Severe Thyrotoxicosis Caused by Molar Pregnancy: A Case Report and Review of the Literature.

Severe thyrotoxicosis is an acute and life-threatening state of hyperthyroidism. While it is a rare presentation of hyperthyroidism, it is clinically significant because of its high mortality and necessitates early identification and treatment to reduce the incidence of poor outcomes. The most common causes of this hypermetabolic state are Graves' disease, toxic thyroid adenoma or multinodular goiter, thyroiditis, iodine-induced hyperthyroidism, and excessive intake of levothyroxine. The less common causes include trauma, medications (i.e., amiodarone), discontinuation of anti-thyroid medications, and interactions with sympathomimetic medications such as ketamine that may be administered during general anesthesia. Regardless of etiology, thyrotoxicosis management should be coordinated using an interdisciplinary team-based approach to optimize outcomes. We discuss a molar pregnancy requiring emergency surgery as an uncommon cause of thyrotoxicosis and highlight appropriate management steps. The patient's symptoms resolved post-operatively, and her post-operative laboratory results (thyroid function and beta-human chorionic gonadotropin {ß-hCG}) were followed until they normalized. The patient's preoperative presentation and preparation with a multidisciplinary team discussion, intraoperative anesthetic considerations and course, and post-operative management and follow-up are described.

Hyaluronic Acid hydrogels support cord-like structures from endothelial colony-forming cells.

The generation of functional vascular networks has the potential to improve treatment for vascular diseases and to facilitate successful organ transplantation. Endothelial colony-forming cells (ECFCs) have robust proliferative potential and can form vascular networks in vivo. ECFCs are recruited from a bone marrow niche to the site of vascularization, where cues from the extracellular matrix instigate vascular morphogenesis. Although this process has been elucidated using natural matrix, little is known about vascular morphogenesis by ECFCs in synthetic matrix, a xeno-free scaffold that can provide a more controllable and clinically relevant alternative for regenerative medicine. We sought to study hyaluronic acid (HA) hydrogels as three-dimensional scaffolds for capillary-like structure formation from ECFCs, and to determine the crucial parameters needed to design such synthetic scaffolds. We found that ECFCs express HA-specific receptors and that vascular endothelial growth factor stimulates hyaluronidase expression in ECFCs. Using a well-defined and controllable three-dimensional HA culture system, we were able to decouple the effect of matrix viscoelasticity from changes in adhesion peptide density. We determined that decreasing matrix viscoelasticity, which corresponds to a loose ultrastructure, significantly increases ECFC vascular tube length and area, and that the effect of local delivery of vascular endothelial growth factor within the hydrogel depends on the makeup of the synthetic environment. Collectively, these results set forth initial design criteria that need to be considered in developing vascularized tissue constructs.

Adaptation to oxygen deprivation in cultures of human pluripotent stem cells, endothelial progenitor cells, and umbilical vein endothelial cells.

Hypoxia plays an important role in vascular development through hypoxia-inducible factor-1alpha (HIF-1alpha) accumulation and downstream pathway activation. We sought to explore the in vitro response of cultures of human embryonic stem cells (hESCs), induced pluripotent stem cells (iPSCs), human endothelial progenitor cells (hEPCs), and human umbilical cord vein endothelial cells (HUVECs) to normoxic and hypoxic oxygen tensions. We first measured dissolved oxygen (DO) in the media of adherent cultures in atmospheric (21% O(2)), physiological (5% O(2)), and hypoxic oxygen conditions (1% O(2)). In cultures of both hEPCs and HUVECs, lower oxygen consumption was observed when cultured in 1% O(2). At each oxygen tension, feeder-free cultured hESCs and iPSCs were found to consume comparable amounts of oxygen. Transport analysis revealed that the oxygen uptake rate (OUR) of hESCs and iPSCs decreased distinctly as DO availability decreased, whereas the OUR of all cell types was found to be low when cultured in 1% O(2), demonstrating cell adaptation to lower oxygen tensions by limiting oxygen consumption. Next, we examined HIF-1alpha accumulation and the expression of target genes, including VEGF and angiopoietins (ANGPT; angiogenic response), GLUT-1 (glucose transport), BNIP3, and BNIP3L (autophagy and apoptosis). Accumulations of HIF-1alpha were detected in all four cell lines cultured in 1% O(2). Corresponding upregulation of VEGF, ANGPT2, and GLUT-1 was observed in response to HIF-1alpha accumulation, whereas upregulation of ANGPT1 was detected only in hESCs and iPSCs. Upregulation of BNIP3 and BNIP3L was detected in all cells after 24-h culture in hypoxic conditions, whereas apoptosis was not detectable using flow cytometry analysis, suggesting that BNIP3 and BNIP3L can lead to cell autophagy rather than apoptosis. These results demonstrate adaptation of all cell types to hypoxia but different cellular responses, suggesting that continuous measurements and control over oxygen environments will enable us to guide cellular responses.