57 research outputs found

    Teacher Wellbeing: The Importance of Teacher–Student Relationships

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    Many studies have examined the importance of teacher-student relationships for the development of children. Much less is known, however, about how these relationships impact the professional and personal lives of teachers. This review considers the importance of teacher-student relationships for the wellbeing of teachers guided by the Transactional Model of Stress and Coping of Lazarus (1991). Based on theories on interpersonal relationships, it is postulated that teachers have a basic need for relatedness with the students in their class that originates from the close proximity between teacher and student. It is discussed that teachers internalize experiences with students in representational models of relationships that guide emotional responses in daily interactions with students, and changes teacher wellbeing in the long run. In addition, the notion of mental representations of relationships at different levels of generalization could offer a window to understand how individual teacher-student relationships may affect the professional and personal self-esteem of teachers. Lastly, it is argued that the influence of student misbehavior on teacher stress may be more fully understood from a relationship perspective. The review shows that few studies have directly tested these propositions and offers suggestions for future research

    Tracking human multiple myeloma xenografts in NOD-Rag-1/IL-2 receptor gamma chain-null mice with the novel biomarker AKAP-4

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    <p>Abstract</p> <p>Background</p> <p>Multiple myeloma (MM) is a fatal malignancy ranking second in prevalence among hematological tumors. Continuous efforts are being made to develop innovative and more effective treatments. The preclinical evaluation of new therapies relies on the use of murine models of the disease.</p> <p>Methods</p> <p>Here we describe a new MM animal model in NOD-Rag1null IL2rgnull (NRG) mice that supports the engraftment of cell lines and primary MM cells that can be tracked with the tumor antigen, AKAP-4.</p> <p>Results</p> <p>Human MM cell lines, U266 and H929, and primary MM cells were successfully engrafted in NRG mice after intravenous administration, and were found in the bone marrow, blood and spleen of tumor-challenged animals. The AKAP-4 expression pattern was similar to that of known MM markers, such as paraproteins, CD38 and CD45.</p> <p>Conclusions</p> <p>We developed for the first time a murine model allowing for the growth of both MM cell lines and primary cells in multifocal sites, thus mimicking the disease seen in patients. Additionally, we validated the use of AKAP-4 antigen to track tumor growth <it>in vivo </it>and to specifically identify MM cells in mouse tissues. We expect that our model will significantly improve the pre-clinical evaluation of new anti-myeloma therapies.</p

    Galectin-3C Inhibits Tumor Growth and Increases the Anticancer Activity of Bortezomib in a Murine Model of Human Multiple Myeloma

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    Galectin-3 is a human lectin involved in many cellular processes including differentiation, apoptosis, angiogenesis, neoplastic transformation, and metastasis. We evaluated galectin-3C, an N-terminally truncated form of galectin-3 that is thought to act as a dominant negative inhibitor, as a potential treatment for multiple myeloma (MM). Galectin-3 was expressed at varying levels by all 9 human MM cell lines tested. In vitro galectin-3C exhibited modest anti-proliferative effects on MM cells and inhibited chemotaxis and invasion of U266 MM cells induced by stromal cell-derived factor (SDF)-1α. Galectin-3C facilitated the anticancer activity of bortezomib, a proteasome inhibitor approved by the FDA for MM treatment. Galectin-3C and bortezomib also synergistically inhibited MM-induced angiogenesis activity in vitro. Delivery of galectin-3C intravenously via an osmotic pump in a subcutaneous U266 cell NOD/SCID mouse model of MM significantly inhibited tumor growth. The average tumor volume of bortezomib-treated animals was 19.6% and of galectin-3C treated animals was 13.5% of the average volume of the untreated controls at day 35. The maximal effect was obtained with the combination of galectin-3C with bortezomib that afforded a reduction of 94% in the mean tumor volume compared to the untreated controls at day 35. In conclusion, this is the first study to show that inhibition of galectin-3 is efficacious in a murine model of human MM. Our results demonstrated that galectin-3C alone was efficacious in a xenograft mouse model of human MM, and that it enhanced the anti-tumor activity of bortezomib in vitro and in vivo. These data provide the rationale for continued testing of galectin-3C towards initiation of clinical trials for treatment of MM

    Upregulation of p27 and its inhibition of CDK2/cyclin E activity following DNA damage by a novel platinum agent are dependent on the expression of p21

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    The cisplatin analogue 1R,2R-diaminocyclohexane(trans-diacetato)(dichloro)platinumIV (DAP) is a DNA-damaging agent that will be entering clinical trials for its potent cytotoxic effects against cisplatin-resistant tumour cells. This cytotoxicity may reside in its ability to selectively activate G1-phase checkpoint response by inhibiting CDKs via the p53/p21 pathway. We have now evaluated the role of another CDK inhibitor p27 as a contributor to DAP-mediated inhibition of G1-phase CDK2 activity. Our studies in ovarian A2780 tumour cells demonstrate that p27 levels induced by DAP are comparable to or greater than those seen for p21. The induction of p27 is not through a transcriptional mechanism, but rather is due to a four-fold increase in protein stabilisation through a mechanism dependent on p21. Moreover, DAP-induced p21 promoted the selective increase of p27 in the CDK2 complex, but not in CDK4 complex, and this selective increase contributed to inhibition of the CDK2 kinase activity. The inhibited complex contained either p27 or p21, but not both, with the relative levels of cyclin E associated with p27 and p21 indicating that about 25% of the inhibition of CDK2 activity was due to p27 and 75% due to p21. This study provides the first evidence that p27 upregulation is directly attributable to activation of the p53/p21 pathway by a DNA-damaging agent, and promulgates p53/p21/p27 axis as a significant component of checkpoint response

    Short-term variability of the Sun-Earth system: an overview of progress made during the CAWSES-II period

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    RECURRENCE OF PAROXYSMAL ATRIAL-FIBRILLATION OR FLUTTER AFTER SUCCESSFUL CARDIOVERSION IN PATIENTS WITH NORMAL LEFT-VENTRICULAR FUNCTION

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    One hundred twenty-four consecutive patients (85%) with paroxysmal atrial fibrillation (AF) and 21 (15%) with atrial flutter (AFI) were studied immediately after pharmacologic or electrical cardioversion to sinus rhythm. Mean age was 59 +/- 13 years (range 23 to 79). Patients with reduced left ventricular function were excluded from the study. After restoration to sinus rhythm, the clinical course of all patients was followed for the first recurrence of paroxysmal AF or AFI irrespective of the therapeutic approach. Mean follow-up was 23 +/- 16 months. After 12 months of follow-up, 50% of all patients remained in sinus rhythm. Univariate analysis indicated that coronary artery disease (relative risk 1.9; 95% confidence interval 0.9-3.9), history of paroxysmal AF or AFI (2.3; 1.1-5.0), female sex (2.3; 1.1-4.6), pulmonary disease (3.9; 1.9-7.6) and valvular heart disease (4.4; 2.2-8.8) were associated with an increased risk for recurrent or frequent episodes of paroxysmal AF or AFI. No predictors were found to be associated with a decrease in length of the recurrence-free period after successful conversion to sinus rhythm. Multivariate analysis identified history of AF or AFI (odds ratio 2.5; 95% confidence interval 0.9-6.4), coronary artery disease (3.1; 1.1-8.2) and female sex (3.4; 1.3-8.9) as independent predictors for recurrent or frequent episodes of paroxysmal AF or AFI. The presence of these risk factors should be taken into account when prophylactic therapy with antiarrhythmic drugs is being considered in the treatment of paroxysmal AF or AFI

    Solid phase synthesis and antiprotozoal evaluation of di- and trisubstituted 5 '-carboxamidoadenosine analogues

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    The rapid increase of resistance to drugs commonly used in the treatment of tropical diseases such as malaria and African sleeping sickness calls for the prompt development of new safe and efficacious drugs. The pathogenic protozoan parasites lack the capability of synthesising purines de novo and they take up preformed purines from their host through various transmembrane transporters. Adenosine derivatives constitute a class of potential therapeutics due to their selective internalisation by these transporters. Automated solid-phase synthesis can speed up the process of lead finding and we pursued the solid-phase synthesis of di- and trisubstituted 5′-carboxamidoadenosine derivatives by using a safety-catch approach. While efforts with Kenner's sulfonamide linker remained fruitless, successful application of the hydrazide safety-catch linker allowed the construction of two representative combinatorial libraries. Their antiprotozoal evaluation identified two compounds with promising activity: N6-benzyl-5′-N-phenylcarboxamidoadenosine with an IC 50 value of 0.91 μM against Trypanosoma brucei rhodesiense and N6-diphenylethyl-5′-phenylcarboxamidoadenosine with an IC 50 value of 1.8 μM against chloroquine resistant Plasmodium falciparum
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