March 08, 2013

Laura Randall ‘13Hamline UniversityBiology Senior SeminarAbstract:The Use of Stem Cell Therapies for Tooth Replacement

The oral cavity is crucial to the body because it allows us to talk, breathe and start the breakdown of the food that we eat. When the oral cavity isn’t taken care of properly the teeth can develop cavities and the surrounding tissues can rot. When these happen the normally the tooth is filled, capped or pulled and then an implant is put in. While all of these are viable options they do have their flaws. Etsuko Ikeda et al. tested a theory on regenerative stem cells, which had previously worked to reproduce hair follicles and mammary glands, to produce a third molar in a mouse. By taking stem cells from the epithelial and mesochymal oral tissues of a 14.5 day old mouse they were able to create a tooth germ. This germ was implanted into an adult mouse that had a molar pulled. The result was that the tooth did grow, although it was not as big nor did it align perfectly with the other teeth. When tested for hardness of dentin and enamel by a Knoop hardness test, the tooth was statistically as hard as a normal mouse tooth. The study also found that periodontal ligaments had formed, allowing for mechanical stress. After applying mechanical stress for 17 days the tooth behaved and performed as well as a normal tooth. Overall, the regenerative stem cells were successfully implanted and a fully functioning bioengineered tooth was formed.

Allison Loosbrock ‘13Hamline UniversityBiology Senior SeminarAbstract:Filarial Parasite Development and Reproduction in Response to Host Immune Effectors Filarial nematodes one of many parasites that are wonderful at surviving within their host, even though the host's immune system is forcefully trying to fight them off. There has been evidence suggesting that the immune response to parasitic infection may enhance parasitic development instead of hindering it. Scientists hypothesize that parasites are able to survive through adaptive phenotypic plasticity, and that parasitic helminths are able to adjust their development and reproductive schedules through exposure to host immune effectors. One host immune effector such as an eosinophil is necessary to rid the body of parasitic infection. It is suggested that the presence of eosinophils act as a cue for development. It is also suggested that adaptive immunity positively affects early parasitic growth. If this is so, the many experimental vaccines used to fight off parasitic infections need to be evaluated because they rely on these host immune effectors that filarial nemotodes are using as cues for development.