Second instrument tip breaks during phacoemulsification

Background: Second instrument tip breaks during phacoemulsification are complications that are anecdotally recalled, yet little information exists on why and how often they occur, whether they are consistently tracked, and how they are managed. They may be an underreported, but potentially serious, complication of phacoemulsification. Methods:We surveyed 114 cataract surgeons in Ontario to determine reported rates of second instrument tip breaks, their management, and presumed etiology.We reviewed 4 Toronto cataract centres for incident reports, instrument sterilization processes, and purchase histories. Using scanning electron microscopy (SEM), we compared the characteristics of a broken Sweeney tip to new and used second instruments. Results: Of the 35 surgeons responding to the survey, 34% had experienced a second instrument tip break during their careers. Approximately 73% (16 cases) of the 22 cases reported were managed successfully during the procedure by the primary surgeon, 14% (3 cases) required imaging by computerized tomography or x-ray, and another 14% (3 cases) required pars plana vitrectomy for tip retrieval. Purchase histories revealed that 1 Sweeney hook was exchanged monthly, equivalent to 100 to 150 surgeries. SEM of new and used second instruments revealed signs of metal fatigue on both new and used second instruments. Interpretation: Although both physicians and hospitals lack a method for ensuring quality control of second instruments, approximately one third of cataract surgeons encounter second instrument tip breaks during the course of their careers. Although most cases are managed intraoperatively, consistent hospital tracking records and standardized instrument inspection by institutions and surgeons are needed to determine how these complications occur and to establish protocols for complication reporting and management.link_to_subscribed_fulltex

Activation of Notch signaling in human colon adenocarcinoma.

Notch and Wnt signaling function together to regulate colonic progenitor cell division and differentiation. Studies in mice have also shown that Notch signaling is required for adenoma formation in response to elevated Wnt-pathway signaling that occurs in the APCMin mouse model of human adenomatous polyposis coli. We therefore used in situ hybridization to analyze expression of Notch ligands, receptors and fringe genes, as well as the Notch target gene, HES1, in human colorectal cancer (CRC). In a small cohort of tumors, JAGGED ligands, NOTCH1, LFNG and HES1 were expressed at levels similar to, or higher than, levels observed in the crypt. To explore the possibility that Notch signaling may play a quantitative role in human CRC we next analyzed HES1 mRNA expression in 130 tumors, each associated with outcome data. The vast majority of these tumors expressed HES1, although at varying levels. Absolute expression levels did not correlate with patient survival. These results establish that JAG ligands and NOTCH1, as well as Notch receptor activation are consistent features of human CRC and support the notion that many of these tumors, like the APCMin mouse, may respond to anti-Notch therapeutic regimes