Abrogation of the radiation-induced G2 checkpoint by the staurosporine derivative UCN-01 is associated with radiosensitisation in a subset of colorectal tumour cell lines

Ionising radiation is commonly used in the treatment of colorectal cancer. Tumour cells with mutant p53 undergo cell cycle arrest at G2/M after ionising radiation and evidence suggests that abrogation of this G2 arrest can lead to a premature, aberrant mitosis, thus enhancing ionising radiation-induced cell killing. The G2 checkpoint inhibitor UCN-01 was thus investigated to determine whether it would abrogate the G2 checkpoint induced by 5 Gy ionising radiation in a range of colorectal tumour cell lines. Data presented show that, at doses that are alone non-toxic to the cells, UCN-01 inhibits the ionising radiation-induced G2 checkpoint in five colorectal tumour cell lines with mutant p53. The ability of UCN-01 to sensitise cells to ionising radiation-induced growth inhibition and apoptosis was also investigated and UCN-01 was found to radiosensitise two out of five cell lines. These results were confirmed by long-term colony forming efficiency studies. These results demonstrate that abrogation of the ionising radiation-induced G2 checkpoint is not necessarily associated with sensitisation to ionising radiation, however, some colorectal tumour cell lines can be radiosensitised by UCN-01. Although the mechanism of radiosensitisation is not clear, this may still be an important treatment strategy

Biodiversity inventories in high gear: DNA barcoding facilitates a rapid biotic survey of a temperate nature reserve

Comprehensive biotic surveys, or ‘all taxon biodiversity inventories’ (ATBI), have traditionally been limited in scale or scope due to the complications surrounding specimen sorting and species identification. To circumvent these issues, several ATBI projects have successfully integrated DNA barcoding into their identification procedures and witnessed acceleration in their surveys and subsequent increase in project scope and scale. The Biodiversity Institute of Ontario partnered with the rare Charitable Research Reserve and delegates of the 6th International Barcode of Life Conference to complete its own rapid, barcode-assisted ATBI of an established land trust in Cambridge, Ontario, Canada

The molecular logic of endocannabinoid signalling

The endocannabinoids are a family of lipid messengers that engage the cell surface receptors that are targeted by Δ9-tetrahydrocannabinol, the active principle in marijuana (Cannabis). They are made on demand through cleavage of membrane precursors and are involved in various short-range signalling processes. In the brain, they combine with CB1 cannabinoid receptors on axon terminals to regulate ion channel activity and neurotransmitter release. Their ability to modulate synaptic efficacy has a wide range of functional consequences and provides unique therapeutic possibilities. © 2003, Nature Publishing Group. All rights reserved

A Leadership Study of Efforts to Improve Special Education Teachers Use of Tier I Strategies to Support SWD in Grades 4–5 in ELA

The focus of this study was to explore my leadership practices to improve teachers\u27 acumen and use of research-based Tier 1 strategies to propel student engagement, thereby increasing student achievement. More specifically, the problem addressed was the decline of student performance for students with disabilities in English Language Arts and the organizational change theories and practices used to eliminate this trajectory. Using improvement science, this 12-week study consisted of two iterative and consecutive Plan -Do-Study-Act cycles that focused on professionally developing teachers to incorporate Tier 1 strategies using the Lesson Study, a collaborative and collegial inquiry approach. The data confirmed that effective use of targeted Tier 1 strategies led to an increase in student learning outcomes, improvements in student engagement, and expansion of students’ ability to engage in more complex learning tasks. Teachers reported a desire to expand Lesson Study to the entire school as a professional development approach due to the shared learning experiences and collective teacher efficacy that resulted from their collaboration. They also noted the benefits of using improvement science to tackle an adaptive challenge. Additionally, teachers significantly benefited from shared leadership practices such as teacher facilitation that were utilized during the study. As a result, the intentional focus on adaptive leadership practices coupled with adult learning theory positively impacted the teachers and was successful in fostering academic improvement