Articles by Greg Herr in JoVE
Induction and Analysis of Epithelial to Mesenchymal Transition Yixin Tang1, Greg Herr2, Wade Johnson2, Ernesto Resnik1, Joy Aho2 1Antibody Development Department, R&D Systems, Inc., 2Stem Cells and Developmental Biology Department, R&D Systems, Inc. A straightforward method is described for the induction of epithelial to mesenchymal transition (EMT) in a variety of cell types. Methods for the analysis of cells in EMT states by immunocytochemistry are included.
Other articles by Greg Herr on PubMed
The PACS Initiative: What Does It Take? Biomedical Instrumentation & Technology / Association for the Advancement of Medical Instrumentation. 2004-2005 | Pubmed ID: 18634175 Successful implementation of a PACS requires both a technology infusion and a re-engineering of the film-based workflow used for more than 100 years in health care. Because of the sensitivity of a PACS, high-level administrative support is needed to address resistance to change and other roadblocks. A PACS project team must look at how the system will operate not only in the primary imaging department, but also throughout the health care institution. The project plan developed must take into account the technology and workflow changes required, the potential risks to the project, and key milestones that must be met. Frequent ongoing review of the project at a high level is required. Technology enables PACS to improve workflow, and that technology encompasses modalities, networks, diagnostic workstations, archives, interfaces, Web distribution, and other systems (i.e. RIS, HIS). Support from information technology and clinical engineering departments, PACS vendors, modality original equipment manufacturers (OEMs), and third-party software is required. Adopting PACS means dependency on this technology. Improvements realized via PACS become every day expectations; therefore, PACS must have operational support and documented downtime procedures. The potential benefits of PACS-instant, multiple-user accessibility to high-resolution imagery-promise hospitals a significant return on investment.
Human Neural Precursor Cells Express Functional Kappa-opioid Receptors The Journal of Pharmacology and Experimental Therapeutics. Sep, 2007 | Pubmed ID: 17538007 Neural stem cells (NSCs) play an important role in the developing as well as adult brain. NSCs have been shown to migrate toward sites of injury in the brain and to participate in the process of brain repair. Like NSCs, cultured human neural precursor cells (NPCs) are self-renewing, multipotent cells capable of differentiating into neurons, astrocytes, and oligodendrocytes and of migrating toward chemotactic stimuli. Cellular and environmental factors are important for NPC proliferation and migration. Expression of kappa-opioid receptors (KORs) and mu-opioid receptors (MORs) in murine embryonic stem cells and of MORs and delta-opioid receptors in rodent neuronal precursors, as well as hippocampal progenitors has been reported by other investigators. In this study, we demonstrated robust expression of KORs in highly enriched (>90% nestin-positive) human fetal brain-derived NPCs. We found that KOR ligands, dynorphin(1-17) and trans-3,4-dichloro-N-methyl-N[2-(1-pyrolidinyl)cyclohexyl] benzeneacetamide methanesulfonate (U50,488) but not dynorphin(2-17), stimulated proliferation and migration of NPCs in a concentration-dependent manner. NPC proliferation was maximally stimulated at 10(-14) M dynorphin(1-17) and 10(-12) M U50,488. The KOR selective antagonist, nor-binaltorphimine, partially blocked the migratory and proliferative effects of KOR agonists supporting, at least in part, the involvement of a KOR-related mechanism. As has been described for rodent P19 embryonal carcinoma stem cells, retinoic acid treatment markedly suppressed KOR mRNA expression in human NPCs. Taken together, the results of this study suggest that activation of KORs alters functional properties of NPCs/NSCs that are relevant to human brain development and repair.