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PubMed1998

Effect of microfiller fraction and silane treatment on resin composite properties.

A series of microfilled resin composites were formulated by incrementally mixing either agglomerated 20 nm or unagglomerated 50 nm silica microfillers into monomers composed of diphenyloxymethacrylate and TEGDMA. The microfiller particles were prepared with and without a gamma-methacryloxypropyl-trimethoxy silane coupling agent. Following polymerization, five material properties were tested: uniaxial tensile strength, Young's modulus in slow compression, Knoop hardness, water sorption, and toothbrush abrasion resistance. Results from these tests indicated that microfiller content clearly was the most influential parameter affecting material property performance. Composites containing 20 nm particles demonstrated greater water sorption, higher Knoop hardness, and better resistance to toothbrush wear. Surprisingly, the application of silane to microfiller surfaces did not greatly improve composite performance for most of the material properties tested in this study. However, water sorption behavior over a 3-year period was observed to be more stable for materials possessing silane-treated particles. Future evaluation of coupling agents should include long-term water storage prior to conducting mechanical tests.

Biocompatible Materials↗

PubMed1996

Were the Roman emperors Claudius and Vitellius bulimic?

OBJECTIVE: To investigate the eating habits of Romans during the first two centuries A.D. and their attitudes towards these eating habits in the light of contemporary Latin literary and historical sources and influential Greek medical sources. METHOD: An extensive search of sources on the Roman Empire and emperors in the first two centuries A.D. was carried out. Two historical cases of binging and self-induced vomiting, namely the Emperors Claudius and Vitellius, were identified and described in translated extracts from the original Latin source. DISCUSSION: It is noted that cultural and social factors are important influences on eating habits which would now be considered pathological.

Bulimia↗

PubMed1996

Attachment disruption in anorexia nervosa and bulimia nervosa: a review of theory and empirical research.

OBJECTIVE: To critically review both the theoretical propositions about the connections between attachment disruption and eating disorders and the empirical work directly examining these associations. METHOD: The major theoretical positions advocating an influential role for disruptions in the early development of secure attachments in the development of eating disorders were identified and a comprehensive review of empirical studies derived from these positions undertaken. RESULTS: There is evidence for the presence of attachment disturbances in eating-disordered populations and for an association of these disturbances with key aspects of eating disorder psychopathology. DISCUSSION: Because of the limitation of the single pathway conceptualization adopted by the theoreticians and researchers reviewed, few inferences about the role of attachment processes in the etiology and maintenance of eating disorders can be drawn from the existing literature. The paper argues for the development of multifactorial and process-orientated models of the role of attachment functions in the pathogenesis of eating disorders.

Adolescent↗

PubMed1997

Childhood sexual abuse and precursors of binge eating in an adolescent female population.

OBJECTIVE: We examined the cross-sectional association between childhood sexual abuse (CSA) and self-reported binge eating in an adolescent female population. METHODS: Study subjects were recruited from clinics specializing in the treatment of CSA, and control subjects were from high schools in the same cities. Height and weight were measured and subjects completed four questionnaires pertaining to binge eating, depression, locus of control, and self-esteem. RESULTS: Study subjects showed significantly higher depression, external locus of control, and binge eating, and significantly lower self-esteem and weight satisfaction scores than did control subjects. After adjusting for all covariables simultaneously, CSA was not an independent correlate of binge eating score. The strongest correlates of binge eating score in the multivariable analysis were depression, body mass index (BMI), and weight satisfaction. CONCLUSIONS: Psychological factors such as depression or weight satisfaction were more influential than is sexual abuse per se in the relationship between CSA and eating disorders.

Adolescent↗

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↗

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↗

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↗

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↗

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↗

PubMed1988

The Level of Expressed Emotion Scale: a new measure of expressed emotion.

The Level of Expressed Emotion (LEE) scale was developed to provide an index of the perceived emotional climate in a person's influential relationships. Unlike existing measures, the scale was constructed on the basis of a conceptual framework described by expressed emotion theorists. In addition to providing an overall score, the 60-item scale assesses the following four characteristic attitudes or response styles of significant others: Intrusiveness, emotional response, attitude toward illness, and tolerance/expectations. The scale underwent extensive psychometric development procedures: (1) theoretically based item generation; (2) pilot testing with normal and psychiatric populations to select the final items; and (3) construct validation within a schizophrenic population. The results were quite favorable and indicate that the LEE scale has sound psychometric properties of internal consistency; reliability; independence from sex, age, and amount of contacts; and construct validity.

Adaptation, Psychological↗

PubMed1989

The contributions of self-defeating philosophies, perceived helplessness, and repression to anxiety among psychiatric patients.

Four of the most influential psychological explanations for the development of anxiety attribute it to (1) repressed awareness of undesirable emotions; (2) the emergence of unacceptable feelings from the unconscious; (3) adherence to irrational, self-defeating philosophies; and (4) perceived helplessness/lack of control over one's affairs. To test these theories, the authors administered the Trait Anxiety, Denial, Irrational Beliefs, and Locus of Control scales to 190 psychiatric inpatients. Appropriate zero-order, attenuation-corrected, multiple, and partial correlations were run. Denial was correlated negatively with Trait Anxiety; this is consistent with the view that awareness of unpleasant emotions generates anxiety, but does not support the claim that it is the result of repression. The correlations of Trait Anxiety with the Irrational Beliefs scale were substantial. However, its relationships with Locus of Control were limited and nonsignificant after the effects of the Denial and Irrational Beliefs scales were removed statistically. The findings lend support to the positions that anxiety results from self-defeating philosophies and/or the emergence of unpleasant thoughts about oneself, but give only modest support to the "perceived helplessness" hypothesis and seem to contradict the "excessive repression" explanation.

Adjustment Disorders↗