The Functional Morphology Of The Anterior Masticatory Apparatus In Tree-gouging Marmosets (cebidae, Primates)
adductor muscle force; Anatomy & Morphology; bone; callithrix-jacchus; callitrichines; decussation; dental enamel; dietary; distribution; exudativory; fiber architecture; iterative selection method; mandible; mandibular form; stress; symphyseal fusion; teeth; thickness
Although all genera of Callitrichinae feed on tree exudates, marmosets (Callithrix and Cebuella) use specialized anterior teeth to gouge holes in trees and actively stimulate exudate flow. Behavioral studies demonstrate that marmosets use large jaw gapes but do not appear to generate large bite forces (relative to maximal ability) during gouging. Nonetheless, the anterior teeth of marmosets likely experience different loads during gouging compared to nongouging platyrrhines. We use histological data from sectioned teeth, mu CTs of jaws and teeth, and in vitro tests of symphyseal strength to compare the anterior masticatory apparatus in Callithrix to nongouging tamarins (Saguinus) and other cebids. We test the hypotheses that (1) marmoset anterior teeth are adapted to accommodate relatively high stresses linked to dissipating gouging forces and (2) the mandibular symphysis does not provide increased load resistance ability compared with closely related nongouging platyrrhines. Differences in decussation between Callithrix and Saguinus are greatest in the anterior teeth, suggesting an increased load resistance ability specifically in incisor and canine enamel of Callithrix. Callithrix lower incisor crowns are labiolingually thicker suggesting increased bending resistance in this plane and improved wedging ability compared with Saguinus. Anterior tooth roots are larger relative to symphyseal bone volume in Callithrix. Anterior tooth root surface areas also are larger in marmosets for their symphyseal volume, but it remains unclear whether this relative increase is an adaptation for dissipating dental stresses versus a growth-related byproduct of relatively elongated incisors. Finally, simulated jaw loading suggests a reduced ability to withstand external forces in the Callithrix symphysis. The contrast between increased load resistance ability in the anterior dentition versus relatively reduced symphyseal strength (1) suggests a complex loading environment during gouging, (2) highlights the possibility of distinct loading patterns in the anterior teeth versus the symphysis, and (3) points to a potential mosaic pattern of dentofacial adaptations to tree gouging. J. Morphol. 272:833-849, 2011. (C) 2011 Wiley-Liss, Inc.
Hogg R T; Ravosa M J; Ryan T M; Vinyard C J
Journal of Morphology
2011
2011-07
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1002/jmor.10951" target="_blank" rel="noreferrer noopener">10.1002/jmor.10951</a>
Identification of Novel Agents for the Treatment of Brain Metastases of Breast Cancer.
Female; Humans; Animals; Mice; Apoptosis; Cell Line; ADME; Antineoplastic Agents/*therapeutic use; brain cancer; Brain Neoplasms/*drug therapy/pathology/*secondary; Breast Neoplasms/*pathology; chemotherapy; CNS; distribution; drug discovery; Drug resistance; Tumor
BACKGROUND: Brain cancer from metastasized breast cancer has a high mortality rate in women. The treatment of lesions is hampered in large part by the blood-brain barrier (BBB), which prevents adequate distribution of anti-cancer compounds to brain metastases. METHOD: In this study we used a novel screening method to identify candidate molecules that are well-suited to utilizing the BBB choline transporter for distribution into the brain parenchyma. RESULTS: From our screen we identified two compounds, Ch-1 and Ch-2 that were able to reduce the brain tumor burden in a murine mouse model of brain metastasis of breast cancer. These compounds also significantly increased the survival of mice by more than 10 days. Mechanistic studies indicated that Ch-1 is able to prevent the activation of the pro-survival mitogen-activated kinases (MAPKs) by osteoactivin (OA; Glycoprotein nonmetastatic melanoma protein B GPNMB). CONCLUSION: The results from this study show that nutrient transporter virtual screening is a viable novel alternative to traditional drug screening programs to identify anti-cancer compounds for the treatment of brain cancers.
Venishetty Vinay K; Geldenhuys Werner J; Terell-Hall Tori B; Griffith Jessica I G; Sondag Gregory R; Safadi Fayez F; Lockman Paul R
Current cancer drug targets
2017
1905-7
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.2174/1568009617666161121123948" target="_blank" rel="noreferrer noopener">10.2174/1568009617666161121123948</a>