taking school lunches between 1996 and 1998.

RESULTS

School Food Groups (SFGs) were set up in both intervention schools. All catering interventions were actioned via the SFGs. Of the food availability targets, only the target to increase the availability of high-fibre bread in both intervention schools was met. The availability of food items at the control school remained stable. The proportion of pupils consuming fruit and vegetables/salad was very low in all schools at baseline. There were positive changes for consumption of fruit and non-fried potato in one intervention school, and for high-fibre bread and non-cream cakes at the other in the short term, but only that for high-fibre bread was close to being sustained at the end of the two years. The dietary consumption target for vegetables/salad was achieved by the final monitoring period in one school.

CONCLUSION

Overall there were no significant changes in school-based eating at the end of the study. Some positive changes were made, with some of the dietary targets being achieved at an early stage but not sustained. Ultimately this study has shown how difficult it is to achieve sustained dietary changes in the eating habits of secondary school children, even with considerable input.

Vectors for the expression of tagged proteins in Drosophila

Regulated expression systems have been extremely useful in developmental studies, allowing the expression of specific proteins in defined spatial and temporal patterns. If these proteins are fused to an appropriate molecular tag, then they can be purified or visualized without the need to raise specific antibodies. If the tag is inherently fluorescent, then the proteins can even be visualized directly, in living tissue. We have constructed a series of P element-based transformation vectors for the most widely used expression system in Drosophila, GAL4/UAS. These vectors provide a series of useful tags for antibody detection, protein purification, and/or direct visualization, together with a convenient multiple cloning site into which the cDNA of interest can be inserted.

Seasonality of birth for cancer in Northern England, UK

Environmental factors operating around the time of birth may influence the subsequent development of childhood cancer, particularly leukaemia. Certain factors may vary with season (e.g. infections), and we therefore investigated whether there was any evidence of seasonality of month of birth, based on data from 4199 children diagnosed with cancer under the age of 15 years. We extracted details of (i) children born 1960-95 and diagnosed 1968-95 from two population-based registries, covering the Northern (n = 2053) and Yorkshire (n = 1977) Regional Health Authority and (ii) children born in Cumbria 1950-93 and diagnosed anywhere in the UK before 1994 from a birth cohort database (n = 397). The following diagnostic categories were analysed: 0-14 years--all cancers, leukaemias, acute lymphoblastic leukaemias, central nervous system tumours, all other solid tumours; 1-6 years--leukaemias, acute lymphoblastic leukaemias. Seasonal variation was tested using Walter and Elwood's test, and logistic regression analysis allowing for cyclical variation in month of birth. No evidence of seasonality was present for any group except acute lymphoblastic leukaemia diagnosed among 1- to 6-year-olds. Seasonal trends varied by region: in the Northern and Cumbrian datasets, seasonality patterns were significant and similar (P < 0.05) with a predicted peak in early spring, whereas in Yorkshire there was less strong evidence of seasonality (P = 0.08) with a peak predicted in late summer. These findings suggest that local seasonal environmental factors operating around the time of birth are not associated with the totality of childhood cancer, but possible links with acute lymphoblastic leukaemia are supportive of a hypothesis of an infectious aetiology.

Use trends and geographic variation in neuroimaging: nationwide medicare data for 1993 and 1998

BACKGROUND AND PURPOSE

Powerful tools, including CT and MR imaging, have revolutionized neuroimaging. These are routinely used, but the extent and variation of use has not been studied. Our purposes were to determine the use rates of MR imaging and CT (of spine, brain, or head and neck), myelography, conventional angiography, and MR angiography in diagnosing neurologic disorders; to study trends in use; and to determine regional variations in use.

METHODS

We used the National Part B Medicare Database for 1993 and 1998 to compare rates of use for these procedures in 10 geographic regions.

RESULTS

In 1993 and 1998, respectively, 13,897 and 19,431 (39.8% increase) neuroimaging procedures were performed per 100,000 Medicare beneficiaries nationwide. Use of brain or head and neck CT (30.4%) and MR imaging (43.6%), spinal CT (3.5%) and MR imaging (83.0%), myelography (56.6%), and conventional angiography (24.3%) increased in 1998 versus 1993. Increases in MR angiography were not assessed, because this procedure was not reimbursable in 1993. Regional use of brain or head and neck and spinal CT and MR studies varied considerably; ratios of highest and lowest rates were 1.38-1.56. Use of MR angiography, myelography, and conventional angiography varied three- to fourfold.

CONCLUSION

Use of MR and CT studies of the brain or head and neck and of the spine increased considerably in the Medicare population between 1993 and 1998. Use of conventional invasive procedures such as myelography and angiography increased strikingly, contrary to the expected decline. Regional use varied substantially.

Intraoperative sonographic localization of breast masses: success with specimen sonography and surgical bed sonography to confirm excision

OBJECTIVE

To assess the use of intraoperative sonography for localization of breast masses at excisional biopsy, with specimen and surgical bed sonography to confirm excision.

METHODS

A computer search of the 5-year period from January 1993 through January 1998 revealed 138 consecutive women referred for sonographically guided excisional biopsy of 148 masses; 35 masses were excluded because they had no postoperative mammograms. One hundred thirteen masses constituted the study group. Specimen sonography (n = 60) or surgical bed sonography (n = 53) was performed as the initial evaluation to confirm excision, but ultimately, surgical bed sonography may have been necessary after specimen sonography, and specimen sonography may have been necessary after surgical bed sonography. The miss rates determined by postoperative imaging were calculated for each group and compared with those of mammographically guided needle localization series from the literature.

RESULTS

Follow-up physical examination and mammography showed no residual mass in the region of surgery in any patient. However, follow-up sonography had 1 miss in the initial specimen sonogram group (1 [1.7%] of 60) and 1 miss in the initial surgical bed group (1 [1.9%] of 53). As shown by the Fisher exact test, there was no significant difference between the miss rates of the 2 initial methods of confirming lesion excision or between the miss rates of these initial methods, both groups combined, and 6 mammographic localization series from the literature.

CONCLUSION

Intraoperative breast sonography, using specimen sonography and scanning the surgical bed, has miss rates comparable with those of mammographic needle localization. Follow-up sonography must be performed if there is any doubt of complete excision.

Comparison of unenhanced and contrast-enhanced spiral CT for assessing interval change in patients with colorectal liver metastases

RATIONALE AND OBJECTIVES

The purpose of this study was to determine whether the interval change in hepatic colorectal metastases as assessed with serial computed tomographic (CT) scans without contrast material enhancement differs from that as assessed using serial, portal dominant phase, contrast-enhanced CT scans.

MATERIALS AND METHODS

Unenhanced and contrast-enhanced abdominal CT scans were obtained in 28 patients. Three radiologists separately reviewed serial unenhanced and contrast-enhanced studies to assess the interval change in liver metastases. These radiologists recorded total number of lesions, bidimensional measurements of the largest lesions (as many as three), and overall impressions regarding the interval change (none, worse, or better).

RESULTS

Among the 84 judgments (28 patients x 3 radiologists), comparisons of unenhanced and contrast-enhanced CT studies were concordant in 60 assessments (71%). Nineteen (23%) showed mild disagreement. Of these, contrast-enhanced CT studies demonstrated disease stability when unenhanced CT studies demonstrated otherwise in 11 judgments, whereas unenhanced CT studies demonstrated stability when contrast-enhanced CT studies demonstrated otherwise in eight assessments. Furthermore, of the five marked disagreements, two resulted from a conclusion of interval improvement on unenhanced CT studies and a conclusion of interval worsening on contrast-enhanced CT studies, whereas three demonstrated the opposite. Neither set of serial CT studies systematically resulted in under- or overestimation of disease progression (McNemar Q test, P < .25).

CONCLUSION

The authors found no consistent pattern to demonstrate that serial unenhanced or contrast-enhanced CT studies resulted in over- or underestimation of disease progression.

How complete and accurate are cancer registrations notified by the National Health Service Central Register for England and Wales?

STUDY OBJECTIVE

To assess the completeness and accuracy of notification of cancers by the National Health Service Central Register (NHSCR) for England and Wales.

DESIGN

Comparison of 720 cancer registrations ascertained from NHSCR up to May 1999 with those ascertained for the same cohort from six other sources and a pathology review of the NHSCR cancer registrations.

PARTICIPANTS

People born in Cumbria, north west England, 1950-89, and diagnosed with cancer throughout the UK, 1971-1989.

MAIN RESULTS

Cancer diagnoses notified by NHSCR differed substantially from those determined by this pathology review for 47 of the 688 notified cases reviewed (7%; 95% CI 5%, 9%). Over one third of these discrepancies were attributable to failures in data capture or coding by the cancer registration system and almost half to changes in diagnosis; 26 of the 47 discrepant cases were reclassified as non-malignant and 21 as malignancies but with a substantially different diagnosis. The 694 confirmed malignancies represented 94% (95%CI 92%, 95%) of the 740 cancers ascertained from all sources.

CONCLUSIONS

It is estimated that the cancer registration system missed at least 10% (95%CI 6%, 15%) of all incident cases of malignant disease. Without additional ascertainment from multiple sources and diagnostic review, it would be incautious to use NHSCR cancer registrations as the sole basis of an epidemiological study.

Thyroid cancer in children and young adults in the North of England. Is increasing incidence related to the Chernobyl accident?

Population-based data on thyroid carcinomas was obtained from the Northern Region Young Person's Malignant Disease Registry to analyse the incidence of thyroid cancers in young people (<25 years) in the North of England for the period 1968 and 1997 and to assess if changes in incidence were consistent with the spatial and temporal distribution of the fallout from the Chernobyl nuclear accident. We compared incidence rates for differentiated (papillary or follicular) thyroid carcinomas 1968-1986 with those for 1987-1997. There were 75 cases of thyroid carcinoma diagnosed over the study period, of which 63 were differentiated carcinoma and 12 were medullary carcinoma. There were 26 young adults (15-24 years) diagnosed with differentiated thyroid carcinoma in the 19-year period 1968-1986 and 30 in the subsequent 11 years 1987-1997, Age standardised rate (ASR) 3.0 versus 6.5, respectively (rate ratio 2.2, 95% confidence interval (CI): 1.3-3.6). There were three children (aged <15 years) diagnosed with differentiated carcinoma in the period 1968-1986 and four in the period 1987-1997, ASR 0.2 versus 0.6 (rate ratio 2.7, 95% CI: 0.6-12.1). Regression models showed a significant increase in the incidence of thyroid cancer after the Chernobyl accident (P=0.002). In Cumbria, the area receiving the heaviest fallout in the UK, the increase in incidence was much greater (rate ratio 12.19, 95% CI 1.5-101.2). These temporal and spatial changes in incidence are consistent with a causal association with the Chernobyl accident although a greater effect in the younger rather than the older age group would have been anticipated. However, factors including improvements in ascertainment and earlier detection of tumours may also have contributed to the increasing incidence. Further collaborative international studies are needed to investigate changes in the incidence of thyroid cancer in children and young adults.

The origins of height fear: an evaluation of neoconditioning explanations

The present research sought to establish a reliable and valid instrument for assessing the relevance of neoconditioning factors (e.g. latent inhibition, UCS inflation/revaluation, prior fear levels, prior expectancies of harm, fear and pain levels experienced during supposed learning events), in the development of human fear. Fifty-four undergraduate height-fearful students completed the new origins instrument (OQ-II), while 54 matched controls completed a modified version (OQM-II) that examined their prior experiences with heights. In general, few differences between groups were found. Height-fearful and control subjects did not differ on trait anxiety, the frequency of negative encounters with heights, the age at which these events had occurred, prior fear levels, prior expectancies of harm, or reports of UCS inflation/revaluation procedures. However, in a finding directly opposite to that expected from a conditioning account, the mean fear and pain scores reported by subjects who had experienced direct conditioning events were significantly higher in the non-fearful group than in the height-fearful group. These findings are discussed in terms of associative and non-associative models of fear.

Childhood cancer registrations in the developing world: still more boys than girls

It has been shown previously that in many developing countries the reported incidence of childhood cancer for boys is substantially higher than for girls and that this difference is related to economic development of the country under study. The aim of the present study was to investigate the relationship between the sex ratio of children registered with malignant diseases and national economic development. Sex ratios for childhood cancer registration were obtained for populations within 53 countries from the second volume of the International Incidence of Childhood Cancer (range boys:girls 1.09-2.05). Demographic, economic and health data for the corresponding countries were obtained from published statistics and used to determine the extent to which sex ratios were associated with national economic status. The ratio of boys:girls registered with childhood cancer increased with decreasing gross domestic product and with increasing infant mortality, suggesting that boys are increasingly more likely than girls to be registered with increasing economic disadvantage. Combining these results with childhood cancer registration data from northern England suggests that little of the predominance of boys reaching a specialist centre can be explained by differences between boys and girls in early deaths from the disease. The previously observed differences in the childhood cancer registration sex ratio in developing countries still exist. Hence, international differences in the incidence of childhood cancer should be interpreted cautiously as they may not necessarily reflect only differences in the underlying occurrence of disease