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PurposeA disconnect often exists between those with the expertise to manage and analyze complex, multi-source data sets, and the clinical, social services, advocacy, and public health professionals who can pose the most relevant questions and best apply the answers. We describe development and implementation of a cancer informatics infrastructure aimed at broadening the usability of community cancer data to inform cancer control research and practice; and we share lessons learned. MethodsWe built a multi-level database known as The Ohio Cancer Assessment and Surveillance Engine (OH-CASE) to link data from Ohio’s cancer registry with community data from the U.S. Census and other sources. Space- and place-based characteristics were assigned to individuals according to residential address. Stakeholder input informed development of an interface for generating queries based on geographic, demographic, and disease inputs and for outputting results aggregated at the state, county, municipality, or zip code levels. ResultsOH-CASE contains 723,410 patient records for Ohioans diagnosed with cancer from 1/1/2006 – 12/31/2017 across 88 counties containing 1215 municipalities and 1197 zip codes. Stakeholder feedback from cancer center community outreach teams, advocacy organizations, public health, and researchers suggests a broad range of uses of such multi-level data resources accessible via a user interface. ConclusionOH-CASE represents a prototype of a transportable model for curating and synthesizing data to understand cancer burden across communities. Beyond supporting collaborative research, this infrastructure can serve the clinical, social services, public health, and advocacy communities by enabling targeting of outreach, funding, and interventions to narrow cancer disparities.

Purpose The purpose of this study was to evaluate agreement between eye banks (EBs) and an image analysis reading center on endothelial cell density (ECD) determinations using the same image analysis method. Methods The Cornea Image Analysis Reading Center (CIARC) determined ECD with a single experienced analyst on EB-obtained central endothelial images from donors intended for keratoplasty from 2 eye banks, Eversight and Lions VisionGift, using the Konan center analysis method. The EBs performed ECD determination on their respective sets of images using the same analysis method with experienced eye bank technicians. Results The mean age of the 200 donors was 54 years (range 30-75 years). Seventy (35%) of the 200 patients were women, and 57 (29%) were diabetic. The mean ECD was 10 cells/mm2 greater by the EBs than by CIARC (P = 0.39), with 95% limits of agreement of [-304 to 323 cells/mm2]. The mean difference was not substantially changed when the difference between EBs and CIARC ECD was adjusted for sex, donor age, donor diabetes, CV, HEX, number of cells analyzed, and EBs as a random effect (estimated mean difference of 20 cells/mm2 after adjustment in a linear mixed model; P = 0.73). The EB-determined preoperative ECD was within 10% of the CIARC-determined ECD for 178 (89%) image sets, with 15 (8%) higher by >10% and 7 (3%) lower by >10%. Conclusions Well-trained eye bank technicians achieve comparable results for ECD determination with an experienced image analyst from an image analysis reading center when the same image analysis method is used.

Background: Cleveland, Ohio, is home to three major hospital systems serving approximately 80% of the Northeast Ohio population. The Cleveland Clinic, University Hospitals Health System, and MetroHealth are direct competitors for primary and specialty care, and patient overlap between these systems is high. Fragmentation of health data that exist in silos at these health systems produces an overestimation of disease burden due to double and sometimes triple counting of patients. As a result, longitudinal population-based studies across the Cleveland patient population are impeded unless accurate and actionable clinically derived health data sets can be created. Methods: The Cleveland Institute for Computational Biology has developed the De-Duplicate and De-Identify Research Engine (DeDeRE) that, without any exchange of personal health identifiers (PHI) between health systems, will effectively de-duplicate the patients between one or more health entities. Results: The immediate utility of this software for cancer epidemiology is the increased accuracy in measuring cancer burden and the potential to perform longitudinal studies with de-duplicated, de-identified data sets. Conclusions: The DeDeRE software developed and tested here accomplishes its goals without exposing PHIs using a state-of-the-art, trusted privacy preservation network enabled by a hash-based matching algorithm. Impact: This paper will guide the reader through the functions currently developed in DeDeRE and how a healthcare organization (HCO) employing the release version of this technology can begin sharing data with one or more additional HCOs in a collaborative and noncompetitive manner to create a regional population health resource for cancer researchers. See all articles in this CEBP Focus section, “Modernizing Population Science.”

Purpose To determine whether intracameral moxifloxacin 500 μg is noninferior to 250 μg for central endothelial cell loss (ECL) after phacoemulsification. Setting Aravind Eye Care System. Design Prospective masked randomized study. Methods Eyes with bilateral nuclear cataracts, central endothelial cell density (ECD) of more than 2000 cells/mm, and ECD not differing between eyes by more than 200 cells/mm underwent phacoemulsification at least 14 days apart. Intraoperatively, the first eye was randomized to receive either a 500 or 250 μg dose of moxifloxacin intracamerally and received the other dose for the second-eye surgery. Postoperative course was monitored at 1 day, 1 week, 1 month, and 3 months. Preoperative and 30-day and 90-day postoperative central ECD was determined by a reading center for a masked analysis of ECL at 3 months postoperatively. Results Fifty eyes of 25 patients (aged 48 to 69 years) underwent uneventful surgery and had normal postoperative courses. The point estimate (PE) and 95% CI for the mean difference in % ECL between the 500 μg and 250 μg doses at 3 months postoperatively was 0.8% (-5.8%, 7.4%). Upon identifying and removing 2 outliers, noninferiority was proven with a mean difference of the PE, -2.2% (CI, -6.5%, 2.1%). Conclusions Clinical and corneal endothelial cell were comparable in this study population for the 250 μg and 500 μg doses of intracameral moxifloxacin. Both doses were well tolerated clinically, supporting the use of the higher dose for improved antimicrobial coverage for the prevention of postoperative endophthalmitis.

PURPOSE: To determine whether preoperative endothelial cell density (ECD) and/or postoperative ECD after Descemet stripping automated endothelial keratoplasty (DSAEK) are associated with late endothelial graft failure (LEGF) in the Cornea Preservation Time Study (CPTS). DESIGN: Cohort study within multicenter randomized clinical trial. PARTICIPANTS: 1,007 individuals (1,223 study eyes), mean age 70 years, undergoing DSAEK for Fuchs’ dystrophy (94% of eyes) or pseudophakic/aphakic corneal edema (PACE) (6% of eyes) and followed for up to 5 years. METHODS: Central ECD was determined by a central image analysis reading center. Preoperative ECD was determined for 1209 eyes that did not fail and 14 eyes that experienced LEGF. ECD at 6 and 12 months after DSAEK, the change in ECD from preoperative to 6 and 12 months, surgeon-reported operative complications, and postoperative graft dislocation, were investigated for an association with LEGFs unrelated to other postoperative events. Univariable and multivariable Cox proportional hazards regression models were used to assess associations. RESULTS: The cumulative probability of LEGF was 1.3% (95% CI 0.8% to 2.4%). Median (IQR) preoperative ECDs were similar for eyes with LEGF (2523 (2367, 3161) cells/mm(2)) and eyes without failure (2727 (2508, 2973) cells/mm(2)) (p=0.34). ECD at 6 months was associated with LEGF (p

The purpose of this study was to evaluate agreement between eye banks (EBs) and an image analysis reading center on endothelial cell density (ECD) determinations using the same image analysis method.The Cornea Image Analysis Reading Center (CIARC) determined ECD with a single experienced analyst on EB-obtained central endothelial images from donors intended for keratoplasty from 2 eye banks, Eversight and Lions VisionGift, using the Konan center analysis method. The EBs performed ECD determination on their respective sets of images using the same analysis method with experienced eye bank technicians.The mean age of the 200 donors was 54 years (range 30-75 years). Seventy (35%) of the 200 patients were women, and 57 (29%) were diabetic. The mean ECD was 10 cells/mm2 greater by the EBs than by CIARC (P = 0.39), with 95% limits of agreement of [-304 to 323 cells/mm2]. The mean difference was not substantially changed when the difference between EBs and CIARC ECD was adjusted for sex, donor age, donor diabetes, CV, HEX, number of cells analyzed, and EBs as a random effect (estimated mean difference of 20 cells/mm2 after adjustment in a linear mixed model; P = 0.73). The EB-determined preoperative ECD was within 10% of the CIARC-determined ECD for 178 (89%) image sets, with 15 (8%) higher by10% and 7 (3%) lower by10%.Well-trained eye bank technicians achieve comparable results for ECD determination with an experienced image analyst from an image analysis reading center when the same image analysis method is used.

PURPOSE: To evaluate agreement between eye banks (EBs) and a reading center on endothelial cell density (ECD) determinations in the Cornea Preservation Time Study. METHODS: The Cornea Image Analysis Reading Center (CIARC) performed variable frame image analysis on EB-obtained–preoperative central endothelial images (after lamellar dissection for Descemet stripping automated endothelial keratoplasty by the EBs or before shipping, if surgeon prepared) to determine ECD. The EBs performed their usual method of ECD determination. The CIARC and EBs also provided ECD determinations from screening central endothelial images taken by the EBs during donor evaluation. Two independent masked CIARC readers determined ECD with measurements averaged. RESULTS: The mean preoperative ECD was 15 cells/mm(2) greater by the EBs than by CIARC (N = 1286, P < 0.001) with 95% limits of agreement of (−644, 675 cells/mm(2)). The limits of agreement in preoperative ECD were wider in the After-Lamellar-Dissection Group (−687, 683 cells/mm(2)) than in the Before Shipping Group [(−505, 633 cells/mm(2)); P = 0.03]. The EBs-determined preoperative ECD was within 10% of the CIARC-determined ECD for 886 (69%) image sets, with 236 (18%) higher by >10% and 164 (13%) lower by >10%. Excellent agreement appeared between the EBs and CIARC when 100–300 cells could be analyzed in contrast to

Purpose The effects of repeated intravitreal aflibercept injection (IAI) on the corneal endothelium were studied in patients with unilateral neovascular age-related macular degeneration. Methods RE-VIEW was a phase 4, open-label, single-arm, multicenter study. Patients received IAI every 8 weeks after 3 monthly doses. Slit-lamp biomicroscopy was performed at all study visits. The central corneal endothelial health was evaluated by specular microscopy in the treated versus untreated fellow eyes at baseline and weeks 24 and 52. Results No slit-lamp abnormalities were noted in 154 enrolled patients (eyes). Baseline versus 52-week mean (±SD) endothelial morphometric values (n = 118) for the treated versus untreated fellow eyes were respectively as follows: endothelial cell density was 2410 ± 364 versus 2388 ± 384 cells/mm at baseline and remained unchanged at 2401 ± 353 versus 2376 ± 364 cells/mm at 52 weeks (P = 0.87); the coefficient of variation was 33.5 ± 4.4% versus 34.0 ± 5.0% at baseline and remained unchanged at 34.2 ± 4.7% versus 34.1 ± 4.9% at 52 weeks (P = 0.18); the percentage of hexagonal cells was 59.5 ± 5.8% versus 59.6 ± 6.4% at baseline and remained unchanged at 59.5 ± 6.0% versus 59.5 ± 5.8% at 52 weeks (P = 0.96). Conclusions Repeated IAI for 52 weeks had no apparent corneal endothelial toxicity noted on specular microscopy in patients treated for neovascular age-related macular degeneration.

Images of the endothelial cell layer of the cornea can be used to evaluate corneal health. Quantitative biomarkers extracted from these images such as cell density, coefficient of variation of cell area, and cell hexagonality are commonly used to evaluate the status of the endothelium. Currently, fully-automated endothelial image analysis systems in use often give inaccurate results, while semi-automated methods, requiring trained image analysis readers to identify cells manually, are both challenging and time-consuming. We are investigating two deep learning methods to automatically segment cells in such images. We compare the performance of two deep neural networks, namely U-Net and SegNet. To train and test the classifiers, a dataset of 130 images was collected, with expert reader annotated cell borders in each image. We applied standard training and testing techniques to evaluate pixel-wise segmentation performance, and report corresponding metrics such as the Dice and Jaccard coefficients. Visual evaluation of results showed that most pixel-wise errors in the U-Net were rather non-consequential. Results from the U-Net approach are being applied to create endothelial cell segmentations and quantify important morphological measurements for evaluating cornea health.

We are developing automated analysis of corneal-endothelial-cell-layer, specular microscopic images so as to determine quantitative biomarkers indicative of corneal health following corneal transplantation. Especially on these images of varying quality, commercial automated image analysis systems can give inaccurate results, and manual methods are very labor intensive. We have developed a method to automatically segment endothelial cells with a process that included image flattening, U-Net deep learning, and postprocessing to create individual cell segmentations. We used 130 corneal endothelial cell images following one type of corneal transplantation (Descemet stripping automated endothelial keratoplasty) with expert-reader annotated cell borders. We obtained very good pixelwise segmentation performance (e.g., Dice coefficient = 0.87 ± 0.17, Jaccard index = 0.80 ± 0.18, across 10 folds). The automated method segmented cells left unmarked by analysts and sometimes segmented cells differently than analysts (e.g., one cell was split or two cells were merged). A clinically informative visual analysis of the held-out test set showed that 92% of cells within manually labeled regions were acceptably segmented and that, as compared to manual segmentation, automation added 21% more correctly segmented cells. We speculate that automation could reduce 15 to 30 min of manual segmentation to 3 to 5 min of manual review and editing.

PURPOSE To evaluate a single eye bank's measurement of endothelial cell density (ECD) of Descemet membrane endothelial keratoplasty (DMEK) grafts before and after preparation using 2 separate counting methods. METHODS A series of 60 donor tissues were prepared for DMEK surgery. One to 4 specular images of the central endothelium were taken both before and after preparation, and ECDs were evaluated for a total of 345 unique images. Images were then masked and provided to the Cornea Image Analysis Reading Center (CIARC) for independent analysis. RESULTS Before preparation, average eye bank-determined ECD with the center method was 2678 ± 259 cells/mm and was 2599 ± 280 cells/mm CIARC-determined by the variable frame method (P < 0.001, n = 176). After preparation, eye bank-determined ECD was 2719 ± 265 cells/mm and CIARC-determined ECD was 2615 ± 344 cells/mm (P < 0.001, n = 169). The difference in ECD before and after DMEK preparation was not found to be statistically significant when evaluated using either analysis method (P = 0.19; P = 0.64) before and after preparation, respectively. CONCLUSIONS Although the absolute ECD value may differ by the analysis method statistically, pre- and post-DMEK preparation ECDs did not significantly change by either analysis method. Other methods such as vital staining to assess tissue damage after preparation in conjunction with specular microscopy are suggested.

To evaluate corneal endothelial cell density (ECD) and morphology 2 years after phacoemulsification in subjects from the COMPASS trial (ClinicalTrials.gov, NCT01085357) who had mild-to-moderate primary open-angle glaucoma and visually significant cataracts.The central corneal endothelium was evaluated by serial specular microscopy at 0 to 24 months. ECD, coefficient of variation, and percentage of hexagonal cells were evaluated by a central image analysis reading center and central corneal thickness (CCT) was evaluated by ultrasound pachymetry.Of 131 subjects who underwent routine phacoemulsification, analyzable endothelial images at 24 months were available for 126 subjects (96.2%). Mean ± SD central ECD at baseline was 2453 ± 359 cells/mm, decreasing by 10% ± 14% to 2195 ± 517 cells/mm at 3 months (P0.001) but stabilizing thereafter with mean endothelial cell loss (ECL) from baseline to 24 months of 9% ± 13% (P0.001). Twelve (9.5%) and 10 (7.9%) subjects experienced30% ECL at 12 and 24 months, respectively. Neither coefficient of variation nor percentage of hexagonal cells changed significantly from baseline at any time point. Mean CCT was similar at baseline (550 ± 35 μm) and at 12 months (551 ± 37 μm) and 24 months (555 ± 35 μm). Age was significantly associated with ECL after cataract surgery (P = 0.02), but baseline intraocular pressure, number of glaucoma medications, and CCT were not. Similar results were observed in patients who underwent CyPass micro-stent implantation accompanying phacoemulsification.Phacoemulsification in eyes with mild-to-moderate primary open-angle glaucoma results in early ECL, with ECD stabilizing after 3 months and no effect on other endothelial stress markers up to 2 years postoperatively.

Importance Determining factors associated with endothelial cell loss after Descemet stripping automated endothelial keratoplasty (DSAEK) could improve long-term graft survival. Objective To evaluate the associations of donor, recipient, and operative factors with endothelial cell density (ECD) 3 years after DSAEK in the Cornea Preservation Time Study. Design, Setting, and Participants This cohort study was a secondary analysis of data collected in a multicenter, double-masked, randomized clinical trial. Forty US clinical sites with 70 surgeons participated, with donor corneas provided by 23 US eye banks. Individuals undergoing DSAEK for Fuchs dystrophy or pseudophakic/aphakic corneal edema were included. Interventions The DSAEK procedure, with random assignment of a donor cornea with a preservation time of 0 to 7 days or 8 to 14 days. Main Outcomes and Measures Endothelial cell density at 3 years as determined by a reading center from eye bank and clinical specular or confocal central endothelial images. Results The study included 1090 participants (median age, 70 years) with 1330 affected eyes (240 bilateral cases [22.0%]), who underwent DSAEK for Fuchs dystrophy (1255 eyes [94.4%]) or pseudophakic/aphakic corneal edema (PACE) (75 eyes [5.6%]). Of these, 801 eyes (60.2%) belonged to women and 1207 (90.8%) to white individuals. A total of 749 participants (913 eyes; 164 [21.9%] bilateral cases) had functioning grafts with acceptable endothelial images preoperatively and at 3 years postoperatively and were included in this analysis. Factors associated with a lower ECD at 3 years (estimated effect with 99% CI) in the final multivariable model included donors with diabetes (−103 [−196 to −9] cells/mm 2 ), lower screening ECD (−234 [−331 to −137] per 500 cells/mm 2 ), recipient diagnosis of PACE (−257 [−483 to −31] in cells/mm 2 ), and operative complications (−324 [−516 to −133] in cells/mm 2 ). Endothelial cell loss (ECL) from a preoperative measurement to a 3-year postoperative measurement was 47% (99% CI, 42%-52%) for participants receiving tissue from donors with diabetes vs 43% (99% CI, 39%-48%) without diabetes; it was 53% (99% CI, 44%-62%) for participants diagnosed with PACE vs 44% (99% CI, 39%-49%) for those diagnosed with Fuchs dystrophy, and 55% (99% CI, 48%-63%) in participants who experienced operative complications vs 44% (99% CI, 39%-48%) in those who did not. No other donor, recipient, or operative factors were significantly associated with 3-year ECD. Conclusions and Relevance Donor diabetes, lower screening ECD, a PACE diagnosis in the recipient, and operative complications were associated with lower ECD at 3 years after DSAEK surgery and may be associated with long-term graft success. While causation cannot be inferred, further studies on the association of donor diabetes and PACE in recipients with lower 3-year ECD warrant further study.

Purpose To assess 3-year outcomes of Descemet's stripping automated endothelial keratoplasty (DSAEK) in comparison with penetrating keratoplasty (PKP) from the Cornea Donor Study (CDS). Design Prospective, multicenter, nonrandomized clinical trial. Participants A total of 173 subjects undergoing DSAEK for a moderate risk condition (principally Fuchs' dystrophy or pseudophakic corneal edema) compared with 1101 subjects undergoing PKP from the CDS. Methods The DSAEK procedures were performed by 2 experienced surgeons using the same donor and similar recipient criteria as for the CDS PKP procedures, performed by 68 surgeons. Graft success was assessed by Kaplan-Meier survival analysis. Central endothelial cell density (ECD) was determined from baseline donor and postoperative central endothelial images by the reading center used in the CDS Specular Microscopy Ancillary Study. Main Outcome Measures Graft clarity and ECD. Results The donor and recipient demographics were comparable in the DSAEK and PKP groups, except that the proportion of Fuchs' dystrophy cases was higher in the DSAEK cohort. The 3-year survival rate did not differ significantly between DSAEK and PKP procedures performed for either Fuchs' dystrophy (96% for both; P = 0.81) or non-Fuchs' cases (86% vs. 84%, respectively; P = 0.41). Principal causes of graft failure or regraft within 3 years after DSAEK and PKP were immunologic graft rejection (0.6% vs. 3.1%), endothelial decompensation in the absence of documented rejection (1.7% vs 2.1%), unsatisfactory visual or refractive outcome (1.7% vs. 0.5%), and infection (0% vs. 1.1%), respectively. The 3-year predicted probability of a rejection episode was 9% with DSAEK versus 20% with PKP ( P = 0.0005). The median 3-year cell loss for DSAEK and PKP was 46% and 51%, respectively ( P = 0.33), in Fuchs' dystrophy cases and 59% and 61%, respectively ( P = 0.70), in the non-Fuchs' cases. At 3 years, use of a smaller DSAEK insertion incision was associated with significantly higher cell loss (60% vs. 33% for 3.2- and 5.0-mm incisions, respectively; P = 0.0007), but not with a significant difference in graft survival ( P = 0.45). Conclusions The graft success rate and endothelial cell loss were comparable at 3 years for DSAEK and PKP procedures. A 5-mm DSAEK incision width was associated with significantly less cell loss than a 3.2-mm incision. Financial Disclosure(s) Proprietary or commercial disclosure may be found after the references.

To assess 3-year outcomes of Descemet's stripping automated endothelial keratoplasty (DSAEK) in comparison with penetrating keratoplasty (PKP) from the Cornea Donor Study (CDS).Prospective, multicenter, nonrandomized clinical trial.A total of 173 subjects undergoing DSAEK for a moderate risk condition (principally Fuchs' dystrophy or pseudophakic corneal edema) compared with 1101 subjects undergoing PKP from the CDS.The DSAEK procedures were performed by 2 experienced surgeons using the same donor and similar recipient criteria as for the CDS PKP procedures, performed by 68 surgeons. Graft success was assessed by Kaplan-Meier survival analysis. Central endothelial cell density (ECD) was determined from baseline donor and postoperative central endothelial images by the reading center used in the CDS Specular Microscopy Ancillary Study.Graft clarity and ECD.The donor and recipient demographics were comparable in the DSAEK and PKP groups, except that the proportion of Fuchs' dystrophy cases was higher in the DSAEK cohort. The 3-year survival rate did not differ significantly between DSAEK and PKP procedures performed for either Fuchs' dystrophy (96% for both; P = 0.81) or non-Fuchs' cases (86% vs. 84%, respectively; P = 0.41). Principal causes of graft failure or regraft within 3 years after DSAEK and PKP were immunologic graft rejection (0.6% vs. 3.1%), endothelial decompensation in the absence of documented rejection (1.7% vs 2.1%), unsatisfactory visual or refractive outcome (1.7% vs. 0.5%), and infection (0% vs. 1.1%), respectively. The 3-year predicted probability of a rejection episode was 9% with DSAEK versus 20% with PKP (P = 0.0005). The median 3-year cell loss for DSAEK and PKP was 46% and 51%, respectively (P = 0.33), in Fuchs' dystrophy cases and 59% and 61%, respectively (P = 0.70), in the non-Fuchs' cases. At 3 years, use of a smaller DSAEK insertion incision was associated with significantly higher cell loss (60% vs. 33% for 3.2- and 5.0-mm incisions, respectively; P = 0.0007), but not with a significant difference in graft survival (P = 0.45).The graft success rate and endothelial cell loss were comparable at 3 years for DSAEK and PKP procedures. A 5-mm DSAEK incision width was associated with significantly less cell loss than a 3.2-mm incision.

To assess the effect of incision width (5.0 and 3.2 mm) on graft survival and endothelial cell loss 6 months and 1 year after Descemet stripping automated endothelial keratoplasty (DSAEK).One hundred sixty-seven subjects with endothelial decompensation from a moderate-risk condition (principally Fuchs dystrophy or pseudophakic corneal edema) underwent DSAEK by 2 experienced surgeons. The donor was folded over and inserted with single-point fixation forceps. This retrospective analysis assessed graft survival, complications, and endothelial cell loss, which was calculated from baseline donor and 6-month and 1-year postoperative central endothelial images evaluated by an independent specular microscopy reading center.No primary graft failures occurred in either group. One-year graft survival rates were comparable (98% vs 97%) in the 5.0- and 3.2-mm groups, respectively (P = 1.0). Complications included graft dislocation, graft rejection episodes, and elevated intraocular pressure and occurred at similar rates in both groups (Por = 0.28). Pupillary block glaucoma did not occur in either group. Mean baseline donor endothelial cell density did not differ: 2782 cells per square millimeter in the 5.0-mm (n = 64) and 2784 cells per square millimeter in the 3.2-mm (n = 103) groups. Percent endothelial cell loss was 27% +/- 20% (n = 55) versus 40% +/- 22% (n = 71; 6 months) and 31% +/- 19% (n = 45) versus 44% +/- 22% (n = 62; 12 months) in the 5.0- and 3.2-mm incision groups, respectively (both P0.001).One year after DSAEK, overall graft success was comparable for the 2 groups; however, the 5.0-mm incision width resulted in substantially lower endothelial cell loss at 6 and 12 months.

To assess outcomes 1 year after Descemet's stripping automated endothelial keratoplasty (DSAEK) in comparison with penetrating keratoplasty (PKP) from the Specular Microscopy Ancillary Study (SMAS) of the Cornea Donor Study.Multicenter, prospective, nonrandomized clinical trial.A total of 173 subjects undergoing DSAEK for a moderate risk condition (principally Fuchs' dystrophy or pseudophakic/aphakic corneal edema) compared with 410 subjects undergoing PKP from the SMAS who had clear grafts with at least 1 postoperative specular image within a 15-month follow-up period.The DSAEK procedures were performed by 2 experienced surgeons per their individual techniques, using the same donor and similar recipient criteria as for the PKP procedures in the SMAS performed by 68 surgeons at 45 sites, with donors provided from 31 eye banks. Graft success and complications for the DSAEK group were assessed and compared with the SMAS group. Endothelial cell density (ECD) was determined from baseline donor, 6-month (range, 5-7 months), and 12-month (range, 9-15 months) postoperative central endothelial images by the same reading center used in the SMAS.Endothelial cell density and graft survival at 1 year.Although the DSAEK recipient group criteria were similar to the PKP group, Fuchs' dystrophy was more prevalent in the DSAEK group (85% vs. 64%) and pseudophakic corneal edema was less prevalent (13% vs. 32%, P0.001). The regraft rate within 15 months was 2.3% (DSAEK group) and 1.3% (PKP group) (P = 0.50). Percent endothelial cell loss was 34+/-22% versus 11+/-20% (6 months) and 38+/-22% versus 20+/-23% (12 months) in the DSAEK and PKP groups, respectively (both P0.001). Preoperative diagnosis affected endothelial cell loss over time; in the PKP group, the subjects with pseudophakic/aphakic corneal edema experienced significantly higher 12-month cell loss than the subjects with Fuchs' dystrophy (28% vs. 16%, P = 0.01), whereas in the DSAEK group, the 12-month cell loss was comparable for the 2 diagnoses (41% vs. 37%, P = 0.59).One year post-transplantation, overall graft success was comparable for DSAEK and PKP procedures and endothelial cell loss was higher with DSAEK.

A549 cells held for 4 hr in Hank's balanced salt solution, after 10 Gy irradiation, exhibit potentially lethal damage recovery (PLDR) which is dependent on extracellular pH (pHe). Recovery factors of 2.2 to 3.5 are observed when pHe is 6.40 to 7.30, but recovery factors of less than 1.0 are found when pHe is reduced to 6.20 or 6.00. The K+/H+ ionophore nigericin, when added to cells post-irradiation, inhibits PLDR in a pHe-dependent manner; it is increasingly more effective as pHe is reduced from 6.80 to 6.40. The presence of nigericin thus causes inhibition of PLDR at pHe's that normally promote recovery. The drug does not affect radiation response of A549 cells when present only during irradiation. Effects of low pHe buffer, with and without nigericin, on intracellular pH (pHi) and on ATP levels were examined in an effort to elucidate the mechanisms for inhibition of PLDR and enhancement of radiation response. Incubation of cells in pHe 6.00 buffer results in a slight decrease in pHi and does not induce a drop in ATP levels. In contrast, post-irradiation incubation of cells in pHe 6.40 buffer containing 2 microM nigericin causes an immediate and dramatic decrease in pHi, and a gradual loss of ATP to 30% of control levels by 4 hr. The data obtained so far suggest that a very slight lowering of pHi may influence post-irradiation holding recovery, and that the mechanisms by which pHe 6.00 buffer alone, or pHe 6.40 buffer containing nigericin, affect holding recovery are different.

CLK3, a member of the LAMMER family of dual-specificity protein kinases, is abundantly expressed in the reproductive system of male mice. Specifically, high levels of CLK3 protein expression are found in mature spermatozoa in the testis and epididymis. The majority of the CLK3 protein in the testis is a full-length kinase-containing form, and only a small amount of a catalytically inactive N-terminally truncated splice variant protein product is observed. Within the mature spermatozoa CLK3 is localized to the acrosome and tail. CLK3 is expelled from the sperm following the acrosome reaction and inactivated, likely by degradation by the proteases released by the sperm during the acrosome reaction. The CLK family of kinases has previously been implicated in mRNA splicing; however, the bulk of the CLK3 protein in these cells is located in the cytoplasm, suggesting that CLK3 may have additional roles in the cell.

The K+/H+ ionophore negericin dramatically increases killing of V79 cells and A549 cells by photodynamic therapy (PDT) sensitized by chloroaluminum phthalocyanine. Previous studies suggested that the interaction between PDT and nigericin is related to the ability of this ionophore to reduce intracellular pH (pHi). The present study was undertaken to test the possibility that nigericin, by lowering pHi, inhibits reductive detoxification of PDT-produced peroxides by enzymes of the glutathione (GSH) redox cycle and the pentose cycle. To test this possibility we examined the effects of nigericin on the toxicity and metabolism of a model peroxide, tert-butylhydroperoxide (tert-BOOH), in A549 cells, a cell line in which the GSH redox cycle is known to be the principal pathway for reduction and detoxification of tert-BOOH. We found that nigericin equilibrates pHi of A549 cells with extracellular pH (pHe) in a time-dependent manner. It increases the toxicity of tert-BOOH toward A549 cells, inhibits loss of tert-BOOH from the buffer overlying the cells, and reduces the rate of 14CO2 release from radiolabelled glucose, which is measure of pentose cycle activity. These effects are significantly greater at pHe 6.40 than at 7.40. Monensin, a Na+/H+ ionophore which does not reduce pHi, does not enhance the toxicity of tert-BOOH and has only a minimal effect on tert-BOOH reduction. These data suggest that nigericin-induced inhibition of peroxide detoxification is at least a plausible mechanism by which the ionophore might interact with PDT.

Phthalocyanines are receiving increasing attention as second-generation sensitizers for photodynamic therapy (PDT). This paper discusses some of the investigations into the mechanism of the phototoxic responses of phthalocyanine-sensitized PDT exploiting the interaction of PDT with other metabolic modulators. Among the agents which interact strongly with PDT is the K+/H+ ionophore nigericin. Under the conditions studied with chloroaluminum phthalocyanine (AlPcCl), the Na+/H+ ionophore monensin, the Ca++ ionophore A23187, and the lysosomotrophic agent chloroquine, but not the K+ ionophore valinomycin, also potentiate photodynamic cell killing. None of the latter compounds interact with PDT as strongly as does nigericin. Both nigericin and monensin partially inhibit cellular respiration; however, KCN, which inhibits respiration completely, is less effective in potentiating PDT damage than is nigericin. Nigericin treatment alone does not deplete glutathione; however, the GSH level decreases after treatment of cells with PDT and nigericin. The potentiation of the PDT response is much greater at an extracellular pH (pHe) of 6.70 than at pHe 7.30. When nigericin is present at pHe 6.70, the intracellular pH (pHi) is equilibrated with pHe. None of the other ionophores tested was able to cause the acidification of the intracellular milieu as did nigericin. The evidence to date suggests that the lowering of pHi is an important component of the mechanism by which nigericin potentiates PDT.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.