Cortical activations in sequential bilateral cochlear implant users.

This study aimed to examine auditory and visual cortical activations in bilateral cochlear implant recipients using [(18)F]-FDG positron emission tomography. We aimed to compare the activations from use of the first implant alone, the second implant alone, and both implants together. When both implants were activated simultaneously, summation of cortical activity did not occur. The first and second implants demonstrated evidence of developing distinct neural networks. The first implants show stronger bilateral recruitment of the auditory areas than the second implants. Visual cortical activations occur in response to stimulation of the second but not the first implants. When both implants were activated together, there were no visual activations suggesting interaction between the first- and second-implant networks. These findings add to the existing knowledge of plasticity following cochlear implantation and demonstrate a variability of these processes that was previously unreported.

The hypoxia-selective cytotoxin NLCQ-1 (NSC 709257) controls metastatic disease when used as an adjuvant to radiotherapy.

BACKGROUND: Metastases cause most cancer-related deaths. We investigated the use of hypoxia-selective cytotoxins as adjuvants to radiotherapy in the control of metastatic tumour growth. METHODS: The NLCQ-1, RB6145 and tirapazamine were assessed against the spontaneously metastasising KHT model. Subcutaneous KHT tumours (250 mm(3)) were irradiated with 25 Gy (single fraction) to control primary growth. Equitoxic drug treatments (NLCQ-1 (10 mg kg(-1)) once daily; RB6145 (75 mg kg(-1)) and tirapazamine (13 mg kg(-1)) twice daily) were administered 3-6 days post-radiotherapy when hypoxic cells were evident in lung micrometastases. Mice were culled when 50% of controls exhibited detrimental signs of lung metastases. RESULTS: In total, 95% of control mice presented with lung disease. This was significantly reduced by NLCQ-1 (33%; P=0.0002) and RB6145 (60%; P=0.02). Semi-quantitative grading of lung disease revealed a significant improvement with all treatments, with NLCQ-1 proving most efficacious (median grades: control, 4; NLCQ, 0 (P<0.0001); RB6145, 1 (P<0.001), tirapazamine, 3 (P=0.007)). Positron emission tomography (PET) was evaluated as a non-invasive means of assessing metastatic development. Primary and metastatic KHT tumours showed robust uptake of [(18)F]fluorodeoxyglucose ([(18)F]FDG). Metastatic burden discernable by [(18)F]FDG PET correlated well with macroscopic and histological lung analysis. CONCLUSION: The hypoxia-selective cytotoxin NLCQ-1 controls metastatic disease and may be a successful adjuvant to radiotherapy in the clinical setting.