Faculty Bibliography

BACKGROUND: We present initial data on the construct, content, and face validity of the LAPMentor (Simbionix), virtual reality laparoscopic surgical simulator. STUDY DESIGN: Medical students (MS), residents and fellows (R/F), and experienced laparoscopic surgeons (ES), with < 30 laparoscopic cases per year (ES<30) and those with > 30 laparoscopic cases per year (ES>30), were tested on 9 basic skill tasks (SK) including manipulation of 0-degree and 30-degree cameras (SK1, SK2), eye-hand coordination (SK3), clipping (SK4), grasping and clipping (SK5), two-handed maneuvers (SK6), cutting (SK7), fulguration (SK8), and object-translocation (SK9). RESULTS: Mean MS (n=23), R/F (n=24), ES<30 (n=26), and ES>30 (n=30) ages were 26 years (range 21 to 32 years), 31 years (range 27 to 39 years), 49 years (range 31 to 70 years) and 47 years (range 34 to 69 years), respectively. In the lower level skill tasks (SK3, SK4, SK5, and SK6) the ES>30, ES<30, and R/F had similar scores, but were all substantially better than the MS scores. In the higher level skill tasks (SK7, SK8, and SK9), the ES>30 scores tended to be better than the R/F and ES<30, which were similar, and these, in turn, were markedly better than the MS. The ES>30 had notably higher SK8 scores than the R/F and ES<30, who had similar scores, and these had notably better scores than the MS. CONCLUSIONS: The noncamera skills (SK3 to 9) of the LAPMentor surgical simulator can distinguish between laparoscopically naive and ES. SK8 showed the highest level of construct validity, by accurately differentiating among the MS, R/F, ES<30 and ES>30.

BACKGROUND AND PURPOSE: Advances in electro-optics continue to improve the urologist's ability to perform minimally invasive procedures. While the development of flexible fiberoptic cystoscopes more than 20 years ago greatly impacted the practice of urology, distal-sensor digital technology may represent the next step in the evolution of endoscopy. We compared a new distal-sensor digital flexible cystoscope with two standard fiberoptic flexible cystoscopes. MATERIALS AND METHODS: We evaluated the resolution, contrast, and color discrimination of a new ACMIICN distal-sensor digital cystoscope with >165,000 effective pixels in its clear aperture (viewing area), a new ACMI-ACN II fiberoptic cystoscope with <15,000 pixels in its clear aperture, and a Storz 1127 office fiberoptic cystoscope. Five subjects compared each cystoscope across 13 test parameters. RESULTS: There was no difference in the performance of the two fiberoptic cystoscopes. The ICN cystoscope was statistically superior to one or both fiberoptic cystoscopes across 12 of the 13 tests, including color differentiation between shades of dark red (P < 0.05), contrast discrimination along a 15-step grayscale gradient (P < 0.001 compared with the 1127 fiberoptic cystoscope only), resolution at 10 mm (7.52 line pairs/mm [lp/mm] (ICN) nu 3.58 lp/mm for both fiberoptic cystoscopes; (P < 0.001), and clear resolution of a 1-mm target at a distance of 6.1 cm (ICN) nu 3.3 cm (1127) and 3.8 cm (ACN II) (P < 0.001). CONCLUSIONS: The ICM distal-sensor all-digital cystoscope was clearly superior to two representative fiberoptic cystoscopes in vitro in terms of resolution, contrast discrimination, and red color differentiation. In-vivo performance remains to be assessed.

We describe using hemostatic gelatin matrix (FloSeal; Baxter Inc., Irvine, CA) to provide hemostasis of the tract after percutaneous nephrolithotomy, thereby obviating a nephrostomy tube. For patients who are rendered stone free, a 7F, 11.5-mm occlusion balloon catheter, passed retrograde, is used to occlude the collecting system at the level of entry of the 30F Amplatz sheath. FloSeal is then injected through the partially retracted Amplatz sheath while withdrawing the applicator and the sheath in tandem. The guidewire is withdrawn per urethra until its tip resides in the renal pelvis. A 36-cm, 7F tail stent is passed retrograde, and the skin is closed with cyanoacrylate adhesive (Ethicon, Somerville, NJ). A Foley catheter is placed, to be removed the next morning; the patient can be discharged on postoperative day 1. The ureteral stent is removed in 5 to 7 days as an outpatient procedure.

We report a case of a primary intratesticular mucinous cystadenoma in an asymptomatic 39-year-old man. The mass was found incidentally during a consultation for infertility. Pathologic examination of the orchiectomy specimen revealed a unilocular cyst lined with bland mucinous epithelium and mucinous extravasation, consistent with a diagnosis of mucinous cystadenoma. Foci of bone were also found in association with extensive chronic inflammation. Immunohistochemical stains performed showed immunoreactivity for cytokeratin 7, and nonreactivity for cytokeratin 20, CA125, chromogranin, and synaptophysin. The immunohistochemical staining patterns of the present case are compared with those of known mucinous cystadenomas of the ovary and nonneoplastic colonic mucosa. The histogenesis of this entity is discussed in light of the literature and the immunohistochemical findings in this rare case.

BACKGROUND: Although somatostatin is recognized as an inhibitor of neuroendocrine cell secretion, its effect on cell proliferation has not been well defined. Generation of low acid and hypergastrinemia through irreversible H2-receptor blockade (loxtidine) in the African rodent mastomys results in gastric carcinoids (ECLomas) within 4 months. This study was undertaken to evaluate and characterize the precise somatostatin receptor (SSTR) subtype on the mastomys enterochromaffin-like (ECL) cell and to define its role in the regulation of ECL cell secretion and proliferation. METHODS: A pure preparation (approximately 90%) of ECL cells was derived by a combination of pronase digestion and density gradient separation. We assessed the effect of somatostatin (10(-15) to 10(-7) mol/L) on gastrin-stimulated ECL cell histamine secretion and DNA synthesis (bromodeoxyuridine uptake). SSTR2 subtype was evaluated by reverse transcription-polymerase chain reaction (RT-PCR) using gene specific primers and mRNA isolated from normal and hypergastrinemia-induced ECLoma. The polymerase chain reaction product was confirmed by Southern analysis, subcloned, and sequenced. RESULTS: Somatostatin inhibited both gastrin-stimulated histamine secretion (IC50, 5 x 10(-13) mol/L) and DNA synthesis (IC50, 10(-10) mol/L). SSTR2 was identified in the mastomys' brain, and both normal and tumor ECL cells and comparison of the brain and ECL cell SSTR2 nucleotide sequences revealed homology of 99%. CONCLUSIONS: The SSTR2 is expressed by the mastomys' ECL cell and ECLoma. Receptor activation inhibits both ECL cell secretory and proliferative functions.