Embryonic stem (ES) cells are permanent pluripotent stem cell lines established from pre-implantation mouse embryos. There is currently great interest in the potential therapeutic applications of analogous cells derived from human embryos. The isolation of ES cells is commonly presented as a straightforward transfer of cells in the early embryo into culture. In reality, however, continuous expansion of pluripotent cells does not occur in vivo, and in vitro is the exception rather than the norm. Both genetic and epigenetic factors influence the ability to derive ES cells. We have tracked the expression of a key marker and determinant of pluripotency, the transcription factor Oct-4, in primary cultures of mouse epiblasts and used this to assay the effect of experimental manipulations on the maintenance of a pluripotent cell compartment. We find that expression of Oct-4 is often lost prior to overt cytodifferentiation of the epiblast. The rate and extent of Oct-4 extinction varies with genetic background. We report that treatment with the MAP kinase/ERK kinase inhibitor PD98059, which suppresses activation of the mitogen-activated protein kinases Erk1 and Erk2, results in increased persistence of Oct-4-expressing cells. Oct-4 expression is also relatively sustained in cultures of diapause embryos and of isolated inner cell masses. Combination of all three conditions allowed the derivation of germline-competent ES cells from the normally refractory CBA mouse strain. These findings suggest that the genesis of an ES cell is a relatively complex process requiring epigenetic modulation of key gene expression over a brief time-window. Procedures that extend this time-window and/or directly regulate the critical genes should increase the efficiency of ES cell derivation.
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http://dx.doi.org/10.1098/rstb.2003.1327 | DOI Listing |
Introduction: Solitary plasmacytomas are tumors characterized by a local increase of malignant plasma cells in soft tissue or bone and may occur anywhere without evidence of systemic disease. The aim was to focus on the main surgical techniques and outcomes for this rare chest wall tumor.
Methods: Patients with solitary plasmacytoma involving a rib, who were operated for diagnostic or treatment purposes between 2018 and 2023 were retrospectively reviewed.
Mycobacterium tuberculosis (M.tb) infection can lead to various outcomes, including active tuberculosis or latent tuberculosis infection (LTBI). Household contacts of TB cases have a high risk of acquiring LTBI.
View Article and Find Full Text PDFPlant Physiol Biochem
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Laboratory of Microbial Genetics, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India. Electronic address:
Nitric oxide synthases (NOSs) are heme-based monooxygenases that catalyze the NADPH-dependent oxidation of L-arginine to produce NO and L-citrulline. Over the past five years, the identification and characterization of NOS homologs in cyanobacteria have significantly advanced our understanding of these enzymes. However, the precise mechanisms through which NOS-derived NO influences nitrogen metabolism remain incompletely elucidated.
View Article and Find Full Text PDFInt J Med Inform
January 2025
Department of Computer Science and Artificial Intelligence, University of Udine, 33100, Italy.
Background: Segmentation models for clinical data experience severe performance degradation when trained on a single client from one domain and distributed to other clients from different domain. Federated Learning (FL) provides a solution by enabling multi-party collaborative learning without compromising the confidentiality of clients' private data.
Methods: In this paper, we propose a cross-domain FL method for Weakly Supervised Semantic Segmentation (FL-W3S) of white blood cells in microscopic images.
J Med Food
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Department of Infectious Diseases and Liver Diseases, Ningbo Medical Centre Lihuili Hospital, Affiliated Lihuili Hospital of Ningbo University, Ningbo, China.
Disturbances of the intestinal barrier enabling bacterial translocation exacerbate alcoholic liver disease (ALD). GG (LGG) has been shown to exert beneficial effects in gut dysbiosis and chronic liver disease. The current study assessed the combined effects of LGG and metformin, which play roles in anti-inflammatory and immunoregulatory processes, in alcohol-induced liver disease mice.
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