Immunohistochemical Evaluation of Vascular Endothelial Growth Factor(VEGF)in Splenic Hemangiomas and Hemangiosarcomas in Dogs

Formation of new blood vessels is paramount for tumour growth and metastatic dissemination and vascular endothelial growth factor (VEGF) is one of the key regulators of this process. The purpose of this study was to evaluate the immunohistochemical expression of VEGF in 23 splenic hemangiosarcomas and 7 splenic hemangiomas in dogs. Blood tests performed previous to splenectomy were analysed for correlation with tumour VEGF expression. Results showed significantly higher VEGF expression in hemangiosarcomas than hemangiomas and lower hematocrit values and red cell count in dogs affected with malignant neoplasia (P < 0.05). These findings suggest the presence of high VEGF levels may be related to the malignant vascular proliferation seen in hemangiosarcomas.

Multidimensional Pain Inventory(MPI):Adaptation to Orthodontic Patients and Its Psychometric Properties

Background: Pain perception may result from orthodontic treatment and should be considered in clinical management. Its assessment should not be limited to the intensity of perceived pain but should also consider the psychosocial and behavioral aspects involved. Objective: The aims of this study were to adapt and validate the Multidimensional Pain Inventory (MPI) for orthodontic patients, and present a proposal to calculate an overall score of the pain-related aspects and compare these scores with the usual methodology used. Methods: Face validity of the MPI was estimated and orthodontic version (MPI-Orthodontic) was developed. Factorial validity was evaluated by confirmatory analysis. Convergent and discriminant validity and reliability were estimated. The fit of Second-Order Hierarchical Models was estimated. Concurrent validity of MPI-Orthodontic was evaluated against the Visual Analogue Scale. Invariance of the factorial models was evaluated for independent samples and according to sex and age. Overall score was calculated using the matrix of regression weights and compared to simple arithmetic mean. Results: 507 individuals (63.3% women;age: 26.32 (SD = 11.70) years) participated. For the fit of Part I (psychosocial aspects) of the MPI-Orthodontic, it added correlation between two items and excluded one item;for Part II (behavioral aspects) two items were excluded. The models presented adequate fit to the sample. Reliability was adequate. MPI-Orthodontic presented invariance for independent samples and adequate concurrent and divergent validity. Score obtained with the simple arithmetic mean was overestimated for Part I and underestimated for Part II. Conclusion: MPI-Orthodontic was valid, reliable and invariant for the evaluation of the orthodontic pain. It is recommended to calculate overall weighted scores for pain assessment.

Student’s Academic Efficacy or Inefficacy?An Example on How to Evaluate the Psychometric Properties of a Measuring Instrument and Evaluate the Effects of Item Wording

This study evaluated the effect of item inversion on the construct validity and reliability of psychometric scales and proposed a theoretical framework for the evaluation of the psychometric properties of data gathered with psychometric instruments. To this propose, we used the Maslach Burnout Inventory, which is the most used psychometric inventory to measure burnout in different professional context (Students, Teachers, Police, Doctors, Nurses, etc…). The version of the MBI used was the MBI-Student Survey (MBI-SS). This inventory is composed of three key dimensions: Exhaustion, Cynicism and Professional Efficacy. The two first dimensions—which have positive formulated items—are moderate to strong positive correlated, and show moderate to strong negative correlations with the 3rd dimension—which has negative formulated items. We tested the hypothesis that, in college students, formulating the 3rd dimension of burnout as Inefficacy (reverting the negatively worded items in the Efficacy dimension) improves the correlation of the 3rd dimension with the other two dimensions, improves its internal consistency, and the overall MBI-SS’ construct validity and reliability. Confirmatory factor analysis results, estimated by Maximum Likelihood, revealed adequate factorial fit for both forms of the MBI-SS (with Efficacy) vs. the MBI-SSi (with Inefficacy). Also both forms showed adequate convergent and discriminant related validity. However, reliability and convergent validity were higher for the MBI-SSi. There were also stronger (positive) correlations between the 3 factors in MBI-SSi than the ones observed in MBI-SS. Results show that positively rewording of the 3rd dimension of the MBI-SS improves its validity and reliability. We therefore propose that the 3rd dimension of the MBI-SS should be named Professional Inefficacy and its items should be positively worded.