• Clinical and Experimental Pediatrics
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• v.49 no.2
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• pp.162-166
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• 2006

Purpose : There are few reports in Korean literature on the diagnostic efficacy of fine needle aspiration cytology(FNAC) for pediatric cervical lymphadenopathy. This study examined the diagnostic value of FNAC on cervical lymphadenopathy in children. Methods : Data from 57 pediatric patients(aged 0.3 to 14 years) who underwent FNAC due to cervical lymphadenopathy between January 2001 and March 2005 was reviewed retrospectively. Results : Reactive cervical lymphadenitis was the most common result of the FNAC(52.5 percent). Malignant disease were revealed in 14 percent of all cases. The sensitivity, specificity was 86 percent and 96 percent, respectively. The positive and negative predictive values for malignant disease was 75 percent and 98 percent, respectively. There were two false-positive cases on FNAC; one case of Langerhans cell histiocytosis, and another with infectious mononucleosis. A false-negative case on FNAC was found to be acute lymphocytic leukemia. In seven cases(12 percent), the final diagnosis was confirmed by an open biopsy after the FNAC. There were four FNAC cases where the specimen was not satisfactory for making a diagnosis(7 percent). There were no serious complications of the FNAC procedure. Conclusion : FNAC had a high diagnostic efficacy for evaluating children with cervical lymphadenopathy.

• Tuberculosis and Respiratory Diseases
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• v.56 no.4
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• pp.381-392
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• 2004

Arsenic trioxide($As_2O_3$) was introduced into the treatment of refractory or relapsed acute promyelocytic Ieukemia. Some investigators have reported that arsenic trioxide had induced apoptosis in a variety of solid human tumor cell lines, including non-small cell lung cancer. Non-steroidal anti-inflammatory drugs(NSAIDs) are powerful chemopreventive agents for gastrointestinal cancers and the growth of established tumors are reduced by inducing apoptosis. It's also reported that NSAIDs enhanced tumor response to chemotherapeutic drugs or radiation. In this study, we aimed to determine whether combination of arsenic trioxide with sulindac augmented its apoptotic potential in NCI-H157 human lung cancer cells. The human lung cancer cell line NCI-H157 was treated with arsenic trioxide and sulindac. Cell viability was measured by the MTT assay. Apoptosis was measured by nuclear staining and flow cytometric analysis. The catalytic activity of the caspase families were measured by the fluorogenic cleavage of biosubstrates. The western blotting were also performed to define the mechanical basis of apoptosis. Combination treatment of arsenic trioxide and sulindac decreased the viability of NCI-H157 human lung cancer cells in a dose-dependent manner. The catalytic activity of caspase-3, 8 and 9 proteases were increased after combination treatment. Consistently PARP was cleaved from 116kDa to 85kDa fragments, and the expression of ICAD was decreased by time-dependent manner. Also combination treatment increased the expression of Fas and Fas/L. Combination therapy of arsenic trioxide with sulindac augments cell death and induces apoptosis via the activation of caspase cascade in NCI-H157 human lung carcinoma cells.

• Journal of Life Science
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• v.28 no.11
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• pp.1268-1276
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• 2018

The cytidine analog decitabine (DEC) acts as a nucleic acid synthesis inhibitor, whereas ammonium pyrrolidine dithiocarbamate (PDTC) is an inhibitor of nuclear factor-${\kappa}B$. The aim of this study was to investigate the possible synergistic inhibitory effect of these two inhibitors on proliferation of human gastric cancer AGS cells. The inhibitory effect of PDTC on AGS cell proliferation was significantly increased by DEC in a concentration-dependent manner, and this inhibition was associated with cell cycle arrest at the G2/M phase and the induction of apoptosis. This induction of apoptosis by the co-treatment with PDTC and DEC was related to the induction of DNA damage, as assessed by H2AX phosphorylation. Further studies demonstrated that co-treatment with PDTC and DEC induced the disruption of mitochondrial membrane potential, increased the generation of intracellular reactive oxygen species (ROS) and the expression of pro-apoptotic Bax, and down-regulated the expression of anti-apoptotic Bcl-2, ultimately resulting in the release of cytochrome c from the mitochondria into the cytoplasm. Co-treatment with PDTC and DEC also activated caspase-8 and caspase-9, which are representative caspases of the extrinsic and intrinsic apoptosis pathways. Co-treatment also activated caspase-3, which was accompanied by proteolytic degradation of poly (ADP-ribose) polymerase. Taken together, these data clearly indicated that co-treatment with PDTC and DEC suppressed the proliferation of AGS cells by increasing DNA damage and activating the ROS-mediated extrinsic and intrinsic apoptosis pathways.

• Journal of Life Science
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• v.32 no.2
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• pp.167-174
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• 2022

In modern society, interest in antioxidants is increasing as the stress caused by oxidants increases. However, the demand for synthetic antioxidants is decreasing because some studies have confirmed that they are harmful when consumed in large quantities; thus, studies on antioxidants derived from natural substances are actively being conducted to replace synthetic antioxidants. Blueberry, known as one of the world's top ten long-lived foods, is a plant of the Vaccinium (Ericaceae) family, and various pharmacological activities of blueberry including antioxidant activity have been studied. Vaccinium oldhamii (VO) is a deciduous broad-leaved shrub in the same genus as blueberries, and in this paper, we summarize the studies on the efficacy analysis of VO extracts and purified products. The content of phenolic compounds in VO fruits was proportional to antioxidant and anti-influenza activity such as the inhibition of NO production, and the total content of polyphenols and anthocyanin was higher than that in blueberries. VO fruit extracts showed anti-inflammatory activity and anti-cancer activity against human acute leukemia; in contrast, VO branch extracts showed anti-inflammatory activity, activity to inhibit osteoclast differentiation and bone resorption due to inflammatory response, and anti-cancer activity against several human cancer cell lines. Compared to blueberries, VO showed higher phenolic compound content, antioxidant activity, and various physiological activities. In addition, VO is considered to have sufficient value as an alternative crop to blueberries, such as it can be grown natively in Korea, with simple mass cultivation and no need to pay royalties for commercialization.

• Journal of Life Science
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• v.34 no.6
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• pp.418-425
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• 2024

Solid tumors are heterogeneous populations of multiple cell types. While the majority of the cells that comprise cancer are unable to divide, cancer stem cells have self-renewal and differentiation properties. Normal stem cell pathways that control self-renewal are overactivated in cancer stem cells, making cancer stem cells important for cancer cell expansion and progression. Dick first proposed the definition of cancer stem cells in acute myeloid leukemia, according to which cancer stem cells can be classified based on the expression of cell surface markers. Cancer stem cells maintain their potential in the tumor microenvironment. Multiple cell types in the tumor microenvironment maintain quiescent cancer stem cells and serve as regulators of cancer growth. Since current cancer treatments target proliferative cells, quiescent state cancer stem cells that are resistant to treatment increase the risk of recurrence or metastasis. Various signals of the tumor microenvironment induce changes to become a tumor-supportive environment by remodeling the vasculature and extracellular matrix. To effectively treat cancer, cancer stem cells and the tumor microenvironment must be targeted. Therefore, it is important to understand how the tumor microenvironment induces reprogramming of the immune response to promote cancer growth, immune resistance, and metastasis. In this review, we discuss the cellular and molecular mechanisms that can enhance immunosuppression in the tumor microenvironment.

• Journal of Chest Surgery
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• v.35 no.12
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• pp.854-861
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• 2002

In this study, we reviewed our early and long-term surgical results of complete atrioventricular septal defect during the last 16 years at our hospital. Materials and Methods: Between April 1986 and March 2002, 73 patients with complete atrioventricular septal defect underwent total correction without preceding palliation. Age at repair ranged from 2 to 85 (median age, 7) months, and weight ranged from 3 to 22 (median weight, 5.9)kg. Follow-up was complete with a mean duration of 69$\pm$51 months. Results: Overall operative mortality was 16.4%(12) with 3 late deaths. One, 5, and 10 year actuarial survival rates were 96.3 %, 94.2 % and 94.2 % respectively Sixteen of 61 (22.2%) operative survivors have undergone reoperation for postoperative mitral regurgitation or left ventricular outflow tract obstruction (LVOTO). Freedom from mitral reoperation at 1, 5, and 10 years were 87.8 %, 72.4 %, and 57.8 % and freedom from LVOTO at 1, 5, and 10 years were 98.2 %, 86.3 %, and 83.2 % respectively. Summary: In this study, we found that our early surgical results improved with quite an acceptable long-term outcome. Close observation of remaining mitral regurgitation was necessary, A precise evaluation of the atrioventricular valve morphology, a meticulous surgical technique, and the adequate postoperative management are mandatory for the excellent results.

• Journal of Chest Surgery
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• v.32 no.3
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• pp.281-286
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• 1999

Background: The purpose of this study is to analyze the types of complications, the incidences of complications, and preoperative and postoperative risk factors affecting the incidence of the complication. Material and Method: Between August 1990 and August 1997 in Asan Medical Center, 42 patients(24 men and 18 women) underwent surgical resection for pulmonary aspergilloma. The mean age was 46.6${\pm}$11.5 years(range 29 to 69 years). Hemoptysis(90%) was the most common presentation. Pulmonary tuberculosis was the most common predisposing cause(81%). The associated diseases were bronchiectasis(n=11), active puolmonary tuberculosis(n=9), diabetes mellitus(n=8), lung carcinoid(n=1), and acute myeloblastic leukemia(n=1). Lobectomy was done in 32 cases(76%), segmentectomy or wedge resection in 4, pneumonectomy in 2, and lobectomy combined with segmentectomy in 4. Result: Operative mortality was 2%. The most common postoperative complication was persistent air leakage(n=6). The variables such as age, sex, pulmonary function test, amount and duration of hemoptysis, associated diseases(diabetes mellitus, active pulmonary tuberculosis), mode of preoperative management(steroid, antifungal agent, bronchial arterial embolization), and modes of operative procedures were statistically insignificant. The radiologic extent of infiltration to normal lung parenchyme was statistically significant(p=0.04). Conclusion: We conclude that the extent of the infiltration to normal lung parenchyme in preoperative radiologic studies should be carefully evaluated to reduce the postoperative complications in surgery for pulmonary aspergilloma.

• Pediatric Infection and Vaccine
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• v.30 no.2
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• pp.73-83
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• 2023

Purpose: This study aimed to investigate the viral load dynamics in children with underlying malignancies diagnosed with symptomatic coronavirus disease 2019 (COVID-19). Methods: This was a retrospective longitudinal cohort study of patients <19 years old with underlying hemato-oncologic malignancies that were diagnosed with their first symptomatic severe acute respiratory syndrome coronavirus 2 polymerase chain reaction (PCR)-confirmed COVID-19 infection during March 1 to August 30, 2022. Review of electronic medical records and telephone surveys were undertaken to assess the clinical presentations and transmission route of the patients. Thresholds of negligible likelihood of infectious virus was defined as E gene reverse transcription (RT)-PCR cycle threshold (Ct) value ≥25. Results: During the 6-month study period, a total of 43 children with 44 episodes of COVID-19 were included. Of the 44 episodes, the median age of the patients included was 8 years old (interquartile range [IQR], 4.9-10.5), and the most common underlying disease was acute lymphoid leukemia (n=30, 68.2%), followed by patients post-hematopoietic stem cell transplantation (n=8, 18.2%). Majority of the patients had mild COVID-19 (n=32, 72.7%), and three patients (7.0%) had severe/critical COVID-19. Furthermore, 2.3% (n=1) died of COVID-19 associated acute respiratory distress syndrome. The largest percentage of the patients showed E gene RT-PCR Ct value ≥25 between 15-21 days (n=13, 39.4%), followed by 22-28 days (n=10, 30.3%). In 15.2% (n=5), E gene RT-PCR Ct value remained <25 beyond 28 days after initial positive PCR. Refractory malignancy status (β, 67.0; 95% confidence interval, 7.0-17.0; P=0.030) was significantly associated with prolonged duration of E gene RT-PCR <25. A patient with prolonged duration of E gene RT-PCR Ct value <25 was suspected to have infectivity shown by the transmission of the virus to his mother at day 86 after his initial positive test. Conclusions: Children that acquire symptomatic COVID-19 during refractory malignancy state are at a high risk for prolonged shedding warranting PCR-based transmission precautions in this cohort of patients.

• Korean Journal of Veterinary Research
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• v.9 no.1
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• pp.23-62
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• 1969

Throughout the studies the following experimental results were obtained and are summarized: 1. Multiplication of agents in primary cell cultures of both GF classical and CR-64 acute strain of Marek's disease infected chicken kidneys was accompanied by the formation of distinct transformed cell foci. This characteristic nature of cell transformation was passaged regularly by addition of dispersed cell from infected cultures to normal chicken kidney cell cultures, and also transferred was the nature of cell transformation to normal chick-embryo liver and neuroglial cell cultures. No cytopathic changes were noticed in inoculated chick-embryo fibroblast cultures. 2. The same cytopathic effects were noticed in normal kidney cell monolayers after the inoculation of whole blood and huffy coat cells derived from both forms of Marek's disease infected chickens. In these cases, however, the number of transformed cell foci appearing was far less than that of uninoculated monolayers prepared directly from the kidneys of Marek's disease infected chickens. 3. The change in cell culture IS regarded as a specific cell transformation focus induced by an oncogenic virus rather than it plaque in slowly progressing cytopathic effect by non-oncogenic viruses, and it is quite similar to RSV focus in chick-embryo fibroblasts in many respects. 4. The infective agent (cell transformable) were extremely cell-associated and could not be separated in an infective state from cells under the experimental conditions. 5. The focus assay of these agents was valid as shown by the high degree of linear correlation (r=0.97 and 0.99) between the relative infected cell concentration (in inoculum) and the transformed cell foci counted. 6. No differences were observed between the GF classical strain and the CR-64 acute strain of Marek's disease as far as cell culture behavior. 7. Characterization of the isolates by physical and chemical treatments, development of internuclear inclusions in Infected cells, and nucleic acid typing by differential stainings and cytochemical treatments indicated that the natures of these cell transformation agents closely resemble to those described fer the group B herpes viruses. 8. Susceptible chicks inoculated with infected kidney tissue culture cells developed specific lesions of Marek's disease, and in a case of prolonged observation after inoculation (5 weeks) the birds developed clinical symptoms and gross lesions of Marek's disease. Kidney cell cultures prepared from those inoculated birds and sacrificed showed a superior recovery of cell transformation property by formation of distinct foci. 9. Electron microscopic study of infected kidney culture cells (GF agent) by negative staining technique revealed virus particles furnishing the properties of herpes viruses. The particle was measured about $100m{\mu}$ and, so far, no herpes virus envelop has been seen from these preparations. 10. No relationship of both isolates to avian leukosis/sarcoma group viruses and PPLO was observed.

• Journal of Veterinary Clinics
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• v.24 no.4
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• pp.479-485
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• 2007

A retrospective study of 94 hypercalcemic dogs was performed to find out most common causes that lead to hypercalcemia through investigating dogs referred to the Veterinary Teaching Hospital of Konkuk University from 2002 to 2004. During the study period, hypercalcemia was found in 94 dogs of 19 breeds, and they were evaluated as case group. Control group was made up of 94 dogs of 18 breeds without hypercalcemia admitted for the same study period. For general signalments, there were no significant differences between case and control group with the exception of age distribution. Shih-tzu(17.02%) and Yorkshire terrier(26.60%) was the most common breed in case and control group, respectively. The most common diseases associated with hypercalcemia were chronic renal failure (18.09%), acute renal failure(14.89%), and renal calculi(6.38%). Malignant neoplasia(lymphoma, hemangiosarcoma, chronic lymphocytic leukemia, mammary gland tumor, and multiple myeloma) and endocrinopathies(hyperadrenocorticism, hyperthyroidism, hypoadrenocorticism, and hypothyroidism) occupied 8.5% and 6.4%, respectively. This report is a first retrospective study of hypercalcemic dogs in South Korea.