Glucose metabolism and oscillatory behavior of pancreatic islets

A variety of oscillations are observed in pancreatic islets.We establish a model, incorporating two oscillatory systems of different time scales: One is the well-known bursting model in pancreatic beta-cells and the other is the glucose-insulin feedback model which considers direct and indirect feedback of secreted insulin. These two are coupled to interact with each other in the combined model, and two basic assumptions are made on the basis of biological observations: The conductance g_{K(ATP)} for the ATP-dependent potassium current is a decreasing function of the glucose concentration whereas the insulin secretion rate is given by a function of the intracellular calcium concentration. Obtained via extensive numerical simulations are complex oscillations including clusters of bursts, slow and fast calcium oscillations, and so on. We also consider how the intracellular glucose concentration depends upon the extracellular glucose concentration, and examine the inhibitory effects of insulin.Comment: 11 pages, 16 figure

Human neutrophil phosphodiesterase

Extracts of human neutrophils were examined for phosphodiesterase activity using a radiochemical assay. As reported by other investigators, both high- and low- K m forms of the enzyme were found. Although calmodulin could be measured in these extracts, human neutrophil phosphodiesterase proved not to be calmodulin dependent. Activity of the neutrophil phosphodiesterase was also not altered by physiologic concentrations of indomethacin, p -bromophenacyl bromide, eicosatetraenoic acid, or eicosatetraynoic acid, all inhibitors of arachidonic acid metabolism. These results are relevant to stimulus-secretion coupling in neutrophils, wherein calmodulin-dependent reactions play a vital role.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44535/1/10753_2004_Article_BF00916094.pd

Treating rheumatoid arthritis to target: the patient version of the international recommendations

To transcribe the treat-to-target (T2T) recommendations into a version that can be easily understood by patients. A core group of physicians and patients involved in the elaboration of the T2T recommendations produced a draft version of the T2T recommendations in lay language. This version was discussed, changed and reworded during a 1-day meeting with nine patients with rheumatoid arthritis (RA) from nine different European countries. Finally, the level of agreement with the translation and with the content of the recommendations was assessed by the patient participants. The project resulted in a patient version of the T2T recommendations. The level of agreement with the translation and the content was high. The group discussion revealed a number of potential barriers for the implementation of the recommendations in clinical practice, such as inequalities in arthritis healthcare provision across Europe. An accurate version of the T2T recommendations that can be easily understood by patients is available and can improve the shared decision process in the management of RA