The question of the Eotriassic tetrapod genus Weltugasaurus in Greenland and thoughts on the fossa coniformis entopherygoidea

Cranial specimens of Eotriassic tetrapods from central East Greenland which in the mid-1930s were assigned to the genus Wetlugasaurus have been re-examined and found to represent a new, capitosaur-like genus, named Selenocara. A cone-shaped fossa in the entopterygoid bone is the focus of particular attention. This depression appears to have engaged with the affacial process and not, as has often been maintained, with the basipterygoid process. The consequences of this reinterpretation of the fossa coniformis entopterygo idea are far-reaching, and some of them are, to an extent, discussed herein

Intercellular Mitochondrial Transfer Using 3D Bioprinting

Mitochondria are one of the most complex and vital organelles in eukaryotic cells. In recent years, it has been shown that through intercellular mitochondrial transfer, this important organelle provides a critical role in tissue homeostasis, damaged tissue repair, and tumor progression under physiological conditions. However, the mechanism of mitochondrial transfer and its effect on various cellular microenvironments has not yet been defined. Understanding the metabolic effects of mitochondrial transfer between cells and exploring the signaling leading to the intercellular mechanisms could provide advancements in both translational medicine and cell therapy for cancer progression and age-related diseases. Our group has studied the ability of the normal mammary microenvironment to redirect cancer cells to a normal mammary epithelial cell fate both in vivo and in vitro using our 3D bioprinting system. Therefore, we sought to determine if mitochondrial transfer may play a role in mammary epithelium induced redirection of cancer cells. We used MCF-7 breast cancer cells and MCF-12a epithelial breast cells for experimentation. Using a fluorescent GFP-MITO lentivirus, we were able to mark mitochondrial protein in the MCF-12a epithelial cells to track mitochondrial transfer activity. The MCF-7 cells were labeled red to distinguish the two cell types. The cells were then co-cultured in 2D tissue flasks and printed into hydrogels using the 3D bioprinter. Using fluorescent microscopy, mitochondrial protein was observed traveling from epithelial to mammary cancer cells. We hypothesize this is done for cancer cells to stabilize mitochondria and improve metabolic function and ATP production. Further research to establish mitochondrial transfer, its mechanism(s), and molecular effects could lead insight into how this cellular communication rescues and normalizes metabolic factors of the mammary and stem cell microenvironment leading to potential fate redirection and cellular revitalization.https://digitalcommons.odu.edu/gradposters2022_healthsciences/1010/thumbnail.jp

Combined 3D Bioprinting and Tissue-Specific ECM System Reveals the Influence of Brain Matrix on Stem Cell Differentiation

We have previously shown that human and murine breast extracellular matrix (ECM) can significantly impact cellular behavior, including stem cell fate determination. It has been established that tissue-specific extracellular matrix from the central nervous system has the capacity to support neuronal survival. However, the characterization of its influence on stem cell differentiation and its adaptation to robust 3D culture models is underdeveloped. To address these issues, we combined our 3D bioprinter with hydrogels containing porcine brain extracellular matrix (BMX) to test the influence of the extracellular matrix on stem cell differentiation. Our 3D bioprinting system generated reproducible 3D neural structures derived from mouse embryonic stem cells (mESCs). We demonstrate that the addition of BMX preferentially influences 3D bioprinted mESCs towards neural lineages compared to standard basement membrane (Geltrex/Matrigel) hydrogels alone. Furthermore, we demonstrate that we can transplant these 3D bioprinted neural cellular structures into a mouse’s cleared mammary fat pad, where they continue to grow into larger neural outgrowths. Finally, we demonstrate that direct injection of human induced pluripotent stem cells (hiPSCS) and neural stem cells (NSCs) suspended in pure BMX formed neural structures in vivo. Combined, these findings describe a unique system for studying brain ECM/stem cell interactions and demonstrate that BMX can direct pluripotent stem cells to differentiate down a neural cellular lineage without any additional specific differentiation stimuli

The lancet weight determines wheal diameter in response to skin prick testing with histamine

BACKGROUND:Skin prick test (SPT) is a common test for diagnosing immunoglobulin E-mediated allergies. In clinical routine, technicalities, human errors or patient-related biases, occasionally results in suboptimal diagnosis of sensitization. OBJECTIVE:Although not previously assessed qualitatively, lancet weight is hypothesized to be important when performing SPT to minimize the frequency of false positives, false negatives, and unwanted discomfort. METHODS:Accurate weight-controlled SPT was performed on the volar forearms and backs of 20 healthy subjects. Four predetermined lancet weights were applied (25 g, 85 g, 135 g and 265 g) using two positive control histamine solutions (1 mg/mL and 10 mg/mL) and one negative control (saline). A total of 400 SPTs were conducted. The outcome parameters were: wheal size, neurogenic inflammation (measured by superficial blood perfusion), frequency of bleeding, and the lancet provoked pain response. RESULTS:The mean wheal diameter increased significantly as higher weights were applied to the SPT lancet, e.g. from 3.2 ± 0.28 mm at 25 g to 5.4 ± 1.7 mm at 265 g (p<0.01). Similarly, the frequency of bleeding, the provoked pain, and the neurogenic inflammatory response increased significantly. At 265 g saline evoked two wheal responses (/160 pricks) below 3 mm. CONCLUSION AND CLINICAL RELEVANCE:The applied weight of the lancet during the SPT-procedure is an important factor. Higher lancet weights precipitate significantly larger wheal reactions with potential diagnostic implications. This warrants additional research of the optimal lancet weight in relation to SPT-guidelines to improve the specificity and sensitivity of the procedure