Use of cone-beam computed tomography to characterize urinary bladder variations and optimize delivery of radiation therapy for canine bladder cancer

2011 Summer.Includes bibliographical references.Urinary bladder cancer is the most common cancer of the canine urinary tract, with transitional cell carcinoma (TCC) being the most commonly diagnosed tumor type. TCC is aggressive, invasive and fatal for most dogs. If left untreated, TCC of the canine bladder has average survival times less than one year. Optimal treatment of this malignancy remains a topic of debate. Different treatment options exist, but many complicating factors make the probability of cure very low, regardless of treatment type, and most care is palliative in nature. Radiation therapy is a possible treatment option, however dailyshape, size, and positional changes (motion) of the bladder and surrounding soft tissue structures often make this modality difficult to incorporate into a curative-intent treatment plan. This study was designed to investigate and quantify the motion characteristics experienced by the canine urinary bladder from day to day. Additionally, this information was then used to examine possible treatment scenarios and determine which of those scenarios would be optimal for canine bladder cancer patients. Retrospective cone beam CT (CBCT) image data from ten dogs were used in this study. Organs of interest were contoured on each daily treatment CBCT data set and the images, along with the contours, were registered (fused) to the original (reference) planning CT. Quantification of bladder motion was determined by making measurements relative to the planning CT. Dosimetric data for the organs of interest were determined using dose volume histograms generated from sample treatment plans. Results indicate a wide range in bladder motion throughout treatment, which partly depends on the methods used for patient positioning (set-up). Of the three patient positioning methods evaluated (dorsal, sternal, and lateral recumbency), the least amount of bladder variability, as well as lowest rectal dose, is seen when dogs are placed in lateral recumbency. Using these motion characteristics, we were able to develop different treatment planning and set-up scenarios that allow for a curative dose to be delivered to the bladder, while simultaneously reducing the dose delivered to the nearby sensitive rectal tissue. All advanced treatment planning techniques produce a better dose distribution than traditional parallel opposed planning, with adaptive radiation therapy (ART) planning techniques showing the most advantageous dose distribution. These results allow for a more informed approach to the treatment of canine bladder cancer, as well as providing possible curative-intent treatment options for canine patients with this malignancy

Bear Smart UM: Creating a University Campus Safe for Bears and Students

Universities nestled in the mountains across the globe like the University of Montana may find themselves dealing with human-bear conflict while lacking the proper resources to approach management. At UM, there has been an increase in bear activity over the past five years and it is expected to increase. Developing a plan to prevent bear activity on campus can be costly, time-consuming, and tedious. Our student group’s solution includes two intertwining parts: A bear management plan and educational outreach surrounding bear safety. The recommendations in the bear management plan were created by consulting bear-conflict specialists from Missoula County, craftspeople who construct bear-proof enclosures, and hotspots for bear activity gathered by the UM Chapter of the Wildlife Society. The bear management plan includes recommendations related to waste management for different locations on campus, fruit trees and native plants that are bear attractants, and a corresponding budget. The educational outreach has involved creating informational PowerPoints and flyers and presenting them to classes at UM to educate students about bear-safe behavior and to encourage students to attend our bear spray safety demonstration by the Bear Aware Campaign on April 4, 2023. Both parts of our project are essential in providing useful solutions for UM as we move into yet another bear season and seek to reduce bear-human conflict

Bear Smart UM: Creating a University Campus Safe for Bears and Students

Bear Smart UM: Creating a University Campus Safe for Bears and Students Biological Sciences Universities nestled in the mountains across the globe like the University of Montana may find themselves dealing with human-bear conflict while lacking the proper resources to approach management. At UM, there has been an increase in bear activity over the past five years and it is expected to continue to increase. Developing a plan to prevent bear activity on campus is often costly, time-consuming, and tedious. Our student group’s solution includes two intertwining parts: A bear management plan and educational outreach surrounding bear safety. The recommendations in the bear management plan were created by consulting bear-conflict specialists from Missoula County, craftspeople who construct bear-proof enclosures, and hotspots for bear activity gathered by the UM Chapter of the Wildlife Society. The bear management plan includes recommendations related to waste management for different locations on campus, fruit trees and native plants that are bear attractants, and a corresponding budget. The educational outreach has involved creating informational PowerPoints and flyers and presenting them to classes at UM to educate students about bear-safe behavior and to encourage students to attend our bear spray safety demonstration by the Bear Aware Campaign on April 4, 2023. Both parts of our project are essential in providing solutions for the intriguing relationship UM has with bears and preventing any further conflict that can harm the UM community and the bear population

α-Catenin-Vinculin Interaction Functions to Organize the Apical Junctional Complex in Epithelial Cells

αE-catenin, a cadherin-associated protein, is required for tight junction (TJ) organization, but its role is poorly understood. We transfected an αE-catenin–deficient colon carcinoma line with a series of αE-catenin mutant constructs. The results showed that the amino acid 326–509 domain of this catenin was required to organize TJs, and its COOH-terminal domain was not essential for this process. The 326–509 internal domain was found to bind vinculin. When an NH2-terminal αE-catenin fragment, which is by itself unable to organize the TJ, was fused with the vinculin tail, this chimeric molecule could induce TJ assembly in the αE-catenin–deficient cells. In vinculin-null F9 cells, their apical junctional organization was impaired, and this phenotype was rescued by reexpression of vinculin. These results indicate that the αE-catenin-vinculin interaction plays a role in the assembly of the apical junctional complex in epithelia

Regulation of Classical Cadherin Membrane Expression and F-Actin Assembly by Alpha-Catenins, during Xenopus Embryogenesis

Alpha (α)-E-catenin is a component of the cadherin complex, and has long been thought to provide a link between cell surface cadherins and the actin skeleton. More recently, it has also been implicated in mechano-sensing, and in the control of tissue size. Here we use the early Xenopus embryos to explore functional differences between two α-catenin family members, α-E- and α-N-catenin, and their interactions with the different classical cadherins that appear as tissues of the embryo become segregated from each other. We show that they play both cadherin-specific and context-specific roles in the emerging tissues of the embryo. α-E-catenin interacts with both C- and E-cadherin. It is specifically required for junctional localization of C-cadherin, but not of E-cadherin or N-cadherin at the neurula stage. α-N-cadherin interacts only with, and is specifically required for junctional localization of, N-cadherin. In addition, α -E-catenin is essential for normal tissue size control in the non-neural ectoderm, but not in the neural ectoderm or the blastula. We also show context specificity in cadherin/ α-catenin interactions. E-cadherin requires α-E-catenin for junctional localization in some tissues, but not in others, during early development. These specific functional cadherin/alpha-catenin interactions may explain the basis of cadherin specificity of actin assembly and morphogenetic movements seen previously in the neural and non-neural ectoderm

The secret life of α-catenin: Moonlighting in morphogenesis

Cadherin-based intercellular adhesions are important determinants of proper tissue architecture. These adhesions must be both stable and dynamic to maintain tissue integrity as cells undergo morphogenetic movements during development. The role of α-catenin in this process has been vigorously debated due to conflicting in vitro and in vivo evidence regarding its molecular mechanism of action. Recent data supports the classical view that α-catenin facilitates actin attachments at adherens junctions, but also suggests that α-catenin may act as a force transducer, and may have additional roles in the cytoplasm. These multiple functions for α-catenin converge on the regulation of adhesion and may help to explain its stable yet dynamic nature