German Kilimnik

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Emerging reports on the organization of the different hormone-secreting cell types (alpha, glucagon; beta, insulin; and delta, somatostatin) in human islets have emphasized the distinct differences between human and mouse islets, raising questions about the relevance of studies of mouse islets to human islet physiology. Here, we examine the differences and(More)
OBJECTIVES To develop a novel approach for local immunoprotection using CD4(+)CD25(high)CD127(-) T regulatory cells (Tregs) attached to the surface of the islets before transplantation. BACKGROUND Tregs expanded ex vivo can control allo and autoreactivity, therefore, Treg-based therapy may offer more effective protection for transplanted islets from(More)
The islet of Langerhans is a unique micro-organ within the exocrine pancreas, which is composed of insulin-secreting beta-cells, glucagon-secreting alpha-cells, somatostatin-secreting delta-cells, pancreatic polypeptide-secreting PP cells and ghrelin-secreting epsilon-cells. Islets also contain non-endocrine cell types such as endothelial cells. However,(More)
Emerging reports on human islets emphasize distinct differences from the widely accepted prototype of rodent islets, raising questions over their suitability for human studies. Here we aim at elucidating architectural differences and similarities of human versus rodent islets. The cellular composition and architecture of human and rodent islets were(More)
Human islets exhibit distinct islet architecture with intermingled alpha- and beta-cells particularly in large islets. In this study, we quantitatively examined pathological changes of the pancreas in patients with type 2 diabetes (T2D). Specifically, we tested a hypothesis that changes in endocrine cell mass and composition are islet-size dependent. A(More)
The islets of Langerhans, responsible for controlling blood glucose levels, are dispersed within the pancreas. A universal power law governing the fractal spatial distribution of islets in two-dimensional pancreatic sections has been reported. However, the fractal geometry in the actual three-dimensional pancreas volume, and the developmental process that(More)
The islet of Langerhans is a highly vascularized micro-organ consisting of not only ß-cells but multiple cell types such as α-, delta-, pancreatic polypeptide- and epsilon-cells that work together to regulate glucose homeostatis. We have recently proposed a new model of the neonatal islet formation in mice by a process of fission following contiguous(More)
The islets of Langerhans, micro-organs for maintaining glucose homeostasis, range in size from small clusters of <10 cells to large islets consisting of several thousand endocrine cells. Islet size distributions among various species are similar and independent of body size, suggesting an intrinsic limit to islet size. Little is known about the mechanisms(More)
Human islets exhibit distinct islet architecture particularly in large islets that comprise of a relatively abundant fraction of α-cells intermingled with β-cells, whereas mouse islets show largely similar architecture of a β-cell core with α-cells in the periphery. In humans, islet architecture is islet-size dependent. Changes in endocrine cell mass(More)
Tracing changes of specific cell populations in health and disease is an important goal of biomedical research. Precisely monitoring pancreatic beta-cell proliferation and islet growth is a challenging area of research. We have developed a method to capture the distribution of beta-cells in the intact pancreas of transgenic mice with fluorescence-tagged(More)