Creation of a neoinfundibulum and serial balloon dilations for the treatment of the excluded calyx: Two cases describing a novel technique.

An excluded calyx is a rare, acquired urologic condition where there is discontinuity between a portion of the renal collecting system with the remainder of the collecting system. Re-establishment of reliable long-term communication between the excluded calyx and the remaining collecting system is crucial for preservation of renal function and possible relief of symptoms. In this manuscript, we discuss two such cases where a previously undescribed novel procedure is used for treatment of this uncommon condition, where percutaneous antegrade transcatheter techniques were used to establish long-term urinary drainage. The first case discusses an excluded calyx in a 17-year-old male who suffered left renal injury after a high speed motor vehicle accident, where the kidney was divided by the injury and subsequently required creation of a neoinfundibulum in order to maintain continuity of the collecting system. The second case involves a 39-year-old female who underwent resection of a renal cell carcinoma, later developing an excluded calyx where radiofrequency wire recanalization was performed and the neoinfundibular track underwent serial retrograde balloon dilation, resulting in a continuous collecting system. Both patients have done well for more than 2 years after neoinfundibulum creation, showing that this novel technique should be considered a viable and safe procedure in the treatment of this rare condition.

Creation of a Ureterocystostomy in a Transplanted Cadaveric Kidney with the Use of a Radiofrequency Guide Wire.

A duplicated collecting system (DCS) is a common anatomical variant of the kidney. As surgeons now perform more donor cadaveric transplants than in the past, the discovery of an occluded DCS may occur in the post-transplant setting. Over a dozen articles have reported on the use of DCS in the renal transplant setting. However, to our knowledge, this case report is the first to describe the creation of a ureterocystostomy with the use of a radiofrequency (RF) guide wire, involving a previously unidentified DCS in a transplanted kidney.

The effect of adsorbed lipid on pyrite oxidation under biotic conditions.

The chemolithoautotrophic bacterium, Acidithiobacillus ferrooxidans, commonly occurs in acid mine drainage (AMD) environments where it is responsible for catalyzing the oxidation of pyrite and concomitant development of acidic conditions. This investigation reports on the growth of this bacterial species on the pyrite surface and in the aqueous phase at a pH close to 2 as well as the role of adsorbed lipid in preventing pyrite dissolution. Both acid washed pyrite and acid-washed pyrite coated with lipids were used as substrates in the studies. The choice of lipid, 1,2-bis(10,12-tricosadiynoyl)-sn-Glycero-3-Phosphocholine lipid (23:2 Diyne PC), a phosphocholine lipid, was based on earlier work that showed that this lipid inhibits the abiotic oxidation rate of pyrite. Atomic force microscopy showed that under the experimental conditions used in this study, the lipid formed approximately 4-20 nm layers on the mineral surface. Surface-bound lipid greatly suppresses the oxidation process catalyzed by A. ferrooxidans. This suppression continued for the duration of the experiments (25 days maximum). Analysis of the bacterial population on the pyrite surface and in solution over the course of the experiments suggested that the pyrite oxidation was dependent in large part on the fraction of bacteria bound to the pyrite surface.

Origin of oxygen in sulfate during pyrite oxidation with water and dissolved oxygen: an in situ horizontal attenuated total reflectance infrared spectroscopy isotope study.

FeS2 (pyrite) is known to react with water and dissolved molecular oxygen to form sulfate and iron oxyhydroxides. This process plays a large role in the environmentally damaging phenomenon known as acid mine drainage. An outstanding scientific issue has been whether the oxygen in the sulfate and oxyhydroxide product was derived from water and/or dissolved oxygen. By monitoring the reaction in situ with horizontal attenuated total reflectance infrared spectroscopy, it was found that when using 18O isotopically substituted water, the majority of the infrared absorbance due to sulfate product red-shifted approximately 70 cm(-1) relative to the absorbance of sulfate using H(2)16O as a reactant. Bands corresponding to the iron oxyhydroxide product did not shift. These results indicate water as the primary source of oxygen in the sulfate product, while the oxygen atoms in the iron oxyhydroxide product are obtained from dissolved molecular oxygen.