28 research outputs found
Pharmacologically blocking p53-dependent apoptosis protects intestinal stem cells and mice from radiation.
Exposure to high levels of ionizing radiation (IR) leads to debilitating and dose-limiting gastrointestinal (GI) toxicity. Using three-dimensional mouse crypt culture, we demonstrated that p53 target PUMA mediates radiation-induced apoptosis via a cell-intrinsic mechanism, and identified the GSK-3 inhibitor CHIR99021 as a potent radioprotector. CHIR99021 treatment improved Lgr5+ cell survival and crypt regeneration after radiation in culture and mice. CHIR99021 treatment specifically blocked apoptosis and PUMA induction and K120 acetylation of p53 mediated by acetyl-transferase Tip60, while it had no effect on p53 stabilization, phosphorylation or p21 induction. CHIR99021 also protected human intestinal cultures from radiation by PUMA but not p21 suppression. These results demonstrate that p53 posttranslational modifications play a key role in the pathological and apoptotic response of the intestinal stem cells to radiation and can be targeted pharmacologically
2000 Wild Blueberry Project Reports
The 2000 edition of the Wild Blueberry Project Reports was prepared for the Maine Wild Blueberry Commission and the University of Maine Wild Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include:
1. Determination of Pesticide Residue Levels in Fresh and Processed Wild Blueberries
2. Factors Affecting the Microbiological Quality of IQF Blueberries
3. Effect of Processed Blueberry Products on Oxidation in Meat Based Food Systems
4. Separation of Maggot Infested Wild Blueberries in the IQF Processing Line
5. Water Use of Wild Blueberries
6. Control Tactics for Blueberry Pest Insects, 2000
7. IPM Strategies
8. Biology and Ecology of Blueberry Pest Insects
9. Survey of Stem Blight and Leaf Spot Diseases in Lowbush Blueberry Fields
10. Phosphorus/Nitrogen Fertilizer Ratio
11. Effect of Boron Application Methods on Boron Uptake in Lowbush Blueberries
12. Effect of Foliar Iron and Copper Application on Growth and Yield of Lowbush Blueberries
13. Effect of Soil pH on Nutrient Uptake
14. Effect of Nutri-Phite (tm) P+K on Growth and Yield of Lowbush Blueberry
15. Effect of Fertilizer Timing on Lowbush Blueberry Growth and Productivity
16. Assessment of Azafenidin for Weed Control in Wild Blueberries
17. Assessment of Rimsulfuron for Weed Control in Wild Blueberries
18. Assessment of Pendimethalin for Weed Control in Wild Blueberries
19. Assessment of VC1447 for Weed Control in Wild Blueberries
20. Cultural Management Using pH for Weed Control in Wild Blueberries
21. Evaluation of Sprout-Less Weederยฎ for Weed Control in Wild Blueberries
22. Evaluation of RoundUp Ultraยฎ and Touchdown 5ยฎ for Weed Control in Wild Blueberries
23. Evaluation and Demonstration of Techniques for Filling in Bare Spots in Wild Blueberry Fields
24. Evaluation of Fungicides Efficacy in Wild Blueberry Fields
25. Velparยฎ and Sinbar/Karmexยฎ Demonstration Plot Comparison Trial
26. Blueberry Extension Education Program in 2000
27. 2000 Hexazinone Groundwater Surve
Optics and Quantum Electronics
Contains table of contents for Section 2 and reports on twenty research projects.Charles S. Draper Laboratory Contract DL-H-404179Joint Services Electronics Program Contract DAALO3-89-C-0001National Sciences Foundation Grant EET 87-00474National Science Foundation Grant EET 88-15834U.S. Air Force - Office of Scientific Research Contract F49620-88-C-0089National Science Foundation Grant ECS 85-52701International Business Machines CorporationMassachusetts General Hospital Contract N00014-86K-0117National Institutes of Health Grant 2-RO1-GM35459U.S. Department of Energy Grant DE-FG02-89-ER14012Lawrence Livermore National Laboratory Subcontract B04870
Optics and Quantum Electronics
Contains table of contents for Section 2 and reports on eighteen research projects.National Science Foundation (Grant EET 87-00474)Joint Services Electronics Program (Contract DAAL03-86-K-0002)Joint Services Electronics Program (Contract DAALO3-89-C-0001)Charles Stark Draper Laboratory (Grant DL-H-285408)Charles Stark Draper Laboratory (Grant DL-H-2854018)National Science Foundation (Grant EET 87-03404)National Science Foundation (Grant ECS 84-06290)U.S. Air Force - Office of Scientific Research (Contract F49620-88-C-0089)AT&T Bell FoundationNational Science Foundation (Grant ECS 85-52701)National Institutes of Health (Grant 5-RO1-GM35459)Massachusetts General Hospital (Office of Naval Research Contract N00014-86-K-0117)Lawrence Livermore National Laboratory (Subcontract B048704
Optics and Quantum Electronics
Contains reports on eleven research projects.National Science Foundation (Grant EET 87-00474)Joint Services Electronics Program (Contract DAALO03-86-K-O002)Charles Stark Draper Laboratory, Inc. (Grant DL-H-2854018)National Science Foundation (Grant DMR 84-18718)National Science Foundation (Grant EET 87-03404)National Science Foundation (ECS 85-52701)US Air Force - Office of Scientific Research (Contract AFOSR-85-0213)National Institutes of Health (Contract 5-RO1-GM35459)US Navy - Office of Naval Research (Contract N00014-86-K-0117
Stem cells in liver regeneration and therapy
The liver has adapted to the inflow of ingested toxins by the evolutionary development of unique regenerative properties and responds to injury or tissue loss by the rapid division of mature cells. Proliferation of the parenchymal cells, i.e. hepatocytes and epithelial cells of the bile duct, is regulated by numerous cytokine/growth-factor-mediated pathways and is synchronised with extracellular matrix degradation and restoration of the vasculature. Resident hepatic stem/progenitor cells have also been identified in small numbers in normal liver and implicated in liver tissue repair. Their putative role in the physiology, pathophysiology and therapy of the liver, however, is not yet precisely known. Hepatic stem/progenitor cells also known as โoval cellsโ in rodents have been implicated in liver tissue repair, at a time when the capacity for hepatocyte and bile duct replication is exhausted or experimentally inhibited (facultative stem/progenitor cell pool). Although much more has to be learned about the role of stem/progenitor cells in the physiology and pathophysiology of the liver, experimental analysis of the therapeutic value of these cells has been initiated. Transplantation of hepatic stem/progenitor cells or in vivo pharmacological activation of the pool of hepatic stem cells may provide novel modalities for the therapy of liver diseases. In addition, extrahepatic stem cells (e.g. bone marrow cells) are being investigated for their contribution to liver regeneration. Hepatic progenitor cells derived from embryonic stem cells are included in this review, which also discusses future perspectives of stem cell-based therapies for liver diseases
Transformation of Human Mesenchymal Cells and Skin Fibroblasts into Hematopoietic Cells
Patients with prolonged myelosuppression require frequent platelet and occasional granulocyte transfusions. Multi-donor transfusions induce alloimmunization, thereby increasing morbidity and mortality. Therefore, an autologous or HLA-matched allogeneic source of platelets and granulocytes is needed. To determine whether nonhematopoietic cells can be reprogrammed into hematopoietic cells, human mesenchymal stromal cells (MSCs) and skin fibroblasts were incubated with the demethylating agent 5-azacytidine (Aza) and the growth factors (GF) granulocyte-macrophage colony-stimulating factor and stem cell factor. This treatment transformed MSCs to round, non-adherent cells expressing T-, B-, myeloid-, or stem/progenitor-cell markers. The transformed cells engrafted as hematopoietic cells in bone marrow of immunodeficient mice. DNA methylation and mRNA array analysis suggested that Aza and GF treatment demethylated and activated HOXB genes. Indeed, transfection of MSCs or skin fibroblasts with HOXB4, HOXB5, and HOXB2 genes transformed them into hematopoietic cells. Further studies are needed to determine whether transformed MSCs or skin fibroblasts are suitable for therapy
A self-renewal assay for cancer stem cells
Cancers of epithelial origin are responsible for the majority of cancer-related deaths in the USA. Unfortunately, although chemotherapy and/or radiation therapy can sometimes shrink tumors, metastatic cancers of epithelial origin are essentially incurable. It is clear that new approaches are needed to treat these diseases. Although cancer cell lines provide invaluable information, their biological properties often differ in crucial ways from de novo cancer cells. Our laboratory has developed a novel mouse model that reliably permits individual cancer cells isolated directly from patientsโ tumors to be assayed. This will allow the characterization of crucial signaling pathways involved in processes such as self-renewal that are critical for tumor formation by the cancer cells within de novo tumors. These tools should lead to new insights into the cellular and molecular mechanisms that drive human breast cancer growth and invasion.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46932/1/280_2005_Article_97.pd