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.

The relationship of clinical and academic productivity in a university hospital radiology department

OBJECTIVE

The purpose of this study was to evaluate the relationship between clinical and academic productivity over a 2-year period in a university hospital radiology department.

MATERIALS AND METHODS

Clinical productivity, as determined by the number of total professional relative value units generated, was compared with academic productivity, which was determined by the number of published peer-reviewed articles, published non-peer-reviewed articles, published abstracts, and presentations delivered by each full-time clinical faculty member. The relationships of age, academic rank, administrative position, and division within the department were also assessed for their effect on relative value units and academic productivity.

RESULTS

We found a significant inverse relationship between relative value units and the number of published peer-reviewed articles, published abstracts, and presentations. Age, academic rank, and administrative responsibilities had no effect on the number of relative value units. Faculty in the neuroradiology and cardiovascular-interventional radiology divisions generated more relative value units than did other faculty members.

CONCLUSION

Faculty members with higher levels of clinical productivity showed significantly lower levels of academic productivity. This finding is consistent with the idea that increases in the clinical workload may diminish research output.

I.v. devices and related infections: causes and complications

The use of intravenous devices has long been established as a life-saving and important part of total patient management. However, such devices are not without risk and their use is frequently complicated by local or systemic infections and complications. Twenty-five million patients are estimated to enter the NHS annually and receive some form of intravenous therapy by the peripheral route (Campbell, 1998). It behoves all staff who are involved in the management of intravenous devices to base their practice on what is agreed by consensus in the literature as being effective in reducing the risk of hospital-acquired infections. This article draws together such literature and presents recommendations for good practice for the management of intravenous-related devices.

Size of colorectal liver metastases at abdominal CT: comparison of precontrast and postcontrast studies

PURPOSE

To investigate whether measurements of hepatic metastases from colorectal carcinoma before contrast material administration are significantly different statistically from measurements after contrast material administration.

MATERIALS AND METHODS

Twenty-four patients with hepatic metastases from colorectal carcinoma underwent spiral computed tomography (CT) with 7-mm collimation. The liver was imaged before and in the portal-dominant phase after intravenous contrast material administration. For each scan, one to three discrete liver lesions were selected for measurement (n = 49). Three experienced radiologists performed independent measurements of the selected lesions on both pre- and postcontrast images at a computer workstation. A three-way analysis of variance (ANOVA) was performed: subjects by raters (the three independent radiologists) by pre- or postcontrast status. The dependent variable was the product of bidimensional measurements.

RESULTS

Sixty-seven percent (33 of 49) of the lesions were measured as larger on precontrast images; 33% (16 of 49), as smaller. There was high interrater reliability, with an intraclass correlation coefficient greater than 0.9 ANOVA showed significant subject, rater, and contrast material effects (P < .001) for the largest lesions in each liver. Contrast material status was a significant factor for all lesion sizes (P < .003).

CONCLUSION

On average, hepatic metastases from colorectal carcinoma are significantly smaller after contrast material administration.

Stillbirths among offspring of male radiation workers at Sellafield nuclear reprocessing plant

BACKGROUND

Ionising radiation is a known mutagen, but few studies have examined transgenerational effects of paternal exposure in human beings. The workforce at the Sellafield nuclear reprocessing plant in the county of Cumbria, UK, is the most highly exposed workforce in western Europe and North America. This study, which is part of a larger programme of work investigating the health of the children of the Sellafield workforce, set out to find whether there was evidence of an association between stillbirth risk and paternal exposure to ionising radiation.

METHODS

We collected details from birth registration documents for all singleton 248,097 livebirths and 3715 stillbirths in the county of Cumbria 1950-89. Within this cohort the 130 stillbirths and 9078 livebirths to partners of male radiation workers employed at Sellafield were identified. Logistic regression was used to analyse the relation between stillbirth risk and father's preconceptional radiation exposure, with adjustment for social class, year of birth, father's age, and birth order.

FINDINGS

A significant positive association was found between the risk of a baby being stillborn and the father's total exposure to external ionising radiation before conception (adjusted odds ratio per 100 mSv 1.24 [95% CI 1.04-1.45], p=0.009). The risk was higher for stillbirths with congenital anomaly and was highest for the nine stillbirths with neural-tube defects. The statistical models predicted that, were the association to be interpreted as causal, between 0 and 31.9 of the 130 stillbirths to the workforce may be attributable to father's radiation exposure.

INTERPRETATION

The findings of an increased risk of stillbirth with increasing paternal occupational exposure to external radiation are qualitatively consistent with those from animal models, though the risk estimate is higher. Although we cannot exclude the possibility of an unmeasured risk factor for stillbirth, confounded with paternal preconceptional irradiation, extensive checks confirmed that the statistical models were a good fit to the data and there was not statistical evidence of unmeasured factors.

Do interventional radiologists pose a significant threat to the practice of vascular surgery?

PURPOSE

Vascular surgeons have become concerned recently about perceived threats to their practices posed by the growth of interventional radiology. The authors studied nationwide 1996 Medicare Part B procedure data to determine the seriousness of these threats.

MATERIALS AND METHODS

The national Health Care Financing Administration (HCFA) Physician/Supplier Procedure Summary Master File for 1996 was searched. Two hundred thirteen distinct Current Procedural Terminology (CPT-4) codes were identified for therapeutic surgical and percutaneous interventional procedures performed to treat noncardiac vascular diseases. For each code, determination was made of total volume, specialty of the physician providers, and Medicare Part B reimbursement dollars paid to the providers as professional fees. In view of the conflicts among various specialties over peripheral vascular interventions, the authors also determined the percentages of these procedures performed by radiologists, surgeons, cardiologists, and other physicians.

RESULTS

A total of 759,548 noncardiac therapeutic vascular procedures (operations or percutaneous interventions) were performed during 1996 in patients receiving Medicare benefits. Radiologists performed 135,103 (17.8%) of these procedures but received only 10.4% of professional reimbursements. By contrast, surgeons performed 510,871 (67.3%) procedures, but received 78.0% of professional reimbursements. Cardiologists performed 4.7% of procedures and other specialists performed the remaining 10.3%. Radiologists performed 75.5% of percutaneous transluminal angioplasties, the majority of thrombolysis procedures, stent placements, and portal decompression procedures, and approximately half of inferior vena cava interruptions. Cardiologists performed 12.6% of percutaneous transluminal angioplasties, surgeons performed 6.3%, and other specialists performed 5.6%.

CONCLUSIONS

In terms of overall physician workload and professional reimbursements paid for invasive treatment of all types of noncardiac vascular disease, surgeons predominate and do not appear to be seriously threatened by interventional radiologists. Radiologists perform three-fourths of noncardiac percutaneous transluminal angioplasties and a majority of other percutaneous interventional therapies for vascular disease, but some inroads have been made by cardiologists and surgeons, particularly the former.

Quantifying the effect of population mixing on childhood leukaemia risk: the Seascale cluster

A statistical model was developed based on Poisson regression of incidence of childhood leukaemia and non-Hodgkin's lymphoma (NHL) in relation to population mixing among all 119 539 children born 1969-1989 to mothers living in Cumbria, north-west England, (excluding Seascale). This model was used to predict the number of cases in Seascale (the village adjacent to the Sellafield nuclear installation) children, born 1950-1989 and diagnosed before 1993. After allowing for age, the incidence of acute lymphoblastic leukaemia (ALL) and NHL was significantly higher among children born in areas with the highest levels of population mixing, relative risk (RR) = 11.7 (95% confidence interval (CI) 3.2-43) and was highest among children of incomers. The model predicted up to 3.0 (95% CI 1.3-6.0) cases of ALL/NHL in children born in Seascale compared to six observed and 2.0 (95% CI 1.0-3.4) cases in children resident, but not born, in Seascale compared to two observed. Population mixing is a significant risk factor for ALL/NHL, especially in young children, accounting for over 50% of cases in Cumbria and most cases in Seascale.

Cell-autonomous and non-autonomous requirements for the zebrafish gene cloche in hematopoiesis

Vertebrate embryonic hematopoiesis is a complex process that involves a number of cellular interactions, notably those occurring between endothelial and blood cells. The zebrafish cloche mutation affects both the hematopoietic and endothelial lineages from an early stage (Stainier, D. Y. R., Weinstein, B. M., Detrich, H. W. R., Zon, L. I. and Fishman, M. C. (1995) Development 121, 3141–3150). cloche mutants lack endocardium, as well as head and trunk endothelium, and nearly all blood cells. Cell transplantation studies have revealed that the endocardial defect in cloche is cell-autonomous: wild-type cells can form endocardium in mutant hosts, but mutant cells never contribute to the endocardium in wild-type or mutant hosts. In this paper, we analyze the cell-autonomy of the blood defect in cloche. The blood cell deficiency in cloche mutants could be an indirect effect of the endothelial defects. Alternatively, cloche could be required cell-autonomously in the blood cells themselves. To distinguish between these possibilities, we cotransplanted wild-type and mutant cells into a single wild-type host in order to compare their respective hematopoietic capacity. We found that transplanted wild-type cells were much more likely than mutant cells to contribute to circulating blood in a wild-type host. Furthermore, in the few cases where both wild-type and mutant donors contributed to blood in a wild-type host, the number of blood cells derived from the wild-type donor was always much greater than the number of blood cells derived from the mutant donor. These data indicate that cloche is required cell-autonomously in blood cells for their differentiation and/or proliferation. When we assessed early expression of the erythropoietic gene gata-1 in transplant recipients, we found that mutant blastomeres were as likely as wild-type blastomeres to give rise to gata-1-expressing cells in a wild-type host. Together, these two sets of data argue that cloche is not required cell-autonomously for the differentiation of red blood cells, as assayed by gata-1 expression, but rather for their proliferation and/or survival, as assayed by their contribution to circulating blood. In addition, we found that transplanted wild-type cells were less likely to express gata-1 in a mutant environment than in a wild-type one, suggesting that cloche also acts non-autonomously in red blood cell differentiation. This non-autonomous function of cloche in red blood cell differentiation may reflect its cell-autonomous requirement in the endothelial lineage. Thus, cloche appears to be required in erythropoiesis cell non-autonomously at a step prior to gata-1 expression, and cell-autonomously subsequently.