Breast-feeding and cancer prevention.
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Breast Feeding↗
Biomedical subjects
L Parker
Publications and source records attributed to L Parker.
Thyroid cancer in children and young adults in the North of England. Is increasing incidence related to the Chernobyl accident?
Population-based data on thyroid carcinomas was obtained from the Northern Region Young Person's Malignant Disease Registry to analyse the incidence of thyroid cancers in young people (<25 years) in the North of England for the period 1968 and 1997 and to assess if changes in incidence were consistent with the spatial and temporal distribution of the fallout from the Chernobyl nuclear accident. We compared incidence rates for differentiated (papillary or follicular) thyroid carcinomas 1968-1986 with those for 1987-1997. There were 75 cases of thyroid carcinoma diagnosed over the study period, of which 63 were differentiated carcinoma and 12 were medullary carcinoma. There were 26 young adults (15-24 years) diagnosed with differentiated thyroid carcinoma in the 19-year period 1968-1986 and 30 in the subsequent 11 years 1987-1997, Age standardised rate (ASR) 3.0 versus 6.5, respectively (rate ratio 2.2, 95% confidence interval (CI): 1.3-3.6). There were three children (aged <15 years) diagnosed with differentiated carcinoma in the period 1968-1986 and four in the period 1987-1997, ASR 0.2 versus 0.6 (rate ratio 2.7, 95% CI: 0.6-12.1). Regression models showed a significant increase in the incidence of thyroid cancer after the Chernobyl accident (P=0.002). In Cumbria, the area receiving the heaviest fallout in the UK, the increase in incidence was much greater (rate ratio 12.19, 95% CI 1.5-101.2). These temporal and spatial changes in incidence are consistent with a causal association with the Chernobyl accident although a greater effect in the younger rather than the older age group would have been anticipated. However, factors including improvements in ascertainment and earlier detection of tumours may also have contributed to the increasing incidence. Further collaborative international studies are needed to investigate changes in the incidence of thyroid cancer in children and young adults.
Adolescent↗
Comparison of unenhanced and contrast-enhanced spiral CT for assessing interval change in patients with colorectal liver metastases.
RATIONALE AND OBJECTIVES: The purpose of this study was to determine whether the interval change in hepatic colorectal metastases as assessed with serial computed tomographic (CT) scans without contrast material enhancement differs from that as assessed using serial, portal dominant phase, contrast-enhanced CT scans. MATERIALS AND METHODS: Unenhanced and contrast-enhanced abdominal CT scans were obtained in 28 patients. Three radiologists separately reviewed serial unenhanced and contrast-enhanced studies to assess the interval change in liver metastases. These radiologists recorded total number of lesions, bidimensional measurements of the largest lesions (as many as three), and overall impressions regarding the interval change (none, worse, or better). RESULTS: Among the 84 judgments (28 patients x 3 radiologists), comparisons of unenhanced and contrast-enhanced CT studies were concordant in 60 assessments (71%). Nineteen (23%) showed mild disagreement. Of these, contrast-enhanced CT studies demonstrated disease stability when unenhanced CT studies demonstrated otherwise in 11 judgments, whereas unenhanced CT studies demonstrated stability when contrast-enhanced CT studies demonstrated otherwise in eight assessments. Furthermore, of the five marked disagreements, two resulted from a conclusion of interval improvement on unenhanced CT studies and a conclusion of interval worsening on contrast-enhanced CT studies, whereas three demonstrated the opposite. Neither set of serial CT studies systematically resulted in under- or overestimation of disease progression (McNemar Q test, P < .25). CONCLUSION: The authors found no consistent pattern to demonstrate that serial unenhanced or contrast-enhanced CT studies resulted in over- or underestimation of disease progression.
Adult↗
Social inequality and cancer deaths.
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Humans↗
Seasonality of birth for cancer in Northern England, UK.
Environmental factors operating around the time of birth may influence the subsequent development of childhood cancer, particularly leukaemia. Certain factors may vary with season (e.g. infections), and we therefore investigated whether there was any evidence of seasonality of month of birth, based on data from 4199 children diagnosed with cancer under the age of 15 years. We extracted details of (i) children born 1960-95 and diagnosed 1968-95 from two population-based registries, covering the Northern (n = 2053) and Yorkshire (n = 1977) Regional Health Authority and (ii) children born in Cumbria 1950-93 and diagnosed anywhere in the UK before 1994 from a birth cohort database (n = 397). The following diagnostic categories were analysed: 0-14 years--all cancers, leukaemias, acute lymphoblastic leukaemias, central nervous system tumours, all other solid tumours; 1-6 years--leukaemias, acute lymphoblastic leukaemias. Seasonal variation was tested using Walter and Elwood's test, and logistic regression analysis allowing for cyclical variation in month of birth. No evidence of seasonality was present for any group except acute lymphoblastic leukaemia diagnosed among 1- to 6-year-olds. Seasonal trends varied by region: in the Northern and Cumbrian datasets, seasonality patterns were significant and similar (P < 0.05) with a predicted peak in early spring, whereas in Yorkshire there was less strong evidence of seasonality (P = 0.08) with a peak predicted in late summer. These findings suggest that local seasonal environmental factors operating around the time of birth are not associated with the totality of childhood cancer, but possible links with acute lymphoblastic leukaemia are supportive of a hypothesis of an infectious aetiology.
Adolescent↗
The Peterborough Schools Nutrition Project: a multiple intervention programme to improve school-based eating in secondary schools.
OBJECTIVE: To evaluate over two years the effectiveness of multiple interventions targeted at lunches in secondary schools with the aim of increasing the consumption of healthier foods by children during the school day. DESIGN: Controlled comparison study of two intervention schools targeted with multiple interventions to increase both the availability and the number of pupils consuming healthier foods, and one control school with no interventions but with the same observations over a two-year period. SETTING: Three secondary schools in Peterborough, England. SUBJECTS: Secondary school children in the three schools taking school lunches between 1996 and 1998. RESULTS: School Food Groups (SFGs) were set up in both intervention schools. All catering interventions were actioned via the SFGs. Of the food availability targets, only the target to increase the availability of high-fibre bread in both intervention schools was met. The availability of food items at the control school remained stable. The proportion of pupils consuming fruit and vegetables/salad was very low in all schools at baseline. There were positive changes for consumption of fruit and non-fried potato in one intervention school, and for high-fibre bread and non-cream cakes at the other in the short term, but only that for high-fibre bread was close to being sustained at the end of the two years. The dietary consumption target for vegetables/salad was achieved by the final monitoring period in one school. CONCLUSION: Overall there were no significant changes in school-based eating at the end of the study. Some positive changes were made, with some of the dietary targets being achieved at an early stage but not sustained. Ultimately this study has shown how difficult it is to achieve sustained dietary changes in the eating habits of secondary school children, even with considerable input.
Adolescent↗
A self-administered instrument for assessing therapeutic approaches of drug-user treatment counselors.
In this article we describe the development and psychometric properties of a self-administered instrument for assessing drug-user treatment counselors' therapeutic approaches such as psychodynamic or interpersonal, cognitive-behavioral, family systems or dynamics, 12-step, and case management. We generated an initial pool of items corresponding to these five approaches and modified them based on expert ratings. We developed three sets of items. The first concerned the beliefs underlying each therapeutic approach. The second and third concerned the practices of each applicable approach within individual and group counseling, respectively. With the exception of case management, an approach that originated within social work and which is only applicable to individual counseling, the other four approaches are applicable, at least theoretically, to both individual and group counseling. Additionally, we included items that describe techniques used exclusively with groups (i.e., group techniques). Finally, we included some items that are not associated with any of the traditional approaches but which reflect the practical approach that drug-user treatment programs often take to both individual and group counseling (i.e., practical counseling). The initial instrument consisted of 17 subscales with a total of 76 items. This instrument was administered to 226 counselors from 45 drug-user treatment programs in Los Angeles County. Based on this data, we further refined these scales using confirmatory factor analysis to ensure both construct validity and discriminant validity. The final instrument consisted of 14 subscales with a total of 48 items.
Adult↗
How complete and accurate are cancer registrations notified by the National Health Service Central Register for England and Wales?
STUDY OBJECTIVE: To assess the completeness and accuracy of notification of cancers by the National Health Service Central Register (NHSCR) for England and Wales. DESIGN: Comparison of 720 cancer registrations ascertained from NHSCR up to May 1999 with those ascertained for the same cohort from six other sources and a pathology review of the NHSCR cancer registrations. PARTICIPANTS: People born in Cumbria, north west England, 1950-89, and diagnosed with cancer throughout the UK, 1971-1989. MAIN RESULTS: Cancer diagnoses notified by NHSCR differed substantially from those determined by this pathology review for 47 of the 688 notified cases reviewed (7%; 95% CI 5%, 9%). Over one third of these discrepancies were attributable to failures in data capture or coding by the cancer registration system and almost half to changes in diagnosis; 26 of the 47 discrepant cases were reclassified as non-malignant and 21 as malignancies but with a substantially different diagnosis. The 694 confirmed malignancies represented 94% (95%CI 92%, 95%) of the 740 cancers ascertained from all sources. CONCLUSIONS: It is estimated that the cancer registration system missed at least 10% (95%CI 6%, 15%) of all incident cases of malignant disease. Without additional ascertainment from multiple sources and diagnostic review, it would be incautious to use NHSCR cancer registrations as the sole basis of an epidemiological study.
Adolescent↗
Rapid MR imaging detection of renal cysts: age-based standards.
PURPOSE: To establish age-based standards for renal cysts depicted at magnetic resonance (MR) imaging and to compare these standards with existing standards for ultrasonography (US). MATERIALS AND METHODS: Three radiologists reviewed subsecond T2-weighted single-shot fast spin-echo kidney MR imaging findings in 528 patients (248 men, 280 women) selected from consecutive abdominal MR studies without regard to clinical indication. Age, sex, and number and diameter of cysts were noted. Results were analyzed with nonparametric tests and were compared with published US results. RESULTS: Men (mean, 2.0; 95% CI: 1.5, 2.5) had more renal cysts than women (mean, 1.2; 95% CI: 0.9, 1.5) (P < .001). Number and diameter of cysts increased with age (P < .001). Of 528 patients, 330 (62.5%) had at least one renal cyst, and 315 (59.7%) had cysts of 10 mm or less. MR imaging findings were comparable to published US criteria for type 1 autosomal dominant polycystic kidney disease (ADPKD) if only cysts larger than 1 cm were considered: Only one subject in the group of 18-29-year-old subjects had at least two renal cysts, and five of 493 subjects aged 30-59 years had at least two cysts in each kidney. CONCLUSION: Compared with reported US results, MR imaging depicted an increased number of simple renal cysts in healthy individuals because of its increased sensitivity for cysts smaller than 1 cm. If only simple renal cysts larger than 1 cm are considered, US criteria for type 1 ADPKD can be applied to MR imaging.
Adolescent↗
Vectors for the expression of tagged proteins in Drosophila.
Regulated expression systems have been extremely useful in developmental studies, allowing the expression of specific proteins in defined spatial and temporal patterns. If these proteins are fused to an appropriate molecular tag, then they can be purified or visualized without the need to raise specific antibodies. If the tag is inherently fluorescent, then the proteins can even be visualized directly, in living tissue. We have constructed a series of P element-based transformation vectors for the most widely used expression system in Drosophila, GAL4/UAS. These vectors provide a series of useful tags for antibody detection, protein purification, and/or direct visualization, together with a convenient multiple cloning site into which the cDNA of interest can be inserted.
Amino Acid Sequence↗
Intraoperative sonographic localization of breast masses: success with specimen sonography and surgical bed sonography to confirm excision.
OBJECTIVE: To assess the use of intraoperative sonography for localization of breast masses at excisional biopsy, with specimen and surgical bed sonography to confirm excision. METHODS: A computer search of the 5-year period from January 1993 through January 1998 revealed 138 consecutive women referred for sonographically guided excisional biopsy of 148 masses; 35 masses were excluded because they had no postoperative mammograms. One hundred thirteen masses constituted the study group. Specimen sonography (n = 60) or surgical bed sonography (n = 53) was performed as the initial evaluation to confirm excision, but ultimately, surgical bed sonography may have been necessary after specimen sonography, and specimen sonography may have been necessary after surgical bed sonography. The miss rates determined by postoperative imaging were calculated for each group and compared with those of mammographically guided needle localization series from the literature. RESULTS: Follow-up physical examination and mammography showed no residual mass in the region of surgery in any patient. However, follow-up sonography had 1 miss in the initial specimen sonogram group (1 [1.7%] of 60) and 1 miss in the initial surgical bed group (1 [1.9%] of 53). As shown by the Fisher exact test, there was no significant difference between the miss rates of the 2 initial methods of confirming lesion excision or between the miss rates of these initial methods, both groups combined, and 6 mammographic localization series from the literature. CONCLUSION: Intraoperative breast sonography, using specimen sonography and scanning the surgical bed, has miss rates comparable with those of mammographic needle localization. Follow-up sonography must be performed if there is any doubt of complete excision.
Adult↗
Use trends and geographic variation in neuroimaging: nationwide medicare data for 1993 and 1998.
BACKGROUND AND PURPOSE: Powerful tools, including CT and MR imaging, have revolutionized neuroimaging. These are routinely used, but the extent and variation of use has not been studied. Our purposes were to determine the use rates of MR imaging and CT (of spine, brain, or head and neck), myelography, conventional angiography, and MR angiography in diagnosing neurologic disorders; to study trends in use; and to determine regional variations in use. METHODS: We used the National Part B Medicare Database for 1993 and 1998 to compare rates of use for these procedures in 10 geographic regions. RESULTS: In 1993 and 1998, respectively, 13,897 and 19,431 (39.8% increase) neuroimaging procedures were performed per 100,000 Medicare beneficiaries nationwide. Use of brain or head and neck CT (30.4%) and MR imaging (43.6%), spinal CT (3.5%) and MR imaging (83.0%), myelography (56.6%), and conventional angiography (24.3%) increased in 1998 versus 1993. Increases in MR angiography were not assessed, because this procedure was not reimbursable in 1993. Regional use of brain or head and neck and spinal CT and MR studies varied considerably; ratios of highest and lowest rates were 1.38-1.56. Use of MR angiography, myelography, and conventional angiography varied three- to fourfold. CONCLUSION: Use of MR and CT studies of the brain or head and neck and of the spine increased considerably in the Medicare population between 1993 and 1998. Use of conventional invasive procedures such as myelography and angiography increased strikingly, contrary to the expected decline. Regional use varied substantially.
Angiography↗
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.
Adolescent↗
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.
Case-Control Studies↗
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.
Cardiovascular Diseases↗
The objective of cancer screening is to reduce disease-specific mortality, including screening for neuroblastoma.
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Adolescent↗
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.
Adolescent↗
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%.
Analysis of Variance↗