Glucose Transporter 1 and Monocarboxylate Transporters 1, 2, and 4 Localization within the Glial Cells of Shark Blood-Brain-Barriers

Although previous studies showed that glucose is used to support the metabolic activity of the cartilaginous fish brain, the distribution and expression levels of glucose transporter (GLUT) isoforms remained undetermined. Optic/ultrastructural immunohistochemistry approaches were used to determine the expression of GLUT1 in the glial blood-brain barrier (gBBB). GLUT1 was observed solely in glial cells; it was primarily located in end-feet processes of the gBBB. Western blot analysis showed a protein with a molecular mass of 50 kDa, and partial sequencing confirmed GLUT1 identity. Similar approaches were used to demonstrate increased GLUT1 polarization to both apical and basolateral membranes in choroid plexus epithelial cells. To explore monocarboxylate transporter (MCT) involvement in shark brain metabolism, the expression of MCTs was analyzed. MCT1, 2 and 4 were expressed in endothelial cells; however, only MCT1 and MCT4 were present in glial cells. In neurons, MCT2 was localized at the cell membrane whereas MCT1 was detected within mitochondria. Previous studies demonstrated that hypoxia modified GLUT and MCT expression in mammalian brain cells, which was mediated by the transcription factor, hypoxia inducible factor-1. Similarly, we observed that hypoxia modified MCT1 cellular distribution and MCT4 expression in shark telencephalic area and brain stem, confirming the role of these transporters in hypoxia adaptation. Finally, using three-dimensional ultrastructural microscopy, the interaction between glial end-feet and leaky blood vessels of shark brain was assessed in the present study. These data suggested that the brains of shark may take up glucose from blood using a different mechanism than that used by mammalian brains, which may induce astrocyte-neuron lactate shuttling and metabolic coupling as observed in mammalian brain. Our data suggested that the structural conditions and expression patterns of GLUT1, MCT1, MCT2 and MCT4 in shark brain may establish the molecular foundation of metabolic coupling between glia and neurons

Diagnostic criteria for temporomandibular disorders (DC/TMD) : interexaminer reliability of the Finnish version of Axis I clinical diagnoses

Recently, updated diagnostic criteria for temporomandibular disorders (DC/TMD) were published to assess TMD in a standardised way in clinical and research settings. The DC/TMD protocol has been translated into Finnish using specific cultural equivalency procedures. To assess the interexaminer reliability using the Finnish translations of the DC/TMD-FIN Axis I clinical diagnostic assessment instruments. Reliability assessment data were collected during a 1-day DC/TMD Examiner Training Course at the University of Turku, Finland, in collaboration with the International DC/TMD Training and Calibration Center in Malmo University. Clinical TMD examinations according to the Finnish pre-final version of the DC/TMD Axis I assessment protocol were performed by four experienced TMD specialists on altogether 16 models. Kappa coefficient, overall percentage agreement (%A) as well as positive (PA) and negative (NA) agreements were used to define the reliability. Myofascial pain with referral, headache attributed to TMD and disc displacement (DD) without reduction without limited opening showed excellent kappa values (range 087-100). Fair-to-good reliability was observed for diagnoses of myalgia (k = 067), arthralgia (k = 071) and DD with reduction (k = 064). The PA was high for all pain-related diagnoses and DD without reduction without limited opening (medians 83%), and acceptable for DD with reduction (median 67%). The NA was high (medians 87%) for all DC/TMD diagnoses, except for myalgia which showed acceptable NA (median 75%). The %A was high for all assessed diagnoses (medians >85%). The findings of this study showed DC/TMD-FIN Axis I to demonstrate sufficiently high reliability for pain-related TMD diagnoses

Comparison of Axis II psychosocial assessment methods of RDC/TMD and DC/TMD as part of DC/TMD-FIN phase II validation studies in tertiary care Finnish TMD pain patients

Abstract Background: The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) and Diagnostic Criteria for TMD (DC/TMD) include Axis II instruments for psychosocial assessment. Objectives: The aims were to compare the Finnish versions of Axis II psychosocial assessment methods of the RDC/TMD and DC/TMD and to study their internal reliability. Methods: The sample comprised 197 tertiary care referral TMD pain patients. The associations between RDC/TMD [Graded Chronic Pain Scale (GCPS) 1.0, Symptom Check List 90-revised (SCL-90R)] and DC/TMD (GCPS 2.0, Patient Health Questionnaire-9 (PHQ-9), PHQ-15) assessment instruments were evaluated using Spearman correlation coefficients, Wilcoxon Signed Rank s, chi-squared test and gamma statistics. The internal reliability and internal inter-item consistency of SCL-90-R, PHQ-9, PHQ-15 and Generalized Anxiety Disorder-7 (GAD-7) were evaluated using Cronbach’s alpha coefficient values. Results: The DC/TMD and RDC/TMD Axis II psychosocial instruments correlated strongly (p < .001). GCPS 1.0 and GCPS 2.0 grades were similarly distributed based on both criteria. The RDC/TMD psychological instruments had a higher tendency to subclassify patients with more severe symptoms of depression and non-specific physical symptoms compared to DC/TMD. The internal reliability and internal inter-item consistency were high for the psychological assessment instruments. Conclusions: The Finnish versions of the RDC/TMD and DC/TMD Axis II psychosocial instruments correlated strongly among tertiary care TMD pain patients. Furthermore, the Axis II psychological assessment instruments indicated high validity and internal inter-item consistency and are applicable in Finnish TMD pain patients as part of other comprehensive specialist level assessments, but further psychometric and cut-off evaluations are still needed