Protein restricted, high carbohydrate diets improve metabolic health in rodents, yet the precise dietary components that are responsible for these effects have not been identified. Further, the applicability of these studies to humans is unclear. Here, we demonstrate in a randomized controlled trial that a moderately protein restricted (PR) diet also improves markers of metabolic health in humans. Intriguingly, we find that feeding mice a diet specifically reduced in branched chain amino acids (BCAAs) is sufficient to improve glucose tolerance and body composition equivalently to a PR diet, via metabolically distinct pathways. Our results highlight a critical role for dietary quality at the level of amino acids in the maintenance of metabolic health, and suggest that diets specifically reduced in BCAAs, or pharmacological interventions in this pathway, may offer a translatable way to achieve many of the metabolic benefits of a PR diet.
Using a 12-mm GIA laparoscopic stapling device, a method of organ entrapment, and a recently developed high-speed electrical tissue morcellator, laparoscopic nephroureterectomy was accomplished in an 82-year-old male with a low-grade transitional cell cancer of the renal pelvis.
In an effort to further evaluate the potential application of laparoscopy to urologic surgery, we explored the feasibility of using this minimally invasive approach for performing a partial nephrectomy. Nine female pigs underwent laparoscopic partial nephrectomy (LPN) utilizing a plastic cable tie (15 mm. x 4 mm. x 1 mm.) to achieve renal ischemia and an Argon Beam Coagulator probe (ABC) (Birtcher Medical Systems) to fulgurate the transected surface. Six weeks after LPN, 6 pigs underwent creatinine clearance, renin level, arteriography, BP samples and were then killed. The renal remnants were weighed and sectioned for histological studies. These studies revealed excellent function of the renal remnant, no AV fistula, and no evidence of renovascular hypertension. LPN is a feasible, repeatable procedure in the pig. Control of the renal hilum, transient parenchymal compression with a plastic cable, and use of the argon beam coagulator are key elements in performing this procedure.
Further improvements in the use of existing materials and development of new materials will hopefully result in clinically successful grafts for bladder wall replacement and for whole bladder substitution.
Laparoscopic nephrectomy is a new procedure in which the kidney is removed via a laparoscopic approach using a surgical entrapment sack and a high-speed 10-mm electrical tissue morcellator. Herein, we report the initial clinical experience with this procedure in 10 consecutive patients. The average operating room time was 5.5 hours. The hospital stay averaged 4.9 days, and convalescence occurred over 12 days. Two patients received a blood transfusion(s). At present, laparoscopic nephrectomy is our method of choice for patients requiring a nephrectomy for benign renal disease. The technology developed for this procedure may be helpful to surgeons in other disciplines, as the method of organ entrapment and morcellation can be applied to the removal of other intra-abdominal or pelvic organs.
The purpose of this study was to determine the relationships among pneumoperitoneum pressure, CO2 insufflation volume, and patient height, weight, and body mass index. Forty-one male patients undergoing laparoscopic urologic procedures prospectively had a record made of the delivered volume of CO2 during insufflation to attain intraabdominal pressures of 5, 10, 15, 20, 25, and 30 mm Hg. The relationship of the delivered volume of CO2 insufflated and the intraabdominal pressure was compared statistically to the patient height, weight, and body mass index. In addition, six domestic female pigs underwent pneumoperitoneum, and the abdominal volume was calculated for intraabdominal pressures of 0, 5, 10, 15, 20, 25, and 30 mm Hg. Four different commercially available 10-mm trocars were tested for force required for placement at intraabdominal pressures of 15 and 30 mm Hg. There was a direct relationship between delivered volume of CO2 insufflated and the pneumoperitoneum pressure. There was no significant relationship between the delivered volume of CO2 insufflated at a given intraabdominal pressure and the patient height, weight, or body mass index. During insufflation, 94% of the abdominal volume is achieved by insufflating to 15 mm Hg. There is no significant difference in the force required for insertion of different ports at 15 mm vs 30 mm Hg pressure. Increasing the abdominal pressure to 30 mm Hg provides a 50% increase in the volume of CO2 insufflated vs a standard 15 mm Hg pneumoperitoneum. However, this additional volume does not significantly change the actual abdominal volume or diminish the pressure necessary to insert a trocar.
Ureteral strictures were created in 18 minipigs. Six weeks after stricture inducement, endourologic incision with a balloon cutting device was performed and a 7 F internal polyurethane stent was placed. After this step, 14 pigs remained in the study and were randomized into three different groups depending upon the time when the stent was removed: 1, 3 or 6 weeks. Twelve weeks after stricture incision, the pigs were killed, the status of the incised ureteral segment was evaluated histologically, and a healing score was determined. There were no statistically significant overall differences among the mean values of the overall healing score throughout the three different groups. However, when the one-week and the six-week groups (p < .05) were compared with respect to strictures requiring more than one incision due to stricture length greater than 2 centimeters, a more favorable outcome occurred in the 1 week group. Based on these findings it may be reasonable to remove ureteral stents as early as 1 week after endoureterotomy and endopyelotomy.
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