A predictive model for medium-term weight loss response in people with type 2 diabetes engaging in behavioural weight management interventions.

AIMS: To develop and evaluate prediction models for medium-term weight loss response in behavioural weight management programmes. MATERIALS AND METHODS: We conducted three longitudinal analyses using the Action for HEalth in Diabetes (LookAHEAD) trial, Weight loss Referrals for Adults in Primary care (WRAP) trial, and routine data from the National Health Service Greater Glasgow and Clyde Weight Management Service (NHS-GGCWMS). We investigated predictors of medium-term weight loss (>5% body weight) over 3 years in NHS-GGCWMS and, separately, predictors of weight loss response in LookAHEAD over 4 years. We validated predictors in both studies using WRAP over 5 years. Predictors of interest included demographic and clinical variables, early weight change in-programme (first 4 weeks) and overall in-programme weight change. RESULTS: In LookAHEAD and WRAP the only baseline variables consistently associated with weight loss response were female sex and older age. Of 1152 participants in NHS-GGCWMS (mean age 57.8 years, 60% female, type 2 diabetes diagnosed for a median of 5.3 years), 139 lost weight over 3 years (12%). The strongest predictor of weight loss response was early weight change (odds ratio 2.22, 95% confidence interval 1.92-2.56) per 1% weight loss. Losing 0.5% weight in the first 4 weeks predicted medium-term weight loss (sensitivity 89.9%, specificity 49.5%, negative predictive value 97.3%). Overall in-programme weight change was also associated with weight loss response over 3 years in NHS-GGCWMS and over 5 years in WRAP. CONCLUSIONS: Not attaining a weight loss threshold of 0.5% early in weight management programmes may identify participants who would benefit from alternative interventions.

Viability and Contractility of Rat Brain Pericytes in Conditions That Mimic Stroke; an in vitro Study.

Reopening of the cerebral artery after occlusion often results in "no-reflow" that has been attributed to the death and contraction (rigor mortis) of pericytes. Since this hypothesis still needs to be confirmed, we explored the effects of oxygen glucose deprivation (OGD) on viability and cell death of primary rat pericytes, in the presence or absence of neurovascular unit-derived cytokines. Two morphodynamic parameters, single cell membrane mobility (SCMM) and fractal dimension (Df), were used to analyze the cell contractions and membrane complexity before and after OGD. We found a marginal reduction in cell viability after 2-6 h OGD; 24 h OGD caused a large reduction in viability and a large increase in the number of apoptotic and dead cells. Application of erythropoietin (EPO), or a combination of EPO and endothelial growth factor (VEGFA1-165) during OGD significantly reduced cell viability; application of Angiopoietin 1 (Ang1) during OGD caused a marginal, insignificant increase in cell viability. Simultaneous application of EPO, VEGFA1-165, and Ang1 significantly increased cell viability during 24 h OGD. Twenty minutes and one hour OGD both significantly reduced SCMM compared to pre-OGD values, while no significant difference was seen in SCMM before and after 3 h OGD. There was a significant decrease in membrane complexity (Df) at 20 min during the OGD that disappeared thereafter. In conclusion, OGD transiently affected cell mobility and shape, which was followed by apoptosis in cultured pericytes. Ang1 may have a potentiality for preventing from the OGD-induced apoptosis. Further studies could clarify the relationship between cell contraction and apoptosis during OGD.

Quantitative Determination of Cellular-and Neurite Motility Speed in Dense Cell Cultures.

Mobility quantification of single cells and cellular processes in dense cultures is a challenge, because single cell tracking is impossible. We developed a software for cell structure segmentation and implemented 2 algorithms to measure motility speed. Complex algorithms were tested to separate cells and cellular components, an important prerequisite for the acquisition of meaningful motility data. Plasma membrane segmentation was performed to measure membrane contraction dynamics and organelle trafficking. The discriminative performance and sensitivity of the algorithms were tested on different cell types and calibrated on computer-simulated cells to obtain absolute values for cellular velocity. Both motility algorithms had advantages in different experimental setups, depending on the complexity of the cellular movement. The correlation algorithm (COPRAMove) performed best under most tested conditions and appeared less sensitive to variable cell densities, brightness and focus changes than the differentiation algorithm (DiffMove). In summary, our software can be used successfully to analyze and quantify cellular and subcellular movements in dense cell cultures.

Rat astrocytes during anoxia: Secretome profile of cytokines and chemokines.

INTRODUCTION: The precise mechanisms of the inflammatory responses after cerebral ischemia in vivo are difficult to elucidate because of the complex nature of multiple series of interactions between cells and molecules. This study explored temporal patterns of secretion of 30 cytokines and chemokines from Sprague Dawley rat astrocytes in primary culture in order to elucidate signaling pathways that are triggered by astrocytes during anoxia. METHODS: Primary cultures of rat brain astrocytes were incubated for periods of 2-24 hr in the absence of oxygen (anoxia) or under normal partial pressure of oxygen (controls). Simultaneous detection of 29 cytokines and chemokines in the samples was performed using a rat cytokine array panel, while the temporal pattern of angiopoietin-1 (Ang-1) secretion was determined separately using ELISA. Wilcoxon-Mann-Whitney test was used to compare normoxic and anoxic samples and the Hodge-Lehman estimator with exact 95% confidence intervals was computed to assess the size of differences in cytokine secretion. The obtained data were imported into the Core Analysis tool of Ingenuity Pathways Analysis software in order to relate changes in secretion of cytokines and chemokines from astrocytes during anoxia to potential molecular signal networks. RESULTS: With the exception of Ang-1, concentrations of all cytokines/chemokines in samples collected after anoxia exposure were either the same, or higher, than in control groups. No clear pattern of changes could be established for groups of cytokines with similar effects (i.e., pro- or anti-inflammatory cytokines). The pattern of changes in cytokine secretion during anoxia was associated with the HIF-1α-mediated response, as well as cytokines IL-1ß and cathepsin S pathways, which are related to initiation of inflammation and antigen presentation, respectively, and to ciliary neurotrophic factor. CONCLUSIONS: These in vitro findings suggest that astrocytes may play a role in triggering inflammation during anoxia/ischemia of the brain.