Deep learning-based optic disc classification is affected by optic-disc tilt.

We aimed to determine the effect of optic disc tilt on deep learning-based optic disc classification. A total of 2507 fundus photographs were acquired from 2236 eyes of 1809 subjects (mean age of 46 years; 53% men). Among all photographs, 1010 (40.3%) had tilted optic discs. Image annotation was performed to label pathologic changes of the optic disc (normal, glaucomatous optic disc changes, disc swelling, and disc pallor). Deep learning-based classification modeling was implemented to develop optic-disc appearance classification models with the photographs of all subjects and those with and without tilted optic discs. Regardless of deep learning algorithms, the classification models showed better overall performance when developed based on data from subjects with non-tilted discs (AUC, 0.988 ± 0.002, 0.991 ± 0.003, and 0.986 ± 0.003 for VGG16, VGG19, and DenseNet121, respectively) than when developed based on data with tilted discs (AUC, 0.924 ± 0.046, 0.928 ± 0.017, and 0.935 ± 0.008). In classification of each pathologic change, non-tilted disc models had better sensitivity and specificity than the tilted disc models. The optic disc appearance classification models developed based all-subject data demonstrated lower accuracy in patients with the appearance of tilted discs than in those with non-tilted discs. Our findings suggested the need to identify and adjust for the effect of optic disc tilt on the optic disc classification algorithm in future development.

Correlation Between Radiologic and Histopathologic Features of Orbital Epidermoid and Dermoid Cysts.

PURPOSE: Epidermoid cysts (EC) and dermoid cysts (DC) typically appear as well-circumscribed lesions on CT. This study aimed to clarify the radiologic and histopathologic characteristics of orbital EC and DC and to determine the correlations between them. METHODS: The medical records of 69 patients who underwent surgery for orbital DC or EC at Samsung Medical Center between January 2001 and August 2016 were retrospectively reviewed. The size and location of the cysts, rim enhancement, homogeneity of contents, presence of hemorrhagic or calcific components, radiodensity of contents, and extent of bony remodeling were evaluated using CT. Additionally, the cyst lining and contents were examined histopathologically. RESULTS: Among patients with orbital cysts, EC and DC were diagnosed in 10 (14.5%) and 59 (85.5%) patients, respectively. Further, 50.0% of EC and 79.7% of DC were located in the superotemporal quadrant of the orbit. On orbital CT, the average radiodensity of EC and DC was 18.9 ± 56.2 and -67.9 ± 63.3 HU, respectively. The cystic contents were more frequently homogeneous than heterogeneous in both EC and DC; however, the radiodensity of cysts differed significantly, which may be attributed to sebaceous gland activity. Focal bony notching, bone remodeling under pressure, and bony changes from dumbbell-shaped cysts were observed more frequently in DC than in EC. CONCLUSIONS: Radiological and histopathological features are correlated in orbital EC and DC. Therefore, orbital EC and DC can be preoperatively differentiated using CT, based on the average radiodensity and bony remodeling.

Retraction Note to: Identification of the Vibrio vulnificus htpG Gene and Its Influence on Cold Shock Recovery.

The Editor in Chief has retracted this article. Based on the conclusions of investigation carried out by the Committee on Research Integrity of Seoul National University, the editorial board concluded that the article represents unjustified authorship. Specially, it was verified that the two high school students who did not contribute to the work had been included as coauthors in the article. Dong-Hyun Kang agrees to this retraction. Slae Choi, Kyungku Jang, Seulah Choi, and Hee-jee Yun have not responded to any correspondence from the editor/publisher about this retraction.

Identification of the Vibrio vulnificus htpG gene and its influence on cold shock recovery.

An htpG gene encoding the heat shock protein HtpG was identified and cloned from Vibrio vulnificus. The deduced amino acid sequence of HtpG from V. vulnificus exhibited 71 and 85% identity to those reported from Escherichia coli and V. cholera, respectively. Functions of HtpG were assessed by the construction of an isogenic mutant whose htpG gene was deleted and by evaluating its phenotype changes during and after cold shock. The results demonstrated that recovery of the wild type from cold shock was significantly faster (p<0.05) than that of the htpG mutant, and indicated that the chaperone protein HtpG contributes to cold shock recovery, rather than cold shock tolerance, of V. vulnificus.