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PubMed1997

Ideal body size beliefs and weight concerns of fourth-grade children.

OBJECTIVE: The purpose of this study was to assess racial and gender differences in perceptions of ideal body size among White and Black fourth-grade children. METHOD: A random sample of 817 children (51.4% female, 51.8% White, and mean age 9 years) participated in a body image and weight concern survey. RESULTS: Using socioeconomic status (SES), race, and gender as independent variables, Black children selected significantly heavier ideal sizes than White children for self, male child, female child, adult male, and adult female. Although almost one half (46%) of Black females wanted to be thinner than their current size, their body size selections were significantly larger than those of White females. Black and White males differed only in the selections of ideal-female child and adult sizes. Cross-gender comparisons indicated females and Whites experience more body dissatisfaction and weight concern than males and Blacks. DISCUSSION: Our study indicates that early in the sociocultural development of children, gender, race, and SES are influential factors in selecting ideal body size and determining body satisfaction.

Black or African American↗

PubMed1998

Dieting awareness and low self-worth: related issues in 8-year-old girls.

OBJECTIVES: Since weight concerns and dieting are apparent before adolescence, this study examined the factors predictive of early dieting awareness. It was hypothesized that early dieting awareness would be negatively associated with perceived self-worth, particularly in girls. METHODS: One hundred seventy six 8-year-old children (86 girls, 90 boys) completed assessments of body shape preference, body and self-esteem, dieting awareness, and body weight and height. RESULTS: Children were more likely to advise a fictitious character, "Mary-Jane," to diet than they were to report dieting themselves. However, self-endorsed dieting was more strongly correlated with negative self-perception, especially in girls. Significant predictors of dieting awareness in girls included global self-worth (negatively), body mass index (BMI), and frequency of mother dieting (positively). CONCLUSIONS: This study supports the view that young girls are drawn to weight control to improve their self-worth, and that mothers are influential in this regard. This early pattern of association is of questionable acceptability.

Body Image↗

PubMed1998

Strategy for mapping minor histocompatibility genes involved in graft-versus-host disease: a novel application of discordant sib pair methodology.

We introduce a novel application for linkage analysis: using bone marrow donor-recipient sib pairs to search for genes influential in graft-versus-host disease (GVHD), a major cause of morbidity and mortality following allogeneic bone marrow transplantation. In particular, we show that transplant sib pairs in which the recipient developed severe GVHD can be used to map genes in the same way as traditional discordant (affected/unaffected) sib pairs (DSPs). For a plausible GVHD model, we demonstrate that the transplant/discordant sib pair analog of the "possible triangle test" [Holmans (1993) Am J Hum Genet 52:362-374] has similar power to that of the simpler "restricted test" proposed by Risch [(1990b) Am J Hum Genet 46:229-241; (1992) Am J Hum Genet 51:673-675]. Moreover, we show that the restricted test has superior power in much of the DSP possible triangle and significantly inferior power in only a small region. Thus, we conclude that the restricted test is preferable for localizing genes with transplant/discordant sib pairs. Finally, we examine the effects of heterogeneity on the power to detect GVHD loci and demonstrate the gain in efficiency by dividing the sample into genetically more homogeneous subgroups.

Chromosome Mapping↗

PubMed2000

Effect of allelic heterogeneity on the power of the transmission disequilibrium test.

Due in part to an influential paper by Risch and Merikangas [(1996) Science 273:1516-1517], which suggested that disequilibrium tests would have greater power to detect genes of small effect than would linkage tests, interest in the use of the Transmission Disequilibrium Test (TDT) as an analysis tool for genomewide studies is steadily growing. However, the paper by Risch and Merikangas made several simplifying assumptions. One such assumption was that the underlying gene showed allelic homogeneity, and another was that the allele being measured was the actual susceptibility allele. Here we investigate the effect of allelic heterogeneity on the power of the TDT using multiplicative, additive, dominant, and recessive modes of inheritances in the context of a genomewide study. We further distinguish two cases: first, that the marker alleles are the actual susceptibility alleles, and second, that alleles are measured at a marker linked to the disease gene with zero recombination. We consider two family structures, either a single affected offspring (SAO) and two parents, or an affected sib-pair (ASP) and two parents. We find that, as expected, the power of the TDT declines as the number of susceptibility alleles at the locus being tested increases and the effect on power can be substantial. When a linked marker is measured rather than a susceptibility allele itself, sample sizes reach unattainable levels when as few as two susceptibility alleles are present. Across all the models we consider, the required number of families for a TDT with ASP sampling varies from 19 to over a million families. Thus, the TDT may not be an optimal test in the context of genomic screens under more biologically realistic assumptions.

Alleles↗

PubMed1997

Pathways to depressed mood for midlife women: observations from the Seattle Midlife Women's Health Study.

The purpose of this study was to develop and test a multidimensional model of depressed mood experienced by women during midlife. Three pathways to depressed mood were tested for their explanatory power, including menopausal transition, stressful life context, and health status pathways in a multiethnic sample (N = 337). Multiple measures for each variable in the three paths included the CESD and SCL 90 depression scales, menopausal changes questions, vasomotor symptoms rated in a daily health diary. Life Events Scale, Attitudes toward Menopause and Attitudes toward Aging Scales, and chronic health problems and perceived health ratings. The stressful life context pathway was most influential in accounting for depressed mood. Health status had a direct effect on depressed mood and an indirect effect through stress. The menopausal changes pathway had little explanatory power. These results support the need for clinicians to look beyond menopausal status to the broader context of midlife women's lives.

Adult↗

PubMedDate not supplied

Using willingness to pay to value close substitutes: carrier screening for cystic fibrosis revisited.

Evidence suggests that previous uses of willingness to pay (WTP) to value close substitutes may have failed to discriminate between the alternatives being evaluated. This paper reports on the application of a new technique for measuring WTP in such contexts. The alternatives evaluated are two methods of screening for cystic fibrosis carrier status. The results suggest that the new method is more discriminating. Furthermore, the paper provides evidence, from reasons for respondents' WTP valuations and regression analyses, that the use of open-ended WTP questions is not valid. This is in line with the recommendations of a recent, influential, report on the use WTP techniques.

Analysis of Variance↗

PubMed1999

Internal markets and health care efficiency: a multiple-output stochastic frontier analysis.

This paper has two purposes. The first purpose is methodological and aims to extend previous work on efficiency analysis by implementing a multiple-output stochastic ray frontier production function model. This model generalizes the single-output stochastic frontier model to multiple-input, multiple-output technologies and allows simultaneous estimation of technical efficiency and analysis of influential variables on efficiency. The second, empirical, purpose is to test for existence and magnitude of the effect of purchaser/provider split combined with new reimbursement schemes on technical efficiency in the Swedish public hospital system. The analysis is carried out with a panel data set covering the total population of 26 Swedish County Councils from 1989 to 1995. Our empirical results support the frontier model specification and indicate that output-based reimbursement improves technical efficiency. The potential saving in costs due to a switch from budget-based allocation to output-based allocation is estimated to be almost 10%.

Adult↗

PubMed1997

Clinical diagnoses and disability of cognitively impaired older persons as predictors of stress in their carers.

BACKGROUND: Aspects of the caring relationship are often promoted as more important than the clinical features of the care recipient in predicting caregiver wellbeing. However, studies of consequences of caring for cognitively impaired people seldom include detailed measures of the diagnostic profile and disability of the care recipient. METHODS: Ninety community-living elderly persons with cognitive impairment were clinically assessed for severity on a range of illnesses. Their disability was examined via informant reports. Informants (88% of whom were primary carers) provided information on the behaviour and personality of the subject and reports of their own (informant) wellbeing. Using multiple regression, features of the subjects' clinical profile (severity of diseases, disability, behavioural problems and personality change) were examined as predictors of informant wellbeing. After controlling for subject clinical profile, we explored the additional associations between informant stress measures and other descriptors of the subject, caregiver and their relationship. RESULTS: The subjects' clinical characteristics, in particular disability and disturbed behaviour, were strong predictors of caregiver wellbeing, accounting for most of the explained variance. After control for the subjects' clinical profile, few of the sociodemographic, caregiver or relationship variables examined had any influence on caregiver outcome measures. The exceptions were caregiver time demands, older subject age and self-identification as primary carer. Coresidence was not associated with caregiver distress. CONCLUSION: Clinical characteristics of the care recipient are determinants of caregiver wellbeing, while socio-demographic, caregiver and relationship characteristics are less influential.

Activities of Daily Living↗

PubMed2000

Steroid regulation of octopamine expression during metamorphic development of the moth Manduca sexta.

Octopamine (OA), a biogenic amine similar to norepinephrine, has profound and well-documented actions on the nervous systems of invertebrates. In the insect, Manduca sexta, we examined the developmental plasticity of OA synthesis, studied its endocrine regulation, and observed previously undescribed OA-immunoreactive (ir) neurons. We found that levels of tyramine beta-hydroxylase (TbetaH), an essential enzyme for the biosynthesis of OA, increase during metamorphosis. Based on the established and influential roles of the steroid hormone 20-hydroxyecdysone (20-HE) during development, we tested the hypothesis that increases in TbetaH levels and OA immunoreactivity are regulated by the rise in 20-HE occurring during pupal-adult development. We determined that the levels of TbetaH in the terminal abdominal ganglion (neuromeres 6-9) remain at a constant level during pupal development and the early stages of adult development. Beginning at ca. pupal stage 8, however, the levels of TbetaH begin to rise, reaching a maximum level by pupal stage 12. By removing the source of ecdysteroid hormone through ligation, and by subsequent replacement of 20-HE via infusion, we found evidence indicating that the preadult rise of 20-HE is both necessary and sufficient for the increased levels of TbetaH. During the course of our study, we also identified previously unreported OA-ir neurons. In particular, adult-specific OA-ir lateral cells were found, as were relatively small OA-ir dorsal median pairs that doubled in size during adult development. Abdominal ganglia not exposed to the preadult rise in 20-HE possessed neither the OA-ir lateral neurons nor the somatic growth of the smaller OA-ir median neurons. These newly described OA-ir neurons probably contribute to the steroid-induced elevations of TbetaH observed at the end of metamorphosis.

Age Factors↗

PubMed1980

An analysis of the age distribution of colon cancer in adenomatosis coli.

For the purpose of elucidating the genetic and environmental interaction in human carcinogenesis, the age distribution of colon cancer in adenomatosis coli (AC) patients in Japan and England were investigated and compated. According to the multiple mutation theory of carcinogenesis, the rate of tumor production is presented by a natural logarithm of the reciprocal of the survival fraction (the proportion on diagnosed colon cancer by age t either among AC patients or total colon cancer cases), and thus is given by a power function of t. The number of hits necessary for colon cancer development in AC patients was estimated to be 4.2 or 4.4 for males and 3.4 or 3.3 for females in Japanese cases, whereas it was 4.7 or 3.9 and 3.6 or 3.2, respectively, in English cases. The estimates are compatible between countries. On the other hand, from the age specific prevalence curve, number of hits in general population was estimated to be 5.0 for both sexes in Japan, which is approximately one hit less than the values for English general population, at least in males. The present results, when taking into account the geographic and/or chronologic variations in colon cancer frequency, suggest that the etiology of colon cancer in younger patients is primarily determined by a genetic predisposition whilst environmental factors are much more influential for the development of colon cancer in older patients.

Adolescent↗

PubMed1981

Selected prognostic variables for mammographic parenchymal patterns.

Conjecture exists about the influence of numerous risk-factors for breast cancer on mammographic parenchymal patterns. To allow more precise documentation of the common variables considered influential in alterations of breast parenchyma, we conducted a randomized retrospective analysis. Of 10,132 women participants in the Louisville Breast Cancer Detection Demonstration Project, every tenth participant was randomly selected for evaluation using SPSS statistical programming. Each accessioned patient had discriminant analysis for the risk factors of age, parity, age at birth of first child, family history, personal history, previous history of breast biopsy, and exogenous estrogen therapy. One-thousand-and-two women were examined for the significance of the selected prognostic variable association with Wolfe mammographic parenchymal patterns (WMPP). Each prognostic factor was tested by chi-square analysis for the low-risk pattern (N1P1) versus the high-risk pattern (P2DY). A high correlation existed between the age of patient and WMPP (P = 0.0002) in the subjects evaluated (50--85 years, mean 60). Similarly, a very significant correlation was evident between WMPP and parity (P = 0.0002), age at birth of first child (P = 0.0014), family history of breast cancer (P = 0.097), and history of previous breast biopsy (P = 0.0066). Little correlation existed between the Wolfe parenchymal pattern classification and a personal history of breast cancer (P = 0.7779) or the use of exogenous estrogens (P = 0.5776).

Age Factors↗

PubMed1986

Genetics and cytogenetics of pediatric cancers.

It is clear that genetic factors play an important role in the development of some human cancers. These factors may be particularly influential in the pediatric age group because environmental exposures have been minimal. Several pediatric solid tumors, including retinoblastoma and Wilms' tumor, are hereditary. Specific constitutional chromosome abnormalities have been found in these patients, thus implicating certain gene regions as being involved in tumorigenesis. Molecular genetic studies have provided insight into the events occurring at the DNA level in these gene regions. The role of genetics in the development of sporadic pediatric malignancies is also beginning to be elucidated as specific acquired chromosome abnormalities are being discovered in the malignant cells of these otherwise karyotypically normal individuals. This paper will review selected hereditary and nonhereditary pediatric cancers that demonstrate the importance of genetic considerations in the diagnosis and management of children with cancer.

Acute Disease↗

PubMed1989

Cytogenetic findings and prognosis in neuroblastoma with emphasis on marker chromosome 1.

The relationship between cytogenetic findings and prognosis in 51 pediatric patients with neuroblastoma is described. Patients were classified into the following four groups based on karyotypic findings: (1) near diploidy, 42 to 47 chromosomes (n = 11); (2) hyperdiploidy, 50 to 56 chromosomes (n = 4); (3) near triploidy, 60 to 77 chromosomes (n = 33); and (4) hypotetraploidy, 80 to 83 chromosomes (n = 3). Patients with near diploid or hypotetraploid karyotypes also had several structural abnormalities including marker chromosome 1, with or without double minutes (DM) or homogeneously staining regions (HSR). Most of these patients were 1 year of age or older and had advanced tumors. The patients who were in the hyperdiploid or near triploid category had few structural abnormalities; all of them, except one, were younger than 1 year of age, had localized tumors, and are long-term, disease-free survivors. Kaplan-Meier analysis of survival rates disclosed a significant difference favoring the latter group (P less than 0.001). N-myc gene amplification was found in five patients of the former group but in no patients of the latter group. The presence or absence of DM or HSR in the former group had no statistically demonstrable effect on survival. However, the presence of marker chromosome 1 appears to indicate a poor prognosis. Five patients with Stage IV-S disease had near triploid abnormalities similar to findings in patients with localized tumors. We propose that localized and Stage IV-S neuroblastomas can be classified as one disease category, and that patients with near diploid or hypotetraploid karyotypes are clinically distinct from those having hyperdiploid or near triploid karyotypes. We consider that chromosomal pattern is a more influential prognostic factor than age, disease stage, or N-myc gene amplification.

Child↗

PubMed1990

A standard dose of radiation for "microscopic disease" is not appropriate.

Elective irradiation of sites of potential occult tumor spread is often part of a patient's radiation therapy program. The required radiation dose (D) depends on the probability that occult disease exists (P(occ)), the number of sites at risk (A), the number of tumor clonogens present (Ni), their radiation sensitivity, and the desired control rate. An exponential model of cell survival is used to quantify the importance of these factors. Control Probability = [1 - Pocc x (1 - e-Ni x (SF2)D/2)]A; SF2 = surviving fraction after 2 Gy. Implications for clinical radiation therapy include: 1. Since the number of clonogens in an occult site may vary from 10 degrees to 10(8), Ni is the major determinant of the required dose. The intrinsic radiation sensitivity of the clonogens (SF2) is also extremely important in determining the dose. Other factors are less influential since they vary less. 2. The variability of Ni (8 logs) is larger than the variation in cell number seen with gross disease (1 cm3 versus 1000 cm3, 3 logs). When Ni approximately 10(8), the required dose approaches that needed for small volume gross disease (10(9) cells, 1 cm3). 3. The dose prescribed to elective sites should reflect the risk of occult disease based on the primary tumor site, stage, and grade. 4. Regions where clinicoradiologic evaluation is difficult (e.g., pelvis and obese neck) require higher doses because macroscopic tumor deposits may exist. 5. Relatively low doses (10 to 30 Gy) are often thought to be inadequate for microscopic tumor. However, similar doses have been reported to sterilize microscopic tumor in ovarian, rectal, bladder, breast, and head and neck carcinomas. Relatively low doses should not be discounted since they may be useful in select cases when normal tissue tolerances and/or previous irradiation treatment limit the radiation dose.

Cell Survival↗

PubMed1994

Involving older Americans in the war on tobacco. The American Stop Smoking Intervention Study for Cancer Prevention.

The American Stop Smoking Intervention Study for Cancer Prevention (ASSIST) is a collaborative effort of the National Cancer Institute, the American Cancer Society, state health departments, and other public and private organizations to develop comprehensive tobacco use control programs in 17 states. The two main goals of the project are to reduce adult smoking prevalence to 15% or less and to reduce the rates of smoking initiation among adolescents by 50% by the year 2000. There is strong consensus within the tobacco-control field of what needs to be done to accomplish these goals. The key elements of a comprehensive tobacco control effort include (1) an excise tax policy based on raising the real price of tobacco, (2) a ban on all forms of tobacco advertising and promotion, (3) product regulation to reduce the harmful constituents found in tobacco and enforce the use of strong and prominent package warnings, (4) the enactment of policies that protect nonsmokers from inhaling tobacco smoke, (5) comprehensive efforts to eliminate minors' access to tobacco products, (6) ongoing and adequately funded efforts to educate the public about the harmful effects of tobacco, (7) the availability of cessation assistance to persons interested in discontinuing the use of tobacco, and (8) the ending of all financial assistance to the tobacco-growing industry. Because older Americans represent a growing and political influential segment of our society, the enactment of effective tobacco control policies depends in part on generating support for such measures among older citizens. This article outlines several ways in which organizations such as American Association of Retired Persons and the American Cancer Society can work together to advocate meaningful tobacco control policies (e.g., higher excise taxes, clean indoor air laws, etc.).

Adolescent↗

PubMed1995

Nutritional aspects of breast cancer.

Nutrition, in its broadest sense, plays a clear role in breast cancer, identified through its relationship to such known risk factors as rate of growth and development, age at menarche, adult height, postmenopausal body weight, and fat distribution. The relative importance of daily diet is hotly debated. There is no agreement on the relative importance of nutrition's effect, the responsible food groups and nutrients, nor the age or ages at which it can be influential. Evidence linking breast cancer and diet comes from human ecologic and observational studies as well as a body of experimental feeding studies in rats and mice. The population studies, including increasing numbers of migrant studies, and the animal experiments suggest that high-fat diets promote breast cancer, particularly among older women. Studies that compare diets of persons with and without breast cancer and those that record breast cancer incidence among women with different dietary histories have been inconclusive enough as to warrant randomized intervention trials. Recognition of differences between the risk factors for premenopausal and postmenopausal women and increasing insight into the ages at which known risk factors exert their influence have helped in the design of these trials. Human feeding studies and the trials themselves are identifying metabolic changes and their biomarkers as well as biomarkers for changes in fat and nutrient intakes. The Women's Health Initiative Dietary Modification Trial was designed to show whether a sustained (9-year) low-fat, high-fruit-and-vegetable eating pattern will lower the incidence of breast cancer among women who will be between ages 59 and 88 when the trial ends, the time of peak incidence. Meanwhile, the Women's Intervention Nutrition Study will learn in approximately 5 years whether a low-fat, adjuvant eating pattern will improve the prognoses of postmenopausal women with early and moderate stage breast cancer and whether tamoxifen should be used as at least part of their treatment. The results of these trials will have important applications for both public health and the provision of medical care.

Adult↗

PubMed2000

Tensile characteristics of ten commercial acrylic bone cements.

The mechanical properties of acrylic bone cement, used in orthopedic surgery, are very influential in determining successful long-term stability of a prosthesis. A large number of commercial formulations are available, differing in chemical composition and physical properties of both powder and monomer constituents. In this study, the static and dynamic tensile characteristics of a number of the most commonly used bone cements (Palacos R, Simplex P, CMW 1 & 3, Sulfix-60, Zimmer Dough), along with some newer formulations (Endurance, Duracem 3, Osteobondtrade mark and Boneloc), have been investigated under the same testing regimes. Testing was performed in air at room temperature. Significant differences in both static and fatigue properties were found between the various bone cements. Tensile tests revealed that Palacos R, Sulfix-60, and Simplex P had the highest values of ultimate tensile strength, closely followed by CMW 3, while Zimmer Dough cement had the lowest strength. Fatigue testing was performed under stress control, using sinusoidal loading in tension-tension, with an upper stress level of 22MPa. The two outstanding cements when tested in these cyclic conditions were Simplex P and Palacos R, with the highest values of Weibull median cycles to failure. Boneloc bone cement demonstrated the lowest cycles to failure. While the testing regimes were not designed to replicate exact conditions experienced by the bone cement mantle in vivo, there was a correlation between these results and clinical outcome.

Bone Cements↗

PubMed1979

Training, role models, and research activity among clinical psychologists.

Compared clinical psychologists (N = 270) with high and low publication rates through questionnaire responses. Highs report dissertation experiences more positively influenced their research motivation. Although the most influential professor in both groups was typically clinical, more highs found the professor emphasized another orientation, particularly empirical research, over clinical expertise. Highs report more time available, collaboration opportunities, and organizational acceptance for their research. Both groups favor empirical methods, although highs and lows agree that a small proportion of psychological research makes a significant contribution. Individual preferences probably interact with situational characteristics, both in training and work settings, to determine research activity.

Academic Dissertations as Topic↗