Existing concepts and models for glucose-stimulated insulin secretion (GSIS) are overviewed and a newer perspective has been formulated toward the physiological understanding of GSIS. A conventional model has been created on the basis of in vitro data on application of a square wave high glucose in the absence of any other stimulatory inputs. Glucose elicits rapid insulin release through an adenosine triphosphate-sensitive K + channel (K ATP channel)-dependent mechanism, which is gradually augmented in a K ATP channel-independent manner. Biphasic GSIS thus occurs. In the body, the b-cells are constantly exposed to stimulatory signals, such as glucagon-like peptide 1 (GLP-1), parasympathetic inputs, free fatty acid (FFA), amino acids and slightly suprathreshold levels of glucose, even at fasting. GLP-1 increases cellular cyclic adenosine monophosphate, parasympathetic stimulation activates protein kinase C, and FFA, amino acids and glucose generate metabolic amplification factors. Plasma glucose concentration gradually rises postprandially under such tonic stimulation. We hypothesize that these stimulatory inputs together make the b-cells responsive to glucose independently from its action on K ATP channels. Robust GSIS in patients with a loss of function mutation of the sulfonylurea receptor, a subunit of K ATP channels, is compatible with this hypothesis. Furthermore, pre-exposure of the islets to an activator of protein kinase A and/or C makes b-cells responsive to glucose in a K ATP channel-and Ca 2+-independent manner. We hypothesize that GSIS occurs in islet b-cells without glucose regulation of K ATP channels in vivo, for which priming with cyclic adenosine monophosphate, protein kinase C and non-glucose nutrients are required. To understand the physiology of GSIS, comprehensive integration of accumulated knowledge is required. (J Diabetes Invest,

The results indicate that the Dental 3D-CT imaging system is suitable for clinical assessment of alveolar bone grafting before and after installation of dental implants or orthodontic treatment of the cleft-adjacent teeth.

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Shoots and foliage on branches of old Pseudotsuga menziesii (Mirb.) Franco var. menziesii (coastal Douglas-fir) trees are constantly renewed by epicormic shoot production. Epicormic shoots are produced in all parts of the crown, and epicormic buds remain dormant for 5 or 6 years on average. Epicormic shoot production results in reiteration of shoot cluster units (SCUs), an architectural unit of shoot organization within branches. Five phases of SCU development were identified based on relative age structures of regular and epicormic shoots. SCUs produce epicormic branchlets as early as 3 or 4 years of age, and peak production occurred around 6-13 years. Epicormic branchlets occur toward the proximal end of main axes of SCUs, where regular lateral branchlets are no longer producing new shoots. In some lower-crown branches, nearly 50% of shoots and foliage are epicormic shoots. Demographic analysis of SCUs showed that upper-crown branches are still growing in size, while mid- and lower-crown branches have reached maximum size, and are being maintained by reiteration of SCUs. Epicormic shoot production maintains shoots and foliage of old P. menziesii trees after height growth and crown expansion have stopped and may contribute to prolonging tree longevity.Key words: aging, branch growth, epicormic shoots, longevity, Pseudotsuga menziesii, reiteration.