Nanoparticles, with their distinct properties that vary from their bulk material equivalent, continue to gain popularity for studies into multi-modal applications in medicine. This research introduces the use of thulium oxide nanoparticles for biological applications and characterizes the potential of this novel nanoparticle for image-guided radiotherapy of brain cancer. In this study, we investigate the structural characteristics of this nanoparticle, and reveal a significant dose enhancement towards radioresistant brain tumour cells in vitro that also underlies an improvement in the CT image contrast of brain tumours in vivo. The thulium oxide nanoparticles utilized in the investigations described in this article were measured to be 40-45 nm from x-ray diffraction and scanning electron microscopy data. In vitro investigations assessed the cell survival and DNA damage in 9 l gliosarcoma cells following irradiation with 150 kVp orthovoltage x-rays. Immediately after the 150 kVp irradiation (15 min) an increase in the number of γ-H2AX induced foci indicates the production of more double-strand DNA breaks. Following from the short time-frame irradiation outcomes, clonogenic cell survival assays confirmed long-term radio-sensitization, with the cell sensitivity increasing by a factor of 1.32 (measured at the 10% survival fraction) for the irradiated 9 l cells exposed to thulium nanoparticles. A simple CT experiment shows that our thulium nanoparticles suspended in water at concentrations >0.5 mg ml −1 (0.05-20 mg ml −1 investigated) are clearly observable against water. Extending the CT experiment to an in vivo investigation, cellular uptake of the nanoparticles was demonstrated through CT image enhancement of the cancer site in 9-to 10-week-old Fisher rats bearing 9 l gliosarcomas, 12 days after cell implantation. The 9 l cancer is clearly visible on the CT image after injecting 40 μg of nanoparticles (2 μl at 20 mg ml −1) directly to the cancer site (5.5 mm from the dura and 3.5 mm right laterally of the bregma, 5 mm depth). To our knowledge, this work demonstrates the first application of thulium nanoparticles in biology and medicine, for radiotherapy and image guidance purposes.

Purpose Hypotension is common following spinal anesthesia (SA) during elective Cesarean delivery (CD). Although common practice is to alleviate inferior vena cava (IVC) compression, limited evidence supports a 15°t ilt for CD. We measured collapsibility of the IVC in supine and 15°left lateral tilt positions with ultrasound before and after SA and phenylephrine infusion in term parturients. Methods Twenty term parturients scheduled for CD were recruited for this prospective study. Ultrasound measurements of the IVC were taken 1) supine before SA, 2) tilted 15°before SA, 3) supine after SA, and 4) tilted 15°a fter SA. A phenylephrine infusion was begun after injection of SA. The primary outcome was to evaluate the impact of position on the IVC collapsibility index (IVCCI): a measure of the difference between the maximum and minimum IVC diameter with respiration. Results The mean (standard deviation) IVCCI (%) before SA was higher in the supine 19.5 (8.0) than in the tilted 15.0 (6.4) position

We conclude that the evoked motor response of the T branch is associated with a higher success rate than a CP response using the modified LSMF block.