Noninvasive measurement of ablation crater size and thermal injury after CO2 laser in the vocal cord with optical coherence tomography.
ObjectiveTo characterize tissue destruction after CO(2) laser-ablation of the vocal cords with the use of optical coherence tomography (OCT).
Study design and settingOCT was used to image fresh porcine vocal cords after laser ablation. OCT and histology estimates of the ablation crater dimensions and the depth of thermal injury were obtained.
ResultsThe vocal cord substructures up to 2.29 mm in depth at 10 microm resolution, and the thermal disruption after laser ablation were identified by OCT. OCT and histology estimates of the lesion dimensions showed no significant differences. Crater depth is directly proportional to laser power, whereas crater width and the zone of thermal injury appear to be unrelated to laser power.
ConclusionsOCT may be used to accurately characterize the native states and the laser-induced thermal injury of laryngeal mucosa, within the inherent limitation in its depth of penetration. OCT may be a useful diagnostic and monitoring tool in an otolaryngology practice.
Accurate chromosome segregation depends on proper kinetochore-microtubule attachment. Upon microtubule interaction, kinetochores are subjected to forces generated by the microtubules. In this work, we used laser ablation to sever microtubules attached to a merotelic kinetochore, which is laterally stretched by opposing pulling forces exerted by microtubules, and inferred the mechanical response of the kinetochore from its length change. In both mammalian PtK1 cells and in the fission yeast Schizosaccharomyces pombe, kinetochores shortened after microtubule severing. Interestingly, the inner kinetochore-centromere relaxed faster than the outer kinetochore. Whereas in fission yeast all kinetochores relaxed to a similar length, in PtK1 cells the more stretched kinetochores remained more stretched. Simple models suggest that these differences arise because the mechanical structure of the mammalian kinetochore is more complex. Our study establishes merotelic kinetochores as an experimental model for studying the mechanical response of the kinetochore in live cells and reveals a viscoelastic behavior of the kinetochore that is conserved in yeast and mammalian cells.
Recent advances in the understanding of the metastatic phenomenon in cancer have led to the description of a metastatic niche. This concept describes a site prepared for the tumor cells in areas frequently associated with metastasis for the individual tumor studied. This niche is a "soil" that allows for the tumor cell or "seed" to lodge and grow. Certain aspects of the biology of infantile hemangioma cells suggest a relationship to the placenta as a possible site of origin for the hemangioma precursor cells. In this article, a relationship between the placenta, with or without a chorangioma and the hemangioma sites of localization, is hypothesized. The placenta is suggested as the site of humoral factors that prepare a niche similar to the function of malignant tumor cells. If the hypothesis proves to be valid, clues for possible treatment are outlined.