Co-Assembly of Cancer Drugs with Cyclo-HH Peptides: Insights from Simulations and Experiments

Peptide-based nanomaterials can serve as promising drug delivery agents, facilitating the release of active pharmaceutical ingredients while reducing the risk of adverse reactions. We previously demonstrated that Cyclo-Histidine-Histidine (Cyclo-HH), co-assembled with cancer drug Epirubicin, zinc, and nitrate ions, can constitute an attractive drug delivery system, combining drug self-encapsulation, enhanced fluorescence, and the ability to transport the drug into cells. Here, we investigated both computationally and experimentally whether Cyclo-HH could co-assemble, in the presence of zinc and nitrate ions, with other cancer drugs with different physicochemical properties. Our studies indicated that Methotrexate, in addition to Epirubicin and its epimer Doxorubicin, and to a lesser extent Mitomycin-C and 5-Fluorouracil, have the capacity to co-assemble with Cyclo-HH, zinc, and nitrate ions, while a significantly lower propensity was observed for Cisplatin. Epirubicin, Doxorubicin, and Methorexate showed improved drug encapsulation and drug release properties, compared to Mitomycin-C and 5-Fluorouracil. We demonstrated the biocompatibility of the co-assembled systems, as well as their ability to intracellularly release the drugs, particularly for Epirubicin, Doxorubicin, and Methorexate. Zinc and nitrate were shown to be important in the co-assembly, coordinating with drugs and/or Cyclo-HH, thereby enabling drug-peptide as well as drug-drug interactions in successfully formed nanocarriers. The insights could be used in the future design of advanced cancer therapeutic systems with improved properties.

The educational and psychosocial needs of students with additional provisions during COVID-19 in Greece: Parents' perspectives against schools' crisis management

BACKGROUND

The sudden breakdown of educational and care services following the COVID-19 outbreak caused severe implications to the educational and psychosocial well-being of students with additional needs.

AIM

The present study investigates the perspectives of parents of students requiring additional provisions in relation to the schools' responsiveness against their children's educational and psychosocial needs during the COVID-19 pandemic, with a focus on (non-) applied inclusive and empowerment practices of parenthood.

METHODS AND PROCEDURES

A sample of 125 parents in Greece filled out a self-reported questionnaire providing information on four main themes: school organisation in accordance with the COVID-19 measures; distance education; support on transition from quarantine and remote education back to school; and parental empowerment.

OUTCOMES AND RESULTS

The data revealed that most of the participating parents felt poorly supported during the pandemic. The feeling of being left alone in supporting their children and in fully meeting their personal needs and emotions was also identified. The demographics of the participating parents with children with additional needs revealed an experiences mosaic in relation to the parents' level of education, the number of children who were present in their households, the children's gender as well as their level of school education (preschool- and primary school-aged or secondary school-aged pupils) and attendance of the school programme in regular or special schools.

CONCLUSIONS AND IMPLICATIONS

Data suggest that regular and special schools in Greece, as orchestrated by the Ministry of Education, deployed practices that left students requiring additional provisions unsupported in relation to their educational and psychosocial needs while their parents felt disempowered during the whole period of the COVID-19 pandemic. A range of implications on a more effective support for families and their children with additional needs in alignment with the principles of inclusive education is detailed and discussed.

WHAT THIS PAPER ADDS

The focus of research on the schools' responsiveness to the needs of students requiring additional provisions from the perspective of their parents is of critical importance as it may offer valuable insights pertaining to the school's inclusive policy practices and the promotion of empowering parent partnerships during crisis times. The knowledge gained by exploring parents' experiences will contribute significantly to inform modifications and changes in education delivery in crisis times so as school, as a social system, become more inclusive, supportive, and effective for pupils with additional needs. So far, little attention has been paid to the above-mentioned issues. In the current paper, the parents perspectives were explored through a self-reported questionnaire to reflect on the way schools responded to theirs and their children's educational and psychosocial needs during the COVID-19 pandemic. Most of the participating parents felt poorly supported. The feeling of being left alone in supporting their children and in fully meeting their personal needs and emotions was also identified. The demographics of the participating parents with children requiring additional provisions revealed an experiences mosaic in relation to the parents' level of education, the number of children who were present in their households, the children's gender as well as their level of school education (preschool and primary school or secondary school education) and attendance of the school programme in regular or special schools. A range of implications on a more effective support for families and their children with additional needs in alignment with the principles of inclusive education is detailed and discussed.

Peptide Self-Assembled Nanocarriers for Cancer Drug Delivery

The design of novel cancer drug nanocarriers is critical in the framework of cancer therapeutics. Nanomaterials are gaining increased interest as cancer drug delivery systems. Self-assembling peptides constitute an emerging novel class of highly attractive nanomaterials with highly promising applications in drug delivery, as they can be used to facilitate drug release and/or stability while reducing side effects. Here, we provide a perspective on peptide self-assembled nanocarriers for cancer drug delivery and highlight the aspects of metal coordination, structure stabilization, and cyclization, as well as minimalism. We review particular challenges in nanomedicine design criteria and, finally, provide future perspectives on addressing a portion of the challenges via self-assembling peptide systems. We consider that the intrinsic advantages of such systems, along with the increasing progress in computational and experimental approaches for their study and design, could possibly lead to novel classes of single or multicomponent systems incorporating such materials for cancer drug delivery.

Understanding the molecular mosaic of cardiotoxicity of light chains in plasma cell dyscrasias and cardiac light chain amyloidosis with the use of patient derived full-length light chains

Background

Cardiac light chain amyloidosis (AL-CA) is a life-threatening disease and the major determinant of prognosis in AL amyloidosis. The management of heart failure (HF) in AL is challenging and gold standard therapies for HF are poorly tolerated or ineffective. Cardiac toxicity of LCs in AL-CA is poorly understood and the comparison of cardiotoxicity of LCs derived from plasma cell dyscrasias (PCDs) such as multiple myeloma (MM) and monoclonal gammopathy of undetermined significance (MGUS), will improve our understanding of the mechanisms of cardiac damage.

Purpose

We aimed to 1) genetically identify and biotechnologically produce full-length LCs from patients with AL-CA, MM, MGUS or non-clonal LCs from healthy volunteers (HV), 2) identify LCs' cardiotoxicity and 3) investigate the underlying mechanisms of cardiotoxicity in vitro.

Methods

Bone marrow derived CD138+ cells from n=7 patients with AL-CA, n=2 patients with MM and n=2 patients with MGUS and peripheral blood mononuclear cells (PBMCs) from n=2 HV were isolated for RNA extraction and characterization of the LC gene family repertoire. At the protein level, LC expression was confirmed by immunoprecipitation in patients' serum followed by top-down proteomics. The overexpressed LC genes in each patient, encoding the full-length clonal LCs were cloned and produced in Shuffle E. coli cells. Two LCs were produced from HV based on the primary protein structure similarity with the patients' LCs. Primary adult ventricular murine cardiomyocytes (pAVMCs) were isolated and exposed at various LC concentrations for evaluation of cell death and investigation of the cardiotoxicity mechanisms via gene and protein expression. LCs folding, oligomerization and amyloidogenic potential were assessed via circular dichroism (CD), SDS page and electron microscopy respectively.

Results

We successfully identified the LCs responsible for the disease and isolated the respective proteins in all cases (7 AL-CA, 2 MM, 2 MGUS and 3 HV). Despite the similarity of the LCs in conformation as beta-sheet and oligomerization mainly as dimers, 5 out of 7 AL-CA derived LCs led to a different extent of cardiotoxicity in pAVMCs compared to the HV, MM and MGUS derived LCs which did not alter cell viability. Interestingly, these 5 LCs bared the highest amyloidogenic potency. LCs induced different molecular responses leading to cardiomyocyte death. AL-CA proteins κ-type induced apoptosis and overexpression of endoplasmic reticulum stress (ERS) markers while LCs λ-type increased unfolded protein response (UPR) markers and autophagy without inducing apoptosis. All LCs of κ-type including from MM and MGUS patients led to inteleukin-6 mediated inflammation indicating that this mechanism is independent of the observed toxicity.

Conclusions

AL-CA derived LCs induce cardiotoxicity, which correlates to their amyloidogenic potential via ERS, UPR, autophagy and apoptosis which can be considered targets for cardioprotection.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Hellenic Foundation for Research and Innovation

Mineralocorticoid receptor signaling is implicated in carfilzomib-induced increase in blood pressure

Introduction

Carfilzomib (Cfz), an irreversible proteasome inhibitor, is a first line antineoplastic agent indicated for relapsed/refractory multiple myeloma, with its clinical use being hampered by cardiovascular adverse effects. Hypertension, is the most common cardiovascular side effect of Cfz, remaining of unknown pathogenicity.

Purpose

Considering that management of Cfz-related hypertension remains an unmet clinical need and that renal function plays a pivotal role in blood pressure regulation we sought to investigate the renal contribution in Cfz-induced hypertension.

Methods

We have previously established a translational model of Cfz-induced cardiomyopathy, based on clinically applicable dose regimens and we have concluded that two and four dose protocols successfully resemble the clinical observations in vivo. Herein, sixty C57Bl/6 male mice (12–14 weeks old) were randomized to: 1. Two doses Protocol: i. Control (N/S 0.9%), ii. Cfz (8mg/kg) for two consecutive days; and 2. Four doses Protocol: i. Control (N/S 0.9%), ii. Cfz (8mg/kg) for seven days intraperitoneally. Systolic (SBP) and diastolic blood pressure (DBP) were measured by tail cuffs; the latter protocol was repeated and urine collection was performed via metabolic cages studies. Renal samples were collected for histological, proteomic, metabolomic and molecular signaling analyses. Finally, eplerenone, a mineralocorticoid receptor (MR) blocker, was orally co-administered with Cfz to the mice daily (165 mg/kg) in the four doses protocol.

Results

Cfz increased SBP only in the four doses protocol (78.50±2.05 vs 68.20±0.73 in the Control group, **P<0.01). Histological evaluation of the kidneys revealed a juxtaglomerular apparatus hyperplasia (JAH) in the same dose regimen. Proteomic analysis presented that metabolic and transport of small molecules pathways were differentially regulated in the Cfz treated murine kidneys. Metabolomic analysis revealed an increase in urea cycle metabolites (L-Alanine, L-Glutamine, glutamate, aspartate) and taurine content in the kidneys. Additionally, mice presented decreased diuresis without any differences in other metabolic parameters. In parallel an upregulation of β-ENaC expression and activation of MR/SGK-1 signaling in the kidneys was observed, indicating that Cfz activates MR signaling. Co-administration of eplerenone and Cfz, restored diuresis, decreased SBP and inhibited MR/SGK-1 signaling in the kidneys.

Conclusions

Activation of MR signaling by Cfz in the kidneys orchestrates renal water/salt retention and drives an increase in blood pressure in vivo. Histological and metabolomic analyses present that Cfz induces an acute kidney injury and a tonicity increase. Eplerenone reversed Cfz-induced blood pressure increase and restored diuresis by inhibiting MR/SGK-1 signaling. Therefore, MR blockade emerges as a potent therapeutic approach against Cfz-related cardiovascular adverse events.

Funding Acknowledgement

Type of funding sources: None.

Effectiveness of fissure sealants on initial caries lesions (ICDAS 1-3) of permanent molars: A 4-year follow-up

AIM

The aim of the present prospective study was to evaluate the retention and effectiveness of two types of sealants (clear vs. opaque) on early pit and fissure occlusal non-cavitated ICDAS II #1-3, caries lesions of permanent posterior teeth of children.

MATERIALS AND METHODS

Study Design: 6986 pit and fissure occlusal surfaces were randomly sealed with clear or opaque sealants out of which, 5828 sealants were placed on sound and 1158 on questionable surfaces, while 3508 were clear and 3478 opaque sealants. The mean age of the sample at initial sealant placement was 9.5 (±2.9) years and the follow-up time was 12-48 months. The median (IQR, range) follow-up time was 17.9 (8.7-28.6) months. Study inclusion and exclusion criteria applied to the combined database in order to select the study sample. Teethmate™ F-1 natural and opaque sealants (Kuraray, Hattersheim am Main, Germany) were applied following the standard procedure of preparation with moisture control kept by cotton rolls handled Dri-Angles" and a 30 seconds acid-etch with 37% ortho-phosphoric acid gel was used followed by 10 sec air-water spraying washing and polymerization for 20x2 sec. Sealants were applied on sound tooth surfaces (ICDAS #0) with no visible defects or on surfaces with early caries lesions (ICDAS #1-3), randomly and interchangeably on the upper or lower Jaw. Total retention was considered when all pits and fissures were completely sealed, while partial or complete loss was scored as one code, although was registered separately.

STATISTICS

Separate analyses were performed for each type of failure (loss of sealant or restoration). Cumulative probabilities of failure over time after sealant placement, overall or by specific characteristics, were calculated using the Kaplan-Meier method. Association between these characteristics and the hazard of failure were investigated using appropriate Cox proportional hazard models.

RESULTS

Sealed surfaces with ICDAS II # 1-3, showed 100% higher probability of having a restoration and 60% higher probability of sealant loss, with both differences being statistically significant (aHR=2.03, p=0.046), adjusted for age, sex, type of sealant and location of surface. Opaque sealants presented statistically significant (p 0.009) higher re-application rate, while fissures had 70% statistically significant (p<0.001) higher probability for resealing with time compared to pits, with gender not affecting sealant retention while the earlier a sealant was placed on children's teeth, the more probable it was to need resealing or restoration (p <0.012).

CONCLUSIONS

The therapeutic use of sealants on occlusal surfaces of posterior permanent molars with early carious lesions (ICDAS II 1-3) is inferior compared to sound surfaces, showing higher sealant failures and restorations.

Experiences of workers with disabilities receiving supported employment services in Greece

People with disabilities (PwDs) are under-represented in the workforce, especially during times of economic recession. Supported employment is recognized as an effective practice for promoting work inclusion of PwDs, including people with intellectual disabilities (IDs). This study aimed at exploring the experiences of workers with ID or mental health conditions who received supported employment services in Greece. Semi-structured interviews were conducted with nine workers with ID and five with mental health conditions. The thematic analysis revealed that emotional pressure was experienced by the participants with mental health conditions and those with ID during the job search and the adaptation period, respectively. On-the-job training was available for the participants with ID and assistance in finding suitable job opportunities was given to those with mental health conditions. All participants highlighted the importance of maintaining employment. The findings can inform efforts on developing employment services targeting social and work inclusion for PwDs.

Reinforcing adherence to lipid-lowering therapy after an acute coronary syndrome: A pragmatic randomized controlled trial

BACKGROUND AND AIMS

Achieving the low-density lipoprotein cholesterol (LDL-C) goal following an acute coronary syndrome (ACS) is a milestone often missed due to suboptimal adherence to secondary prevention treatments. Whether improved adherence could result in reduced LDL-C levels is unclear. We aimed to evaluate whether an educational-motivational intervention increases long-term lipid-lowering therapy (LLT) adherence and LDL-C goal attainment rate among post-ACS patients.

METHODS

IDEAL-LDL was a parallel, two-arm, single-center, pragmatic, investigator-initiated randomized controlled trial. Hospitalized patients for ACS were randomized to a physician-led integrated intervention consisting of an educational session at baseline, followed by regular motivational interviewing phone sessions or usual care. Co-primary outcomes were the LLT adherence (measured by Proportion of Days Covered (PDC); good adherence defined as PDC>80%), and LDL-C goal (<70 mg/dl or 50% reduction from baseline) achievement rate at one year.

RESULTS

In total, 360 patients (mean age 62 years, 81% male) were randomized. Overall, good adherence was positively associated with LDL-C goal achievement rate at one year. Median PDC was higher in the intervention group than the control group [0.92 (IQR, 0.82-1.00) vs. 0.86 (0.62-0.98); p = 0.03] while the intervention group had increased odds of good adherence (odds ratio: 1.76 (95% confidence interval 1.02 to 2.62; p = 0.04). However, neither the LDL-C goal achievement rate (49.6% in the intervention vs. 44.9% in the control group; p = 0.49) nor clinical outcomes differed significantly between the two groups.

CONCLUSIONS

Α multifaceted intervention improved LLT adherence in post-ACS patients without a significant difference in LDL-C goal attainment.

Quality of life and vocational education service quality in students with intellectual disability

The aim of the study was to investigate the relation between subjective quality of life and quality of vocational education services from the view of students with intellectual disability who participate in public special vocational education schools in Greece. The level of quality of life and quality of special vocational education services was explored. The article presents a functional description of service quality in special vocational education and operationalizes quality of life for students with disability. Instruments were developed and adapted in line with the participatory research paradigm. Convenience sampling was used. Data was gathered from 131 students with intellectual disability. All measures showed good evidence of internal consistency and construct validity. The findings suggest relationship between quality of life and quality of special vocational education services received by students with intellectual disability. Low levels of self-determination are highlighted. Practical implications concerning the application of the instruments in special education settings as measures for the quality assessment and the evaluation of educational interventions are discussed.

Treatment practices and lipid profile of patients with acute coronary syndrome: results from a tertiary care hospital

Background: Considering the increasing burden of cardiovascular risk factors and recent advances on the management of acute coronary syndromes (ACS), we studied the epidemiological characteristics and treatment strategies of patients presenting with ACS. We also evaluated the lipid profile and attainment of lipid goals in a 'real world' clinical setting.Methods: This was a substudy of IDEAL-LDL (Motivational interviewing to support low-density lipoprotein cholesterol (LDL-C) therapeutic goals and lipid-lowering therapy compliance in patients with acute coronary syndromes), a single-centre, prospective, randomised controlled trial. Baseline data from a total of 357 ACS patients were gathered using standardised methods.Results: Median age of patients was 60 years and 81.2% were males. Arterial hypertension and smoking were the most prevalent risk factors for coronary artery disease (CAD). Patients with ST-elevation myocardial infarction (STEMI) were heavier smokers, but were younger and exercised more compared to those with non-ST-elevation acute coronary syndrome (NSTE-ACS). Conversely, more NSTE-ACS patients had arterial hypertension, dyslipidaemia and diabetes mellitus. One-fifth of ACS patients was treated conservatively without a percutaneous coronary intervention (PCI). A combination of statin, dual antiplatelet therapy and beta-blockers were prescribed to 79.6% of patients upon discharge. A renin-angiotensin-aldosterone system inhibitor and a beta-blocker were prescribed to 67.3 and 91.8% of patients with LVEF ≤40%, respectively. Of patients with prior history of CAD, 63.1%, 71.4% and 58.3% received regularly statins, antiplatelets and beta-blocker treatment, respectively. Only 22.3% of these CAD patients had an optimal LDL-C of <70 mg/dl at admission.Conclusions: In hospitalised patients with ACS, management practices differed by ACS type and discharge medication was, mostly, in line with the latest guidelines. However, medication adherence and lipid lowering goals of secondary CAD prevention were largely unachieved.

Challenges for the labor market: 2 complementary approaches to premature cessation of occupational activity

OBJECTIVES

Current demographic trends, such as society aging, the spreading of chronic diseases, as well as early retirement choices, lead to the dwindling labor market population. Taking into consideration the foregoing tendencies and their consequences, the issue of the shrinking labor force resources seems to be the most important challenge for the labor market. In response to it, this paper identifies individual and institutional causes of withdrawal from the labor market, and explores the views of Polish stakeholders on existing strategies for the occupational re-integration of persons with chronic diseases (PwCDs).

MATERIAL AND METHODS

Polish results of 2 European projects: "Participation to Healthy Workplaces and Inclusive Strategies in the Work Sector" (the PATHWAYS project) and "The Collaborative Research on Aging in Europe" (COURAGE in Europe) complemented each other. The cross-sectional population data and data from stakeholders' interviews were used.

RESULTS

The authors identified several causes which could encourage people to withdraw from the labor market before attaining the official retirement age at 3 different levels: individual, occupational, and institutional. Although research has shown that the macro-level situation is crucial to staying occupationally active, in Poland stakeholders have reported the lack of effective coordination in the implementation of policies for the occupational re-integration of PwCDs.

CONCLUSIONS

A decision to cease work prematurely reflects a combination of many different factors, such as individual determinates, work characteristics, personal convictions, and systemic solutions. The study demonstrated that, despite the awareness of the dwindling resources of labor force, the employment-related challenges faced by PwCDs as well as people who are close to the retirement age remain unaddressed. Int J Occup Med Environ Health. 2019;32(5):695-721.

What Persons with Chronic Health Conditions Need to Maintain or Return to Work-Results of an Online-Survey in Seven European Countries

Chronic health conditions represent the major share of the disease burden in Europe and have a significant impact on work. This study aims to: (1) identify factors that have a negative or positive impact on the work lives of persons with chronic health conditions; (2) explore the needs of these persons to maintain a job or return to work and (3) compare these results with respect to these persons' occupational status. An online survey was performed in seven European countries. Open-ended survey questions were analyzed using qualitative methods. In total, 487 participants with six chronic health conditions participated. The majority of participants named work-related aspects (such as career development, stress at the workplace, work structure and schedule as well as workload), support of others and attitudes of others as being the factors positively and negatively impact their work lives the most. Our study shed light on the importance of changing the attitudes of supervisors and co-workers to counteract stigmatization of persons with chronic health conditions in the workplace. In conclusion, this study provides a basis for developing new strategies of integration and reintegration at work for persons with chronic health conditions in European countries.

Effectiveness of Integration and Re-Integration into Work Strategies for Persons with Chronic Conditions: A Systematic Review of European Strategies

Due to low employment rates associated to chronic conditions in Europe, it is essential to foster effective integration and re-integration into work strategies. The objective of this systematic review is to summarize the evidence on the effectiveness of strategies for integration and re-integration to work for persons with chronic diseases or with musculoskeletal disorders, implemented in Europe in the past five years. A systematic search was conducted in MedLine, PsycINFO, CDR-HTA, CDR-DARE and Cochrane Systematic Reviews. Overall, 32 relevant publications were identified. Of these, 21 were considered eligible after a methodological assessment and included. Positive changes in employment status, return to work and sick leave outcomes were achieved with graded sickness-absence certificates, part-time sick leave, early ergonomic interventions for back pain, disability evaluation followed by information and advice, and with multidisciplinary, coordinated and tailored return to work interventions. Additionally, a positive association between the co-existence of active labour market policies to promote employment and passive support measures (e.g., pensions or benefits) and the probability of finding a job was observed. Research on the evaluation of the effectiveness of strategies targeting integration and re-integration into work for persons with chronic health conditions needs, however, to be improved and strengthened.

The Roles of Self-Efficacy, Peer Interactions and Attitudes in Bully-Victim Incidents

This study examines the relationship between both bullying and victimization (as a whole and in its different forms) and: (a) self-efficacy measures; (b) peer-interactions and (c) attitudes towards bullying and victimization. It also examined whether bully/victims are a distinct group in terms of the above-mentioned variables. The sample consisted of 448 4th to 6th grade primary education pupils (206 girls, 242 boys). The results of the study clearly indicate that self-efficacy measures, peer interactions and attitudes are associated with both bullying and victimization. In particular: (a) high self-efficacy for aggression is associated with both bullying and victimization, whereas high-self efficacy for assertion and for intervening in bully/victim situations is associated with lower scores on physical victimization for boys and girls respectively; (b) higher scores on positive interactions with peers are associated with lower scores on victimization and (c) higher scores on pro-bully attitudes are associated with higher scores on both bullying and victimization. Bully/victims seem to be a distinct group in terms of their strong pro-bully attitudes and their lack of positive interactions. They are also found to be similar to bullies with respect to self-efficacy for aggression but similar to victims with respect to self-efficacy for assertion. The results of the study are discussed in terms of their implications for school practice and intervention policy.

Motivational beliefs, cognitive engagement, and achievement in language and mathematics in elementary school children

The contextual differences in the patterns of relations among various motivational, cognitive, and metacognitive components of self-regulated learning and performance in two key curriculum subject areas, language and mathematics, were examined in a sample of 263 Greek primary school children of fifth- and sixth-grade classrooms. Age and gender differences were also investigated. Students were asked to complete the Motivated Strategies for Learning Questionnaire (Pintrich & De Groot, 1990 ), which comprised five factors: (a) Self-efficacy, (b) Intrinsic Value, (c) Test Anxiety, (d) Cognitive Strategy Use, and (e) Self-regulation Strategies. They responded to the statements of the questionnaire on a 7-point Likert scale in terms of their behaviour in mathematics and language classes, respectively. Moreover, their teachers were asked to evaluate each of their students' academic achievement in Greek language and mathematics on a 1- to 20-point comparative scale in relation to the rest of the class. The results of the study indicated very few differences in the pattern of relations among self-regulated components within and across the two subject areas and at the same time revealed a context-specific character of self-regulated components at a mean level differences. Further, the current study (a) confirmed the mediatory role of strategies in the motivation-performance relation, (b) stressed the differential role of cognitive and regulatory strategies in predicting performance in subject areas that differ in their structural characteristics of the content, and (c) pointed out the key motivational role of self-efficacy. In fact, self-efficacy proved the most significant predictor not only of performance but of cognitive and regulatory strategy use as well. Gender differences in motivation and strategy use were not reported, while motivation was found to vary mainly with age. The usefulness of these findings for promoting greater clarity among motivational and metacognitive frameworks and ideas for future research are discussed. Cette étude porte sur les différences contextuelles dans les patrons relationnels entre les diverses composantes motivationnelle, cognitive et métacognitive de l'apprentissage et de la performance auto-régulés dans deux domaines d'étude clé du programme, soit la langue et les mathématiques. Ces différences contextuelles ont été examinées dans un échantillon de 263 d'enfants d'une école primaire grecque (of) en cinquième et sixième année. Les différences sexuelles et les différences d'âge ont été aussi étudiées. Les élèves ont été priés de compléter le «Motivated Strategies for Learning Questionnaire» (Pintrich & De Groot, 1990 ) qui comprend cinq facteurs: (a) l'auto-efficacité, (b) la valeur intrinsèque, (c) un test d'anxiété, (d) l'utilisation d'une stratégie cognitive et (e) les stratégies d'auto-régulation. Ils ont répondu aux énoncés du questionnaire sur une échelle de type Likert à 7 points en termes de leur comportement en classe de langue et en classe de mathématiques séparément. De plus, les enseignants ont été priés d'évaluer chaque résultat de leurs élèves dans la langue grecque et en mathématique sur une échelle allant de 1 à 20 points en comparaison au reste de la classe. Les résultats de l'étude ont indiqué très peu de différences dans les patrons relationnels entre les composantes auto-régulées à l'intérieur et entre les domaines d'étude. En même temps, les résultats ont révélé un caractère contextuel spécifique des composantes auto-regulées. De plus, la présente étude (a) a confirmé le rôle médiateur des stratégies dans la relation motivation-performance, (b) a souligné le rôle différé des stratégies cognitive et régulatoire dans la prédiction de la performance dans les domaines d'étude qui diffèrent dans leurs caractéristiques structurelles du contenu et (c) a souligné le rôle motivationnel clé de l'auto-efficacité. En effet, l'auto-efficacité s'est avérée être le prédicteur le plus significatif non seulement de la performance mais aussi de l'utilisation d'une stratégie cognitive et régulatoire. Des différences sexuelles dans la motivation et dans l'utilisation d'une stratégie n'ont pas été rapportées alors qu'il s'est avéré que la motivation variait principalement en fonction de l'âge. L'utilité de ces résultats pour la promotion d'une grande clarté entre les cadres motivationnel et métacognitif et les idées pour les études futures sont discutées. Se examinó, en una muestra de 263 niños griegos de quinto y sexto años de la escuela primaria, las diferencias contextuales en las pautas con las que se dan las relaciones entre varios componentes motivacionales, cognitivos y meta cognitivos del aprendizaje autorregulado y el desempeño en dos áreas clave del currículo, lenguaje y matemáticas. También se investigó las diferencias de edad y género. Se pidió a los alumnos que respondieran el Cuestionario de Estrategias Motivadas para el Aprendizaje (Pintrich & De Groot, 1990 ), compuesto por cinco factores: (a) Auto eficacia, (b) Valor Intrínseco, (c) Ansiedad ante los Exámenes, (d) Empleo de Estrategias Cognitivas, y (e) Estrategias Autorreguladas. Respondieron a los enunciados del cuestionario sobre una escala Likert de 7 puntos en términos de su conducta en las clases de matemáticas y lenguaje por separado. Es más, se pidió a sus profesores que evaluaran el desempeño de cada uno de sus estudiantes en Lenguaje Griego y Matemáticas de acuerdo con una escala comparativa de 1 a 20 puntos, en relación con el resto del grupo escolar. Los resultados del estudio indicaron pocas diferencias en la pauta que describen las relaciones entre los componentes de autorregulación al interior de y entre ambas áreas de estudio y, al mismo tiempo, revelaron un carácter específico del contexto de los componentes de la autorregulación con diferencias en el nivel medio. Más aún, el presente estudio (a) confirmó el papel de mediador que desempeñan las estrategias sobre la relación motivación-desempeño, (b) acentuó el papel diferencial de las estrategias cognitiva y reguladora al predecir el desempeño en áreas de estudio que difieren en las características estructurales de su contenido, y (c) señaló el papel motivacional clave que desempeña la auto eficacia. De hecho, la auto eficacia predijo de manera más significativa no sólo el desempeño, sino también el uso de la estrategia cognitiva y reguladora. No hubo diferencias de género respecto a la motivación y al uso de la estrategia, aunque se encontró que la motivación varía principalmente con la edad. Se discute la utilidad de estos hallazgos para aclarar los referentes motivacionales y meta cognitivos y promover ideas para investigaciones futuras.

Phosphorylation-dependent binding of hepatitis B virus core particles to the nuclear pore complex

Although many viruses replicate in the nucleus, little is known about the processes involved in the nuclear import of viral genomes. We show here that in vitro generated core particles of human hepatitis B virus bind to nuclear pore complexes (NPCs) in digitonin-permeabilized mammalian cells. This only occurred if the cores contained phosphorylated core proteins. Binding was inhibited by wheat germ agglutinin, by antinuclear pore complex antibodies, and by peptides corresponding either to classical nuclear localization signals (NLS) or to COOH-terminal sequences of the core protein. Binding was dependent on the nuclear transport factors importins (karyopherins) alpha and beta. The results suggested that phosphorylation induces exposure of NLS in the COOH-terminal portion of the core protein that allows core binding to the NPCs by the importin- (karyopherin-) mediated pathway. Thus, phosphorylation of the core protein emerged as an important step in the viral replication cycle necessary for transport of the viral genome to the nucleus.

Fluoride concentrations of infant foods and drinks in the United Kingdom

Fluoride analyses of baby foods were carried out using a microdiffusion technique, which was found to be reproducible and accurate with less than 8% error. Analysis of 113 baby foods and drinks showed a wide range of fluoride concentrations: 0.01-0.31 mg F/kg for baby milk products; 0.04-0.72 mg F/kg for meat products; 0.04-0.70 mg F/kg for cereals; 0.03-0.48 mg F/kg for vegetable products; 0.03-0.07 mg F/kg for fruits; 0.02-0.28 mg F/kg for desserts, and 0.01-0.51 mg F/l for baby drinks. None of the baby foods and drinks contained fluoride of a sufficiently high concentration to be of concern or likely to contribute to enamel mottling, when used in the normal way.