Stillbirths in relation to the coastline of Cumbria, 1950-89

The nuclear installation at Sellafield, in west Cumbria in the north of England, has discharged radioactive waste into the Irish Sea since 1952. The objective of this paper was to investigate whether women living near to the coast in Cumbria had an increased risk of having stillborn children. A retrospective cohort analysis was carried out using all 259,050 births (4017 stillbirths) to women normally resident in Cumbria during 1950-89, allowing for year of birth, social class and birth order using (i) comparison of observed and expected numbers of stillbirths in distance bands relative to the coast, (ii) comparison of cumulative observed and expected numbers of stillbirths by distance from the coast, and (iii) logistic regression analysis of stillbirth risk in relation to distance from the coast. Comparison of observed and expected numbers of stillbirths in distance bands within 10 km of the coast did not provide evidence of an excess risk of stillbirth closer to the coast. The comparison of the cumulative observed and expected numbers of stillbirths within 10 km of the coast supported this result. Logistic regression analysis of all births in Cumbria showed that distance from the coast did not significantly influence stillbirth risk (P > 0.05). There was no evidence to suggest an increased risk of stillbirth in mothers resident nearer to the coast.

Repeat tear of postoperative meniscus: potential MR imaging signs

PURPOSE

To determine the usefulness of five magnetic resonance (MR) signs of repeat tears of the postoperative meniscus.

MATERIALS AND METHODS

Fat-saturated proton-density-weighted and T2-weighted MR images in 20 patients who had undergone at least two knee surgeries were reviewed. Second-look arthroscopic confirmation of meniscal status was available in all patients. MR images of 39 menisci (10 repeat tears, 11 postoperative menisci without repeat tears, three tears in previously normal menisci, and 15 normal menisci) were evaluated for (a) a linear area of abnormal signal intensity extending to an articular surface on intermediate-weighted images, (b) abnormal meniscal morphology, (c) likelihood of a typical postoperative appearance, (d) fluid extending into the linear area on T2-weighted images, and (e) cartilage defects. Two radiologists rated their confidence on a five-point scale for the presence of these signs and were compared for level of agreement.

RESULTS

The intraclass correlation coefficient (range, 0.75-0.91) indicated a high level of agreement. Areas under the receiver operating characteristic curves were large (range, 0.70-0.87) for all five signs, with a line (grade 3 signal intensity) and fluid within a line having the highest areas. These two signs also had the highest statistical scores (chi 2 = 14.12 and 13.30; P < .002; odds ratio, 1.588 and 1.599 for the line and the fluid within the line, respectively).

CONCLUSION

The two best MR signs of repeat tear of the postoperative meniscus were the presence of a line and fluid within the line extending to an articular surface.

Increased soft-tissue blood flow in patients with reflex sympathetic dystrophy of the lower extremity revealed by power Doppler sonography

OBJECTIVE

We evaluated the ability of power Doppler sonography to show increased soft-tissue blood flow in patients with reflex sympathetic dystrophy of the lower extremity.

SUBJECTS AND METHODS

Power Doppler sonography was performed in 30 patients with reflex sympathetic dystrophy of the lower extremity and in 26 asymptomatic control subjects. The bilateral power Doppler sonograms that were obtained of the soft tissues of the dorsum of the foot of each subject were grouped in pairs, and three sonologists who were unaware of clinical information independently reviewed the images. Images were evaluated for the amount of power Doppler signal shown on the following scale: 1 = no flow or minimal flow; 2 = mild flow; 3 = moderate flow; and 4 = marked flow.

RESULTS

More power Doppler flow was seen in the patients with reflex sympathetic dystrophy than in the control subjects (p < .005). In addition, side-to-side asymmetry of flow was seen in patients, but this trend was not statistically significant (p < .20). Receiver operating characteristic (ROC) analysis showed that combined flow and asymmetry were more related to reflex sympathetic dystrophy than either parameter alone (area under the ROC curve: for flow, 0.748; for asymmetry, 0.566; for both, 0.799). We found that when the sum of power Doppler flow in both feet was greater than or equal to five, and asymmetry of flow was greater than or equal to one, the sensitivity of power Doppler sonography for reflex sympathetic dystrophy was 73% and the specificity was 92%.

CONCLUSION

Patients with reflex sympathetic dystrophy of the lower extremity have increased power Doppler flow compared with asymptomatic control subjects. Patients may also exhibit more side-to-side asymmetry of flow than control subjects.

Moving beyond content validation of nursing diagnoses

TOPIC

Studies to establish construct and criterion-related validity of nursing diagnoses.

PURPOSE

The overwhelming majority of previous studies addressed content validation by nurse experts. This paper describes strategies to move beyond content validation research to construct and criterion-related validation.

SOURCES

The range of studies that should be conducted for development of nursing diagnoses are reviewed with examples drawn from the field of psychology. Existing studies on the diagnoses of ineffective breathing pattern, ineffective airway clearance and impaired gas exchange are used as examples.

CONCLUSIONS

Many types of studies are needed for each nursing diagnosis. Increased funding and support for nursing diagnosis research will be facilitated by attention to the accuracy of nurses' diagnoses and outcomes of the diagnostic process.

Neuroblastoma in Europe: differences in the pattern of disease in the UK. SENSE. Study group for the Evaluation of Neuroblastoma Screening in Europe

BACKGROUND

Neuroblastoma is a major contributor to childhood cancer mortality, but its prognosis varies with age and stage of disease, and some tumours regress spontaneously. Urinary screening programmes or clinical examination may detect the disease before symptoms appear, but the benefit of early diagnosis is uncertain. We examined the incidence, pattern, and presentation of neuroblastoma in four European countries.

METHOD

Population-based incidence rates were derived for France, Austria, Germany, and the UK. Age, sex, and stage distribution were analysed by Mantel-Haenszel techniques and Poisson regression. The proportion of incidental diagnoses (cases without symptoms found at routine health checks or during investigation of other disorders) and mortality rates were also compared.

FINDINGS

Between 1987 and 1991, 1672 cases of neuroblastoma were diagnosed in children under 15 years old (France, 624; Austria, 69; Germany, 493; UK, 486). Age-standardised annual incidence was significantly lower in the UK (10.1/million) than in France (12.5) and Germany (11.4). In the UK a deficit of low-stage disease in infants was accompanied by an excess of stage IV in older children. The UK had significantly fewer incidental diagnoses (8%) than Austria (27%) and Germany (34%). UK mortality rates were significantly higher than German or French rates.

INTERPRETATION

In the UK, neuroblastoma diagnosis is delayed, possibly because of a less rigorous system of health checks for children. Although some overdiagnosis occurs in mainland Europe, our data suggest that in the UK some low-stage cases, undetected in infancy, may later present as advanced disease. This finding has implications for screening programmes and organisation of routine surveillance of infant health in the UK.

10 years' neuroblastoma screening in Europe: preliminary results of a clinical and biological review from the Study Group for Evaluation of Neuroblastoma Screening in Europe (SENSE)

Between January 1986 and May 1996, 870,313 children were tested in European neuroblastoma (NB) screening programmes. Among these children, 82 cases of NB (age range 4-24 months, median 11 months) were detected by screening. 83% of the patients had localised NB and 17% were diagnosed with generalised NB (stage 4, 10%; stage 4s, 7%). Unfavourable biological markers (MYCN amplification, loss of heterozygosity (LOH) 1p36, DNA di/tetraploidy) were observed in 14% of 76 biologically examined cases. The median follow-up time of all the patients was 21.5 months (range 1-101 months). To date, 69 patients are in complete remission (CR) and 2 patients have died due to therapy (stage 4, 1 patient; stage 3, 1 patient with unfavourable markers). Apart from screened patients, 16 other patients with NB were found who had previously had a normal screening test, i.e. 'false negative' patients (age range 10-41 months, median 31.5 months). The median interval between screening and diagnosis was 24.5 months (range 6-35 months). 11 of the 'false negative' patients suffered from generalised NB (stage 4) and 5 had localised NB at diagnosis. Unfavourable biological markers were observed in 7/12 patients. 5 patients have died, 2 achieved partial remission and 9 CR. 9 of the 11 patients with unfavourable biological markers diagnosed due to NB screening are currently in CR. It is very likely that, among the patients without unfavourable biological markers, we detected tumours which may have regressed spontaneously. These children may have undergone 'unnecessary,' but unavoidable, diagnostic procedures and therapy. To reduce the number of 'false negative' patients, a later screening could be helpful and should be evaluated.

Type of health care coverage and the likelihood of being screened for cancer

OBJECTIVES

This study explored whether type of outpatient health coverage affected the likelihood of men and women aged 20 to 64 years receiving recommended cancer screening procedures.

METHODS

Data from the 1989 and 1990 California Behavioral Risk Factor Surveillance Surveys were used to compare Pap smear, mammogram, fecal occult blood test, and proctoscopic examination rates for adults with three different types of private health care coverage (Group/staff model health maintenance organization, Independent Practice Association Model health maintenance organization, indemnity plan) and no outpatient health insurance. Logistic regression models were used to control for sociodemographic and health characteristics and whether individuals had a usual health care provider.

RESULTS

Individuals with Group Model health maintenance organization coverage were significantly more likely than those with indemnity plans to have had recent cervical, breast, and colorectal cancer screening, whereas screening likelihood for those with Independent Practice Association model health maintenance organization coverage did not differ substantially from those with indemnity plans. Individuals with no outpatient coverage were less likely to be screened than those with outpatient coverage. The most consistently significant predictor across cancer screening procedures for both men and women was having a usual doctor who knew their medical history.

CONCLUSIONS

Adults who had private outpatient insurance were more likely to undergo recommended cancer detection procedures than those who did not. Adults who belonged to a health maintenance organization, which emphasizes and pays for a broader spectrum preventive care, were more likely to receive Pap smears, mammograms, and fecal occult blood tests than those covered by indemnity plans. Receiving care primarily from one doctor significantly increased the likelihood of having screening procedures, irrespective of type of health plan.

The North Cumbria Community Genetics Project

The aim of the North Cumbria Community Genetics Project is to establish a store of DNA, plasma, and viable cells from a cohort of around 8000 Cumbrian infants. To meet this objective, specimens of umbilical cord blood and tissue will be collected with maternal consent from babies born at the West Cumberland Hospital, Whitehaven over a five year period from January 1996. These samples will be used in a series of genetic and epidemiological studies investigating the interaction between genes, the environment, and health. There is little population movement in West Cumbria and so it will be possible to follow many of the babies throughout their childhood and to investigate the relationship between their genetic constitution and health outcome.

Early life and later determinants of adult disease: a 50 year follow-up study of the Newcastle Thousand Families cohort

The relative contribution of socioeconomic, behavioural and biological factors operating in fetal and infant life, childhood and adulthood to risk for cardiovascular disease, respiratory diseases and non-insulin-dependent diabetes in middle age has become an important research issue. All 1142 babies born in Newcastle upon Tyne in May and June 1947 were recruited into a prospective cohort study of child health (the 'Thousand Families' study) and followed in great detail to the age of 15 y, with a brief further follow up at age 22 y. Children from poorer families were at greatest risk of severe respiratory tract infection in infancy. Children from professional and managerial families were on average taller and heavier throughout childhood than those from semi- and unskilled manual social classes. Repeated infections in early childhood greatly increased the risk of developing chronic respiratory disease by age 15 y. This paper outlines a new investigation designed to trace surviving members of this cohort and to chart the relationships between their socioeconomic circumstances, lifestyles, experiences and health from birth through to the present day. Existing data on socioeconomic circumstances and infections in infancy and childhood, infant nutrition, birthweight and physical development to age 22 y will be linked to information gained from a new study. This comprises a postal questionnaire survey of study members' adult health, socioeconomic circumstances and lifestyle, and a hospital based clinical examination including heart and lung function, glucose tolerance, blood lipids and anthropometric measurements at age 49-51 y. Out of a target sample of 979 people for whom sufficient data are available on the first year of life, 866 (88%) have been traced and 649 are still resident in the North of England. Those study members who have been traced are highly representative of the original cohort. The Thousand Families cohort provides a unique opportunity for detailed epidemiological study because of the wealth of data available on infant and childhood socioeconomic and family circumstances, all of which was collected prospectively. In addition, there has been comparatively little loss to follow-up since 1948.

Phasic and tonic reflexes evoked in human antagonistic wrist muscles by tendon vibration

The electromyographic reflex responses of the voluntarily contracting wrist flexor and extensor muscles to periods of vibration-evoked enhanced, Ia-dominated afferent discharge from flexor carpi radialis (FCR) were studied in normal human subjects. Three main response phases were characterised, namely, (i) phasic 'on' responses elicited at the commencement of stimulation, (ii) tonic response levels occurring during prolonged stimulation and (iii) phasic 'off' responses elicited at the termination of stimulation. The phasic 'on' reflex responses of FCR and extensor carpi radialis (ECR) comprised, respectively, a peak of autogenetic excitation of group mean latency 18.8 ms and a trough of reciprocal inhibition of group mean latency 38.0 ms. Prolonged (2 s) trains of FCR (agonist) vibration evoked a phase of tonic reflex excitation in FCR whose mean level was significantly increased, by 20%, above pre-stimulus activity and which did not change over the 0.5-2.0 s vibration period. Progressive reduction of the duration (from 2000 ms to 100 ms) of vibration trains demonstrated that phasic disfacilitatory 'off' troughs regularly occurred, with a consistent latency (mean 24.2 ms), on withdrawal of each period of enhanced Ia-input. This indicates that the responsible excitatory reflex mechanism was operational for the entire duration of each of the vibration periods tested. The extra latency (on average 5.4 ms) of phasic 'off' relative to 'on' responses may be attributed to factors (e.g. 5-10 ms duration of unitary muscle action potentials and afterdischarge in reflex pathways) which inevitably delay the appearance of overt disfacilitatory reductions in EMG rather than the involvement of different reflex pathways. Thus, short-latency, possibly monosynaptic, reflex excitation contributed throughout the entire tonic excitatory response. Sustained FCR (antagonist) vibration produced a significant tonic reciprocal inhibitory reflex depression, by 7% pre-stimulus EMG, of ECR activity which remained steady during the 0.5-2.0 s vibration period. The absence of well-defined phasic disinhibitory 'off' responses in ECR suggests that the contribution of oligosynaptic reflex inhibitory mechanisms to the tonic suppression of activity occurring during continuing vibration is relatively small.

Stillbirth rates around the nuclear installation at Sellafield, North West England: 1950-1989

BACKGROUND

The aim of the study was to investigate whether proximity to the nuclear installation at Sellafield, in Cumbria, North West of England, increases the risk of stillbirth in the resident population. The cohort consisted of all 256066 live and 4034 stillbirths to mothers usually domiciled in Cumbria, 1950-1989.

METHODS

The study was a retrospective cohort analysis allowing for year of birth, social class and birth order using: (i) Poisson probability mapping, (ii) comparison of cumulative observed and expected numbers of stillbirths by distance from Sellafield, (iii) logistic regression of stillbirth risk in relation to distance and direction from Sellafield.

RESULTS

Poisson probability mapping of stillbirths within 25 km of Sellafield provided no evidence to suggest that proximity to Sellafield increased the risk of stillbirth, either overall or in any specific direction. Comparison of the cumulative observed and expected numbers of stillbirths also showed no increased risk with proximity to Sellafield. Logistic regression analysis of all Cumbrian births supported these results, showing, in particular, that distance from Sellafield did not significantly influence stillbirth risk (P = 0.30). Although there was significant variation in stillbirth risk with direction (P = 0.0004), this was due to stillbirths in areas much further than 25 km from Sellafield. There was no significant effect with distance from Sellafield within any of six directional sectors (P > 0.05).

CONCLUSIONS

There was no evidence to suggest that proximity to Sellafield increases the risk of stillbirth in the resident population.

Neonatal vitamin K administration and childhood cancer in the north of England: retrospective case-control study

OBJECTIVE

To explore the possible association between intramuscular vitamin K given to neonates and the subsequent development of childhood cancer.

DESIGN

Retrospective case-control study on the basis of hospital records.

SETTING

The former Northern Health region of England.

SUBJECTS

685 children who were born and lived in the region and who developed cancer before their 15th birthday, and 3442 controls also born between 1960 and 1991 and matched only for date and hospital of birth. The notes of a further 701 index cases were untraceable.

MAIN EXPOSURE MEASURE

Administration of intramuscular vitamin K versus no exposure to vitamin K.

RESULTS

There was no association between the administration of vitamin K and the development of all childhood cancers (unadjusted odds ratio 0.89; 95% confidence interval 0.69 to 1.15) or for all acute lymphoblastic leukaemia (1.20; 0.75 to 1.92), but there was a raised odds ratio for acute lymphoblastic leukaemia developing 1-6 years after birth (1.79; 1.02 to 3.15). No such association was seen in a separate cohort-based study not dependent on case note retrieval in which the rates of acute lymphoblastic leukaemia in children born in hospital units where all babies received vitamin K were compared with those born in units where less than a third received prophylaxis.

CONCLUSIONS

It is not possible, on the basis of currently published evidence, to refute the suggestion that neonatal intramuscular vitamin K administration increases the risk of early childhood leukaemia. Any association may have been masked in earlier studies that did not use controls matched for time and locality by other unidentified factors affecting the spatiotemporal variations in incidence of leukaemia.

Sex ratio in relation to fathers' occupations

OBJECTIVE

To investigate whether the sex ratio of children varies between fathers of different occupations.

METHODS

The sex ratio (the ratio of the number of boys to the number of girls at birth) was calculated in relation to paternal occupation in the cohort of all 253,433 live births in Cumbria, north west England, from 1950-89. Exact binomial confidence intervals were used to estimate whether the sex ratio in each occupational category was significantly different from that for the rest of the cohort.

RESULTS

There were fewer occupational categories with significantly different sex ratios at the 5% level than expected by chance alone, assuming the same binomial distribution of sexes at birth within each paternal occupation.

CONCLUSIONS

Significant variation of the sex ratio with fathers' occupations was not found. There is some evidence that the sex ratio shows less variance than expected under a binomial model which assumes independence of the sex of each child; a possible explanation of this may be parental preference for limiting family size after children of both sexes have been born or some other factor which results in children within a family being more likely to be of both sexes rather than the same sex.

Audit of ascertainment of deaths to children born in Cumbria, UK, 1950-89 through the NHS central register

STUDY OBJECTIVE

To evaluate the completeness of notification of deaths by the National Health Service Central Register (NHSCR) for England and Wales.

DESIGN

Deaths for a birth cohort were ascertained through scanning the relevant volumes of NHSCR. Attempts were made to confirm these deaths and additional deaths were ascertained through searching local records. Logistic regression was used to investigate how the probability of a death being missed by NHSCR varied with the year of birth, age at death, sex, and social class.

SETTING

Deaths up to the end of 1989 in the CA postal area among 264,046 children born between 1950 and 1989 to mothers living in Cumbria.

RESULTS

NHSCR originally ascertained 4139 deaths; local searches confirmed 3338 (81%) of these and found an additional 342. Most deaths missed by the NHSCR were neonatal deaths in the 1950s and 1960s. In the 1950s, 31% of children who died in the neonatal period either were not entered on NHSCR or, if they were entered, there was no record of their death. For children born from 1970 onwards, ascertainment of deaths through NHSCR was over 99% complete.

CONCLUSIONS

The NHSCR was started in 1948 for the administration of records of National Health Service patients. It seems that many babies who died soon after birth were not therefore recorded. In parallel with the increasing use of NHSCR for epidemiological purposes, there has been a substantial and continuing improvement in its clerical procedures since the mid 1960's.

KLP38B: a mitotic kinesin-related protein that binds PP1

We have identified a new member of the kinesin superfamily in Drosophila, KLP38B (kinesin-like protein at 38B). KLP38B was isolated through its two-hybrid interaction with the catalytic subunit of type 1 serine/threonine phosphoprotein phosphatase (PP1). We demonstrate that recombinant KLP38B and PP1 associate in vitro. This is the first demonstration of direct binding of a kinesin-related protein to a regulatory enzyme. Though most closely related to the Unc-104 subfamily of kinesin-related proteins, KLP38B is expressed only in proliferating cells. KLP38B mutants show cell proliferation defects in many tissues. KLP38B is required for normal chromatin condensation as embryos from KLP38B mutant mothers have undercondensed chromatin at metaphase and anaphase. This is the first time that a kinesin-related protein has been shown to have such a role. Incomplete lethality of a strong KLP38B allele suggests partial redundancy with one or more additional kinesin-related proteins.

Newborn screening for neuroblastoma

Following favorable reports of infant screening for neuroblastoma, mass screening was introduced throughout Japan in 1985. Since then, reports from Japan, North America, and Europe have all confirmed that screening is associated with substantial overdiagnosis. Recent reports from both Japan and North America suggest that screening at under 1 year of age does not reduce the incidence of disease in older children or of advanced stage disease and is therefore likely to confer little survival advantage. Current screening studies in Europe are investigating the effects of screening in older children (10 to 14 months) in an attempt to reduce overdiagnosis. The effect of screening on mortality remains unknown. Mortality from neuroblastoma in Japan is falling, but most of the fall predates the possible effect of screening. Longer follow-up of the North American study and the recently implemented German study may eventually provide an answer.