PubMed Health⌕ Search

Biomedical subjects

J K Thompson

Publications and source records attributed to J K Thompson.

At least 19 recordsLinked to original sources
PubMed2001

Media influence and body image in 8-11-year-old boys and girls: a preliminary report on the multidimensional media influence scale.

OBJECTIVE: To develop a scale for the assessment of multiple components of a media-based influence on body image. METHOD: Seventy-five boys and 107 girls, ranging in age from 8 to 11, completed a measure designed to assess five facets of a media influence previously conceptualized by researchers. RESULTS: Three distinct scales emerged, which appeared to focus on concepts defined as internalization, awareness, and pressure. Correlations between subscales of the Multidimensional Media Influence Scale (MMIS) and the Eating Disorder Inventory-Body Dissatisfaction subscale were significant for both boys and girls. Girls had higher levels on all three subscales and regression analyses indicated that the MMIS scores predicted 30% of the variance associated with body dissatisfaction for girls, but an R(2) of only 0.10 emerged for boys. Internalization levels predicted significant variance beyond that explained by awareness and pressures, but only for the female sample. DISCUSSION: The findings are discussed with regard to the usefulness of the MMIS for future research and the role of internalization as a risk factor for the development of body image disturbances and eating disorders.

Body Image↗
PubMed2000

Targeted disruption of an erythrocyte binding antigen in Plasmodium falciparum is associated with a switch toward a sialic acid-independent pathway of invasion.

Erythrocyte invasion by Plasmodium requires molecules present both on the merozoite surface and within the specialized organelles of the apical complex. The Plasmodium erythrocyte binding protein family includes the Plasmodium falciparum sialic acid-binding protein, EBA-175 (erythrocyte binding antigen-175), which binds sialic acid present on glycophorin A of human erythrocytes. We address the role of the conserved 3'-cysteine rich region, the transmembrane, and cytoplasmic domains through targeted gene disruption. Truncation of EBA-175 had no measurable effect on either the level of EBA-175 protein expression or its subcellular localization. Similarly, there appears to be no impairment in the ability of soluble EBA-175 to be released into the culture supernatant after schizont rupture. Additionally, the 3'-cys rich region, transmembrane, and cytoplasmic domains of EBA-175 are apparently non-essential for merozoite invasion. In contrast, erythrocyte invasion via the EBA-175/glycophorin A route appears to have been disrupted to such a degree that the mutant lines have undergone a stable switch in invasion phenotype. As such, EBA-175 appears to have been functionally inactivated within the truncation mutants. The sialic acid-independent invasion pathway within the mutant parasites accounts for approximately 85% of invasion into normal erythrocytes. These data demonstrate the ability of P. falciparum to utilize alternate pathways for invasion of red blood cells, a property that most likely provides a substantial survival advantage in terms of overcoming host receptor heterogeneity and/or immune pressure.

Animals↗
PubMed2000

Genomic distribution and functional characterisation of two distinct and conserved Plasmodium falciparum var gene 5' flanking sequences.

Approximately 50 highly diverse var genes distributed throughout the haploid genome of the malaria parasite Plasmodium falciparum code for PfEMP1 variants located on the surface of infected erythrocytes. PfEMP1 is involved in cytoadherence of parasitised red blood cells and undergoes antigenic variation through differential expression of var genes. Members of the var gene family are located in chromosome-internal positions on chromosomes 4, 7, 8 and 12, and in subtelomeric regions of all chromosomes. Here we show that there are two distinct and conserved types of 5' upstream regions (var17-type and 5B1-type) of var genes, and suggest that most subtelomeric var genes are flanked by a var17-type 5' upstream sequence. In contrast, 5B1-type 5' upstream are localised to chromosomes that have been shown to contain var genes within chromosome-internal regions. Transcriptional analysis using RT-PCR revealed that var genes flanked by either type of 5' upstream sequence are transcribed in in vitro cultured trophozoite stage parasites. In addition, we have shown that the 5' flanking sequences of four different var genes are able to drive transient expression of the cat reporter gene. Our results suggest that at least the minimal regulatory sequences required for transcription of var genes are conserved among both subgroups of the var gene family. Furthermore, these sequences provide new markers for the investigation of the chromosomal organisation of var genes.

5' Untranslated Regions↗
PubMed2000

A cross-cultural examination of weight-related teasing, body image, and eating disturbance in Swedish and Australian samples.

OBJECTIVE: To evaluate, cross-culturally, a model for the prediction of eating disturbance from factors such as body image disturbance, negative verbal feedback regarding appearance (teasing), and body mass index (BMI). METHODS: Three samples of adolescent girls from Sweden (Grade 8: n = 260; mean age = 14.3) and Australia (Grade 7: n = 159; mean age = 12.8 and Grade 8: n = 210; mean age = 13.7) completed two measures of eating restraint and one scale each reflective of bulimic symptomatology, teasing history, and body dissatisfaction. RESULTS: Path analyses revealed that BMI predicted teasing and body dissatisfaction, and body dissatisfaction predicted level of eating restraint. In all three samples, there was evidence of partial mediation by teasing of the connection between BMI and restraint. DISCUSSION: The results partially replicate previous work with U.S. samples. The findings are discussed with regard to the need for further cross-cultural work and its relevance for identifying factors for early intervention and prevention programs.

Adolescent↗
PubMed1999

The adhesion of Plasmodium falciparum-infected erythrocytes to chondroitin sulfate A is mediated by P. falciparum erythrocyte membrane protein 1.

Chondroitin sulfate A (CSA) is an important receptor for the sequestration of Plasmodium falciparum in the placenta, but the parasite ligand involved in adhesion has not previously been identified. Here we report the identification of a var gene transcribed in association with binding to CSA and present evidence that the P. falciparum erythrocyte membrane protein 1 product of the gene is the parasite ligand mediating CSA binding. Description of this gene and the implication of P. falciparum erythrocyte membrane protein 1 as the parasite ligand paves the way to a more detailed understanding of the pathogenesis of placental infection and potential therapeutic strategies targeting the interaction.

Animals↗
PubMed1999

Body image among men and women in a biracial cohort: the CARDIA Study.

OBJECTIVE: To examine body image in a population-based, biracial cohort. METHOD: Body image measures were obtained on 1,837 men (45% Black) and 1,895 women (51% Black) in the CARDIA study. Subscales of the Multidimensional Body Self-Relations Questionnaire (Appearance Evaluation and Appearance Orientation) and a measure of body size dissatisfaction were obtained. RESULTS: Blacks were more invested in appearance than Whites and women were more invested than men. Women were more dissatisfied with size and overall appearance than men, and White men were more dissatisfied with appearance than Black men. Black and White women were similarly dissatisfied with size and appearance. However, after adjustment for age, body mass index, and education, Black women were more satisfied with both dimensions than White women. Obesity was strongly associated with body dissatisfaction across all gender-ethnicity groups. DISCUSSION: Significant differences in body image were apparent by gender and ethnicity, and different patterns were evident depending on the dimension considered.

Adolescent↗
PubMed1999

Body image, psychological functioning, and parental feedback regarding physical appearance.

OBJECTIVE: To investigate the role of parental appearance-related commentary, body image, and psychological functioning in females and males. METHOD: Retrospective reports of teasing and appearance-based feedback were assessed, along with current levels of body image and overall psychological functioning. RESULTS: Women and men did not differ in their reports of comments received from mothers, however, women received significantly more appearance-related messages from fathers. Correlational analyses demonstrated significant relationships between feedback and body satisfaction for women, but not for men. Regression analyses indicated that fathers' and mothers' teasing about weight were predictive of daughters' body image. For both males and females, psychological functioning was significantly predicted from the combination of mothers' and fathers' feedback regarding appearance. DISCUSSION: The findings further support an emerging theoretical model of appearance-related commentary as a factor in body image disturbance and overall psychological functioning.

Adult↗
PubMed1999

Body image, social comparison, and eating disturbance: a covariance structure modeling investigation.

OBJECTIVE: To evaluate the role of appearance-based social comparison processes as a possible mediational link between developmental factors (negative social feedback, i.e., teasing about appearance; biological status, i.e., early physical maturation) and levels of body dissatisfaction, eating disturbance, and global psychological functioning. METHOD: In this study of 173 female undergraduates, covariance structure modeling (CSM) was used to examine direct and mediational relationships among these variables. RESULTS: Appearance-based social comparison mediated the effect of appearance-related teasing on body image and eating disturbance; body image mediated the effect of teasing on eating disturbance; eating disturbance had a direct effect on overall psychological functioning. DISCUSSION: Implications for devising and testing other theoretical models are discussed.

Adolescent↗
PubMed1999

Essential neuronal pathways for reflex and conditioned response initiation in an intracerebellar stimulation paradigm and the impact of unconditioned stimulus preexposure on learning rate.

It has been demonstrated previously that pairing of tone CS and intracerebellar stimulation of lobule HVI white matter as the US produces conditioning that is robust and in many ways similar to that obtained with an airpuff US. The first study in this report addressed the effect of interpositus lesions on conditioned performance in rabbits trained with white matter stimulation as the US. It was found that interpositus lesions effectively eliminated the CR irrespective of the behavioral response measured. In addition, it was shown that the interpositus lesions also abolished the UR, providing strong evidence that the effects of the electrical stimulation were confined to the cerebellum and did not require the activation of brainstem structures. The second experiment examined performance on US-alone trials of varying durations. Response initiation within 100 ms of the US onset, regardless of US duration, indicated that reflex generation could not be due to rebound excitation of the interpositus following termination of Purkinje cell inhibition of that structure but instead likely reflects orthodromic activation of interpositus neurons via climbing fiber and/or mossy fiber collaterals. The impact of US preexposure on associative conditioning in this paradigm was also determined. Animals which received only 108 US-alone trials were massively impaired during subsequent training compared to rabbits that received fewer than 12 US-alone trials.

Animals↗
PubMed1999

Complete sequence of plasmid pLH1 from lactobacillus helveticus ATCC15009: analysis reveals the presence of regions homologous to other native plasmids from the host strain.

The complete sequence for plasmid pLH1 from Lactobacillus helveticus ATCC15009 has been determined. Analysis of the 19,360-bp primary sequence revealed a putative replication origin and initiation protein, information that could provide the basis for the construction of cloning vectors for L. helveticus. Evidence that pLH1 is theta-replicating could be deduced from the plasmid size, from the homology to the replication protein of the Bacillus natto theta-replicating plasmid pLS32, and from the identification of a putative resolvase gene (orf-195). Although 14 open reading frames capable of encoding polypeptides longer than 100 amino acids were identified, none, on the basis of homology with known sequences, appeared to encode a well-characterized trait relevant to milk fermentation. Plasmid pLH1 revealed regions of identity with the smaller cryptic plasmids (pLH2 and pLH3) from the same strain and with other tracts of DNA, including insertion sequence elements, from a variety of other lactic acid bacteria. The presence of such regions provides a basis for developing an explanation of the phenotypic variability observed in these bacteria. The plasmid also appears to possess a number of genetic elements present in other lactic acid bacterial plasmids, conservation of which would be consistent with an important functional or evolutionary role. It could be argued that the plasmid complement of L. helveticus ATCC15009 consists of parasitic entities concerned only with their own replication and survival.

Amino Acid Sequence↗
PubMed1998

Relation of self-image to body size and weight loss attempts in black women: the CARDIA study. Coronary Artery Risk Development in Young Adults.

It has been suggested that the prevalence of obesity in black women is high partly because self-image in black women is not strongly dependent on body size. To determine associations between self-image, body size, and dieting behavior among black women, the authors assessed an Appearance Evaluation Subscale (AES) score (range, 1-5), a Body Image Satisfaction (BIS) score (range, 2-11), and reported dieting behavior in a population-based sample of 1,143 black women aged 24-42 years from the fourth follow-up examination (1992-1993) of the Coronary Artery Risk Development in Young Adults (CARDIA) Study. Lower AES and BIS scores indicate poorer self-image and lower body size satisfaction, respectively. After adjustment for age, education, smoking, and physical activity, women in the lowest, middle, and highest tertiles of body mass index (weight (kg)/height (m)2) had mean AES scores of 3.7, 3.3, and 2.9, respectively (p < 0.001), and mean BIS scores of 7.8, 6.7, and 5.9, respectively (p < 0.001). After additional control for body mass index as a continuous variable, both AES and BIS scores were inversely related to ever dieting, current dieting, and previous weight loss of 10 pounds (4.5 kg) or more in all tertiles of body mass index. These results suggest that among black women, a higher body mass index is associated with poorer self-image and lower body size satisfaction and that these perceptions may be an avenue to promoting weight control.

Adolescent↗
PubMed1998

Assessment of body image disturbance in obesity.

Disturbance in body image has long been noted as one of the most distressing psychological factors for obese individuals. Yet, only in recent years have researchers and clinicians begun to appreciate the need to integrate systematic evaluation of this component into intervention programs. Accordingly, this mini-review offers an overview of selected strategies for the assessment of body image disturbance in obesity.

Body Constitution↗
PubMed1998

Evidence of plasticity in the pontocerebellar conditioned stimulus pathway during classical conditioning of the eyeblink response in the rabbit.

Electrical stimulation thresholds required to elicit eyeblinks with either pontine or cerebellar interpositus stimulation were measured before and after classical eyeblink conditioning with paired pontine stimulation (conditioned stimulus, CS) and corneal airpuff (unconditioned stimulus, US). Pontine stimulation thresholds dropped dramatically after training and returned to baseline levels following extinction, whereas interpositus thresholds and input-output functions remained stable across training sessions. Learning rate, magnitude of threshold change, and electrode placements were correlated. Pontine projection patterns to the cerebellum were confirmed with retrograde labeling techniques. These results add to the body of literature suggesting that the pons relays CS information to the cerebellum and provide further evidence of synaptic plasticity in the cerebellar network.

Animals↗
PubMed1997

Prognostic value of MIB-1 in advanced ovarian carcinoma as determined using automated immunohistochemistry and quantitative image analysis.

BACKGROUND AND OBJECTIVES: The monoclonal antibody MIB-1 is an immunohistochemical marker reacting most strongly with cells in late S phase, G2, and M portions of the cell cycle. This antibody, reactive in formalin-fixed, paraffin-embedded tissue, allows the quantitation of a proliferation index (PI) in both current clinical cases and archival material using a computerized image analyzer (CIA). METHODS: Since many laboratories make use of automated immunohistochemistry (AIH), this study was performed to explore the technical feasibility of using AIH (Ventana ES 320) in combination with CIA (CAS 200) to evaluate MIB-1 PI as a prognostic marker as assessed by overall survival in 50 archival (formalin-fixed, paraffin-embedded), advanced stage primary ovarian carcinomas. RESULTS: Exploratory methods confirmed that 15% was a cutpoint that could dichotomize these 50 patients into two prognostic groups based on overall survival. The median survival of patients whose carcinoma had a high MIB-1 expression (> or = 15%) was 16 months compared with 30 months in the patients whose tumors demonstrated low MIB-1 expression (< 15%, P = 0.01). After adjustment for age, MIB-1 retained its prognostic significance (P = 0.02). Patients 60 years and older had shorter survival than younger patients (P = 0.06), but these two groups did not differ with respect to PI (P = 0.76). Those patients with a negative second look laparotomy had a longer median survival of 70 months compared with 18.5 months in patients with a positive second look (P < 0.001); the median PIs were 17% and 27%, respectively (P = 0.36). There were no significant relationships between clinical stage, nuclear grade, DNA ploidy, p53, and either survival or PI. CONCLUSIONS: In this study, we concluded that the combination of AIH and CIA yielded a reliable quantitation of MIB-1 proliferative index and that this proliferative marker had prognostic significance in late stage ovarian carcinoma. Further studies in a larger group of patients are needed to confirm the relationship between proliferation index and other known clinicopathologic and genetic variables.

Antibodies, Monoclonal↗
PubMed1997

Overt and covert sexual abuse: relationship to body image and eating disturbance.

OBJECTIVE: To separate forms of overt and covert sexual abuse and assess their independent contribution to the development of body image and eating disturbance. METHOD: A new measure was developed--the Covert-Overt Sexual Abuse Questionnaire (COSAQ)--and correlated with levels of body image, eating disturbance, social desirability, self-esteem, and depression. RESULTS: Factor analyses on three independent samples yielded two distinct subscales which were labelled Overt and Covert. Each scale had excellent internal consistency and test-retest reliability. Regression analyses demonstrated the ability of the Covert factor to explain variance associated with body image disturbance and eating dysfunction beyond that accounted for by levels of social desirability, self-esteem, depression, and overt sexual abuse. DISCUSSION: These findings support the importance of a more "subtle" form of early trauma--covert sexual abuse--in the development of body image and eating-related problems.

Adaptation, Psychological↗