Inducible upregulation of oestrogen receptor-beta1 affects oestrogen and tamoxifen responsiveness in MCF7 human breast cancer cells

To investigate the effect of altered oestrogen receptor (ER)alpha and ERbeta expression on oestrogen and anti-oestrogen action in breast cancer, we have stably expressed an inducible ERbeta1 in MCF7 breast cancer cells. Stably expressing clones were isolated and over-expression of ERbeta1 correlated with increased levels of specific radiolabelled oestradiol (E2) binding. Increased ERbeta1 did not affect endogenous levels of ERalpha but increased progesterone receptor (PR) levels. Over-expression of ERbeta1 reduced growth responses to E2 in contrast to little if any effect of over-expression of ERalpha. In oestrogen-replete conditions, over-expression of ERbeta1 but not ERalpha reduced proliferation. Over-expression of ERbeta1 did not result in anti-oestrogen resistance but was associated with increased sensitivity to 4-hydroxytamoxifen. Our results suggested that over-expression of ERbeta1 in the presence of an endogenously expressed ERalpha was associated with tamoxifen sensitivity but may negatively modulate ERalpha-mediated growth. However, not all ERalpha activities were inhibited since endogenous PR expression was increased by both ERalpha and ERbeta1 over-expression. These data paralleled those seen in some in vivo studies showing a relationship between PR and ERbeta expression as well as ERbeta expression and tamoxifen sensitivity of ER-positive breast cancer patients. These models are relevant and will be useful for dissecting the role of ERbeta1 expression in ER-positive breast cancer.

Benefits of interprofessional learning: an interprofessional MSc in child health

This article addresses interprofessional education (IPE) using a case study evaluating a multidisciplinary MSc course in child health. The participants felt that the nature of the course increased their interprofessional working skills and professional confidence. They described benefits, including new insights, a balanced variety of views, development of respect and equality between professionals, improved communication and a holistic approach to child health.

Comparison of laser ion acceleration from the front and rear surfaces of thin foils

The comparative efficiency and beam characteristics of high-energy ions generated by high-intensity short-pulse lasers (approximately 1-6 x 10(19) W/cm2) from both the front and rear surfaces of thin metal foils have been measured under identical conditions. Using direct beam measurements and nuclear activation techniques, we find that rear-surface acceleration produces higher energy particles with smaller divergence and a higher efficiency than front-surface acceleration. Our observations are well reproduced by realistic particle-in-cell simulations, and we predict optimal criteria for future applications.

Can you age bruises accurately in children? A systematic review

AIMS

To investigate whether it is possible to determine the age of a bruise in a child in clinical practice by means of a systematic review.

METHODS

An all language literature search up to 2004. Included studies assessed the age of bruises in live children less than 18 years old. Excluded: review articles, expert opinion, and single case reports. Standardised data extraction and critical appraisal forms were used. Two reviewers independently reviewed studies.

RESULTS

Of 167 studies reviewed, three were included: two studies described colour assessment in vivo and one from photographs. Although the Bariciak et al study showed a significant association between red/blue/purple colour and recent bruising and yellow/brown and green with older bruising, both this study and Stephenson and Bialas reported that any colour could be present in fresh, intermediate, and old bruises. Results on yellow colouration were conflicting. Stephenson and Bialas showed yellow colour in 10 bruises only after 24 hours, Carpenter after 48 hours, and Bariciak et al noted yellow/green/brown within 48 hours. Stephenson and Bialas reported that red was only seen in those of one week or less. The accuracy with which clinicians correctly aged a bruise to within 24 hours of its occurrence was less than 40%. The accuracy with which they could identify fresh, intermediate, or old bruises was 55-63%. Intra- and inter-observer reliability was poor.

CONCLUSION

A bruise cannot accurately be aged from clinical assessment in vivo or on a photograph. At this point in time the practice of estimating the age of a bruise from its colour has no scientific basis and should be avoided in child protection proceedings.

Are there patterns of bruising in childhood which are diagnostic or suggestive of abuse? A systematic review

AIMS

To investigate what patterns of bruising are diagnostic or suggestive of child abuse by means of a systematic review.

METHODS

All language literature search 1951-2004. Included: studies that defined patterns of bruising in non-abused or abused children <18 years. Excluded: personal practice, review articles, single case reports, inadequate confirmation of abuse. Two independent full text reviews using standardised data extraction and critical appraisal forms. Studies ranked by study design and definition of abuse used.

RESULTS

Twenty three studies included: seven non-abusive bruising, 14 abusive bruising, and two both. Non-abusive: The prevalence, number, and location of bruises is related to increased motor development. Bruising in non-independently mobile babies is very uncommon (<1%). Seventeen per cent of infants who are starting to mobilise, 53% of walkers, and the majority of schoolchildren have bruises. These are small, sustained over bony prominences, and found on the front of the body. Abuse: Bruising is common in children who are abused. Any part of the body is vulnerable. Bruises are away from bony prominences; the commonest site is head and neck (particularly face) followed by the buttocks, trunk, and arms. Bruises are large, commonly multiple, and occur in clusters. They are often associated with other injury types that may be older. Some bruises carry the imprint of the implement used.

CONCLUSION

When abuse is suspected, bruising must be assessed in the context of medical, social, and developmental history, the explanation given, and the patterns of non-abusive bruising. Bruises in non-mobile infants, over soft tissue areas, that carry the imprint of an implement and multiple bruises of uniform shape are suggestive of abuse. Quality research across the whole spectrum of children is urgently needed.

Musculoskeletal health in elite male adolescent middle-distance runners

The impact of high training volumes on musculoskeletal adaptations of male adolescents is poorly understood. We compared bone mineral content (BMC) of total body, lumbar spine and proximal femur using Dual X-ray Absorptiometry (Lunar Prodigy, GE Medical Systems, Madison WI) in elite level (n=20), male adolescent middle distance runners (mean 16.8 yrs, range 14-18 yrs) and age-matched (n=20) controls. Athletes averaged 14 hrs of physical activity per week and controls reported participating in physical activity an average of two hrs per week. Total body mass was 10.97 kg less in athletes than controls (p=0.005). Within the total body mass difference, fat tissue mass of athletes was 10.93 kg less in athletes than controls (p= 0.001). Multiple regression analysis identified total body lean mass and total body fat mass as the strongest predictors of total body BMC (R2 0.71). After adjusting for lean tissue mass per kg of body weight (p=0.07), no difference in BMC was detected. Lower limb muscle strength and macronutrient intakes were also measured but no between group differences were found. The number of weeks of training and/or competition missed through injury was not associated with total body BMC (R2=0.19) among athletes. Our results imply high training volumes in middle distance running are not detrimental to musculoskeletal health and are associated with positive body composition profiles in elite adolescent male athletes.

Exposure to infant siblings during early life and risk of multiple sclerosis

CONTEXT

The "hygiene hypothesis" has implicated sibship as a marker of infection load during early life and suggests that exposure or reexposure to infections can influence the developing immune system. Viral infection has also been implicated in the pathogenesis of multiple sclerosis (MS).

OBJECTIVES

To evaluate whether exposure to infant siblings in early life is associated with the risk of MS, and to explore the possible mechanism for any apparent protective effect, including altered Epstein-Barr virus (EBV) infection patterns.

DESIGN, SETTING, AND PATIENTS

Population-based case-control study in Tasmania, Australia, from 1999 to 2001 based on 136 cases of magnetic resonance imaging-confirmed MS and 272 community controls, matched on sex and year of birth.

MAIN OUTCOME MEASURE

Risk of MS by duration of contact with younger siblings aged less than 2 years in the first 6 years of life.

RESULTS

Increasing duration of contact with a younger sibling aged less than 2 years in the first 6 years of life was associated with reduced MS risk (adjusted odds ratios [AORs]: <1 infant-year, 1.00 [reference]; 1 to <3 infant-years, 0.57 [95% confidence interval {CI}, 0.33-0.98]; 3 to <5 infant-years, 0.40 [95% CI, 0.19-0.92]; > or =5 infant-years, 0.12 [95% CI, 0.02-0.88]; test for trend, P = .002). A history of exposure to infant siblings was associated with a reduced IgG response to EBV among controls. Controls with at least 1 infant-year contact had a reduced risk of infectious mononucleosis and a reduced risk of very high composite EBV IgG titers (AOR, 0.33; 95% CI, 0.11-0.98) compared with other controls. The inverse association between higher infant contact and MS was independent of EBV IgG titer.

CONCLUSION

Higher infant sibling exposure in the first 6 years of life was associated with a reduced risk of MS, possibly by altering childhood infection patterns and related immune responses.

Managing childhood food allergies and anaphylaxis

BACKGROUND

Food allergies in children are becoming more common causing concern for parents, child carers, teachers and school principals.

OBJECTIVE

This article aims to provide practical information on childhood food allergies and their ongoing management including assessment, prescription of self or carer administered adrenaline, emergency action plans, patient education, school based strategies, and family support.

DISCUSSION

With most schools, preschools and child care centres having at least one child with food allergies, general practitioners are increasingly likely to be involved in school liaison and education, as well as caring for families with food allergic children.

ASCIA guidelines for prevention of food anaphylactic reactions in schools, preschools and child-care centres

These guidelines have been developed by the anaphylaxis working party of the Australasian Society of Clinical Immunology and Allergy to provide advice for minimizing the risk of food-induced anaphylaxis in schools, preschools and child-care centres. The guidelines outline four steps for the prevention of food anaphylactic reactions in children at risk and food policy measures specific to school age and preschool age children.

Making clinical decisions when the stakes are high and the evidence unclear

Children with peanut allergy are often provided with adrenaline (epinephrine) in case of a severe reaction. The probability of a life threatening reaction is low, however, and the criteria for provision are controversial. How should the costs and benefits be balanced?

Ratchetlike dynamics of fluxons in annular Josephson junctions driven by biharmonic microwave fields

Experimental observation of the unidirectional motion of a topological soliton driven by a biharmonic ac force of zero mean is reported. The observation is made by measuring the current-voltage characteristics for a fluxon trapped in an annular Josephson junction that was placed into a microwave field. The dependence of the fluxon mean velocity at zero dc bias versus the phase shift between the first and second harmonic of the driving force is in qualitative agreement with theoretical expectations.

A prospective association between cocoon use in infancy and childhood asthma

There is increasing evidence for a role for bedding items in the development of asthma. The use of some forms of synthetic bedding, such as foam mattresses and pillows, is associated with a significantly increased risk of childhood wheeze. Our aim was to examine prospectively whether the use of synthetic cocoon/baby nests in infancy is associated with the subsequent development of wheeze in childhood. Data collected in 1988 as part of the Tasmanian Infant Health Survey were linked to the cross-sectional Childhood Asthma Survey conducted in 1995 in Tasmania, Australia. We were able to match 863 records out of the 1111 in the 1988 survey. Information including parental, child-care, and the infant's sleeping environment was collected at home interview in 1988 when the infant was 1 month of age. Data including sleep environment and asthma symptoms were available for each child at age 7 years. A generalised linear model was used to calculate the adjusted relative risk (RR) estimates for symptoms of wheeze and infant cocoon use. For children who were placed in a cocoon in infancy, there was an increased risk of recent wheeze (adjusted RR = 4.33 [95% CI 2.08, 9.02]) and night wheeze (adjusted RR = 3.35 [95% CI 1.52, 7.39]) at age 7 years. In view of the increasing prevalence of childhood asthma, the identification of potentially modifiable environmental factors which might operate in infancy is of importance. The present findings implicate infant bedding choice as a significant factor and further studies on the infant sleeping environment are indicated.

Asthma prevention: breast is best?

Whilst breastfeeding has been considered to exert a preventative effect on the development of allergic disease, several recent publications have challenged this view, particularly with respect to the long-term outcomes for asthma. There are many other beneficial effects of breastfeeding apart from the possibility of allergy prevention. The suggestion that breastfeeding may increase the development of allergic disease raises concerns about the appropriate steps to take for primary prevention of allergy. It is concluded that breastfeeding can still be recommended for the beneficial effects in reducing atopic disease in childhood in addition to the other demonstrated benefits, and that there are unresolved questions concerning the few studies that suggest the possibility of increased allergic disease in later life.

Ultralow emittance, multi-MeV proton beams from a laser virtual-cathode plasma accelerator

The laminarity of high-current multi-MeV proton beams produced by irradiating thin metallic foils with ultraintense lasers has been measured. For proton energies >10 MeV, the transverse and longitudinal emittance are, respectively, <0.004 mm mrad and <10(-4) eV s, i.e., at least 100-fold and may be as much as 10(4)-fold better than conventional accelerator beams. The fast acceleration being electrostatic from an initially cold surface, only collisions with the accelerating fast electrons appear to limit the beam laminarity. The ion beam source size is measured to be <15 microm (FWHM) for proton energies >10 MeV.

The bedding environment, sleep position, and frequent wheeze in childhood

OBJECTIVE

Synthetic quilt use has been associated with increased childhood wheeze in previous studies. Our aim was to examine whether the adverse effect of synthetic quilt use on frequent wheeze differed by usual sleep position.

DESIGN, SETTING, AND PARTICIPANTS

A population-based cross-sectional study of 6378 (92% of those eligible) 7-year-olds in Tasmania, Australia, was conducted in 1995. Exercise-challenge lung function was obtained on a subset of 414 children from randomly selected schools.

EXPOSURE MEASURES

Child bedding including pillow and overbedding composition and usual sleep position by parental questionnaire.

OUTCOME MEASURES

Frequent wheeze (>12 wheeze episodes over the past year), using the International Study of Asthma and Allergies in Childhood parental questionnaire, and baseline and postexercise forced expiratory volume in 1 second lung-function measures.

RESULTS

Frequent wheeze (n = 117) was positively associated with synthetic quilts, synthetic pillows, electric blankets, and sleeping in a bottom bunk bed but did not vary by sleep position. In a nested case-control analysis, the association between synthetic quilt use and frequent wheeze differed by sleep position. Among children who slept supine, synthetic (versus feather) quilt use was associated with frequent wheeze (adjusted odds ratio: 2.37 [1.08, 5.23]). However, among nonsupine sleepers, overlying synthetic quilt use was not associated with frequent wheeze (adjusted odds ratio: 1.06 [0.60, 1.88]). This difference in quilt effect by sleep position was highly significant. Similarly, synthetic quilt use was associated with lower postexercise forced expiratory volume in 1 second measures among supine but not nonsupine sleeping children.

CONCLUSION

An increasing focus on the bedding environment immediately adjacent to the nose and mouth is required for respiratory disorders provoked by bedding, such as child asthma characterized by frequent wheeze.

The General Practice Research Network: the capabilities of an electronic patient management system for longitudinal patient data

PURPOSE

To evaluate the potential of a general practice research database derived directly from de-identified electronic medical records to provide national prescribing data in Australia. To observe the utilisation of a computer-based patient management system over time. To evaluate the impact of the research network participation on data quality in participants' electronic records.

METHOD

A random sample of 297 general practitioners (GPs) from 128 practices provided longitudinal patient data from electronic medical records (using Medical Director software) retrospectively from 1 January 1999 to April 2002. The General Practice Research Network (GPRN) database contains approximately 600,000 patients, representing over 4 million prescriptions from 4 million encounters. The quality and representativeness of data for prescribing, morbidity and software usage were evaluated by comparison with National data.

RESULTS

Older GPs (> 55) were under-represented, perhaps due to lower computer usage rates, but patient visits were similar to the national distribution. Over time, there were increases in: the quality of prescribing data (with reason for visit/prescription being compulsorily recorded); recording of non-prescribing visits; and the use of other features of the electronic patient management software.

CONCLUSIONS

Data derived from electronic general practice records is of sufficient quality to be used to provide national prescribing estimates and has potential value for pharmacoepidemiology and population health monitoring. Such longitudinal data has previously been unavailable in Australia. Monitoring of software usage demonstrates the evolution of the Australian GP user and will be increasingly useful in assessing and improving the quality of electronic medical records.

Spatial uniformity of laser-accelerated ultrahigh-current MeV electron propagation in metals and insulators

The evolution of laser-generated MeV, MA electron beams propagating through conductors and insulators has been studied by comparing measurement and modeling of the distribution of MeV protons that are sheath accelerated by the propagated electrons. We find that electron flow through metals is uniform and can be laser imprinted, whereas propagation through insulators induces spatial disruption of the fast electrons. Agreement is found with material dependent modeling.

Quantum dynamics of a single vortex

Vortices occur naturally in a wide range of gases and fluids, from macroscopic to microscopic scales. In Bose-Einstein condensates of dilute atomic gases, superfluid helium and superconductors, the existence of vortices is a consequence of the quantum nature of the system. Quantized vortices of supercurrent are generated by magnetic flux penetrating the material, and play a key role in determining the material properties and the performance of superconductor-based devices. At high temperatures the dynamics of such vortices are essentially classical, while at low temperatures previous experiments have suggested collective quantum dynamics. However, the question of whether vortex tunnelling occurs at low temperatures has been addressed only for large collections of vortices. Here we study the quantum dynamics of an individual vortex in a superconducting Josephson junction. By measuring the statistics of the vortex escape from a controllable pinning potential, we demonstrate the existence of quantized levels of the vortex energy within the trapping potential well and quantum tunnelling of the vortex through the pinning barrier.

The use of mutually exclusive categories for atopic sensitization: a contrasting effect for family size on house dust mite sensitization compared with ryegrass sensitization

Our aim was to examine the relative importance of family size on sensitization to two different allergens: ryegrass and house dust mite (HDM), using a mutually exclusive classification for allergen-specific sensitization. An 8-year follow-up birth cohort study of children born between 1988-89 was conducted. The follow-up sample consisted of 498 children residing in Northern Tasmania in 1997 (84% of eligible). Outcome measures included skin prick test (SPT) reaction to nine aeroallergens and parental questionnaire. Family size was defined as sibling number in 1997. Children with a positive SPT to either Der p or Der f house dust mite but not ryegrass were classified as HDM-exclusive (n = 84). Children with a positive SPT to ryegrass but not HDM were classified as ryegrass-exclusive (n = 43). Family size was associated with reduced ryegrass-exclusive sensitization [AOR 0.57 (0.39, 0.84) per increase in sibling number] but not HDM-exclusive sensitization [AOR 0.97 (0.77,1.23)]. The difference in the family size effect on these sensitization outcomes was significant (p = 0.02). Similarly, family size tended to be associated with reduced asthma among ryegrass-exclusive sensitized children [AOR 0.45 (0.18,1.12)] but not HDM-exclusive sensitized children [(AOR 1.46(0.80-2.65)]. Large family size was strongly associated with reduced sensitization for ryegrass allergens but not HDM allergens using mutually exclusive sensitization categories. If this difference is confirmed in other studies, the contrasting effect of family size may reflect differences between these allergens with regard to level or timing of early life exposure, differences in allergen -specific potentiation for sensitization or unidentified confounding. The use of mutually exclusive categories for allergen sensitization will assist future work on child atopic disease.

Immune deviation and the hygiene hypothesis: a review of the epidemiological evidence

The epidemiological evidence for the proposal that early life immune deviation is the principal mechanism by which microbial agents prevent the development of atopy has been reviewed. Seven criteria are proposed which should ideally be fulfilled. The majority of studies only fulfill two or three criteria. For mycobacteria, measles and respiratory viruses there are studies that demonstrate a significant increase in atopy or allergic disease. Parasite infections, which provide a strong TH2 stimulus, are associated with reduced rather than enhanced allergen sensitization. The available epidemiological evidence does not provide support for a mechanism of early life immune deviation. The principal environmental influences on atopic disease are likely to occur throughout life and involve interactions between microbes and other non-infective and lifestyle factors.

An association between plastic mattress covers and sheepskin underbedding use in infancy and house dust mite sensitization in childhood: a prospective study

BACKGROUND

Higher house dust mite (HDM) allergen exposure during infancy has been associated with increased HDM sensitization. Infant bedding has been associated with the accumulation of varying levels of HDM. Prospective data on the relationship between infant bedding and the development of HDM sensitization has not been previously examined.

OBJECTIVES

To determine if particular types of bedding used in infancy are associated with increased risk of house dust mite sensitization in childhood.

METHODS

A population-based sample (n = 498) of children born in 1988 or 1989, and who were resident in Northern Tasmania in 1997, participated in this study. These children were part of a birth cohort study (1988-95), the Tasmanian Infant Health Survey. Data on infant underbedding and mattresses was available on 460 and 457 children, respectively. The main outcome measure was HDM sensitization defined as a skin prick test (SPT) reaction of 3 mm or more to the allergens of Dermatophagoides pteronyssinus and/or Dermatophagoides farinae.

RESULTS

The use of either sheepskin underbedding or plastic mattress covers in infancy was associated with an increased risk of sensitization to HDM allergens at age 8 years. The adjusted risk ratio (RR) for sensitization to HDM with sheepskin in infancy was 2.27 (95% CI: 1.14, 4.55), P = 0.020. The adjusted RR for sensitization to HDM with the use of plastic mattress covers in infancy was 2.06 (95% CI: 1.22, 3.51), P = 0.007. The use of a foam mattress in infancy was not related to subsequent HDM sensitization.

CONCLUSION

Infant's bedding plays a role in the development of HDM sensitization in childhood. Intervention studies to examine mite allergen levels and the role of underbedding on the development of HDM sensitization are required.

Synthetic bedding and wheeze in childhood

BACKGROUND

The reasons for the increase in childhood asthma over time are unclear. The indoor environment is of particular concern. An adverse role for synthetic bedding on asthma development in childhood has been suggested by cross-sectional studies that have found an association between synthetic pillow use and childhood wheeze. Prospective data on infant bedding have not been available.

METHODS

Bedding data at 1 month of age were available from an infant survey for children who were participating in a 1995 follow-up study (N = 863; 78% traced). The 1995 follow-up was embedded in a larger cross-sectional survey involving 6,378 seven year olds in Tasmania (N = 92% of eligible). Outcome measures included respiratory symptoms as defined in the International Study of Asthma and Allergies in Childhood protocol. Frequent wheeze was defined as more than 12 wheeze episodes over the past year compared with no wheeze.

RESULTS

Synthetic pillow use at 1 month of age was associated with frequent wheeze at age 7 (adjusted relative risk [aRR] = 2.5; 95% confidence interval [CI] = 1.2-5.5) independent of childhood exposure. Current synthetic pillow and quilt use was strongly associated with frequent wheeze (aRR = 5.2; CI = 1.3-20.6). Substantial trends were evident for an association of increasing number of synthetic bedding items with frequent wheeze and with increasing wheeze frequency. Among children with asthma, the age of onset of asthma occurred earlier if synthetic bedding was used in infancy.

CONCLUSIONS

In this cohort, synthetic bedding was strongly and consistently associated with frequent childhood wheeze. The association did not appear to be attributable to bedding choice as part of an asthma management strategy.

Modification of the home environment for the reduction of injuries

BACKGROUND

Injury in the home is extremely common, accounting for around a third of all injuries. The majority of injuries of children under five and people aged 75 and over occur at home. Multi-factorial injury prevention interventions have been shown to reduce injuries in the home. However, few studies have focussed specifically on the impact of physical adaptations to the home environment and the effectiveness of such intervention needs to be ascertained.

OBJECTIVES

To review the evidence for the effect on injuries of modification of the home environment with a primary focus on interventions to reduce physical hazards.

SEARCH STRATEGY

We searched the following databases: APId, ASSIA, British Nursing Index, CINAHL, Cochrane Library databases, Dissertation Abstracts, EMBASE, HealthSTAR, ICONDA, ISI Science (and Social Science) Citation Index, MEDLINE, National Research Register, PREMEDLINE, SIGLE and Urbadisk. Conference proceedings and reference lists were scanned. Experts in the field and trialists were contacted. Searches were not restricted to English language. Handsearching of relevant journals was not conducted.

SELECTION CRITERIA

Randomised controlled trials, non-randomised controlled trials, controlled before-and-after studies and interrupted time series studies.

DATA COLLECTION AND ANALYSIS

All abstracts were screened by two reviewers for relevance, outcome and design. Two reviewers independently evaluated methodological quality and extracted data from each eligible study.

MAIN RESULTS

We found 28 published trials and one unpublished study. Trials were not sufficiently similar to allow for the combination of data by statistical analyses, so this review takes a narrative form. Studies were divided into three groups based on the primary population sample: children, older people and the general population. None of the 11 childhood studies demonstrated a reduction in injuries that might have been due to environmental adaptation in the home. One study reported a reduction in injuries and in hazards but the two could not be linked. The majority of studies used hazard reduction as the outcome. Of the 15 studies in older people, none demonstrated a reduction in injuries due to hazard reduction, although two demonstrated a reduction in falls that could be due to hazard reduction. In the mixed age group there were two trials; neither demonstrated an effect on injuries.

REVIEWER'S CONCLUSIONS

There is insufficient evidence to determine the effects of interventions to modify environmental home hazards. Further interventions to reduce hazards in the home should be evaluated by adequately designed randomised controlled trials measuring injury outcomes. Recruitment of large study samples to measure effect may be a major consideration for future trials.

Unique dentition of lungfish

Lungfish are a group of ancient fish, represented almost continuously in the fossil record from their first appearance in the Devonian to the present time. They have numerous unique characters in the dentition, found only among lungfish, as well as some that are shared with other groups of fish and with higher vertebrates, such as a thin layer of true enamel, instead of the enameloid found in the dentition of most fish. Unique characters include the diversity of forms of dentine in the tooth plates, as well as the organisation of the dentines and the unusual mode of continuous growth of the dentition. Their enamel is based on amelogenin formed by the ameloblasts of the dental lamina, and is mineralised by long crystals of calcium hydroxyapatite deposited in layers over the developing tooth. The different forms of dentine, which show progressive evolutionary change within the group, are based on an extracellular matrix of collagen, mineralised with calcium hydroxapatite of variable crystalline form. Cells that line the oral cavity produce the ameloblasts that are endodermal in origin, and cells that form the dental papillae are, like the other cells that secrete skeletal tissues, derived from head mesoderm, as in other vertebrates. Unique to all dipnoans is the fusion of the dental tissues to the underlying bone and the way in which bone, included within the tooth plate, remodels to permit growth in the whole dentition.

Atopic allergy and delayed type hypersensitivity in Estonian children

BACKGROUND

A shift in the balance ofT helper (Th) cell subsets towards a polarized Th2 population is generally accepted to occur in atopic disease, however, both Th1 and Th2 disorders have increased over the past decades in Western communities.

OBJECTIVE

The aim of our study was to investigate delayed type hypersensitivity (DTH) response in atopic and non-atopic children in a population with a low prevalence of allergic disorders.

METHODS

Skin prick tests (SPT) were performed with fresh egg white and extracts of five inhalant allergens, i.e. cat, dog, house dust mite (Dermatophagoides pteronyssinus), birch and timothy, and DTH response was evaluated by Multitest CMI in 72 Estonian 4- to 6-year-old children.

RESULTS

The frequency of response to diphtheria was significantly increased in SPT-positive children (55% vs. 26%, chi2 = 5.5; P = 0.038). The induration to diphtheria (2.4 +/- 0.5 vs. 0.9 +/- 0.2 mm; P = 0.004), and tetanus (3.5 +/- 0.6 vs. 2.1 +/- 0.3 mm; P = 0.025) was significantly greater in the SPT-positive children. The cumulative size of induration in the positive DTH tests was significantly greater in the SPT-positive children (9.0 +/- 1.2 vs. 5.2 +/- 0.6 mm, P = 0.01).

CONCLUSION

In this group of children our findings do not support the hypothesis of an immune deviation with decreased Th1 and increased Th2 responses leading to atopic disease, but rather a process of immune modulation whereby both Th1 and Th2 responses are increased in atopic subjects.

Test-retest reliability of the emotional stroop task: examining the paradox of measurement change

The Emotional Stroop (ES) task (I. H. Gotlib & C. D. McCann, 1984) has been proposed as an experimental measure to assess the processing of emotion or the bias in attention of emotion-laden information. However, study results have not been consistent. To further examine its reliability for empirical research, the authors of this study administered the ES task to 33 participants on 2 separate occasions separated by 1 week. Results indicated that retest reliabilities for reaction times (RTs) derived from the 3 separate emotion conditions (manic, neutral, and depressive) across the 1 week interval were very high. However, consistent with previous research, the reliabilities were very low for the interference indices (manic and depressive). These low reliabilities reflect the very high intercorrelation between the RTs derived from the 3 conditions. The authors concluded that a better indicator of the reliability for this task is the individual RTs from each emotion condition.

The 2000 epidemic of Rift Valley fever in Saudi Arabia: mosquito vector studies

In mid-September 2000, Rift Valley fever (RVF) virus was diagnosed as the cause of infection in humans and livestock in Jizan Region, Saudi Arabia. This is the first time that this arbovirus has been found outside Africa and Madagascar. Collections of mosquitoes (Diptera: Culicidae) were therefore undertaken (from 25 September to 10 October) at eight sites during the epidemic to obtain mosquitoes for attempted RVF virus isolation. Among 23 699 mosquito females tested, six isolations of RVF virus were made from 15 428 Culex (Culex) tritaeniorhynchus Giles and seven from 8091 Aedes (Aedimorphus) vexans arabiensis Patton [corrected]. Minimum mosquito infection rates per 1000 at sites with infected mosquitoes were 0.3-13.8 Cx. tritaeniorhynchus and 1.94-9.03 Ae. v. arabiensis. Viral activity moved northwards as collecting was in progress and collectors 'caught up' with the virus at the two most northerly sites on the last two trapping evenings. Other species occurred in small numbers and were identified but not tested. Both Cx. tritaeniorhynchus and Ae. v. arabiensis were susceptible to RVF virus and transmitted between hamsters, and an additional quantitative test with Cx. tritaeniorhynchus showed that 71-73% of mosquitoes became infected after ingesting 6.9-7.9 log10 FFU/mL of virus; transmission rates were 10% (post-infection day 14) and 26% (post-infection day 20). It was concluded that both species were vectors on grounds of abundance, distribution, preference for humans and sheep, the virus isolations and vector competence tests.

Efficient, high repetition-rate femtosecond blue source using a compact Cr:LiSAF laser

We present a practical route to designing a portable femtosecond blue light source that is rugged, compact and battery-powered. An opticaloptical second-harmonic generation (SHG) efficiency of 30% is reported using a diode-pumped, femtosecond Cr:LiSAF laser requiring only ~1.2W of electrical drive. 12mW of blue average power is generated using a 3mm KNbO3 crystal in a simple, single-pass extracavity geometry. The corresponding electrical-blue efficiency of 1% is, to our knowledge, the highest reported efficiency of any femtosecond blue source. Despite conditions of large group velocity mismatch, we show that the temporally-broadened blue pulses remain well within the femtosecond regime, at ~540fs.

Feather bedding and house dust mite sensitization and airway disease in childhood

Feather bedding has been inversely associated with child wheeze and also with house dust mite (HDM) allergen levels. We conducted a cross-sectional analysis of the childhood component of a birth cohort study. Our aim was to examine the relation between feather bedding and HDM sensitization and airway disease. A total of 498 children (84% of eligible) residing in Northern Tasmania in 1997 who were eligible for the Tasmanian Infant Health Survey at birth in 1988 or 1989 participated. Outcome measures included atopic sensitization to Dermatophagoides farinae or Dermatophagoides pteronyssinus allergens, spirometric lung function, and child respiratory symptoms using questions from the ISAAC study. HDM sensitization was strongly associated with frequent wheeze (more than 12 episodes of wheeze compared with no wheeze in the past year) (rate ratio [RR], 19.61; confidence interval [CI], 6.94-55.56) but only weakly associated with asthma ever (RR, 1.65; CI, 1.30-2.09). Feather quilt use was associated with reduced HDM sensitization (adjusted RR [ARR], 0.60; CI, 0.45-0.80) and also reduced frequent wheeze episodes over the past year (ARR, 0.24; CI, 0.07-0.86). The reduction in wheeze was more evident among HDM-sensitized children. These findings are consistent with the possible mechanisms for feather bedding of a reduction in initial HDM sensitization and an improvement in respiratory symptoms among HDM-sensitized children. However, prospective studies are required to fully exclude selection bias.

Development and use of a population based injury surveillance system: the all Wales Injury Surveillance System (AWISS)

This report details the development and use of a population based emergency room surveillance system in the UK. Despite some difficulties in accessing high quality data the system has stimulated a considerable number of research and intervention projects. While surveillance systems with high quality data collection and coding parameters remain the gold standard, imperfect systems, particularly if population based, can play a substantial part in stimulating injury prevention initiatives.

Relationships between intestinal calcium absorption, serum vitamin D metabolites and smoking in postmenopausal women

Smoking has been associated with low bone density, fractures and poor intestinal calcium absorption. Calcium absorption is a critical factor in calcium balance in postmenopausal women but the mechanisms causing decreased absorption efficiency in postmenopausal smokers are controversial and poorly defined. We performed a cross-sectional study of 405 postmenopausal women attending a clinic for the management of osteoporosis to compare intestinal calcium absorption efficiency, serum vitamin D metabolites and parathyroid hormone levels in postmenopausal women who had never smoked, who were smokers previously or who were current smokers, to examine the relationships between these variables in smokers. Two hundred and fifty-two of the women had never smoked, 79 had smoked previously and 74 were current smokers. The hourly fractional rate of calcium absorption was similar in non-smokers and those who had previously smoked. Radiocalcium absorption was less in the 74 smokers compared with the 331 non-smokers [0.60 (0.29 SD) vs 0.71 (0.27); p = 0.004], as were serum calcitriol (p<0.001) and parathyroid hormone (PTH) (p<0.01). There was no difference in the relationship between calcium absorption and serum calcitriol between smokers (r = 0.38) and non-smokers (r = 0.28); hence the impaired calcium absorption in the smokers was almost entirely attributable to suppression of the PTH-calcitriol endocrine axis. In postmenopausal women smoking is associated with a reduction in calcium absorption efficiency due to suppression of the PTH-calcitriol axis. This impairment of calcium absorption could lead to accelerated bone loss and limit the usefulness of dietary calcium supplementation.

A prospective study of the association between home gas appliance use during infancy and subsequent dust mite sensitization and lung function in childhood

BACKGROUND

Home gas appliance use has been associated with child respiratory illness but prospective data on the relationship between infant exposure and the development of child allergic disease has not been readily available.

OBJECTIVES

(a) To determine if home gas appliance use is associated with increased risk of house dust mite (HDM) sensitization. (b) To examine whether any association between current home gas use and airway obstruction is influenced by HDM sensitization.

METHODS

DESIGN

an 8-year follow-up birth cohort study of children born during 1988 and 1989.

PARTICIPANTS

a population-based sample (n = 498) of children who participated in the Tasmanian Infant Health Survey (TIHS) and resided in Northern Tasmania in 1997 (84% of eligible children).

MAIN OUTCOME MEASURES

(a) Skin prick test reaction to nine allergens, including Dermatophagoides pteronyssinus (Der p 1) and Dermatophagoides farinae (Der f 1). (b) Spirometric lung function indices, including forced expiratory volume in one second (FEV(1)) and forced vital capacity (FVC).

RESULTS

The relative risk for home gas appliance use at 1 month of age and HDM sensitization was 1.98 (1.04, 3.79) in a cohort analysis with confounder matching. Current home gas use was also associated with HDM sensitization (ARR 1.73 (1.43, 2.76)). Current home gas use was related to a stronger (P = 0.006) reduction in the FEV(1) : FVC ratio among HDM-sensitive children (adjusted difference - 6.2% (- 10.0 to - 2.4)) than non-HDM-sensitive children (adjusted difference - 0.3% (- 2.5 to 1.8)).

CONCLUSION

Indoor pollutants from gas combustion may increase the likelihood of initial sensitization to HDM and play a role in the development of atopic asthma. HDM-sensitized children may be more vulnerable to indoor pollutant-induced airway obstruction. The ability of this study to detect such effects may partly reflect unflued gas appliance use among this sample.

Biolistic transformation of Arabidopsis root hairs: a novel technique to facilitate map-based cloning

The final stage of map-based gene isolation is complementation of the mutant phenotype with wild-type DNA to determine the exact location of the gene of interest. This usually involves Agrobacterium tumefaciens-mediated transformation, which is reliable and produces stable transformants. However, the process of Agrobacterium transformation may take up to three months to complete. If the mutant phenotype can be seen in a single cell, and the wild-type copy of the gene can act cell autonomously, then complementation of the whole plant is not strictly necessary. We have developed a technique for the biolistic transformation of Arabidopsis thaliana root hairs, and used this to test large insert clones for complementation of two recessive mutant phenotypes, a procedure that takes less than a day. Our results show that biolistic transformation can be used with transient assays to conduct rapid tests for complementation by large insert clones.

The -590C/T and -34C/T interleukin-4 promoter polymorphisms are not associated with atopic eczema in childhood

Susceptibility to the development of asthma and other atopic diseases is known to have a genetic component. To date, several studies have linked chromosome 5q31 to asthma and atopy in human beings. This region harbors a cluster of cytokine and growth factor genes, IL-4 presenting as a prime atopy candidate gene, inasmuch as it plays a pivotal role in the atopy pathway. Our approach was to identify polymorphisms within the promoter regions of IL-4 and test their association with atopic eczema. Polymorphisms were typed in a cohort of 76 small nuclear families and 25 triads with childhood atopic eczema. The genotypes were used to test for linkage in the presence of association with atopic eczema. A new polymorphism, -34C/T, was identified and studied with a known polymorphism, -590C/T. On its own, each polymorphism showed no association with atopic eczema. The 2 polymorphisms were used to generate haplotypes, and a significant result was found for the -590C/-34C haplotype. However, after Bonferroni correction for multiple testing, the association became nonsignificant. Neither polymorphism predisposes to early-onset atopic eczema by itself, but suggestive linkage was found for the -590C/-34C haplotype in this study.

Stagnation pressure of imploding shells and ignition energy scaling of inertial confinement fusion targets

The stagnation pressure p(s) of imploding cylindrical ( n = 2) and spherical ( n = 3) shells is found to scale as p(s)/p(0)~M(2(n+1)/(gamma+1))(0), where M0 is the Mach number of the imploding shell and p(0) its maximum pressure. The result holds approximately for Mach numbers in the range 2<M0<25 relevant for inertial confinement fusion capsules and is of key importance for their ignition energy scaling. It is derived analytically on the basis of similarity solutions for an ideal gas with adiabatic exponent gamma.

Preliminary report: skeletal muscle cell lipid and oxygen supply

In a group of 12 normal-weight, normotensive, nondiabetic adult females, the intramyocellular lipid (IMCL) to creatine ratio of the soleus muscle was determined using localized (1)H-magnetic resonance spectroscopy ((1)H-MRS) and related to skeletal muscle blood (and oxygen) supply (as assessed by near infrared spectroscopy [NIRS] of the forearm). A significant positive association was found between IMCL content and reoxygenation rate of forearm muscle hemoglobin (Hb) after 1 minute of ischemic exercise (r = .70, P = .01). The relative efficiency of skeletal muscle oxygen supply may be a determining factor of IMCL content in skeletal muscle.

Bronchial granuloma - where's the foreign body?

Airway masses are uncommon in children. The majority of bronchial tumors are granulomata secondary to an inhaled foreign body. However, other rare diseases like primary bronchopulmonary tumors should always be considered in the evaluation of a bronchial granuloma in children. The differential diagnosis of bronchial granuloma is presented. We report a 7-year-old girl with a 3-year history of recurrent cough and fevers who was found to have a bronchial granuloma in the left upper lobe bronchus. The diagnosis of foreign body-related granuloma was eventually made after combined and repeated rigid and flexible bronchoscopy. This case highlights the need to search aggressively for a foreign body in the presence of an airway granuloma in children, even in the absence of a history of aspiration.

Experimental detection of Rift Valley fever virus by reverse transcription-polymerase chain reaction assay in large samples of mosquitoes

A reverse transcription-polymerase chain reaction (RT-PCR) was assessed in laboratory tests to detect the presence of single Aedes aegypti (L.) or Eretmapodites quinquevittatus Theobald mosquitoes infected with Rift Valley fever virus in pools of mosquitoes, 50-600 in size, from laboratory colonies or mixed field collections. The viral RNA was detected in all pools containing infected mosquitoes and was shown to be as sensitive as infant mice but more sensitive than Vero cell cultures for virus detection. Pools diluted down to the equivalent of 1:16 000 mosquitoes were also positive by RT-PCR. RNAs from 4 other phleboviruses were negative, there were no false positives and the procedure followed, with the 2 particular primers chosen, gave consistently clear bands of the PCR products on agarose gels without nested PCR being necessary.

The relation between infant indoor environment and subsequent asthma

Our aim was to examine the contribution of an infant's indoor environment to childhood asthma using prospective data. We conducted a cross-sectional asthma survey in 1995 on 92% (6,378/6,911) of 7-year-olds in Tasmania, Australia. We linked these data with data collected in 1988 as part of the Tasmanian Infant Health Survey, which was designed to investigate sudden infant death. We were able to match 863 records out of the 1,111 in the 1988 survey and the 6,378 in the 1995 survey. The former group was interviewed at home at 1 month of age. In homes where at least one adult smoked in 1988, reported infant exposure to smoking in the same room in 1988 was associated with increased asthma by 1995 (relative risk = 1.52; 95% confidence interval = 1.01-2.29) after adjustment for confounders. The associations between infant exposure to environmental tobacco smoke and asthma were not consistent, however. Gas heater use in 1988 was associated with asthma (relative risk = 1.92; 95% confidence interval = 1.33-2.76). Markers of aeroallergen exposure at 1 month of age were not materially associated with asthma or wheeze. In some settings, air circulation practice with regard to bedroom door closure appeared important. Poor indoor air quality may play an important role in the development of childhood asthma.

Relationship between early life respiratory illness, family size over time, and the development of asthma and hay fever: a seven year follow up study

BACKGROUND

The timing and mechanism of the inverse association between increasing sibling number and atopic disease are not yet understood. A study was undertaken to examine how family size at birth predicts early respiratory illness, to report the association between infant respiratory illness and childhood atopic disease, and to determine whether the protective effect of large family size operates during infancy or later childhood.

METHODS

A prospective follow up study was carried out on 863 children (78%) of 1111 participants in the Tasmanian Infant Health Survey performed in 1988. In 1988 household size and history of respiratory illness were obtained by parental interview at home (median age 35 days) and later by telephone (median age 85 days). In 1995 asthma, hay fever, and household size were assessed by parental questionnaire in a large cross sectional survey.

RESULTS

In 1988 increasing resident number (per resident) (adjusted odds ratio (AOR) 1.17 (95% CI 1.05 to 1.31)) and resident density (AOR 1.77 (95% CI 1.07 to 2.94)) were related to parental report of an upper respiratory tract infection (URTI) by one month of age. Children with a reported URTI by home interview were more likely to have subsequent asthma (adjusted relative risk (ARR) 1.27 (95% CI 1.05 to 1.53)). The association between lower respiratory tract infection (LRTI) at telephone interview (relative risk (RR) 1.34 (95% CI 1.02 to 1.75) and asthma was reduced after adjustment for family history of asthma (ARR 1.27 (95% CI 0.98 to 1.66)). Antibiotic use by home interview was not associated with subsequent asthma or hay fever. Indicators of family size in 1988 were associated with hay fever but not asthma but, in contrast, resident number in 1995 was inversely associated with asthma (AOR 0.82 (95% CI 0.72 to 0.92) per resident) and hay fever (AOR 0.82 (95% CI 0.71 to 0.96) per resident). Children with no siblings were at risk for current asthma, particularly if symptoms began after the age of four (RR 2.81 (95% CI 1.36 to 5.84)).

CONCLUSIONS

The apparent protective effect of large household size and asthma could not be explained by an increase in reported early respiratory illness. The first year of life may not be the most critical time for the protective effect of large household size to be mediated in relation to asthma, but this effect occurred by the seventh year of life.