Opting into breast screening over the age of 70 years: seeking evidence to support informed choice

AIM

To provide evidence specific to the Scottish population regarding the risk-benefit balance of women >70 years opting into continued breast screening, which may be used as a basis for patient information documentation.

MATERIALS AND METHODS

The present study consisted of a parallel, retrospective data analysis of breast cancer mortality data for breast cancer cases diagnosed between 2009 and 2013 (n=22,013) followed up to 31/12/18, and breast screening programme data from 2010 and 2015 (n=47,235). Screening outcome measures included recall for assessment, oncome of assessment, and tumour features. Tumours were classified as high, intermediate, or low risk according to grade and presence of invasion. Mortality data were linked to age at diagnosis and cause of death was recorded.

RESULTS

The proportion of all deaths due breast cancer is inversely related to age at diagnosis. From 77 years, women are more likely to die with breast cancer, than directly due to breast cancer. Mammographic screening accurately identifies breast cancer in older women; however, many of the cancers detected were considered intermediate or low risk.

CONCLUSIONS

Harms may outweigh the benefits of continued breast screening in older women. This information should be available to all older women.

α-Melanocyte stimulating hormone promotes muscle glucose uptake via melanocortin 5 receptors

Objective

Central melanocortin pathways are well-established regulators of energy balance. However, scant data exist about the role of systemic melanocortin peptides. We set out to determine if peripheral α-melanocyte stimulating hormone (α-MSH) plays a role in glucose homeostasis and tested the hypothesis that the pituitary is able to sense a physiological increase in circulating glucose and responds by secreting α-MSH.

Methods

We established glucose-stimulated α-MSH secretion using humans, non-human primates, and mouse models. Continuous α-MSH infusions were performed during glucose tolerance tests and hyperinsulinemic-euglycemic clamps to evaluate the systemic effect of α-MSH in glucose regulation. Complementary ex vivo and in vitro techniques were employed to delineate the direct action of α-MSH via the melanocortin 5 receptor (MC5R)–PKA axis in skeletal muscles. Combined treatment of non-selective/selective phosphodiesterase inhibitor and α-MSH was adopted to restore glucose tolerance in obese mice.

Results

Here we demonstrate that pituitary secretion of α-MSH is increased by glucose. Peripheral α-MSH increases temperature in skeletal muscles, acts directly on soleus and gastrocnemius muscles to significantly increase glucose uptake, and enhances whole-body glucose clearance via the activation of muscle MC5R and protein kinase A. These actions are absent in obese mice, accompanied by a blunting of α-MSH-induced cAMP levels in skeletal muscles of obese mice. Both selective and non-selective phosphodiesterase inhibition restores α-MSH induced skeletal muscle glucose uptake and improves glucose disposal in obese mice.

Conclusion

These data describe a novel endocrine circuit that modulates glucose homeostasis by pituitary α-MSH, which increases muscle glucose uptake and thermogenesis through the activation of a MC5R-PKA-pathway, which is disrupted in obesity.

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Glucose stimulates α-MSH release from the pituitary.

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Systemic α-MSH drives glucose disposal and thermogenesis in skeletal muscles.

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α-MSH acts on MC5R expressed on skeletal muscles and activate cAMP-PKA pathway.

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The combined treatment of nonselective or selective PDE 4 inhibitor and α-MSH ameliorates glucose intolerance in obese mice.

Maternal high-fat diet impacts endothelial function in nonhuman primate offspring

OBJECTIVE:

The link between maternal under-nutrition and cardiovascular disease (CVD) in the offspring later in life is well recognized, but the impact of maternal over-nutrition on the offspring's cardiovascular function and subsequent risk for CVD later in life remains unclear. Here, we investigated the impact of maternal exposure to a high-fat/calorie diet (HFD) during pregnancy and early postnatal period on endothelial function of the offspring in a nonhuman primate model.

METHODS:

Offspring, naturally born to either a control (CTR) diet (14% fat calories) or a HFD (36% fat calories) consumption dam, were breast-fed until weaning at about 8 months of age. After weaning, the offspring were either maintained on the same diet (CTR/CTR, HFD/HFD), or underwent a diet switch (CTR/HFD, HFD/CTR). Blood samples and arterial tissues were collected at necropsy when the animals were about 13 months of age.

RESULTS:

HFD/HFD juveniles displayed an increased plasma insulin level and glucose-stimulated insulin secretion in comparison with CTR/CTR. In abdominal aorta, but not the renal artery, acetylcholine-induced vasorelaxation was decreased remarkably for HFD/HFD juveniles compared with CTR/CTR. HFD/HFD animals also showed a thicker intima wall and an abnormal vascular-morphology, concurrent with elevated expression levels of several markers related to vascular inflammation and fibrinolytic function. Diet-switching animals (HFD/CTR and CTR/HFD) displayed modest damage on the abdominal vessel.

CONCLUSION:

Our data indicate that maternal HFD exposure impairs offspring's endothelial function. Both early programming events and postweaning diet contribute to the abnormalities that could be reversed partially by diet intervention.

Maternal high-fat diet disturbs uteroplacental hemodynamics and increases the frequency of stillbirth in a nonhuman primate model of excess nutrition

Prepregnancy maternal obesity confers an increased risk of stillbirth, but the mechanisms are unknown. Maternal obesity is associated with placental inflammation. We considered that maternal diet may predispose to the increased risk of placental inflammation and stillbirth. We hypothesized that a chronic high-fat diet (HFD) is associated with abnormal uteroplacental circulation and placental inflammation. Here we used a nonhuman primate model to determine the effect of chronic HFD on the uterine and placental hemodynamics, placental histology, and inflammation in a prospective, observational study of 24 Japanese macaques. Overall, there was a statistically significant (38-56%) reduction in uterine volume blood flow from HFD animals, whether they were lean or obese. Consumption of a HFD, independent of obesity, increased placental inflammatory cytokines and the expression of Toll-like receptor 4. We show that HFD consumption by obese mothers with hyperinsulinemia also reduced volume blood flow on the fetal side of the placenta and significantly increased the frequency of both placental infarctions and stillbirth. These results suggest that a HFD, independent of obesity, decreases uterine volume blood flow. Maternal obesity and insulin resistance further exacerbates the placental dysfunction and results in an increased frequency of stillbirth.

Early overnutrition results in early-onset arcuate leptin resistance and increased sensitivity to high-fat diet

Childhood obesity increases the risk of adult obesity and diabetes, suggesting that early overnutrition permanently programs altered energy and glucose homeostasis. In the present studies, we used a mouse model to investigate whether early overnutrition increases susceptibility to obesity and insulin resistance in response to a high-fat diet (HFD). Litters from Swiss Webster dams were culled to three [chronic postnatal overnutrition (CPO)] or 10 (control) pups and then weaned onto standard chow at postnatal day (P) 23. At 6 wk of age, a subset of mice was placed on HFD, and glucose and insulin tolerance were examined at 16-17 wk of age. Leptin sensitivity was determined by hypothalamic phosphorylated signal transducer and activator of transcription-3 immunoreactivity at P16 and adulthood after ip leptin. CPO mice exhibited accelerated body weight gain and hyperleptinemia during the preweaning period but only a slightly heavier body weight and normal glucose tolerance in adulthood on standard chow diet. Importantly, CPO mice exhibited significant leptin resistance in the arcuate nucleus, demonstrated by reduced activation of phospho-signal transducer and activator of transcription-3, as early as P16 and throughout life, despite normalized leptin levels. In response to HFD, CPO but not control mice displayed insulin resistance in response to an insulin tolerance test. In conclusion, CPO mice exhibited early and persistent leptin resistance in the arcuate nucleus and, in response to HFD, rapid development of obesity and insulin resistance. These studies suggest that early overnutrition can permanently alter energy homeostasis and significantly increase susceptibility to obesity and insulin resistance.

Systematically missing confounders in individual participant data meta-analysis of observational cohort studies

One difficulty in performing meta-analyses of observational cohort studies is that the availability of confounders may vary between cohorts, so that some cohorts provide fully adjusted analyses while others only provide partially adjusted analyses. Commonly, analyses of the association between an exposure and disease either are restricted to cohorts with full confounder information, or use all cohorts but do not fully adjust for confounding. We propose using a bivariate random-effects meta-analysis model to use information from all available cohorts while still adjusting for all the potential confounders. Our method uses both the fully adjusted and the partially adjusted estimated effects in the cohorts with full confounder information, together with an estimate of their within-cohort correlation. The method is applied to estimate the association between fibrinogen level and coronary heart disease incidence using data from 154 012 participants in 31 cohorts.† Copyright © 2009 John Wiley & Sons, Ltd.

Factors influencing total cholesterol and high-density lipoprotein cholesterol concentrations in a population at high coronary risk

Serum total cholesterol and high-density lipoprotein (HDL) cholesterol concentrations were measured in 1122 men and 1147 women aged between 25 and 64 years during the first Belfast MONICA survey, and the results subjected to multiple regression analysis. In both men and women, total cholesterol increased with age. Although HDL-cholesterol showed little variation with age, the values were considerably higher in women than men. Total cholesterol increased with body mass index while HDL-cholesterol decreased, and these findings persisted after adjustment for age. Regular exercise was associated with higher HDL-cholesterol values, even after adjustment for age and body mass index. Among men and women who abstained from alcohol, lower values of HDL-cholesterol were observed. In both sexes, cigarette smoking was associated with significant increases in total cholesterol values and decreases in HDL-cholesterol values, though some of these findings became apparent only after adjustment for other relevant factors. Perhaps surprisingly, a measure of health knowledge showed no association with blood lipid concentrations.

Diet-induced obesity causes severe but reversible leptin resistance in arcuate melanocortin neurons

Despite high leptin levels, most obese humans and rodents lack responsiveness to its appetite-suppressing effects. We demonstrate that leptin modulates NPY/AgRP and alpha-MSH secretion from the ARH of lean mice. High-fat diet-induced obese (DIO) mice have normal ObRb levels and increased SOCS-3 levels, but leptin fails to modulate peptide secretion and any element of the leptin signaling cascade. Despite this leptin resistance, the melanocortin system downstream of the ARH in DIO mice is over-responsive to melanocortin agonists, probably due to upregulation of MC4R. Lastly, we show that by decreasing the fat content of the mouse's diet, leptin responsiveness of NPY/AgRP and POMC neurons recovered simultaneously, with mice regaining normal leptin sensitivity and glycemic control. These results highlight the physiological importance of leptin sensing in the melanocortin circuits and show that their loss of leptin sensing likely contributes to the pathology of leptin resistance.

Leptin resistance and obesity

The prevalence of obesity, and the human and economic costs of the disease, creates a need for better therapeutics and better understanding of the physiological processes that balance energy intake and energy expenditure. Leptin is the primary signal from energy stores and exerts negative feedback effects on energy intake. In common obesity, leptin loses the ability to inhibit energy intake and increase energy expenditure; this is termed leptin resistance. This review discusses the evidence in support of leptin resistance in mouse models and humans and the possible mechanisms of leptin resistance.

Peptide YY(3-36) inhibits morning, but not evening, food intake and decreases body weight in rhesus macaques

Peptide YY(3-36) [PYY(3-36)] is a hormone that is released after meal ingestion that is currently being investigated for the treatment of obesity; however, there are conflicting reports of the effects of PYY(3-36) on energy balance in rodent models. To shed light on this controversy, we studied the effect of PYY(3-36) on food intake and body weight in a nonhuman primate. Intravenous PYY(3-36) infusions before a morning meal transiently suppressed the rate of food intake but did not suppress the evening meal or 24-h intake. Twice-daily or continuous intravenous PYY(3-36) infusions to supraphysiological levels (levels that exceeded normal physiological levels) again suppressed the rate of feeding for the morning but not the evening meal. Twice-daily intravenous PYY(3-36) infusions for 2 weeks significantly decreased body weight in all test animals (average weight loss 1.9%) without changing insulin response to glucose infusion. These results show that endogenous PYY(3-36) may alter morning but not evening meal intake, and supraphysiological doses are required for effective suppression of food intake.

Plasma fibrinogen level and the risk of major cardiovascular diseases and nonvascular mortality: an individual participant meta-analysis

CONTEXT

Plasma fibrinogen levels may be associated with the risk of coronary heart disease (CHD) and stroke.

OBJECTIVE

To assess the relationships of fibrinogen levels with risk of major vascular and with risk of nonvascular outcomes based on individual participant data.

DATA SOURCES

Relevant studies were identified by computer-assisted searches, hand searches of reference lists, and personal communication with relevant investigators.

STUDY SELECTION

All identified prospective studies were included with information available on baseline fibrinogen levels and details of subsequent major vascular morbidity and/or cause-specific mortality during at least 1 year of follow-up. Studies were excluded if they recruited participants on the basis of having had a previous history of cardiovascular disease; participants with known preexisting CHD or stroke were excluded.

DATA EXTRACTION

Individual records were provided on each of 154,211 participants in 31 prospective studies. During 1.38 million person-years of follow-up, there were 6944 first nonfatal myocardial infarctions or stroke events and 13,210 deaths. Cause-specific mortality was generally available. Analyses involved proportional hazards modeling with adjustment for confounding by known cardiovascular risk factors and for regression dilution bias.

DATA SYNTHESIS

Within each age group considered (40-59, 60-69, and > or =70 years), there was an approximately log-linear association with usual fibrinogen level for the risk of any CHD, any stroke, other vascular (eg, non-CHD, nonstroke) mortality, and nonvascular mortality. There was no evidence of a threshold within the range of usual fibrinogen level studied at any age. The age- and sex- adjusted hazard ratio per 1-g/L increase in usual fibrinogen level for CHD was 2.42 (95% confidence interval [CI], 2.24-2.60); stroke, 2.06 (95% CI, 1.83-2.33); other vascular mortality, 2.76 (95% CI, 2.28-3.35); and nonvascular mortality, 2.03 (95% CI, 1.90-2.18). The hazard ratios for CHD and stroke were reduced to about 1.8 after further adjustment for measured values of several established vascular risk factors. In a subset of 7011 participants with available C-reactive protein values, the findings for CHD were essentially unchanged following additional adjustment for C-reactive protein. The associations of fibrinogen level with CHD or stroke did not differ substantially according to sex, smoking, blood pressure, blood lipid levels, or several features of study design.

CONCLUSIONS

In this large individual participant meta-analysis, moderately strong associations were found between usual plasma fibrinogen level and the risks of CHD, stroke, other vascular mortality, and nonvascular mortality in a wide range of circumstances in healthy middle-aged adults. Assessment of any causal relevance of elevated fibrinogen levels to disease requires additional research.

Development of multidimensional scales to measure key leaders' perceptions of community capacity and organizational capacity for teen pregnancy prevention

This study discusses the development of scales to measure key leaders' self-reported involvement in community capacity building, perceptions of organizational capacity for teen pregnancy prevention, and the relationship between capacity and teen pregnancy rates. Data were collected from 1,516 key leaders across a rural southern state. Findings indicate that key leaders' perceptions of organizational capacity are related to their involvement in community capacity building efforts and community capacity is associated with teen pregnancy rates. This research represents progress toward measuring community and organizational capacity and may be used to inform future work focusing on developing quantitative measures of community capacity.

Hypoxia-regulated glucose transporter Glut-1 may influence chemosensitivity to some alkylating agents: results of EORTC (First Translational Award) study of the relevance of tumour hypoxia to the outcome of chemotherapy in human tumour-derived xenografts

Tumour hypoxia confers poor prognosis in a wide range of solid tumours, due to an increased malignancy, increased likelihood of metastasis and treatment resistance. Poorly oxygenated tumours are resistant to both radiation therapy and chemotherapy. However, although the link between radiation therapy and hypoxia is well established in a range of clinical studies, evidence of its influence on chemotherapy response is lacking. In this study, a panel of human tumour-derived xenografts that have been characterised previously for in vivo response to a large series of anti-cancer agents, and have been found to show chemosensitivities that correlate strongly with the parent tumour, were used to address this issue. Immunohistochemistry was carried out on formalin-fixed, paraffin-embedded sections of xenograft samples to detect expression of the intrinsic hypoxia marker Glut-1 and adducts of the bioreductive hypoxia marker pimonidazole. Glut-1 scores correlated significantly with T/C values for CCNU sensitivity (r = 0.439, P = 0.036, n = 23) and showed a borderline significant correlation with dacarbazine T/C (r = 0.405, P = 0.076, n = 20). However, there was no correlation between both Glut-1 and pimonidazole scores and T/C obtained for the bioreductive drug mitomycin C. The use of human tumour-derived xenografts offers a potentially useful way of using archival material to determine the influence of hypoxia and other tumour-microenvironmental factors on chemosensitivity without the direct use of human subjects.

Current smoking and the risk of non-fatal myocardial infarction in the WHO MONICA Project populations

BACKGROUND

Cohort studies have shown that smoking has a substantial influence on coronary heart disease mortality in young people. Population based data on non-fatal events have been sparse, however.

OBJECTIVE

To study the impact of smoking on the risk of non-fatal acute myocardial infarction (MI) in young middle age people.

METHODS

From 1985 to 1994 all non-fatal MI events in the age group 35-64 were registered in men and women in the WHO MONICA (multinational monitoring of trends and determinants in cardiovascular disease) project populations (18,762 events in men and 4047 in women from 32 populations from 21 countries). In the same populations and age groups 65,741 men and 66,717 women participated in the surveys of risk factors (overall response rate 72%). The relative risk of non-fatal MI for current smokers was compared with non-smokers, by sex and five year age group.

RESULTS

The prevalence of smoking in people aged 35-39 years who experienced non-fatal MI events was 81% in men and 77% in women. It declined with increasing age to 45% in men aged 60-64 years and 36% in women, respectively. In the 35-39 years age group the relative risk of non-fatal MI for smokers was 4.9 (95% confidence interval (CI) 3.9 to 6.1) in men and 5.3 (95% CI 3.2 to 8.7) in women, and the population attributable fractions were 65% and 55%, respectively.

CONCLUSIONS

During the study period more than half of the non-fatal MIs occurring in young middle age people can be attributed to smoking.

Pre-hospital coronary care and coronary fatality in the Belfast and Glasgow MONICA populations

BACKGROUND

The aim of this study was to describe and compare coronary event case fatality and care pathways in two defined populations with access to different models of pre-hospital care provision.

METHODS

Secondary analysis of MONItoring of Trends and Determinants in CArdiovascular Disease (MONICA) population coronary event registers (1988, 1989, 1990, 1992 and 1993).

RESULTS

Case fatality at 28 days following an acute coronary event was 6.5% greater in the Glasgow MONICA Project (GMP) population (46.7%) than in the Belfast MONICA Project (BMP) population (40.2%). Pre-hospital case fatality was 33.9% in the GMP population and 28.3% in the BMP population. These differences could not be fully explained by mobile coronary care unit (MCCU) responses in the BMP area. Initial care was provided in hospital for 28.3% of the BMP events and only 7.7% of the GMP events. Additional data collected by the Belfast and Glasgow MONICA investigators support a large difference between the median delay to main medical care in the BMP events (120 min) and the median delay to ward admission in the GMP area (220 min) at this time.

CONCLUSIONS

Our findings suggest that the delay between coronary event onset and access to specialist coronary care was the most likely critical difference, irrespective of hospital-based MCCU provision in the BMP area. An established 'culture of early intervention' in Belfast may have been an important factor. As a large proportion of coronary event fatalities continue to occur outside hospital, there is a need to strengthen the evidence base underpinning the provision of appropriate skilled care and treatment at the earliest possible opportunity.

Investigation of the C242T polymorphism of NAD(P)H oxidase p22 phox gene and ischaemic heart disease using family-based association methods

Ischaemic heart disease is a complex phenotype arising from the interaction of genetic and environmental factors. Excessive production of reactive oxygen species leading to endothelial dysfunction is believed to be important in the pathogenesis of ischaemic heart disease. The NAD(P)H oxidase system generates superoxide anions in vascular cells; however, the role of the C242T polymorphism of the NAD(P)H oxidase p22 phox gene in ischaemic heart disease is unclear due to contradictory results from case-control studies. Consequently, we applied family-based association tests to investigate the role of this polymorphism in ischaemic heart disease in a well-defined Irish population. A total of 1023 individuals from 388 families (discordant sibships and parent/child trios) were recruited. Linkage disequilibrium between the polymorphism and ischaemic heart disease was tested using the combined transmission disequilibrium test (TDT)/sib-TDT (cTDT) and pedigree disequilibrium test (PDT). Both cTDT and PDT analyses found no statistically significant excess transmission of either allele to affected individuals (P =0.30 and P =0.28, respectively). Using robust family-based association tests specifically designed for the study of complex diseases, we found no evidence that the C242T polymorphism of the p22 phox gene has a significant role in the development of ischaemic heart disease in our population.

Development of a youth survey to measure risk behaviors, attitudes and assets: examining multiple influences

Currently, most surveys assessing adolescent health concerns focus primarily on risk behaviors and negative influences rather than positive influences such as assets. The purpose of this paper is to describe the development and validation of the Adolescent Health Attitude and Behavior Survey (AHABS). This instrument was developed to measure the prevalence of youth health risk behaviors, attitudes towards adolescent sexual behavior and youth assets in a statewide evaluation effort. The questionnaire was completed by 4368 public high school students in Grades 9-12. Content validity was established through an extensive review of literature, a group process and factor analyses. Reliability was established through Cronbach's alpha coefficients. Factor loadings ranged from 0.48 to 0.84 for scales measuring attitudes towards adolescent sexual behavior and alpha coefficients ranged from 0.61 to 0.81. Factor loadings ranged from 0.34 to 0.90 for scales measuring youth assets and alpha coefficients ranged from 0.69 to 0.85. Because of several limitations (e.g. construct validity was not measured), additional development work is needed. Therefore, the AHABS is still in a developing, but promising, state. Additional psychometric work will provide program practitioners and evaluators with a psychometrically sound tool to measure behaviors, attitudes and assets.

Electrophysiological actions of peripheral hormones on melanocortin neurons

Neurons of the arcuate nucleus of the hypothalamus (ARH) appear to be sites of convergence of central and peripheral signals of energy stores, and profoundly modulate the activity of the melanocortin circuits, providing a strong rationale for pursuing these circuits as therapeutic targets for disorders of energy homeostasis. Recently, tremendous advances have been made in identifying genes and pathways important to regulating energy homeostasis, particularly the hormone leptin and its receptor. This hormone/receptor pair is expressed at high levels in the so-called satiety centers in the hypothalamus, and at lower levels elsewhere in the body. Recent studies in our lab and those of our collaborators have shown that leptin modulates different populations of hypothalamic cells in different ways, rapidly activating POMC neurons and inhibiting NPY/AgRP neurons. In this report, we outline an integrated model of leptin's action in the arcuate nucleus of the hypothalamus, derived from our electrophysiological studies of brain slice preparations taken from transgenic mice that have been bred to express a variety of fluorescent proteins in specific cell types. We also discuss the recently withdrawn obesity drug fenfluramine, which appears to act on POMC neurons via the serotonin 2C receptor. Nutrient-sensing serotonin neurons may project from the raphe nuclei in the brainstem to the hypothalamus; within the arcuate nucleus, serotonin signals are integrated with others such as leptin, ghrelin, and peptide YY(3-36) from the gut, to produce a coordinated response to nutrient state. Finally, we review the current inquiries into the ability of the hormone ghrelin to stimulate appetite by its action of NPY neurons and inhibition of POMC neurons.

Smoking, atopy and certain furry pets are major determinants of respiratory symptoms in children: the International Study of Asthma and Allergies in Childhood Study (Ireland)

BACKGROUND

Environmental, cultural and health care differences may account for variation among countries in the prevalence of asthma and respiratory symptoms in teenagers.

OBJECTIVE

To examine the prevalence of respiratory symptoms and the level of diagnosis, and to compare determinants of asthma and severe wheeze in two countries.

METHODS

Self-completion questionnaires based on the International Study of Asthma and Allergies in Childhood (ISAAC) protocol were provided to school children in Ireland (Republic and Northern Ireland). In the Republic of Ireland, all children in classes largely aged 13-14 years from 30 post-primary schools were selected by random sampling stratified by school size, composition and Health Board in Spring 1995. In Northern Ireland, all children largely aged 13-14 years of age from 26 post-primary schools were selected by random sampling stratified by school type, composition and Education and Library Board in Spring 1996.

RESULTS

Questionnaires were completed by 2,364 children from Northern Ireland and 2,671 from the Republic, about 90% of those eligible to participate. The prevalences of wheeze at various levels of severity, of diagnosed asthma and of treated wheeze were very similar in Northern Ireland and the Republic of Ireland. A significant proportion of those reporting more severe symptomatology (four or more attacks of wheeze in the past 12 months and/or one or more nights disturbed and/or moderate or greater disruption of daily activities and/or speech restriction due to wheeze) had been neither diagnosed nor treated for asthma (20-37%). To investigate the determinants of the more severe symptomatology of asthma or treated wheeze a series of stepwise multiple regression analyses was performed. A history of atopy, cigarette smoking, the possession of a furry pet other than a dog or cat and age were each independently associated with severe wheeze, whilst atopy, a furry pet (as above) and gender were each independently associated with asthma or treated wheeze.

CONCLUSIONS

Cigarette smoking is closely associated with the reporting of significant respiratory symptoms together with atopy and exposure to furry pets. Some 20-37% of severe symptoms were neither diagnosed nor treated as asthma.

Psychosocial risk factors for heart disease in France and Northern Ireland: the Prospective Epidemiological Study of Myocardial Infarction (PRIME)

BACKGROUND

France has a substantially lower level of premature mortality from cardiovascular diseases (CVD) relative to its comparators. Compared with Northern Ireland, France has one-half the rate, despite having a similar cardiovascular risk profile to Northern Ireland. In this prospective longitudinal study the psychosocial risk hypothesis for CVD was tested.

METHOD

A cohort of 9758 men (7359 in France and 2399 in Northern Ireland) aged 50-59 years who were initially free of any CVD were recruited. At baseline the subjects completed a psychosocial questionnaire, measuring hostility, depression, social support, and the Type A behaviour pattern. At 5-years follow-up their clinical status was determined.

RESULTS

Multivariate analysis indicated that, contrary to prediction, France had a substantially more negative psychosocial risk profile than Northern Ireland. The psychosocial risk factors were not successful at predicting at 5-years follow-up the hard clinical endpoint of definite fatal/non-fatal myocardial infarction. In the case of the softer clinical endpoint, angina pectoris/unstable angina, only depression predicted outcome with a small effect size.

CONCLUSION

The findings provide little support for the psychosocial risk hypothesis. The psychosocial risk profile was more negative in France, the opposite of that predicted. The finding of a relationship between depression and angina may reflect a tendency for individuals who respond negatively on mood state to report more cardiac symptoms irrespective of physical disease state.

Prevalence and awareness of excess weight in 13 and 14 year olds in Northern Ireland using recent international guidelines

Concern has been expressed in recent years over the rising trends in overweight and obesity, particularly in children in developed countries. No recent data were available for Northern Ireland, therefore measurements of height and weight were included in a study in Northern Ireland originally designed as part of an international study to estimate the prevalence of symptoms of asthma and atopy in childhood. Twenty-six schools across the province were sampled. 2484 children aged mainly 13 and 14 y completed questionnaires, and 2307 were weighed and measured. Using recently proposed international guidelines on defining overweight and obesity in children the prevalence of overweight in boys was 16%, with 4% being obese. In girls 16% were also overweight and 2% were obese. This concurs with figures for English and Scottish schoolchildren up to 12 y of age from 1994. Less than one-sixth of obese boys but more than one-third of obese girls were on weight-reducing diets (the majority self-prescribed), reflecting differing attitudes towards excess weight.

CONCLUSION

In line with figures in younger children from England and Scotland this study shows that 16% of boys and girls from Northern Ireland are classed as overweight using recent international guidelines. Only 15% of obese boys compared with 38% of obese girls stated that they were on weight-reducing diets.

[Expression of the neurotrophin-receptor TrkB predicts outcome in nephroblastomas: results of a pilot-study]

BACKGROUND

The neurotrophin-receptor TrkB plays an important role in pathogenesis, biology and prognosis of neuroblastoma. Expression of TrkB on aggressive neuroblastomas leads to proliferation and survival of the tumor cells and is associated with an unfavorable prognosis. It is now known that Trk receptors are also expressed in extraneural tissues including the kidney.

PATIENTS AND METHODS

To study the role of the neurotrophin-receptor TrkB in nephroblastoma/Wilms' Tumor (WT), we determined TrkB mRNA expression by semiquantitative duplex RT-PCR in 39 primary WT. Comparison of mRNA expression levels with clinical variables was performed using Cox regression analysis.

RESULTS

The 5-year overall survival was significantly worse for patients with tumors expressing high levels of a functional TrkB-receptor (TrkBfull) in comparison to patients with low levels of TrkBfull (70 % versus 100 %, p=0.005). Conversely, children with tumors expressing high mRNA levels of a functionally inactive truncated TrkB receptor (TrkBtrunc) had a significantly higher 5-year overall survival rate in comparison to patients with low levels of TrkBtrunc (100 % versus 68 %, p=0.003). The hazard ratios for TrkBfull and TrkBtrunc remained significant after adjusting for tumor stage. All WT with high levels of TrkB also expressed the ligand brain-derived neurotrophic factor (BDNF).

CONCLUSIONS

Full-length and truncated TrkB appear to be important prognostic factors in WT. Their expression should be assessed prospectively in a larger panel of WT and may have a future role in patient assignment to risk-based treatment strategies. TrkB signaling may be reduced in WT with favorable outcome due to low numbers of TrkB receptors or a competitive effect of functionally inactive TrkBtrunc.

Expression of the neurotrophin receptor TrkB is associated with unfavorable outcome in Wilms' tumor

PURPOSE

Neurotrophins and their receptors regulate the proliferation, differentiation, and death of neuronal cells, and they have been implicated in the pathogenesis and prognosis of neuroblastomas and medulloblastomas. Tyrosine kinase (Trk) receptors also are expressed in extraneural tissues.

PATIENTS AND METHODS

To study the role of neurotrophin receptors and ligands in Wilms' tumor (WT), we determined their expression by semiquantitative duplex reverse transcriptase polymerase chain reaction in 39 patients with primary WT. Comparison of mRNA expression levels with clinical variables was performed by use of Cox regression analysis.

RESULTS

Children with WT that expressed high levels of full-length TrkB mRNA (TrkBfull) had a significantly greater risk of death than children whose tumors had little or no TrkBfull expression (hazard ratio, 9.7; P =.02). The 5-year relapse-free survival was 100% versus 65% for patients with low versus high tumor expression of TrkBfull (P <.003). Conversely, children with tumors that expressed high mRNA levels of a functionally inactive truncated TrkB receptor (TrkBtrunc) had a greater chance of survival than children with low levels of TrkBtrunc (hazard ratio, 0.08; P =.005). The 5-year relapse-free survival was 95% versus 68% for patients with high versus low levels of TrkBtrunc (P =.01). The hazard ratios for TrkBfull and TrkBtrunc remained significant after they were adjusted for tumor stage (P =.01 and P =.017, respectively). All WTs with high levels of TrkB expression also expressed the brain-derived nerve growth factor ligand.

CONCLUSION

Expression of TrkBfull in WT is associated with worse outcome, perhaps because it provides an autocrine survival pathway. Conversely, TrkBtrunc expression is associated with excellent outcome, perhaps as a result of a dominant negative effect.