Metabolism and epigenetics of pancreatic cancer stem cells.

Pancreatic Cancer (PDA) is an aggressive malignancy characterized by early spread and a high mortality. Current studies suggest that a subpopulation of cells exist within tumors, cancer stem cell (CSC), which are capable of self-renewal and give rise to unique progeny which form the major neoplastic cellular component of tumors. While CSCs constitute a small cellular subpopulation within the tumor, their resistance to chemotherapy and radiation make them an important therapeutic target for eradication. Along with distinctive phenotypic properties, CSCs possess a unique metabolic plasticity allowing them to rapidly respond and adapt to environmental changes. These cells and their progeny also display a significantly altered epigenetic state with distinctive patterns of DNA methylation. Several mechanisms of cross-talk between epigenetic and metabolic pathways in PDA exist which ultimately contribute to the observed cellular plasticity and enhanced tumorigenesis. In this review we discuss various examples of this metabolic-epigenetic interplay and how it may constitute a new avenue for therapy specifically targeting CSCs in PDA.

Psychometric properties and validation of the Sociocultural Attitudes Towards Appearance Questionnaire-4 (SATAQ-4) with a sample of Japanese adolescent girls.

The Sociocultural Attitudes Towards Appearance Questionnaire-4 (SATAQ-4) is a 22-item five-factor measure that assesses thin- and muscular-ideal internalization as well as appearance-related pressures from peers, family, and media. The scale has been validated in Western cultures, but has not yet been examined in Eastern samples. Two studies were conducted to examine the psychometric properties of the SATAQ-4 among 946 Japanese adolescent girls. In Study 1, exploratory factor analysis of the SATAQ-4 indicated that the five-factor structure was largely replicated with the exception of two cross-loading items. In Study 2, confirmatory factor analysis indicated good fit for the full 22-item and reduced 20-item versions of the measure. SATAQ-4 subscales exhibited good internal consistency and were correlated in the expected direction with experiences of appearance teasing, strategies to lose and/or gain weight, and drive for muscularity. Overall, results support the reliability and validity of the SATAQ-4 among Japanese adolescent girls.

Using software to predict occupational hearing loss in the mining industry.

Powerful mining systems typically generate high-level noise that can damage the hearing ability of miners. Engineering noise controls are the most desirable and effective control for overexposure to noise. However, the effects of these noise controls on the actual hearing status of workers are not easily measured. A tool that can provide guidance in assigning workers to jobs based on the noise levels to which they will be exposed is highly desirable. Therefore, the Pittsburgh Mining Research Division (PMRD) of the U.S. National Institute for Occupational Safety and Health (NIOSH) developed a tool to estimate in a systematic way the hearing loss due to occupational noise exposure and to evaluate the effectiveness of developed engineering controls. This computer program is based on the ISO 1999 standard and can be used to estimate the loss of hearing ability caused by occupational noise exposures. In this paper, the functionalities of this software are discussed and several case studies related to mining machinery are presented to demonstrate the functionalities of this software.

Positive and negative appearance-related feedback and weight status.

Previous reports have well documented that many overweight and obese individuals experience negative appearance-related commentary regarding their weight status. In the current study, both negative and positive comments were assessed using a new scale (Verbal Commentary on Physical Appearance Scale) within four weight categories (underweight, average weight, overweight and obese) in 246 women. The results indicated that overweight and obese participants received less positive weight-related comments than average and underweight individuals, but there were no group differences in the level of positive non-weight-related comments (i.e., other aspects of appearance). Correlational analyses indicated that less negative and more positive feedback were associated with higher self-esteem for average weight individuals, whereas for the combined overweight and obese sample, higher scores on both positive subscales were associated with higher self-esteem. The findings offer the first empirical evidence regarding the relative levels of negative and positive appearance feedback reported by individuals of different weight categories and their relations with overall self-esteem.

An adolescent male with features of EDNOS and obsessive-compulsive disorder.

OBJECTIVE: The current article describes the case of a 13-year-old boy with mixed diagnostic features suggestive of Eating Disorder Not Otherwise Specified (EDNOS) and obsessive-compulsive disorder. METHOD: A multimodal assessment approach was used to unravel the symptoms in this case. Initial presentation of the case had predominant features of EDNOS, however, obsessive-compulsive disorder features appeared to better explain disordered eating characteristics as the case progressed. In particular, the presence of intrusive images hindered his ability to consume food. RESULTS: A variety of psychological approaches, including components of family and cognitive-behavioral strategies had a slight impact on symptoms. Medication seemed to have a more substantial effect. CONCLUSION: This rather unique case, which contained features of EDNOS and obsessive compulsive disorder, illustrates the need for an ongoing multimodal assessment and interdisciplinary treatment approach.

The drive for muscle leanness: a complex case with features of muscle dysmorphia and eating disorder not otherwise specified.

Muscle dysmorphia has been described as a subtype of body dysmorphic disorder in which an individual experiences severe body image disturbance related to muscularity. The current case is of a 20-year-old man who describes a history of muscle dysmorphia in which the nature of the body image concern is related to leanness (i.e., muscularity in the absence of body fat), as opposed to increasing muscle mass, which is how muscle dysmorphia has typically been characterized in the literature. The case illustrates the need to consider this additional facet of body image when diagnosing muscle dysmorphia.

Perception of teasing in underweight persons: a modification of the perception of teasing scale.

The psychometric properties of the Perception of Teasing Scale-Underweight, a modified version of the Perception of Teasing Scale (1), were examined. One hundred eighty-three college students (81 male; 102 female; age range 17-57 years) completed questionnaires about underweight-related and competency-related teasing experiences, eating attitudes, body image, self-esteem, and mood. Factor analysis suggested the Perception of Teasing Scale-Underweight has a two-factor structure, measuring both underweight-related and competency-related teasing experiences. Significant correlations (p<0.05) were found between the Perception of Teasing Scale-Underweight, Beck Depression Inventory, Fear of Negative Appearance Evaluation Scale, Multidimentional Body-Self Relations Questionnaire-Appearance Scales, Multiaxial Eating Disorder Scale, Social Physique Anxiety Scale, and Rosenberg Self-Esteem Scale. The pattern of correlations differed between the entire sample and those with a body mass index <21. One-way analysis of variance analyses found significant differences (p<0.05) between those with body mass index (BMI) <21 and those with BMI >21 for the weight-related event and weight-related impact scales, indicating that the measure discriminates between those individuals most likely to have been underweight as adolescents versus those most likely to have been normal weight or overweight. This measure provides a sound psychometric tool for examining underweight-related and competency-related teasing experiences. The impact of appearance and competence related teasing in underweight persons is less well understood than in overweight samples; therefore, future work should be conducted with a more underweight sample to bridge this gap in the literature.

The Sociocultural Internalization of Appearance Questionnaire - Adolescents (SIAQ-A): psychometric analysis and normative data for three countries.

A brief measure of internalization of societal norms regarding appearance was developed and validated on six early adolescent female samples (mean ages 11.7-13.3) from three countries (US, Australia, India; total n = 2210). Internal consistency levels were uniformly high in all samples, ranging from 0.83 to 0.92. Convergent validity estimates were high in all samples. Level of internalization was significantly positively correlated with levels of body dissatisfaction and restriction for all samples. Internalization was also significantly positively correlated with bulimic behaviors and negatively correlated with levels of self-esteem for the four samples that included these variables. The findings indicate that the Sociocultural Internalization of Appearance Questionnaire - Adolescents (SIAQ-A) may be used to further explore a media influence cross-culturally, allowing for the investigation of the role of internalization as a potential risk factor for body image problems and eating disturbances in different contexts.

Completed sequence of plasmid pIP501 and origin of spontaneous deletion derivatives.

The sequence of plasmid pIP501 (30,603 bp) was completed using previously published and newly acquired data. The sites at which two spontaneous deletions had occurred were identified. One was between tracts of repeated heptamers and the other between regions of secondary structure associated with plasmid replication. A high level of identity ( >95%) between plasmid pIP501 and part of plasmid pRE25, which had been isolated from Enterococcus faecalis associated with a food source, was confirmed.

DNA cloning in Lactobacillus helveticus by the exconjugation of recombinant mob-containing plasmid constructs from strains of transformable lactic acid bacteria.

A system developed for the genetic transfer of plasmids between strains of nontransformable bacteria (P. Langella, Y. le Loir, S. D. Ehrlich and A. Gruss, 1993, J. Bacteriol., 175, 5806-5813) by the specific inclusion of a mobilization (mob) region into a nonconjugative shuttle vector was used successfully to deliver the genetic determinants for beta-glucanase, beta-glucuronidase, and green fluorescent protein to Lactobacillus helveticus. Expression of two of the genes could be detected in the new host. Data suggested that resolution of cointegrates into components could release the original recombinant plasmid or generate a cointegrate deletion. All the recombinant plasmids were segregationally unstable in Lb. helveticus and there was some evidence for structural instability. Intrinsic instability in the mob-containing vector was reduced by replacing the duplicated pBluescript polylinker with that from pUC19. Sites at which cointegrate formation could occur were localized at two distinct tracts close to the D-loop that forms at the primosome during plasmid replication.

A novel ligand from Plasmodium falciparum that binds to a sialic acid-containing receptor on the surface of human erythrocytes.

Invasion of the merozoite form of Plasmodium falciparum into human erythrocytes involves multiple receptor-ligand interactions. The EBA175 protein of P. falciparum has been shown to be the ligand that binds to a sialic acid-dependent site on glycophorin A. We have identified a novel P. falciparum ligand, termed erythrocyte-binding antigen 140 (EBA140), that shares structural features and homology with EBA175. Subcellular localization of EBA140 suggests that it is located in the micronemes, the same localization as EBA175. EBA140 binds to a sialic acid-dependent receptor on the surface of human erythrocytes. Binding of EBA140 to this erythrocyte receptor is sensitive to neuraminidase and resistant to trypsin, proteinase K and pronase. The protease-resistant properties of the erythrocyte receptor suggests that it is not glycophorin A or C. Additionally, analysis of mutant erythrocytes from humans has shown that EBA140 does not bind glycophorin B. Interestingly, we have identified a parasite line that lacks the eba140 gene, suggesting that this protein is not essential for in vitro invasion. These results suggest that EBA140 may be involved in merozoite invasion using a sialic acid-dependent receptor on human erythrocytes.

An EBA175 homologue which is transcribed but not translated in erythrocytic stages of Plasmodium falciparum.

Plasmodia species can bind to the Duffy blood group antigen (Plasmodium vivax and P. knowlesi) or glycophorin A (P. falciparum) on human erythrocytes as receptors for the invasion of merozoites in the asexual life cycle. A number of proteins have been identified in P. vivax, P. knowlesi and P. falciparum that serve as parasite ligands for these interactions and this group of proteins form the erythrocyte binding protein (EBP) family. The availability of sequence data generated as part of the P. falciparum Genome Project has allowed the identification of other genes related to the known EBP family members. We describe the Psi EBA165 gene and show that it has four exons, a structure identical to that described for EBA175. Analysis using reverse transcriptase-polymerase chain reaction (RT-PCR) has shown that all introns are spliced and that this gene is transcribed. The predicted protein would have the same structure as EBA175 containing the F1/F2 domains, a cysteine-rich region followed by a predicted transmembrane region and a short cytoplasmic tail, but the coding region of Psi EBA165 contains frameshifts. It was possible that the frameshifts may be corrected in the transcript, or alternatively, a mechanism could operate that allowed the translation machinery to read through the frameshifts. Antibodies that recognise EBA165 fusion proteins could not detect this protein in the P. falciparum parasites tested. Additionally, it was possible to disrupt the Psi EBA165 gene without affecting the parasite's ability to invade and grow in erythrocytes. These results suggest that the Psi EBA165 gene is a transcribed pseudogene.

The use of the sociocultural attitudes towards appearance questionnaire with middle school boys and girls.

OBJECTIVE: To assess the psychometric validity of versions of the Sociocultural Attitudes Towards Appearance Questionnaire (SATAQ) designed for use with middle school girls and boys. METHOD: As part of a larger study, the SATAQ was administered to 505 middle school children. To assess concurrent validity, scales concerning the use of Weight Control and Muscle Building Techniques as well as the Body Esteem Scale (BES) were also administered. Body mass index (BMI) was also calculated. RESULTS: Both the girls and boys versions of the SATAQ showed adequate validity. Two SATAQ subscales, Internalization and Awareness of societal ideals of thinness, were identified for girls. For boys, three SATAQ subscales were identified: Internalization and Awareness of a muscular, non-fat ideal and a scale tapping the the importance of a Muscular Look. The subscales and total score showed acceptable concurrent validity. Even after controlling for BMI, they contributed significant explained variance for the use of Weight Control Techniques in both boys and girls and use of Muscle Building Techniques in boys. Patterns of relationships among variables differed by gender. DISCUSSION: The results suggest that sociocultural influences play a role in the use of Weight Control and Muscle Building Techniques for middle school boys although their influence is not as strong as it is for the use of Weight Control Techniques by middle school girls. The SATAQ seems to be an adequate measure of the nature of some of these influences.

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.

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.

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.

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.

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.