A new look at the accelerating universe

We show that the cosmological model having zero cosmological constant, but containing the vacuum energy of a simple quantized free scalar field of low mass (VCDM model), agrees with the cosmic microwave background radiation (CMBR) and supernova (SNe-Ia) data at least as well as the classical cosmological model with a small nonzero cosmological constant. We also show that in the VCDM model the ratio of vacuum pressure to vacuum energy density is less than -1. We display the VCDM results for a set of parameters that give a very good fit to the CMBR power spectrum, and show that the same parameters also give a good fit to the SNe-Ia data.

Neuroblastoma: changing incidence and survival in young people aged 0-24 years. A report from the North of England Young Persons' Malignant Disease Registry

BACKGROUND AND PROCEDURE

Population based data for neuroblastoma in children and young adults under 25 years at diagnosis were ascertained from the Northern Region Young Persons' Malignant Disease Registry for the period 1968-1995. Age-standardised incidence rates were calculated (ASR) and changes in incidence and survival were investigated. Over the study period 144 patients were registered, of these 136 were children under 15 years at diagnosis (median age: 2.2 years, ASR: 8.6 cases per million children per year), and 8 were 15-24 years (ASR 0.6).

RESULTS AND CONCLUSIONS

Incidence of childhood neuroblastoma in the North of England increased significantly over time; ASRs were 5.8 for 1968-1981 and 9.5 for 1982-1995 (rate ratio: 1.6, 95%; CI 1.2-2.3). The increase in incidence was seen in both infants and older children, and in both low stage and advanced disease. Overall 5 year survival was 15% for 1968-1981 and 40% for 1982-1995 (P < 0.0001). Significant improvements in survival were documented across different stage and age-groups, including those over 1 with stage 4 disease (0% versus 18%, P < 0.0001). Further research is needed to investigate the reasons for the increasing incidence of neuroblastoma.

A common variant in BRCA2 is associated with both breast cancer risk and prenatal viability

Inherited mutations in the gene BRCA2 predispose carriers to early onset breast cancer, but such mutations account for fewer than 2% of all cases in East Anglia. It is likely that low penetrance alleles explain the greater part of inherited susceptibility to breast cancer; polymorphic variants in strongly predisposing genes, such as BRCA2, are candidates for this role. BRCA2 is thought to be involved in DNA double strand break-repair. Few mice in which Brca2 is truncated survive to birth; of those that do, most are male, smaller than their normal littermates and have high cancer incidence. Here we show that a common human polymorphism (N372H) in exon 10 of BRCA2 confers an increased risk of breast cancer: the HH homozygotes have a 1.31-fold (95% CI, 1.07-1.61) greater risk than the NN group. Moreover, in normal female controls of all ages there is a significant deficiency of homozygotes compared with that expected from Hardy-Weinberg equilibrium, whereas in males there is an excess of homozygotes: the HH group has an estimated fitness of 0.82 in females and 1.38 in males. Therefore, this variant of BRCA2 appears also to affect fetal survival in a sex-dependent manner.

Three-dimensional multiplanar transvaginal ultrasound of the cervix in pregnancy

OBJECTIVES

To develop a standard technique for using three-dimensional ultrasound (3D US) to study and evaluate the cervix in pregnant women at high risk for premature delivery, comparing the findings on 3D US with those on conventional two-dimensional ultrasound (2D US).

STUDY DESIGN

Twenty-one pregnant women at high risk for premature delivery had a total of 37 transvaginal 2D and 3D US examinations of the cervix between 11 and 32 weeks' gestation. A 3D US vaginal probe (5.0-8.0 MHz, Voluson 530D, Medison, Pleasanton, CA, USA) was used. Measurements made from the 2D and 3D US were compared.

RESULTS

Of the 37 cervical length measurements in 3D US sagittal plane, seven were shorter and three were longer than on 2D US (varying by 5-15 mm) indicating that the true mid-sagittal plane was not obtained in ten (27%) of the 37 2D US examinations. Of 21 examinations showing funneling, funneling was seen on both 2D and 3D US in 15, but was seen only on 3D US in six. There was a significant (P < 0.05) difference between funnel width as measured in the coronal 3D plane versus 2D US, as well as between funnel width in the coronal 3D US plane versus sagittal 3D US plane (P < 0.05). The cerclage was seen in its entirety in nine of 10 examinations; the 3D US axial plane was most valuable for imaging the cerclage.

CONCLUSIONS

3D US appears to offer a more complete assessment of the cervix than 2D US. Multiplanar correlation shows that the standard 2D US sagittal view may under- or over-estimate cervical length. Our preliminary data suggest that 3D US has the potential to improve our understanding of cervical morphology.

Identification of maverick, a novel member of the TGF-beta superfamily in Drosophila

The transforming growth factor-beta (TGF-beta) superfamily of structurally related ligands regulates essential signaling pathways that control many aspects of cell behavior in organisms across the phylogenetic spectrum. Here we report the identification of maverick (mav), a gene that encodes a new member of the TGF-beta superfamily in Drosophila. Phylogenetic analysis and sequence comparison suggest that Mav cannot be easily assigned to any one sub-family, since it is equally related to BMP, activin and TGF-beta ligands. mav maps to the fourth chromosome and is expressed throughout development. In situ hybridization experiments reveal the presence of maternally derived mav transcript in precellular blastoderm embryos. Later in development, mav is expressed in a dynamic pattern in the developing gut, both in endodermal and visceral mesodermal cells. In adult females, high levels of mav mRNA are present in late stage egg chambers.

Vitamin D receptor gene start codon polymorphism (FokI) and bone mineral density in healthy male subjects

OBJECTIVE

The genetic factors determining peak bone mineral density (BMD) in men are not well characterized. Recent studies have investigated the relationship between the start codon polymorphism (SCP) of the vitamin D receptor (VDR) gene and BMD in different populations. We have now examined the relationship between SCP of the VDR gene and BMD in a group of healthy Caucasian men from the north-east of England.

SUBJECTS

Ninety-six healthy men (median age 50, range 40.0-77.0 years).

MEASUREMENTS

Analysis of the FokI genotypes of SCP of the VDR and measurements of BMD at the femoral neck and lumbar spine were performed.

RESULTS

FF, Ff and ff VDR FokI genotypes were found to have the highest, intermediate and the lowest lumbar spine BMD, respectively (Mean +/- SD, for FF 1.07 +/- 0.14, Ff 1.05 +/- 0.16 and ff 0.95 +/- 0.10 g/cm2). There was a significant difference in spine BMD between FF and ff genotypes (P < 0.05, analysis of variance [ANOVA]), but no such difference was apparent between Ff and ff (P > 0.05, ANOVA). Interestingly, there was no association between FokI polymorphism and femoral neck BMD (Mean +/- SD, for FF 0.85 +/- 0.12, Ff 0.87 +/- 0.15 and ff 0.83 +/- 0.15 g/cm2). The distribution of FokI VDR genotypes approached Hardy-Weinberg equilibrium and was similar to that reported for women from different ethnic groups, as the prevalence of FF and ff genotypes was 44% and 16%, respectively.

CONCLUSION

The study shows that in this population of healthy men there is a weak association between lumbar spine bone mineral density and FokI restriction fragment length polymorphism at the translation initiation site of the vitamin D receptor gene.

Role of emergency medicine physicians in US performed in patients in the emergency department: how substantial is their participation?

PURPOSE

To determine the extent to which emergency medicine physicians have assumed responsibility for performing and interpreting ultrasonographic (US) studies in emergency departments (EDs) in the United States.

MATERIALS AND METHODS

The national 1997 Medicare Part B database was searched by using standard US procedure codes, location codes, and physician specialty codes. The authors determined how many US studies were performed in EDs and what percentage of those studies were performed by emergency medicine physicians, radiologists, or other physicians.

RESULTS

During 1997, 234,820 ED US studies within nine major examination categories were performed in Medicare patients nationwide. Emergency medicine physicians performed 1,551 (0.7%) of these studies. When echocardiographic examinations were excluded, emergency medicine physicians performed 458 (0.2%) of the remaining total of 196,158 studies.

CONCLUSION

Although emergency medicine physicians have claimed to be actively involved in ED US on a broad scale, the data reveal that their involvement in 1997 was minimal. This raises doubt as to whether they can properly train their residents to perform US or maintain their own competence at acceptable levels.

Incidence and survival for cancer in children and young adults in the North of England, 1968-1995: a report from the Northern Region Young Persons' Malignant Disease Registry

The Northern Region Young Persons' Malignant Disease Registry records information on young people under 25 years old diagnosed with cancer in the Northern Region of England. Incidence and survival rates were calculated for children and young adults diagnosed with cancer between 1968 and 1995. There were 2099 (M:F 1.28:1) children (age 0-14 years) and 2217 (M:F 1.23:1) young adults (15-24 years) diagnosed with a first cancer between 1968 and 1995. The age-standardized rate (ASR) for childhood cancer was 121 per million 0 to 14 year-olds per year. For young adults the ASR was 175 per million 15 to 24 year-olds, per year. Incidence of childhood cancer increased over time at a rate of 12 extra cases per million children, per decade (P < 0.001). In young adults incidence rates increased by 16 extra cases per million 15 to 24 year-olds, per decade (P < 0.001). For childhood cancer 5-year survival was 42% for those diagnosed 1968-1977, 57% for 1978-1987 and 71% (95% CI 67-75) for 1988-1995. Survival for young adults over the three periods was 45%, 62% and 73% (95% CI 70-78) respectively. The cumulative risk of developing cancer before the age of 25 is 1 in 285. Over the 28-year period there were significant improvements in survival and modest increases in incidence in both children and young adults.

Prevertebral soft tissue swelling following trauma: usefulness following tube placement

OBJECTIVE

Prevertebral soft tissue swelling (PVSTS) is an important marker of spinal trauma. In patients with missed or occult cervical fractures, it may be the only indication of serious injury. It has been anecdotally suggested that PVSTS is not useful following placement of a nasogastric (NGT) or endotracheal (ETT) tube because of possible iatrogenic trauma and/or soft tissue compression. Consequently, we investigated trauma patients for evidence of PVSTS, comparing radiographs performed before and after placement of NGTs and/or ETTs.

DESIGN AND PATIENTS

PVSTS at the C2 and C6 levels was measured on lateral cervical spine radiographs in 102 patients with cervical spine fractures. Measurements were obtained in 66 patients before and after placement of either an NGT (23), ETT (8), or both an NGT and ETT (35). They were also obtained in 36 control patients with fractures and neither an NGT nor ETT, at presentation and after an interval temporally matched to that in the patients with tubes in place.

RESULTS

The group with ETTs showed variable changes to PVSTS (31% increase, 63% decrease, and 6% no change). The group with NGTs also showed variable changes to PVSTS (33% increase, 53% decrease, and 13% no change). The group with ETTs and NGTs similarly showed variable changes to PVSTS (25% increase, 72% decrease, 3% no change). Surprisingly, the control group showed similar temporal changes without tube placement (49% increase, 36% decrease, 13% no change). Analyses using the one-tailed F-test of the ratio of the variance of the tube to non-tube groups and the Mann-Whitney test were performed. No significant difference was found in the prevertebral soft tissues at the C2 level between those with tubes in place and the control subjects. However, at the C6 level there was statistical significance between the groups with NGTs and both NGTs and ETTs versus the non-tube groups. Probability under the F-test for the groups with NGTs and both NGTs and ETTs was 0.001 and 0.005, respectively. Under the Mann-Whitney test, P values for groups with NGTs and both NGTs and ETTs were 0.0002 and 0.0001, respectively.

CONCLUSION

The appearance of PVSTS showed variable and unpredictable changes following ETT, NGT, or combined ETT/NGT placement at the C2 level. This appears to be an artifact of temporal changes. However, at the C6 level, the presence of PVSTS following NGT or ETT and NGT placement (but not ETT placement alone) may be an accurate indirect sign of cervical spine injury.

Individual variation in somatic mutations of the glycophorin-A gene in neonates in relation to pre-natal factors

The frequency of somatic mutations of the glycophorin-A (GPA) gene was measured in red blood cells from a series of newborn babies and related to various epidemiological and lifestyle factors in order to identify those factors that might influence the mutation rate before birth. Although there was substantial variation in the mutation frequencies between individual babies, no specific associations were found with any of the factors explored including smoking, age and social class of the parents, and gender and birth weight of the babies. It is concluded that these factors do not have a substantial effect on the mutational endpoint measured, although this does not necessarily mean that they have no effect on health risk to the offspring. The observed variation in GPA gene mutation frequency must, therefore, be due either to exposure to less obvious external influences or to intrinsic factors.

Applying the principles of infection control to wound care

Human skin in healthy adults is inhospitable organisms. A wound may occur from any accidental or deliberate trauma that breaks the surface of the skin. Once this line of defence is broken there is a risk of infection. All soft tissue injuries, whether chronic, traumatic or surgical, involve the same basic biochemical and cellular processes. This article looks at the risk factors associated with healing of such wounds. The principles of asepsis, wound cleansing agents, choice of dressings and the taking of wound swabs are considered.

Paternal employment in agriculture and childhood kidney cancer

This paper explores the hypothesis that there is an association between risk of childhood kidney cancer and paternal employment in occupations that have potential for exposure to herbicides and/or pesticides. In contrast to a previous study using paternal occupations at the time of the child's death, no significant association was found between such potential paternal exposures (using paternal occupations at the time of the child's birth) and the risk of cancer of the kidney in childhood (OR 0.88, 95% CI 0.20-3.84). In addition, this paper quantifies the extent to which paternal occupational information on death certificates can be used as a proxy for paternal occupation at birth and how such misclassification could affect risk estimates. An example is given showing how a recently reported association between kidney cancer and paternal agricultural employment may have been overestimated as a result of the use of death certificate information.

Additive isotonic regression models in epidemiology

Stone's method for assessing disease risk around a point source through isotonic regression is routinely used in spatial epidemiology. It is useful in situations where the relationship of risk with exposure (distance being commonly used as a surrogate variable) is assumed monotonic but otherwise of unknown form. This paper extends this method to non-spatial epidemiology, where typically two or more risk factors are present. The methodology described is based on the additive isotonic model approach of Bacchetti; versions appropriate to count (Poisson) data and case-control (binomial) data are described. In both cases, adjustment for covariates is incorporated, and a Monte Carlo method of hypothesis testing and interval estimation is presented. The methodology is illustrated through a case-control example concerning the analysis of the possible effect of preconceptional external ionizing radiation doses on the sex ratio at birth among children of fathers working at the Sellafield nuclear installation, Cumbria, U.K.

Can imaging findings help differentiate spinal neuropathic arthropathy from disk space infection? Initial experience

PURPOSE

To determine if radiographic, computed tomographic (CT), and magnetic resonance (MR) imaging findings can help differentiate spinal neuropathic arthropathy from disk space infection.

MATERIALS AND METHODS

Imaging studies in 33 patients were evaluated, including 14 patients with spinal neuropathic arthropathy (12 radiographic, seven CT, and six MR studies) and 19 with disk space infection (13 radiographic, nine CT, and 12 MR studies). Potential imaging discriminators, including endplate sclerosis or erosions, osteophytes, spondylolisthesis, facet involvement (narrowing or erosions), vacuum disk, paraspinal soft-tissue mass, joint disorganization, and osseous joint debris, were recorded, as were MR imaging signal intensity and gadolinium-enhancement characteristics.

RESULTS

The most helpful findings for diagnosis of spinal neuropathic arthropathy were vacuum disk on radiographs and CT images, debris on radiographs and CT and MR images, disorganization on radiographs and CT and MR images, facet involvement on radiographs and CT and MR images, spondylolisthesis on CT and MR images, diffuse signal intensity patterns in vertebral bodies on MR images, and rim enhancement of disks on gadolinium-enhanced MR images. Findings that were not helpful included endplate sclerosis and erosions, osteophytes, paraspinal soft-tissue mass, and decreased disk height.

CONCLUSION

Vacuum disk, facet involvement, vertebral body spondylolisthesis, joint disorganization and debris, and gadolinium-enhancement patterns of vertebral bodies and disks may help differentiate spinal neuropathic arthropathy from infection.

Comparison of fundamental and wideband harmonic contrast imaging of liver tumors

Wideband harmonic imaging (with phase inversion for improved tissue suppression) was compared to fundamental imaging in vivo. Four woodchucks with naturally occurring liver tumors were injected with Imagent (Alliance Pharmaceutical Corp., San Diego, CA). Randomized combinations of dose (0.05, 0.2 and 0.4 ml/kg) and acoustic output power (AO; 5, 25 and 63% or MI < or = 0.9) were imaged in gray scale using a Sonoline Elegra scanner (Siemens Medical Systems, Issaquah, WA). Tumor vascularity, conspicuity and contrast enhancement were rated by three independent observers. Imagent produced marked tumor enhancement and improved depiction of neovascularity at all dosages and AO settings in both modes. Tumor vascularity and enhancement correlated with mode, dose and AO (P < 0.002). Fundamental imaging produced more enhancement (P < 0.05), but tumor vascularity and conspicuity were best appreciated in harmonic mode (P < 0.05). Under the conditions studied here, the best approach was wideband harmonic imaging with 0.2 ml/kg of Imagent at an AO of 25%.

Parental recall of birth weight: how accurate is it?

OBJECTIVE

To assess the accuracy of parental recall of birth weight in a British population and to investigate whether social class and age of the child significantly influence the accuracy of recalled birth weight.

METHODS

A questionnaire was given to parents whose children were participating in a blood pressure study and the hospital records were retrieved to check the birth weight data.

RESULTS

At the time of the study, the children (n = 649) ranged in age from 6 to 15 years. Seventy five per cent of the recalled birth weights were within 50 g of that recorded in the hospital records. No significant associations were found between the difference in birth weights (recalled birth weight minus hospital record) and social class of the parents or age of the child at time of data collection.

CONCLUSION

This large study shows that parental recall of birth weight is good across the social classes and up to 16 years after delivery. There was no evidence of systematic bias, which would prejudice results of studies on the relation of birth weight to adult hypertension.

Proximity to maternity services and stillbirth risk

A study of all 77 995 live births and 1234 stillbirths to mothers living in West Cumbria from 1950 to 1989 found no significant increase in stillbirth risk with distance of mother's residence from the first or second nearest maternity services, after allowing for year of birth, father's social class, and birth order.

Stillbirth risk with social class and deprivation: no evidence for increasing inequality

The objective of this study was to determine whether inequality in stillbirth risk between social strata has changed over time. Subjects were all 288,869 births in Cumbria, northwest England, 1950-1993 and all 8,039,269 births in England and Wales, 1981-1992. Social class of Cumbrian babies was ascertained from birth registrations. Community deprivation scores were calculated from census data for (i) enumeration districts in Cumbria and (ii) county districts in England and Wales. The relative index of inequality was used to measure inequality of stillbirth risk between social strata. Results indicate inequality in stillbirth risk in Cumbria has fallen significantly since 1966 (P< or =0.02) and was not evident in more recent time periods. In England and Wales, there was significant inequality in stillbirth risk in all time periods and no evidence that this has changed over time. Inequality in stillbirth risk has not increased and in some areas has attenuated in recent years.

Risk of cardiovascular disease measured by carotid intima-media thickness at age 49-51: lifecourse study

OBJECTIVE

To quantify the direct and indirect effects of fetal life, childhood, and adult life on risk of cardiovascular disease at age 49-51 years.

DESIGN

Follow up study of the "Newcastle thousand families" birth cohort established in 1947.

PARTICIPANTS

154 men and 193 women who completed a health and lifestyle questionnaire and attended for clinical examination between October 1996 and December 1998.

MAIN OUTCOME MEASURES

Correlations between mean intima-media thickness of the carotid artery (carotid intima-media thickness) and family history, birth weight, and socioeconomic position around birth; socioeconomic position, growth, illness, and adverse life events in childhood; and adult socioeconomic position, lifestyle, and biological risk markers. Proportions of variance in carotid intima-media thickness that were accounted for by each stage of the lifecourse.

RESULTS

Socioeconomic position at birth and birth weight were negatively associated with carotid intima-media thickness, although only social class at birth in women was a statistically significant covariate independent of adult lifestyle. These early life variables accounted directly for 2.2% of total variance in men and 2.0% in women. More variation in carotid intima-media thickness was explained by adult socioeconomic position and lifestyle, which accounted directly and indirectly for 3.4% of variance in men (95% confidence interval 0.5% to 6.2%) and 7.6% in women (2.1% to 13.0%). Biological risk markers measured in adulthood independently accounted for a further 9.5% of variance in men (2.4% to 14.2%) and 4.9% in women (1.6% to 7.4%).

CONCLUSIONS

Adult lifestyle and biological risk markers were the most important determinants of the cardiovascular health of the study members of the Newcastle thousand families cohort at age 49-51 years. The limited overall effect of early life factors may reflect the postwar birth year of this cohort.

Endometrial polyps: MR imaging features and distinction from endometrial carcinoma

PURPOSE

To determine the magnetic resonance (MR) imaging characteristics of endometrial polyps and the accuracy of MR imaging in distinguishing endometrial polyps from endometrial carcinomas in a case-control study.

MATERIALS AND METHODS

Cross-referencing pathology records with MR studies from two institutions disclosed 35 patients with surgically proved endometrial polyp or carcinoma after controlling for tumor size. All MR examinations were performed at 1.5 T with T2-weighted fast spin-echo sequences in multiple planes. Three independent readers blinded to histologic diagnoses and clinical data scored each image for the presence of several defined findings.

RESULTS

A central fibrous core (low signal intensity on T2-weighted images) and intratumoral cysts (high signal intensity on T2-weighted images) were seen more frequently in endometrial polyps than in carcinomas; myometrial invasion and necrosis showed high predictive value for carcinomas. The readers' responses showed a mean sensitivity of 79%, specificity of 89%, accuracy of 86%, positive predictive value of 82%, and negative predictive value of 88% for diagnosis of carcinoma. The mean area under the receiver operating characteristic curve for the three readers was 0.87 for the diagnosis of carcinoma.

CONCLUSION

MR images can help to distinguish most polyps from endometrial carcinomas on the basis of morphologic features. Accuracy does not appear to be sufficient to obviate biopsy, partly because carcinomas and polyps frequently coexist.