My clinical and research efforts continue to be centered around the treatment and understanding the pathogenesis of urinary stone disease. I have recently identified zinc as a critical factor in the early mineralization process. We utilized the synchrotron at the Lawrence Berkeley National Laboratories to identify non-trace amounts of zinc in Randall plaques (early human urinary stones) and in our recent Drosophila fly model. By knocking out specific zinc transporters in our first fruit fly model we were able to demonstrate that stone development dramatically decreases. I have collaborated with researchers at the Buck Institute on Aging, the Advance Light Source at the Lawrence Berkeley National Laboratory, Oakland Children’s Hospital, UC Davis, and Julian Dow in Glasgow to help mature this intriguing invertebrate fly animal model. I recently received a R-21 and P-20 NIH funding to further these studies. Presently, I have three post docs helping with this project. We recently developed an additional fruit fly model that will develop cystine and calcium based stones. We also are investigating the role of uric acid metabolism in stone development. Techniques to stain and visualize these concretions continues to be in progress.

In collaboration with Bob Grubbs at Caltech we are developing a new minimally invasive technique to potentially replace routine endourologic techniques to treat urinary stones. Injection of our specialized tagged bubbles will attach to the offending stone/s and with appropriate energy sources will cavitate and fracture the stones. Proof of concept with high speed photography was performed with collaborators at the University of Washington. Patents have been issued (US2013/0123781) and we are in active discussions with various companies to develop a commercial application.

I am collaborating with NYU and Mass General to develop a unique drink for patients to help reduce recurrent nephrolithiasis. This drink may also be beneficial for individual with bone disease. Patents have been issued and term sheets are in process to move this commercial product (conceived from my clinical and basic science research) forward.

I have collaborated with Rebecca Smith-Bindman in our Radiology Department to determine whether CT imaging of patients presenting with renal colic could be replaced with US imaging. The NIH funded study through AHRQ has finished with >2500 prospectively enrolled patients with a 2 year follow-up; our data was recently published in the New England Journal of Medicine. Our findings may have a profound impact on the management of patients presenting with acute renal colic. Our specific findings reveal that ultrasound imaging (by either a radiologist or emergency room physician) is equivalent to CT imaging. Both imaging modalities had minimal serious adverse events. Hopefully this study will reduce radiation exposure to patients that frequently present with recurrent stone episodes..


Other research endeavors include the development of an ambulatory assist device to replace routine intravenous poles in patient rooms. This has been funded through our T1 catalyst program. I have also developed an ambulatory impedence device to determine bladder volumes to help assist patients determine when they should void. This also has received funding through the T1 catalyst program.

I continue to have an active clinical Endourology program and my last five fellows have gained academic appointments at medical centers around the country.