Il libro di Daniele e l'apocalittica ebraica antica

1. Un genere letterario e una visione del mondo. 2. La letteratura apocalittica ebraica. 3. Le radici dell'apocalittica ebraica. 4. Apocalittica, enochismo, qumranesimo. 5. Il libro di Daniele. 6. Le principali apocalissi non canoniche

Reduction of N-Glycolylneuraminic Acid in Human Induced Pluripotent Stem Cells Generated or Cultured under Feeder- and Serum-Free Defined Conditions

BACKGROUND: The successful establishment of human induced pluripotent stem cells (hiPSCs) has increased the possible applications of stem cell research in biology and medicine. In particular, hiPSCs are a promising source of cells for regenerative medicine and pharmacology. However, one of the major obstacles to such uses for hiPSCs is the risk of contamination from undefined pathogens in conventional culture conditions that use serum replacement and mouse embryonic fibroblasts as feeder cells. METHODOLOGY/PRINCIPAL FINDINGS: Here we report a simple method for generating or culturing hiPSCs under feeder- and serum-free defined culture conditions that we developed previously for human embryonic stem cells. The defined culture condition comprises a basal medium with a minimal number of defined components including five highly purified proteins and fibronectin as a substrate. First, hiPSCs, which were generated using Yamanaka's four factors and conventional undefined culture conditions, adapted to the defined culture conditions. These adapted cells retained the property of self renewal as evaluated morphologically, the expression of self-renewal marker proteins, standard growth rates, and pluripotency as evaluated by differentiation into derivatives of all three primary germ layers in vitro and in vivo (teratoma formation in immunodeficient mice). Moreover, levels of nonhuman N-glycolylneuraminic acid (Neu5Gc), which is a xenoantigenic indicator of pathogen contamination in human iPS cell cultures, were markedly decreased in hiPSCs cultured under the defined conditions. Second, we successfully generated hiPSCs using adult dermal fibroblast under the defined culture conditions from the reprogramming step. For a long therm culture, the generated cells also had the property of self renewal and pluripotency, they carried a normal karyotype, and they were Neu5Gc negative. CONCLUSION/SIGNIFICANCE: This study suggested that generation or adaption culturing under defined culture conditions can eliminate the risk posed by undefined pathogens. This success in generating hiPSCs using adult fibroblast would be beneficial for clinical application

Safety assessment of bone marrow derived MSC grown in platelet-rich plasma

AbstractThe injection of endothelial progenitor cells and mononuclear cells derived from bone marrow at the ischemic region of peripheral artery disease patients is reported to be effective for therapeutic angiogenesis; however, these cell therapies require large amounts of bone marrow to obtain sufficient numbers of cells. To solve this problem, we attempted to culture bone-marrow-derived mesenchymal stem cells (BM-MSC), which are supposed to secrete several cytokines that promote angiogenesis. We also focused on using platelet-rich plasma (PRP) as a supplement for cell culture instead of fetal bovine serum. Human BM-MSC obtained from healthy volunteers expanded rapidly when cultured with 10% PRP prepared from their own blood. FACS analysis revealed that these cultured human MSC were homogeneous populations, and chromosomal analysis showed a normal karyotype. Moreover, the angiogenetic effect was apparent two weeks after human BM-MSC were injected into the ischemic muscle in SCID mice. Tumor formation was not detected three months after injection into SCID mice either subcutaneously or intramuscularly. To simulate clinical settings, canine BM-MSC were grown with canine PRP and injected into their ischemic muscles. We confirmed that donor cells existed in situ two and six weeks after operation without any side effects. These results suggest that cultured human BM-MSC can be a promising cell source for therapeutic angiogenesis

Enzyme-free Passage of Human Pluripotent Stem Cells by Controlling Divalent Cations

AbstractEnzymes used for passaging human pluripotent stem cells (hPSCs) digest cell surface proteins, resulting in cell damage. Moreover, cell dissociation using divalent cation-free solutions causes apoptosis. Here we report that Mg2+ and Ca2+ control cell-fibronectin and cell-cell binding of hPSCs, respectively, under feeder- and serum-free culture conditions without enzyme. The hPSCs were detached from fibronectin-, vitronectin- or laminin-coated dishes in low concentrations of Mg2+ and remained as large colonies in high concentrations of Ca2+. Using enzyme-free solutions containing Ca2+ without Mg2+, we successfully passaged hPSCs as large cell clumps that showed less damage than cells passaged using a divalent cation-free solution or dispase. Under the same conditions, the undifferentiated and early-differentiated cells could also be harvested as a cell sheet without being split off. Our enzyme-free passage of hPSCs under a serum- and feeder-free culture condition reduces cell damage and facilitates easier and safer cultures of hPSCs.</jats:p

Ripply2 is essential for precise somite formation during mouse early development

AbstractThe regions of expression of Ripply1 and Ripply2, presumptive transcriptional corepressors, overlap at the presomitic mesoderm during somitogenesis in mouse and zebrafish. Ripply1 is required for somite segmentation in zebrafish, but the developmental role of Ripply2 remains unclear in both species. Here, we generated Ripply2 knock-out mice to investigate the role of Ripply2. Defects in segmentation of the axial skeleton were observed in the homozygous mutant mice. Moreover, somite segmentation and expression of Notch2 and Uncx4.1 were disrupted. These findings indicate that Ripply2 is involved in somite segmentation and establishment of rostrocaudal polarity

Podocalyxin Is a Glycoprotein Ligand of the Human Pluripotent Stem Cell-Specific Probe rBC2LCN

Abstract In comprehensive glycome analysis with a high-density lectin microarray, we have previously shown that the recombinant N-terminal domain of the lectin BC2L-C from Burkholderia cenocepacia (rBC2LCN) binds exclusively to undifferentiated human induced pluripotent stem (iPS) cells and embryonic stem (ES) cells but not to differentiated somatic cells. Here we demonstrate that podocalyxin, a heavily glycosylated type 1 transmembrane protein, is a glycoprotein ligand of rBC2LCN on human iPS cells and ES cells. When analyzed by DNA microarray, podocalyxin was found to be highly expressed in both iPS cells and ES cells. Western and lectin blotting revealed that rBC2LCN binds to podocalyxin with a high molecular weight of more than 240 kDa in undifferentiated iPS cells of six different origins and four ES cell lines, but no binding was observed in either differentiated mouse feeder cells or somatic cells. The specific binding of rBC2LCN to podocalyxin prepared from a large set of iPS cells (138 types) and ES cells (15 types) was also confirmed using a high-throughput antibody-overlay lectin microarray. Alkaline digestion greatly reduced the binding of rBC2LCN to podocalyxin, indicating that the major glycan ligands of rBC2LCN are presented on O-glycans. Furthermore, rBC2LCN was found to exhibit significant affinity to a branched O-glycan comprising an H type 3 structure (Ka, 2.5 × 104 M−1) prepared from human 201B7 iPS cells, indicating that H type 3 is a most probable potential pluripotency marker. We conclude that podocalyxin is a glycoprotein ligand of rBC2LCN on human iPS cells and ES cells.</jats:p