Hematopoietic stem cells (HSCs) develop in the embryonic aorta-gonad-mesonephros (AGM) region and subsequently relocate to fetal liver. Runx1 transcription factor is essential for HSC development, but is largely dispensable for adult HSCs. Here, we studied tamoxifen-inducible Runx1 inactivation in vivo. Induction at pre-liver stages (up to embryonic day 10.5) reduced erythromyeloid progenitor numbers, but surprisingly did not block the appearance of Runx1-null HSCs in liver. By contrast, ex vivo analysis showed an absolute Runx1 dependency of HSC development in the AGM region. We found that, contrary to current beliefs, significant Cre-inducing tamoxifen activity persists in mouse blood for at least 72 hr after injection. This deferred recombination can hit healthy HSCs, which escaped early Runx1 ablation and result in appearance of Runx1-null HSCs in liver. Such extended recombination activity in vivo is a potential source of misinterpretation, particularly in analysis of dynamic developmental processes during embryogenesis.
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http://dx.doi.org/10.1016/j.stemcr.2018.08.004 | DOI Listing |
Adv Mater
December 2024
Department of Chemical and Biological Engineering, Korea University, Seoul, 02841, Republic of Korea.
In this study, a novel phenomenon is identified where precise control of topology and generation of polyglycerol induce the retention of Na ions in biological buffer systems, effectively inhibiting ice crystal growth during cryopreservation. Unlike linear and hyperbranched counterparts, densely-packed hydroxyl and ether groups in 4th-generation dendritic polyglycerol interact with the ions, activating the formation of hydrogen bonding at the ice interface. By inhibiting both intra- and extracellular ice growth and recrystallization, this biocompatible dendritic polyglycerol proves highly effective as a cryoprotectant; hence, achieving the cell recovery rates of ≈134-147%, relative to those of 10% dimethyl sulfoxide, which is a conventional cryoprotectant for human tongue squamous carcinoma (HSC-3) cell line and human umbilical vein endothelial (HUVEC) cells.
View Article and Find Full Text PDFInt J Pediatr Otorhinolaryngol
December 2024
University of Utah, Department of Otolaryngology - Head & Neck Surgery, United States. Electronic address:
Introduction: Pediatric temporal bone fractures (TBFs) can result in adverse outcomes including meningitis, significant sensorineural hearing loss requiring cochlear implantation (CI), facial nerve weakness, cerebrospinal fluid (CSF) leak, and labyrinthitis. The objective of this study is to determine the risks of these outcomes for TBFs with hearing loss.
Methods: Using the multinational TriNetX database, a retrospective cohort study was performed of patients less than 18 years old with diagnostic codes for other fracture of base of skull and hearing loss to serve as an approximation of TBF.
Public Health
December 2024
School of Public Health, Peking University, Beijing, China; China Center for Health Development Studies, Peking University, Beijing, China. Electronic address:
Objectives: Electronic cigarettes (e-cigarettes) have been attracting users around the world due in part to appealing flavors. Many countries and regions have now taken action to limit the sales of flavored e-cigarettes. In 2022, China implemented a flavor ban on e-cigarettes, prohibiting all but tobacco-flavor.
View Article and Find Full Text PDFFront Cell Dev Biol
December 2024
Microscopic and Developmental Anatomy, Tokyo Women's Medical University, Tokyo, Japan.
Most blood cells derive from hematopoietic stem cells (HSCs), originating from endothelial cells. The induction of HSCs from endothelial cells occurs during mid-gestation, and research has revealed multiple steps in this induction process. Hemogenic endothelial cells emerge within the endothelium, transition to hematopoietic cells (pre-HSCs), and subsequently mature into functional HSCs.
View Article and Find Full Text PDFOsteoporos Int
December 2024
Department of Orthopaedics, West Virginia University, PO Box 9196, Morgantown, WV, 26506, USA.
Atraumatic bilateral femoral neck fractures are rare, especially in younger patients and those without significant comorbidities. However, pregnant individuals appear to be at increased risk due to normal physiological changes in calcium balance, leading to transient osteoporosis of the hip. In these individuals, calcium and bone mineral density are generally decreased, reflecting the calcium demands of the developing fetus.
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