https://scholarworks.korea.ac.kr/kumedicine/handle/2020.sw.kumedicine/552 Sat, 04 Apr 2026 07:38:05 GMT 2026-04-04T07:38:05Z https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/62336 Title: Organelle-specific blue-emitting two-photon probes for calcium ions: Combination with green-emitting two-photon probe for simultaneous detection of proton ions Authors: Hong, Seung Taek; Kim, Mun Seok; Kim, Bo Ra; Lee, Eun Jeong; Yoon, Yeo Uk; Paik, Kyu Cheol; Han, Man So; Kim, Eun Sun; Cho, Bong Rae Abstract: In this study, we developed organelle-specific blue-emitting two-photon (TP) probes for Ca2+ (BCa-1, BCa-2mito, and BCa-3mem), with absorption maxima (λmax) at 350–358 nm, emission maxima (λfl) at 464–466 nm, and TP action cross-section (Φδmax) values of 55–70 × 10−50 cm4s/photon, in the presence of excess Ca2+ at 750 nm. Moreover, the probes had dissociation constants of 0.18, 2.7, and 100 μM, respectively, which are appropriate values for sensing Ca2+ in the cytoplasm, mitochondria, and plasma membrane, respectively. The measurements were conducted using a calcium calibration buffer (10 mM 3-[N-morpholino]propanesulfonic acid and 100 mM KCl) at pH 7.2. The TP microscopy results revealed that the probes could facilitate the real-time detection of Ca2+ in the cytoplasm, mitochondria, and plasma membranes of live cells and tissues. Additionally, we developed a green-emitting TP probe for H+ (FHEt-1lyso) with λmax = 359 nm, λfl = 571 nm, and Φδmax = 70 × 10−50 cm4s/photon at pH 4.3 in a universal buffer (0.1 M citric acid, 0.1 M KH2PO4, 0.1 M Na2B4O7, 0.1 M tris[hydroxymethyl]aminomethane, and 0.1 M KCl); this probe could detect H+ in the lysosomes. Using BCa-1 and FHEt-1lyso, it was possible to simultaneously monitor the changes in cytosolic Ca2+ and lysosomal H+ concentrations in live cells and tissues using dual-color TP microscopy in real time. When used with TP probes emitting wavelengths of green light or longer, these blue-emitting Ca2+ probes can be used to investigate the physiological role of Ca2+ in cellular organelles as well as the crosstalk between Ca2+ and other metal ions in specific organelles. Fri, 01 Jul 2022 00:00:00 GMT https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/62336 2022-07-01T00:00:00Z https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/55382 Title: Classification of the Confocal Microscopy Images of Colorectal Tumor and Inflammatory Colitis Mucosa Tissue Using Deep Learning Authors: Jeong, Jaehoon; Hong, Seung Taek; Ullah, Ihsan; Kim, Eun Sun; Park, Sang Hyun Abstract: Confocal microscopy image analysis is a useful method for neoplasm diagnosis. Many ambiguous cases are difficult to distinguish with the naked eye, thus leading to high inter-observer variability and significant time investments for learning this method. We aimed to develop a deep learning-based neoplasm classification model that classifies confocal microscopy images of 10x magnified colon tissues into three classes: neoplasm, inflammation, and normal tissue. ResNet50 with data augmentation and transfer learning approaches was used to efficiently train the model with limited training data. A class activation map was generated by using global average pooling to confirm which areas had a major effect on the classification. The proposed method achieved an accuracy of 81%, which was 14.05% more accurate than three machine learning-based methods and 22.6% better than the predictions made by four endoscopists. ResNet50 with data augmentation and transfer learning can be utilized to effectively identify neoplasm, inflammation, and normal tissue in confocal microscopy images. The proposed method outperformed three machine learning-based methods and identified the area that had a major influence on the results. Inter-observer variability and the time required for learning can be reduced if the proposed model is used with confocal microscopy image analysis for diagnosis. Tue, 01 Feb 2022 00:00:00 GMT https://scholarworks.korea.ac.kr/kumedicine/handle/2021.sw.kumedicine/55382 2022-02-01T00:00:00Z https://scholarworks.korea.ac.kr/kumedicine/handle/2020.sw.kumedicine/28680 Title: Two-Photon Probes for Golgi Apparatus: Detection of Golgi Apparatus in Live Tissue by Two-Photon Microscopy Authors: Choi, Ji-Woo; Hong, Seung Taek; Kim, Mun Seok; Paik, Kyu Cheol; Han, Man So; Cho, Bong Rae Abstract: We have developed blue-and yellow-emitting two-photon probes (BGolgi-blue and PGolgi-yellow) from 6-(benzo[d]oxazol-2-y1)-2-naphthalylamine and 2,5-bis(benzo[d]-oxazol-2-yl)pyrazine derivatives as the fluorophores and trans-Golgi-network peptide (SDYQRL) as the Golgi-apparatus-targeting moiety. HeLa cells labeled with BGolgi-blue and PGolgi-yellow emitted two-photon-excited fluorescence at 462 and 560 nm, respectively, with effective two photon-action cross-section values of 1860 and 1600 x 10(-50) cm(4).s/photon, respectively. The probes can detect the Golgi apparatus in live cells and deep inside live tissue via two-photon microscopy at widely separated wavelength regions with high selectivity and minimal pH interference, and they are photostable and have low cytotoxicity. Wed, 01 May 2019 00:00:00 GMT https://scholarworks.korea.ac.kr/kumedicine/handle/2020.sw.kumedicine/28680 2019-05-01T00:00:00Z https://scholarworks.korea.ac.kr/kumedicine/handle/2020.sw.kumedicine/4628 Title: Two-Photon Probes for pH: Detection of Human Colon Cancer using Two-Photon Microscopy Authors: Hong, Seung Taek; Kim, Tae Hyeong; Choi, Ji-Woo; Park, Seong Jun; Kwon, Sung An; Paik, Kyu Cheol; Han, Man So; Kim, Eun Sun; Chun, Hoon Jai; Heo, Jung-Nyoung; Cho, Bong Rae Abstract: We have developed two-photon (TP) pH-sensitive probes (BH-2 and BHEt-1) that exhibit absorption and emission maxima at 370 and 466 nm, and TP absorption cross-section values of 51 and 61 GM (1 GM = 10(-50)cm(4)s/photon), respectively, at 750 nm and pH 3.0 in a universal buffer (0.1 M citric acid, 0.1 M KH2PO4, 0.1 M Na2B4O7, 0.1 M Tris, 0.1 M KCl)/1,4-dioxane (7/3) solution. The TPM images of CCD-18co (a normal colon cell line) and HCT116 cells (a colon cancer cell line) labeled with BH-2 were too dim to be distinguished. When the same cells were labeled with BHEt-1, however, the TPM image of the HCT116 cells was Much brighter than that of CCD-18co cells, and the relative proportion of the acidic vesicles (P-acid) of the former was 5-fold larger than that of latter. BHEt-1 could also differentiate HepG2 cells (a human liver cancer cell line) from LX-2 cells (a human hepatic stellate cell line) with a 6-fold larger P-acid value. Human colon cancer tissues labeled with BHEt-1 showed similar results, demonstrating much brighter TPM images and 6-fold larger P-acid values compared to normal tissue. These results suggest the potential utility of BHEt-1 for detecting colon cancer in human tissues using TPM. Fri, 01 Sep 2017 00:00:00 GMT https://scholarworks.korea.ac.kr/kumedicine/handle/2020.sw.kumedicine/4628 2017-09-01T00:00:00Z