Repeatability of Zone Averages Compared to Single-Point Measurements of Maximal Curvature in Keratoconus.

PURPOSE: To evaluate the repeatability of curvature zone averages centered on the point of maximum curvature (Kmax) compared to that of the single-point Kmax. DESIGN: Comparative reliability analysis. METHODS: Setting: American University of Beirut Medical Center, Beirut, Lebanon. STUDY POPULATION: Sixty-five eyes of 65 adult keratoconus patients. Patients with other ocular disease, history of ocular surgery or trauma, and contact lens wear within 2 weeks of image acquisition were excluded. OBSERVATION PROCEDURES: Eyes were evaluated with 3 consecutive scans using the Galilei dual Scheimpflug-Placido system. MAIN OUTCOME MEASURES: Repeatability of axial and instantaneous Kmax single points, and zone averages with radii of 0.1-2.0 mm, centered on them. Repeatability was assessed by within-subject standard deviations, repeatability limits (r), and intraclass correlation coefficients. RESULTS: Axial curvature zone averaging yielded clinically acceptable repeatability only in eyes with Kmax ≤50 diopters (D), for radii of 1.5 mm and 2.0 mm (r = 0.87 D and r = 0.76, respectively, vs r = 0.91 for the single-point axial Kmax). Compared to instantaneous Kmax, clinically acceptable repeatability was achieved with instantaneous zone averages of at least 1.5 mm radius in eyes with Kmax ≤50 D (r = 0.99 D and r = 0.70 D, respectively) and 2.0 mm radius in eyes with Kmax >50 D (r = 2.28 D and r = 0.87 D, respectively). For all eyes, the repeatability limit of the location of Kmax was 0.82 mm and 0.80 mm for axial and instantaneous curvature, respectively. CONCLUSIONS: Instantaneous curvature zone averages centered on Kmax yielded a greater improvement in repeatability than axial zone averages and reached clinical adequacy with radii of at least 1.5 mm, for eyes with Kmax ≤50 D, and with a 2.0 mm radius for eyes with Kmax >50 D.

Retroperitoneoscopic adrenalectomy: comparison of retrograde and antegrade approach among a series of 279 cases.

OBJECTIVE: To compare the results of retroperitoneal laparoscopic adrenalectomy using the antegrade and retrograde approach. MATERIALS AND METHODS: We performed an analysis of a single-center series of 279 retroperitoneal laparoscopic adrenalectomies from 1996 to 2010. We compared 172 cases performed with an antegrade approach and 107 with a retrograde approach without dissection of the renal hilum and initial control of the adrenal vein in comparable populations. RESULTS: The operative time was shorter in the group treated with the retrograde technique, 101±51 vs 140±40 minutes, respectively (Student's t test, P<.001). Blood loss was similar in both groups, 85±224 vs 80±126 mL, respectively (P=NS). Hemodynamic instability was defined as the maximal systolic blood pressure minus the minimal systolic blood pressure divided the maximal systolic blood pressure. It was lower in the group who underwent the retrograde technique (32.7 vs 37.6 mL; Student's t test, P=.005) with a lower perioperative consumption of ephedrine (2.2 vs 5.1 mg, P=.004) and atropine (0.09 vs 0.22 mg, P=.026). No difference was found between the 2 groups in the frequency of perioperative complications or postoperative mortality (1 death in each group of causes unrelated to the surgery). CONCLUSION: Retroperitoneal laparoscopic adrenalectomy using a retrograde approach is a safe and reproducible technique. It makes it possible to perform adrenalectomy without dissection of the renal hilum, with a reduction in the operative time. The good hemodynamic stability observed with this technique makes it very attractive for the treatment of pheochromocytoma.

Appetitive and aversive learning in Spodoptera littoralis larvae.

Adult Lepidoptera are capable of associative learning. This helps them to forage flowers or to find suitable oviposition sites. Larval learning has never been seriously considered because they have limited foraging capabilities and usually depend on adults as concerns their food choices. We tested if Spodoptera littoralis larvae can learn to associate an odor with a tastant using a new classical conditioning paradigm. Groups of larvae were exposed to an unconditioned stimulus (US: fructose or quinine mixed with agar) paired with a conditioned stimulus (CS: hexanol, geraniol or pentyl acetate) in a petri dish. Their reaction to CS was subsequently tested in a petri dish at different time intervals after conditioning. Trained larvae showed a significant preference or avoidance to CS when paired with US depending on the reinforcer used. The training was more efficient when larvae were given a choice between an area where CS-US was paired and an area with no CS (or another odor). In these conditions, the memory formed could be recalled at least 24 h after pairing with an aversive stimulus and only 5 min after pairing with an appetitive stimulus. This learning was specific to CS because trained larvae were able to discriminate CS from another odor that was present during the training but unrewarded. These results suggest that Lepidoptera larvae exhibit more behavioral plasticity than previously appreciated.

Small cell neuroendocrine carcinoma of the urinary bladder: report on two cases and review of the literature.

Small cell (Neuroendocrine) carcinoma of the urinary bladder is a rare but highly aggressive malignancy. The neoplastic cells exhibit both neuroendocrine and epithelial differentiation. It is morphologically indistinguishable from the more common pulmonary small cell carcinoma. It can occur either in association with urothelial (transitional cell) carcinoma or in a pure form. Presenting signs and symptoms are non specific. Histologically, it can mimic poorly differentiated urothelial carcinoma and lymphoma. Muscle invasion is almost invariably present at diagnosis and mortality is mainly due to metastases rather than loco regional recurrence. The optimal therapeutic modality is still controversial. In this article, we report on two cases occurring in a pure form and we briefly review the published literature regarding the clinical presentation, morphology, differential diagnosis, prognosis and treatment.