RESUMEN
The stochastic and elite models have been proposed for the mechanism of induced pluripotent stem (iPS) cell generation. In this study we report a system that supports the elite model. We previously identified multilineage-differentiating stress-enduring (Muse) cells in human dermal fibroblasts that are characterized by stress tolerance, expression of pluripotency markers, self-renewal, and the ability to differentiate into endodermal-, mesodermal-, and ectodermal-lineage cells from a single cell. They can be isolated as stage-specific embryonic antigen-3/CD105 double-positive cells. When human fibroblasts were separated into Muse and non-Muse cells and transduced with Oct3/4, Sox2, Klf4, and c-Myc, iPS cells were generated exclusively from Muse cells but not from non-Muse cells. Although some colonies were formed from non-Muse cells, they were unlike iPS cells. Furthermore, epigenetic alterations were not seen, and some of the major pluripotency markers were not expressed for the entire period during iPS cell generation. These findings were confirmed further using cells transduced with a single polycistronic virus vector encoding all four factors. The results demonstrate that in adult human fibroblasts a subset of preexisting adult stem cells whose properties are similar in some respects to those of iPS cells selectively become iPS cells, but the remaining cells make no contribution to the generation of iPS cells. Therefore this system seems to fit the elite model rather than the stochastic model.
Asunto(s)
Diferenciación Celular , Linaje de la Célula , Fibroblastos/citología , Células Madre Pluripotentes Inducidas/citología , Adaptación Fisiológica , Adulto , Animales , Antígenos CD/metabolismo , Antígenos de Superficie/metabolismo , Antígenos de Carbohidratos Asociados a Tumores/metabolismo , Línea Celular , Células Cultivadas , Dermis/citología , Endoglina , Fibroblastos/metabolismo , Humanos , Inmunohistoquímica , Células Madre Pluripotentes Inducidas/metabolismo , Factor 4 Similar a Kruppel , Factores de Transcripción de Tipo Kruppel/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Ratones , Ratones Endogámicos NOD , Ratones SCID , Factor 3 de Transcripción de Unión a Octámeros/genética , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Receptores de Superficie Celular/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Transcripción SOXB1/genética , Factores de Transcripción SOXB1/metabolismo , Antígenos Embrionarios Específico de Estadio/metabolismo , Estrés Fisiológico , TransfecciónRESUMEN
A new species of Leptostraca, Sarsinebaliaagoensis sp. nov., from Ago Bay, Japan is described from specimens found at a depth of 120 m. The new species differs from other known Sarsinebalia species as follows: the compound eye has three distal lobes; the anterior margin of the first antennal segment has one distal process covered with setae; and the lateral margin of pleopod 1 exopod bears 5-6 simple, robust spines. A taxonomic key to all species of Sarsinebalia is also provided.
RESUMEN
A new species of Leptostraca, Nebalia tagiri sp. nov. is described and illustrated. This species was sampled from 200 m depth at a hydrothermal field in Wakamiko Caldera of Kagoshima Bay, Japan. Nebalia tagiri sp. nov. is different from known Nebalia species as follows: rostral length 2.4 times as long as width; article 4 of antennule with 3-5 robust distal spines; antennular scale approximately twice as long as wide; article 3 of antenna with eight spines and nine spine-like setae along proximal half, two thin setae and six spine-like setae on external lateral face, six spines and four simple setae on distal margin; article 1 of second maxilla longer than article 2; article 2 of mandibular palp with two thin setae; exopod of pleopod 1 with 21 spines along lateral margin; furcal rami longer than combined length of pleonite 7 and telson; rounded denticles of pleonite 6 and 7; anal-plates 'shoulder' not distinct. Furthermore, this specimen is the first genus Nebalia found in the hydrothermal vent. The distribution and ecology of this new species is also discussed and a key to all species of Nebalia is provided.
RESUMEN
A 71-year-old woman previously diagnosed with reactive hypoglycemia was transferred to our emergency unit because of loss of consciousness. Her plasma glucose level was 27 mg/dL, and continuous glucose monitoring (CGM) revealed postprandial asymptomatic hypoglycemia. A hypervascular tumor was identified via computed tomography in the distal pancreas, and the diagnosis of insulinoma was confirmed using the selective arterial calcium stimulation test. Although no episodes of hypoglycemia were observed during CGM after resection, a pathological examination identified regional lymph node metastasis. It is important to consider insulinoma as a cause of postprandial hypoglycemia, and CGM is useful for evaluating treatment outcomes.