Obese subcutaneous adipose tissue impairs human myogenesis, particularly in old skeletal muscle, via resistin-mediated activation of NFκB.

Adiposity and adipokines are implicated in the loss of skeletal muscle mass with age and in several chronic disease states. The aim of this study was to determine the effects of human obese and lean subcutaneous adipose tissue secretome on myogenesis and metabolism in skeletal muscle cells derived from both young (18-30 yr) and elderly (>65 yr) individuals. Obese subcutaneous adipose tissue secretome impaired the myogenesis of old myoblasts but not young myoblasts. Resistin was prolifically secreted by obese subcutaneous adipose tissue and impaired myotube thickness and nuclear fusion by activation of the classical NFκB pathway. Depletion of resistin from obese adipose tissue secretome restored myogenesis. Inhibition of the classical NFκB pathway protected myoblasts from the detrimental effect of resistin on myogenesis. Resistin also promoted intramyocellular lipid accumulation in myotubes and altered myotube metabolism by enhancing fatty acid oxidation and increasing myotube respiration and ATP production. In conclusion, resistin derived from human obese subcutaneous adipose tissue impairs myogenesis of human skeletal muscle, particularly older muscle, and alters muscle metabolism in developing myotubes. These findings may have important implications for the maintenance of muscle mass in older people with chronic inflammatory conditions, or older people who are obese or overweight.

Evolving management of upper-tract transitional-cell carcinoma at a tertiary-care center.

BACKGROUND AND PURPOSE: Traditional management of upper-tract transitional-cell carcinoma (TCC) has been open nephroureterectomy. Minimally invasive options, including laparoscopic and endoscopic techniques, are being applied with increasing frequency, however. To assess the impact of these techniques on the current management of upper-tract TCC, we reviewed our experience managing this problem over the last 3 years. PATIENTS AND METHODS: Since January 1998, 84 patients underwent definitive management of upper-tract TCC using open, laparoscopic, or endoscopic techniques. This study group includes 57 men and 27 women with a mean age of 69.9 years. RESULTS: Fifty-three patients (63.9%) were treated by laparoscopic nephroureterectomy. Twelve patients (14.5%) were treated endoscopically, with percutaneous resection in 7 patients and ureteroscopic resection in 5 patients. The indications for nephron-sparing management in these 12 patients included solitary kidneys in 6 patients, significant comorbidities in 4 patients, and bilateral disease in 1 patient. Endoscopic management was elective in one patient. Nineteen patients (22.9%) underwent open surgical procedures consisting of nephroureterectomy in 16 patients and distal ureterectomy with reimplantation in 3 patients. CONCLUSIONS: Advances in laparoscopy and endourology are significantly impacting the definitive management of upper-tract TCC. Patients with a normal contralateral kidney are currently offered laparoscopic nephroureterectomy, while those with an absent or functionally compromised contralateral kidney are generally managed with endoscopic resection. Although minimally invasive techniques have demonstrated advantages regarding postoperative pain, hospital stay, and return to regular activities, only critical long-term follow-up regarding rates of local and distant recurrence will determine the ultimate role of these techniques.

Laparoscopic partial nephrectomy for renal tumor: duplicating open surgical techniques.

PURPOSE: We describe our technique of and single institutional experience with purely laparoscopic partial nephrectomy for renal tumor, wherein the focus is to duplicate established open techniques of oncologic nephron sparing surgery. MATERIALS AND METHODS: Since August 1999 laparoscopic partial nephrectomy for renal tumor has been performed in 50 patients. Of the patients 24 (48%) had either a compromised contralateral kidney (20) or a solitary kidney (4). Mean tumor size was 3.0 cm. (range 1.4 to 7). In 9 patients (18%) the inner margin of the tumor was in close proximity to the pelvicaliceal system. Our current laparoscopic technique involves preoperative ureteral catheterization, laparoscopic renal ultrasonography, transient atraumatic clamping of the renal artery and vein, tumor excision with an approximate 0.5 cm. margin using cold endoshears and/or J-hook electrocautery, pelvicaliceal suture repair (if necessary) and suture repair of the renal parenchymal defect over surgicel bolsters. In 1 case renal surface hypothermia was achieved laparoscopically with ice slush. All suturing and knot tying were performed with free hand intracorporeal laparoscopic techniques exclusively. RESULTS: All procedures were successfully completed without open conversion. Mean surgical time was 3.0 hours (range, 0.75 to 5.8) and mean blood loss was 270.4 cc (range 40 to 1,500). Mean warm ischemia time was 23 minutes (range, 9.8 to 40). Caliceal entry in 18 cases (36%) was suture repaired in a watertight manner. Following caliceal repair, none of these 18 patients had a postoperative urine leak. Hospital stay averaged 2.2 days (range 1 to 9). Major complications occurred in 3 patients (6%) including intraoperative hemorrhage in 1, delayed hemorrhage necessitating nephrectomy in 1 and urine leak in 1. Renal cell carcinoma was confirmed on pathological examination in 34 patients (68%), and all had negative inked surgical margins for cancer. During a mean followup of 7.2 months (range 1 to 17) no patient has had local or port site recurrence or metastatic disease. CONCLUSIONS: Laparoscopic partial nephrectomy is a viable alternative for select patients with a renal tumor. The largest single institutional experience to date is presented wherein the open techniques of nephron sparing surgery have been duplicated laparoscopically.

Vaginal extraction of the intact specimen following laparoscopic radical nephrectomy.

PURPOSE: We report the detailed technique and results of transvaginal extraction of the intact laparoscopic radical nephrectomy specimen. MATERIALS AND METHODS: Since June 2000, 10 select female patients with a median age of 67 years underwent transvaginal extraction of the intact specimen after laparoscopic radical nephrectomy. In 5 patients open surgery had previously been performed on the uterus, including transabdominal hysterectomy in 2 and cesarean section in 3. Laparoscopic nephrectomy was performed via the transperitoneal and retroperitoneal approach in 5 cases each. After completion of the primary laparoscopic procedure a sponge stick was externally inserted into the sterile prepared vagina and tautly positioned in the posterior fornix. Laparoscopically a transverse posterior colpotomy was created at the apex of the tented up posterior fornix and the drawstring of the entrapped specimen was delivered into the vagina. After laparoscopic exit was completed the patient was placed in the supine lithotomy position. The specimen was extracted intact via the vagina and the posterior colpotomy incision was repaired transvaginally. Patients were mailed a linear scale analog questionnaire to assess various aspects of recovery with responses graded from 0--no pain and/or change to 10--severe pain and/or change. RESULTS: Vaginal extraction was successful in all 10 patients. Median operative time for the vaginal extraction procedure was 35 minutes. Blood loss was minimal. Median tumor size was 3.6 cm. (range 2.4 to 7.4) and median specimen weight was 327 gm. (range 152 to 484). No intraoperative complications occurred. Postoperatively blood spotting via the vagina in 1 patient resolved spontaneously. Postoperative questionnaires revealed excellent patient satisfaction and convalescence. CONCLUSIONS: Vaginal extraction is an efficacious and minimally morbid technique for removing the intact entrapped specimen after laparoscopic radical nephrectomy. It has now become our preferred technique of intact specimen extraction in appropriate female patients.