Assessment of microsatellite instability for screening bladder cancer in high-risk population.

AIMS: This study aims to determine the diagnostic efficacy of microsatellite markers for screening bladder cancer in population at high risk. MATERIALS AND METHODS: A population of 200 people was screened for bladder cancer using a set of microsatellite markers. Urine samples were obtained from four different types of population groups - Group 1 (healthy population group), Group 2 (current smokers with a smoking history of more than 10 years), Group 3 (bladder cancer group), and Group 4 (bladder cancer group who were former smokers with a history of more than 10 years). Polymerase chain reaction (PCR) was performed to amplify microsatellite sequences at D9S63, D9S156, and D9S283. PCR products were separated on 1.8% agarose gel and were scanned using ultraviolet transilluminator. RESULTS: In Group 2 (high-risk population group, mainly current smokers with a history of more than 10 years), microsatellite alterations were found in 36 out of 50 people. We observed microsatellite alterations in 38 out of 50 people in Group 3 (bladder cancer group) and in 39 out of 50 people in Group 4 (bladder cancer group, mainly former smokers with a history of more than 10 years). The sensitivity of this test in Group 2, Group 3, and Group 4 was found to be 72%, 76% and 78%, respectively. The specificity of this test in each group was found to be 90%. CONCLUSION: Using these set of microsatellite markers, medium sensitivity and high specificity were reported for this test. The current findings suggest that a set of microsatellite markers (D9S63, D9S156, and D9S283) can be used to detect bladder cancer in high-risk population.

Design and simulation of a visual and haptic assisted biopsy (ViHAB) system.

Core needle biopsy is a non-invasive technique for confirming breast and prostate cancer. Several non-real time image based systems have been developed to guide the needle to the target. X-ray, ultrasound (US), MRI or x-ray fluoroscopy are used to guide the needle during biopsy. However, these methods are non-real time or, the imaging technique is two dimensional or, ionizing. Our broad objective is to develop a visually guided, haptically assisted breast biopsy system (ViHAB) using real time 3D US imaging and haptic guidance. ViHAB will help the radiologist identify suspicious tissue and provide real time guidance for core needle biopsy. The ViHAB simulator developed at the Virtual Environment Laboratory is capable of reading and displaying 3-D US images, keep track of micro-calcification in near real time in a sequence of images as well as provide haptic and visual guidance to a virtual needle via a joystick.

Determination of key and driving points of a beam model for tissue simulation.

The simulation of catheter, guide wire, rigid tissues, muscles and blood vessels using conventional methods like mass spring model and FEM are computationally expensive. The former is comparatively faster than the latter but less accurate. Earlier, we proposed a new method of simulating of tubular organs using deformable beam models. This method is not only accurate but also promises to be faster than mass-spring model for the simulation of tissues. This paper focuses on an important aspect of this approach--the determination of key and driving points of a beam model.