PubMed Health⌕ Search

Biomedical subjects

S C Duncan

Publications and source records attributed to S C Duncan.

33 records · Page 2Linked to original sources
PubMed1995

On the group entity.

The group entity is postulated as a construct that accounts for phenomena, which, in a group, come to be experienced by group members as "the group" and that are referred to in the literature as the group-as-a-whole. This article reviews the literature on whole group phenomena. It describes the group entity as it is formed and maintained. A process is outlined using the ideas of spatialization, objectization, enlivenment, and participation. These concepts will describe the way in which the group entity arises and comes to be a part of the individual's experience in a group. Projective identification is viewed as the main mechanism responsible for the intragroup dynamics involving the group entity.

Cooperative Behavior↗
PubMed1994

The effects of family cohesiveness and peer encouragement on the development of adolescent alcohol use: a cohort-sequential approach to the analysis of longitudinal data.

This article demonstrates a latent growth curve methodology for analyzing longitudinal data for adolescent alcohol use by combining information from different overlapping age cohorts to form a single developmental trajectory. Hypotheses concerning the form of growth in alcohol use, the extent of individual differences in the common trajectory over time, and covariates influencing both initial status and the form of growth were tested. Utilizing five separate age cohorts each measured over the same 4-year period, results suggested a common trajectory existed across the 8 years represented by the cohort-sequential analysis, with alcohol use increasing more rapidly during the adolescents' transition to high school. Family cohesion and peer encouragement for alcohol use were hypothesized to influence both initial status and the trajectory of alcohol consumption during adolescence. While family cohesion served to suppress initial levels of consumption delaying the upward trajectory of alcohol use, peer encouragement was related not only to initial, and elevated, levels of use, but was predictive of those changes that occurred during adolescence. Discussion involves the importance of family and peer influences in the development of adolescent alcohol use and the utility of the cohort-sequential approach in the analysis of longitudinal data.

Adolescent↗
PubMed1993

The role of cognitive appraisal and friendship provisions in adolescents' affect and motivation toward activity in physical education.

This study investigated the mediational role of affect in the influence of perceived success, causal attributions, and friendship provisions on choice and future expectancies for success and enjoyment, using a multi-sample structural equation modeling approach. Subjects were 422 seventh- and eighth-grade students participating in physical education classes. Higher levels of perceived success, personally controllable attributions, companionship, and esteem support were found to positively influence levels of affect experienced, which in turn enhanced future expectancies for success and enjoyment in physical education and choices to participate in physical activity outside of school. Furthermore, participation experience outside of school influenced adolescents' perceptions within the physical education setting and their consequent affect and motivation.

Adolescent↗
PubMed1991

A latent growth curve approach to investigating developmental dynamics and correlates of change in children's perceptions of physical competence.

In both the physical and academic domains interest has recently grown regarding developmental change in children's perceptions of competence. Recent advances in statistical methodology, such as latent growth modeling, enable the researcher to analyze developmental trends from both an inter- and intraindividual perspective, thus serving to increase our understanding of correlates of change in perceived competence. Using latent growth modeling, the purpose of the present study was to investigate developmental change in children's perceived competence at physical skills, examining maturational factors and chronological age as possible correlates of change. Subjects were male adolescents (N = 94). Data were collected during the child's sixth, eighth, and ninth grade school years. Results revealed a good fit for the hypothesized model, which specified mean level changes in the variables over time and an interrelationship among the latent chronometric common factors. Although a significant relationship existed between maturation and perceived competence, no significant relationship was evident between chronological age and perceived competence. Findings are discussed with particular reference to the utility of latent growth curve models for assessing developmental processes at both the inter- and intraindividual level.

Adolescent↗
PubMed1991

The Quality of Object Relations Scale.

The Quality of Object Relations Scale (QORS) provides a methodological and theoretical framework for personality classification based on relative level and quality of object relations. The authors believe that many available clinical assessment systems have little heuristic value, and propose that the QORS yields more meaningful descriptions of people. They discuss its theoretical basis in psychoanalytic object relations theory, and how its construction and rationale represent an attempt to incorporate recent thought relevant to the classification of personality. They include criteria for its organizational levels, prototypical vignettes, and a case demonstration. They also explore methodological issues relevant to clinical use and present reliability and validity data derived from empirical studies.

Adult↗
PubMed1980

Large cell lymphocytoma.

We studied nine cases of cutaneous lymphoproliferative disease that shared a distinct histologic pattern. The lesions consisted of red-to-violaceous, single or clustered, deep papules or nodules. They proved to be benign on long-term evaluation. Nodular infiltrates of large, pleomorphic lymphocytes, sometimes appearing to be histiocytic and often associated with frequent mitoses, led to the diagnosis of lymphoma or reticulum cell sarcoma in seven of the cases. Sharply marginated, dense clusters of small lymphocytes surrounded or infiltrated the large cell component, a juxtaposition that characterizes large cell lymphocytoma. This pattern was not found in patients with progressive malignant lymphoma. At times, multiple biopsies must be done to establish the diagnosis. All patients are alive, and none has malignant lymphoma. The follow-up periods for six of the patients have been five years or longer.

Adult↗
PubMed1980

Leukoedema of the oral mucosa. Possibly an acquired white sponge nevus.

Leukoedema is a white or whitish-gray edematous lesion of the buccal and labial oral mucosa. The lesions may be diffuse or patchy, and are usually asymptomatic. Leukoedema may be confused with leukoplakia, Darier's disease, white sponge nevus, pachyonychia congenita, or candidal infection. The condition is seen most frequently among black men. The histologic appearance simulates that of white sponge nevus. Symptomatic leukoedema seems to respond to topical application of tretinoin.

Adult↗
PubMed1979

Early histopathology of the cutaneous capillary fragility test (Rumpel-Leede).

The characteristic histologic change seen at 2 h in the Rumpel-Leede (Hess) test is, in addition to focal hemorrhage in the upper dermis, a perivascular lymphocyte infiltrate with focal areas of lymphocytic epidermal invasion. The histologic findings, even with the liquefaction degeneration, are similar to those of purpura simplex and indicate that, early in many forms of vasopermeability, the lymphocyte may be a primary inflammatory cell.

Capillary Fragility↗
PubMed1979

Blastomycosis-like pyoderma.

Seven patients with blastomycosis-like pyoderma had skin lesions of four months' to six years' duration. The criteria for the diagnosis of blastomycosis-like pyoderma include the clinical presentation of large verrucous plaques with multiple pustules and elevated border, pseudoepitheliomatous hyperplasia with abscess histologically, and the growth of at least one pathogenic bacteria from the culture of a tissue-biopsy specimen. The differential diagnosis includes deep fungus infection (especially North American blastomycosis), bromoderma, pyoderma gangrenosum, mycobacterial infections, giant keratoacanthoma, and squamous cell carcinoma. Generally, the patients had one or more conditions that could have affected their systemic or local immunologic competence to infection. We believe that the clinical and histologic features in these cases of blastomycosis-like pyoderma were produced by an unusual, exaggerated, vegetating-tissue reaction to a primary or secondary bacterial infection.

Adult↗
PubMed1979

Lymphoid follicles in subcutaneous inflammatory disease.

A review of inflammatory subcutaneous disease revealed that lymphoid follicles are observed frequently in lupus panniculitis. They are found rarely in other lymphocytic inflammatory diseases involving the panniculus, such as morphea, erythema nodosum, and erythema induratum. The lymphoid follicle may be an indication of immunoreactive and connective tissue disease, and cases should be evaluated with this in mind.

Adipose Tissue↗
PubMed1979

Cancer and scleroderma.

Of 2,141 patients with scleroderma who were seen at the Mayo Clinic, Rochester, Minn, between 1959 and 1975, 78 had 87 internal malignancies. The relative frequency of the types of cancers was similar to that for the general population. The increased numbers of patients with breast and uterine carcinomas were consistent with the female preponderance in scleroderma. Contrary to previous reports, carcinoma of the lung was not the most frequent malignancy associated with scleroderma. The lymphoma-leukemia malignancies were second only to breast carcinoma in frequency, comprising about 17% of the malignancies. Both conditions developed within a three-year period in 68% (45/66) of our patients affected with systemic scleroderma, and this subgroup comprised a high mortality group. This study is not an epidemiologic one in the strictest sense, but it is a review of the experience of the Mayo Clinic with patients who have had both scleroderma and an internal malignancy.

Adolescent↗
PubMed1978

Circulating Sézary cells in hospitalized dermatology patients.

Sézary cells in the circulation were counted daily in 14 hospitalized dermatology patients: six with contact dermatitis, five with atopic dermatitis, and three with exfoliative psoriasis. All had circulating Sézary cells, but absolute counts of Sézary cells of more than 1000/mm3 appeared to correlate with a severe refractory course in two patients. It is probable that low, intermittent levels of circulating Sézary cells accompany many inflammatory dermatoses, and it is reasonable that monitoring this cell population may aid in anticipating more consequential skin disease.

Dermatitis↗
PubMed1978

Migraine and systemic scleroderma.

Scleroderma with typical migraine headaches occurred in 16 well-documented cases observed over a 25-year period. Although the number of cases is within the expected range of coincidence of both diseases, in 13 of the 16 patients the scleroderma developed after 15 years or more of therapy with ergot or methysergide preparations. Eleven of the 13 patients had Raynaud's vasospastic phenomenon as part of their systemic scleroderma. The vascular pathology of scleroderma, Raynaud's phenomenon, and ergotism is similar enough to suggest caution in the administration of these drugs to patients with migraine and extra caution in observing for signs of Raynaud's phenomenon or early vascular scleroderma.

Adult↗