Biomedical subjects

Jong Sang Choi

Publications and source records attributed to Jong Sang Choi.

5 recordsLinked to original sources

PubMed2006

PKCtheta expression in gastrointestinal stromal tumor.

Gastrointestinal stromal tumor is characterized by a gain of function mutation of KIT gene and the expression of c-kit protein, but in 5% of cases, c-kit expression is negative although histological findings of gastrointestinal stromal tumor are most suspicious. The existence of c-kit-negative gastrointestinal stromal tumors points to the need of additional markers for making the diagnosis. In this study, we studied the expression of PKCtheta and correlated their expression with other immunohistochemical profiles of gastrointestinal stromal tumors and evaluated their usability as a diagnostic marker. For this purpose, 220 gastrointestinal stromal tumors were immunohistochemically stained for PKCtheta, c-kit, CD34, alpha-smooth muscle actin and S-100 protein. Additionally, genetic studies of KIT and PDGFRA genes were performed using c-kit-negative or PKCtheta-negative cases. All the 220 masses were either PKCtheta-positive or c-kit-positive. PKCtheta was positive in 212 (96%) cases and c-kit was positive in 216 (98%) cases in the cytoplasm of tumor cells with a diffuse staining pattern. Out of 212 PKCtheta-positive GISTs, 208 (98%) cases were c-kit-positive, 174 (82%) cases were CD34-positive, 62 (29%) cases were SMA-positive and S-100 protein was positive in 54 cases (26%). Genetic analyses on eight PKCtheta-negative cases showed exon 11 mutations of KIT gene in four cases. Two PKCtheta-positive and c-kit-negative GISTs showed mutations of PDGFRA gene. Our study shows that PKCtheta is a useful marker and it may play a role in the development of gastrointestinal stromal tumors. Together with c-kit, PKCtheta immunostaining can be used as an important diagnostic tool in the pathologic diagnosis of gastrointestinal stromal tumors with its high specificity and sensitivity.

Actins↗

PubMed2005

Gastrointestinal stromal tumors in Koreans: it's incidence and the clinical, pathologic and immunohistochemical findings.

Seven hundred forty seven cases of gastrointestinal stromal tumors (GISTs) in Koreans who were diagnosed between 2001 and 2002 were analyzed to evaluate their occurrence and their clinical, pathologic and immunohistochemical findings. The most frequent location of tumor was in the stomach (63%), followed by the small intestine (30%), the colorectum (5%), and the esophagus (2%). c-kit expression was found in 93.6% of the cases, while CD34, SMA and S-100 protein was positive in 80.1%, 28.2%, and 20.2%, respectively. c-kit positivity was high in the stomach (94.2%) and small intestine (94.6%), while it was relatively low in the colorectum (85.0%), and esophagus (81.2%). The positivity for CD34 was correlated with the higher risk of GISTs (p = 0.04). Follow up of the patients showed that 58 primary GISTs patients died and 20 of these patients were recurrent or metastatic at the time of diagnosis. The pathologic diagnosis to predict the risk of aggressive behavior of GISTs was correlated with the numbers of tumor, clinical stage, epithelioid histologic type, cellularity, cellular atypia, necrosis, and mucosal invasion (p = 0.00). GISTs with a poor prognosis were closely related to the clinical stage at presentation, the locations of the tumor, and the ages of the patients.

Actins↗

PubMed2003

Accuracy and reproducibility of telecytology diagnosis of cervical smears. A tool for quality assurance programs.

We randomly selected 50 cervical smears (benign, 14; atypical squamous cells of undetermined significance [ASCUS], 5; low-grade squamous intraepithelial lesion [LSIL], 10; high-grade squamous intraepithelial lesion (HSIL), 12; squamous cell carcinoma, 6; adenocarcinoma, 3) and captured 1,181 digital images (518 MB) at a maximum resolution of 1,600 x 1,200 pixels and transmitted them by e-mail. Diagnosis of glass slides and digital images was done independently in a double-blind manner by 3 pathologists and 3 cytotechnologists, commencing with the diagnosis of digital images followed by diagnosis of glass slides 3 months later. The procedure was repeated after 3 months. Diagnoses were recorded as benign, ASCUS or atypical glandular cells of undetermined significance, LSIL, HSIL, squamous cell carcinoma or adenocarcinoma, and "inadequate for diagnosis." Diagnostic accuracy and interobserver reproducibility were analyzed using an intraclass correlation coefficient (ICC), which revealed good interobserver agreement for the first (0.72) and second (0.64) glass slide diagnoses and the first (0.72) and second (0.60) digital image diagnoses. The kappa values for intraobserver variation between first and second glass slide diagnoses and first and second digital image diagnoses showed moderate to excellent agreement. Digital images are suitable substitutes for glass slides; telecytology can be used as an alternative method for the cytologic diagnosis of cervical smears, particularly in quality assurance programs.

Adenocarcinoma↗

PubMed2002

Practical telepathology using a digital camera and the internet.

Digital camera technology has developed rapidly and a large choice of reasonably priced, user-oriented models are now available. These can be used for both macroscopic and microscopic photography with good resolution. Internet transmission of digital images also makes it possible to consult pathologists anywhere in the world. This study tests a simple, fast, and inexpensive method for practical transmission of images for diagnosis using a digital camera and the Internet. Using a commercial digital camera mounted with a phototube adapter to a light microscope (6 images per case on average), 2210 digital images (310 Mb) from 347 cases of gastrointestinal, lung, and uterus specimens were captured. Each image, stored in medium compression JPEG (Joint Photographers Experts Group) format with 1024 x 768 pixel resolution, required approximately 5 seconds to capture after the case had been reviewed and appropriate fields for imaging selected (30 seconds per case on average). The images were transmitted from Samsung Medical Center, Seoul, to Korea University Hospital, Seoul, and John Hunter Hospital, Newcastle, Australia. Transmission was 100% successful with a total upload time of 3 hours for 310 MB of data (31 seconds per case on average). The images were downloaded in 2 hours and viewed on a 17-inch color monitor with a maximal resolution of 1280 x 1024 pixels. Telepathology diagnoses were made with 95% and 97% concurrence by two pathologists at Korea University Hospital and John Hunter Hospital, respectively. We suggest that the current level of commercial technology yields fast, convenient and economical tools for practical telepathology diagnosis.

Humans↗

PubMed2002

The first human case of hepatic dirofilariasis.

Most of human dirofilariasis are pulmonary or subcutaneous infections, but there have been a few reports of human dirofilariasis in unusual sites, such as large vessels, mesentery, peritoneal cavity, and spermatic cord. We present the first case of human hepatic dirofilariasis, which was surgically diagnosed. A 39-year-old man without any evidence of systemic symptom was found incidentally to have a hepatic nodule during routine physical check-up. The histologic findings of the resected lesion showed a granulomatous lesion with central necrosis containing up to 35 transverse sections of a nematode, ranging 30-80 micro m in diameter. Thin (1.5-5 micro m) cuticle with transverse striations surrounded polymyarian and muscle bundles occupied a sixth of both sides of outer body cavity. Central portion of the body cavity was occupied with an intestine-like tubular structure and a larger reproductive tube. These microscopic findings were consistent with degenerated Dirofilaria immitis. Antibody test by enzyme-linked immunosorbent assay for patient serum reacted positively against adult D. immitis antigen.

Adult↗