Effect of repaglinide on endothelial dysfunction during a glucose tolerance test in subjects with impaired glucose tolerance

BACKGROUND: Impaired glucose tolerance (IGT) is associated with increased cardiovascular risk. The pathophysiological mechanisms linking post-challenge hyperglycemia to accelerated atherosclerosis, however remain to be elucidated. METHODS: A prospective, open, randomised, cross-over study was performed to investigate the effect of 2 mg repaglinide on hyperglycemia and endothelial function during an oral glucose tolerance test (75 g glucose) in 12 subjects with diagnosed IGT. Blood samples for determination of plasma glucose were drawn fasting, 1 and 2 hours after glucose ingestion. Endothelial function was assessed by measuring flow-mediated dilatation (FMD) of the brachial artery with high-resolution ultrasound. RESULTS: Administration of repaglinide resulted in a significant reduction of plasma glucose at 2 hours (172.8+/-48.4 vs. 138.3+/-41.2 mg/dl; p < 0.001). The flow-mediated dilatation (FMD) 2 hours after the glucose-load was significantly reduced in comparison to fasting in the control group (6.21+/-2.69 vs. 7.98+/-2.24 %; p = 0.028), whereas after theadministration of repaglinide the FMD was not significantly different to fasting values (7.24+/-2.57 vs. 8.18+/-2.93 %; p = n.s.). Linear and logistic regression analysis revealed that only the change of glucose was significantly correlated to the change of FMD observed (p < 0.001). Regression analysis after grouping for treatment and time confirmed the strong negative association of the changes of plasma glucose and FMD and indicate that the effect of repaglinide observed is based on the reduction glycemia. CONCLUSION: In subjects with IGT, the endothelial dysfunction observed after a glucose challenge is related to the extent of hyperglycemia. Reduction of hyperglycemia by repaglinide reduces endothelial dysfunction in a glucose dependent manner

In situ study of dynamic recrystallization and hot deformation behavior of a multiphase titanium aluminide alloy

Hot-compression tests were conducted in a high-energy synchrotron x-ray beam to study in situ and in real time microstructural changes in the bulk of a β-solidifying titanium aluminide alloy. The occupancy and spottiness of the diffraction rings have been evaluated in order to access grain growth and refinement, orientation relationships, subgrain formation, dynamic recovery, and dynamic recrystallization, as well as phase transformations. This method has been applied to an alloy consisting of two coexisting phases at high temperature and it was found that the bcc β-phase recrystallizes dynamically, much faster than the hcp α-phase, which deforms predominantly through crystallographic slip underpinned by a dynamic recovery process with only a small component of dynamic recrystallization. The two phases deform to a very large extent independently from each other. The rapid recrystallization dynamics of the β-phase combined with the easy and isotropic slip characteristics of the bcc structure explain the excellent deformation behavior of the material, while the presence of two phases effectively suppresses grain growth

Implementing Model-Based Data Structures using Transient Model Extensions

Abstract — Software is often constructed using a layered approach to encapsulate various functionality in corresponding layers. Individual requirements of each layer demand layer specific data structures. These data structures typically provide redundant information with respect to the data source. Providing a Model Driven Software Development approach for creating these data structures leads to overlapping data models, each containing data structures defined by the data source. Because putting all various requirements of the software layers in a single data model can lead to difficulties, each software layer should only extend the basic data source model with its specifically needed model elements. The approach presented in this paper applies a mechanism for a dynamic extension of a data model. This extension mechanism is used in the implementational activity of a software process, and allows the changing of a model within a local scope. Using this mechanism, a basic data model can be used by every layer, being extended by additional attributes and classes for satisfying layer specific requirements. Index Terms — Model-driven development, Data modeling, Data Intensive Systems, Software layer

Supraglottic airway devices during neonatal resuscitation: An historical perspective, systematic review and meta-analysis of available clinical trials

INTRODUCTION: Various supraglottic airway devices are routinely used to maintain airway patency in children and adults. However, oropharyngeal airways or laryngeal masks (LM) are not routinely used during neonatal resuscitation. METHODS: The aim of this article was to review the available literature about the use of supraglottic airway devices during neonatal resuscitation. We reviewed books, resuscitation manuals and articles from 1830 to the present using the search terms "Infant", "Newborn", "Delivery Room", "Resuscitation", "Airway management", "Positive Pressure Respiration", "Oropharyngeal Airway" and "Laryngeal Mask". RESULTS: No study was identified using oropharyngeal airways during neonatal resuscitation. Four trials including 509 infants compared positive pressure ventilation with a LM, bag and mask or an endotracheal tube. Infants in the LM group were intubated less frequently compared to infants in the bag and mask ventilation group 4/275 vs. 28/234 (OR 0.13, 95% CI 0.05-0.34). Infants resuscitated with the LM had significantly less unsuccessful resuscitations 4/275 vs. 31/234 (OR 0.10, 95% CI 0.03-0.28). Two trials including 34 preterm infants compared surfactant administration via LM vs. endotracheal tube. LM surfactant administration was safe and no adverse events were reported. CONCLUSION: The efficacy and safety of oropharyngeal airways during neonatal resuscitation remain unclear and randomized trials are required. The current evidence suggests that resuscitation with a LM is a feasible and safe alternative to mask ventilation in infants >34 weeks gestation and birth weight >2000 g. However, further randomized control trials are needed to evaluate short- and long-term outcomes following use of laryngeal masks. In addition, surfactant administration via LM should be used only within clinical trials