Detection of Enzyme Activity in a Pancreatic Tumor Model Using CatalyCEST Contrast MRI

Detection of enzyme activity has gained popularity in molecular imaging because increased activity of enzymes such as urokinase plasminogen activator (uPA) can serve as biomarkers and assist in cancer diagnosis. Chemical exchange saturation transfer (CEST) Magnetic Resonance Imaging (MRI) is a non-invasive technique that can be utilized to detect enzyme activity; however, CEST MRI is not the only technique that can assess enzyme activity. Chapter 1 provides an overview of various imaging modalities that have been used to detect enzyme activity in vivo. Advances made in probe-design are discussed, in addition to advantages and disadvantages of each technique. Chapter 2 focuses on detection of uPA activity in a pancreatic cancer tumor model using a catalyCEST MRI contrast agent. Chapter 2 also discusses the importance of uPA in tumor biology, addresses the synthesis of the contrast agent, and evaluates the results of in vivo detection and ex vivo validation of uPA activity in response to therapy of pancreatic tumor models of Capan-2. The in vivo and ex vivo results showed no significant difference in uPA activity between chemotherapy-treated and non-treated mice. Additionally, no significant difference was observed between before and after chemotherapy-treated groups. Chapter 3 addresses some of the limitations of the study detailed in Chapter 2 and proposes improvements

Imaging diagnosis: magnetic resonance imaging of diffuse leptomeningeal oligodendrogliomatosis in a dog with "dural tail sign"

A case of diffuse leptomeningeal oligodendrogliomatosis affecting the brain and spinal cord of a dog is presented. A 7.5-year old, male neutered Staffordshire bull terrier presented for evaluation of a chronic history of tetraparesis and seizures, with a multifocal neuroanatomical localization was determined. Extra-axial intradural lesions with an atypical presentation of a dural tail sign were seen on MRI. Histologically, the lesions were consistent with leptomeningeal oligodendrogliomatosis. To the authors’ knowledge, a dural tail sign has not previously been reported as an MRI characteristic of diffuse leptomeningeal oligodendrogliomatosis in dogs

Safety and Imaging Quality of MRI in Pediatric and Adult Congenital Heart Disease Patients with Pacemakers

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75401/1/j.1540-8159.2009.02304.x.pd

Alternating electric fields (TTFields) inhibit metastatic spread of solid tumors to the lungs

Tumor treating fields (TTFields) are low intensity, intermediate frequency, alternating electric fields used to treat cancerous tumors. This novel treatment modality effectively inhibits the growth of solid tumors in vivo and has shown promise in pilot clinical trials in patients with advanced stage solid tumors. TTFields were tested for their potential to inhibit metastatic spread of solid tumors to the lungs in two animal models: (1) Mice injected with malignant melanoma cells (B16F10) into the tail vein, (2) New Zealand White rabbits implanted with VX-2 tumors within the kidney capsule. Mice and rabbits were treated using two-directional TTFields at 100–200 kHz. Animals were either monitored for survival, or sacrificed for pathological and histological analysis of the lungs. The total number of lung surface metastases and the absolute weight of the lungs were both significantly lower in TTFields treated mice then in sham control mice. TTFields treated rabbits survived longer than sham control animals. This extension in survival was found to be due to an inhibition of metastatic spread, seeding or growth in the lungs of TTFields treated rabbits compared to controls. Histologically, extensive peri- and intra-tumoral immune cell infiltration was seen in TTFields treated rabbits only. These results raise the possibility that in addition to their proven inhibitory effect on the growth of solid tumors, TTFields may also have clinical benefit in the prevention of metastatic spread from primary tumors