• Korean Journal of Heritage: History & Science
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• v.37
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• pp.327-348
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• 2004

In this study, after analyzing several local climate characteristics of South Korea, I validated distribution, invasion, foraging, underground activities, attack season as ecological characteristics and also temperature, relative humidity, and tree species as preference characteristics of Korean termites (Reticulitermes speratus kyushuensis Morimoto). Especially, southern part of the Korean peninsula is a suitable area for inhabitation and motion of termites holding same ecological characteristic like R. speratus kyushuensis. Busan is a neighboring district at field distribution north limiting temperature of Coptotermes formosanus Shiraki and Chuncheon is a passing area through the Korean Peninsula of field distribution north limiting temperature of Reticulitermes speratus Kolbe. The termite attack of wood devices was about 34.5% for 3 years in the forest of Jongmyo. Although the attack rate of termite increased each year, the detection rate decreased and the missing rate was high by degrees. I confirmed a foraging habits which is a part of termite colony was a role of continuous decomposition and another was a role of new food hunt as experimental results. The foraging termites were found under ground at Jongmyo in Seoul from April to November in the 2001 and the most active period was on July and August. The termite invasion rate of bait station increased in every monitoring. Through the increasing attack rate of bait station during 2nd monitoring (November, 2000) and 3rd monitoring(March, 2001), I confirmed that termites moved into the deep underground in winter, and were working continuously to forage. R. speratus kyushuensis inhabiting at the Korean Peninsula is a species which has food consumption rate with higher temperature. The termite revealed the greatest amount of food(filter paper) at $30^{\circ}C$(90% RH), but showed increasing death rate at over $32^{\circ}C$. Also, survival rate of this termite was 97% at 84% RH($30^{\circ}C$), but killed 100% at 52% RH($30^{\circ}C$) and 70% RH($30^{\circ}C$). For wood feeding, this was observed the preference in a pine tree(Pinus densiflora) above all others. Survival of termites was high(87%) at a pine tree, but low(13.5%) at a paulownia tree(Paulownia coreana). In this study, I presented the biological characteristic of termite(R. speratus kyushuensis Morimoto) and confirmed the deterioration degree of termite on wooden cultural heritage in Korea. Depending on climate and soil temperature, each area in the southern part of the Korea Peninsula, has some different active period and different distribution of R. speratus kyushensis. With these results, I expect that this report helps to prepare the integrated pest management(IPM) of the termite on wooden cultural heritage in Korea, and it may help to reduce the economical loss from termite damage in Korea.

• Korean Journal of Environmental Biology
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• v.41 no.3
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• pp.325-334
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• 2023

The invasive red swamp crayfish, Procambarus clarkii, is native to south-central United States and northeastern Mexico. Recently, it has been being spreading in the wild in South Korea. However, its primary sources, introduction routes, establishment, and expansion in South Korea remain unclear. Here, we analyzed genetic diversity and population genetic structures of its domestic natural populations during early invasion, commercial stock from local aquaria (a suspected introduction source), and original United States population using mitochondrial COI gene sequences for 267 individuals and eight microsatellite markers for 158 individuals. Natural and commercial populations of P. clarkii showed reduced genetic diversity (e.g., haplotype diversity and allelic richness). The highest genetic diversity was observed in one original source population based on both genetic markers. Despite a large number of individuals in commercial aquaria, we detected remarkably low genetic diversity and only three haplotypes among 226 individuals, suggesting an inbred population likely originating from a small founder group. Additionally, the low genetic diversity in the natural population indicates a small effective population size during early establishment of P. clarkii in South Korea. Interestingly, genetic differentiation between natural populations and the United States population was lower than that between natural populations and aquarium populations. This suggests that various genetic types from the United States likely have entered different domestic aquariums, leading to distinct natural populations through separate pathways. Results of our study will provide an insight on the level of genetic divergence and population differentiation during the initial stage of invasion of non-indigenous species into new environments.

• Journal of Chest Surgery
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• v.37 no.10
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• pp.845-855
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• 2004

Background: No general consensus has been available regarding the necessity of postoperative radiation therapy (PORT) and its optimal techniques in the patients with chest wall invasion (pT3cw) and node negative (N0) non-small cell lung cancer (NSCLC). We did retrospective analyses on the pT3cwN0 NSCLC patients who received PORT because of presumed inadequate resection margin on surgical findings. And we compared them with the pT3cwN0 NSCLC patients who did not received PORT during the same period. Material and Method: From Aug. of 1994 till June of 2002, 22 pT3cwN0 NSCLC patients received PORT-PORT (＋) group- and 16 pT3cwN0 NSCLC patients had no PORT-PORT (-) group. The radiation target volume for PORT (＋) group was confined to the tumor bed plus the immediate adjacent tissue only, and no regional lymphatics were included. The prognostic factors for all patients were analyzed and survival rates, failure patterns were compared with two groups. Result: Age, tumor size, depth of chest wall invasion, postoperative mobidities were greater in PORT (-) group than PORT (＋) group. In PORT (-) group, four patients who were consulted for PORT did not receive the PORT because of self refusal (3 patients) and delay in the wound repair (1 patient). For all patients, overall survival (OS), disease-free survival (DFS), loco-regional recurrence-free survival (LRFS), and distant metastases-free survival (DMFS) rates at 5 years were 35.3%, 30.3%, 80.9%, 36.3%. In univariate and multivariate analysis, only PORT significantly affect the survival. The 5 year as rates were 43.3% in the PORT (＋) group and 25.0% in PORT (-) group (p=0.03). DFS, LRFS, DMFS rates were 36.9%, 84.9%, 43.1 % in PORT (＋) group and 18.8%, 79.4%, 21.9% in PORT(-) group respectively. Three patients in PORT (-) group died of intercurrent disease without the evidence of recurrence. Few suffered from acute and late radiation side effects, all of which were RTOG grade 2 or lower. Conclusion: The strategy of adding PORT to surgery to improve the probability not only of local control but also of survival could be justified, considering that local control was the most important component in the successful treatment of pT3cw NSCLC patients, especially when the resection margin was not adequate. Authors were successful in the marked reduction of the incidence as well as the severity of the acute and late side effects of PORT, without taking too high risk of the regional failures by eliminating the regional lymphatics from the radiation target volume.

• Journal of Chest Surgery
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• v.37 no.3
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• pp.252-260
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• 2004

The purpose of study is to evaluate the clinical implication of malignant Pleural Lavage Cytology (PLC) in primary lung cancer. 315 patients were examined with pleural lavage cytology in Asan Medical Center between November 1998 and August 2002. The patients were chosen from primary lung cancer patients with no pleural effusion according to preoperative radiologic examination; no tumor invasion into the chest wall and no diffuse pleural adhesion in intraoperative findings, The pleural cavity and lung were washed with 100 $m\ell$ of warm normal saline. The 315 patients consisted of 237 men and 78 women. The incidence of malignant PLC was found in 28 patients (8.9%). For patients in early stages (I & II), survival rate was 93.9% in positive malignant PLC and 85.7% in negative malignant PLC. 31 patients (13.6%) had local or distant recurrences; 2-year recurrence-free rate was 90.1% in negative PLC and 87.5% in positive PLC. The survival and recurrence-free rate in each stage were not statistically associated with the result of PLC. Median follow-up was 16.4 months from the surgery. To access implication of malignant PLC in primary lung cancer, a long-term follow-up and further study are required.

• Journal of Chest Surgery
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• v.37 no.3
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• pp.286-291
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• 2004

Mediastinum is a very rare primary site of liposarcoma. In general, wide surgical excision with adequate resection margin is the treatment of choice for lipesarcoma. We experienced a case of liposarcoma in a 24 year-old male who complained of dyspnea and chest discomfort. Symptoms had been developed a month before admission, and the intensity had been gradually increased. He visited another general hospital, and there he received left closed thoracostomy because hemothorax was suspected. Afterwards, he was transferred to our hospital without a specific diagnosis, on review of outside chest computed tomography film, mass shadow was detected in the mediastinum. For the further evaluation, we checked the chest sonography and chest magnetic resonance imaging. MRI showed 10 cm sized mass contacted with pulmonary artery trunk and left main pulmonary artery. The radiologist strongly suggested sarcoma. On the 4th day after admission, we performed emergent exploratory left thoracotomy for hematoma evacuation because mediastinal shifting progressed and heart rate was increased. Biopsy confirmed that the evacuated materials were extraskeletal myxoid chondresarcoma, so we performed extrapleural left pneumonectomy including diaphragm and a part of the pericardium. The final pathologic diagnosis was myxoid/round cell liposarcoma. He was discharged without complication and systemic chemotherapy was scheduled to begin 2 month later. During chemotherapy, local recurrence and peritoneal metastasis developed, and he died 10 month after the surgical excision. We report this case with reviewal of literature.

• 한국균학회소식:학술대회논문집
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• 2014.05a
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• pp.49-49
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• 2014

South Korea is covered primarily by temperate vegetation; therefore, foliicolous lichens may not be expected to play an important role in its lichen flora. Indeed, more than 100 years after the first lichen record from South Korea reported by Hue, the paper "Pyrenocarpous lichens in Korea" published by Moon and Aptroot, reported on the presence of two foliicolous lichens, Strigula nemathora Mont, and S. smaragdula Fr., for the first time in South Korea. No detailed reports on foliicolous lichens have since been published in South Korea. In Japan, the neighboring country, approximately 83 foliicolous lichen species are distributed at the southernmost part under temperate to subtropical climatic conditions. However, a large number of foliicolous lichens, with many recent records, have been reported in neighboring countries like China and Taiwan. According to Thor et al., studies on foliicolous lichen flora of Asia are comparatively poor compared to those reported from America. There are six lichenogeographical regions: the Neotropics, Valdivia, Tethyan, African Paleotropics, eastern Paleotropics, and Neozelandic-Tasmanian, which are demarcated based on the known worldwide distribution pattern of foliicolous lichen flora. South Korea belongs to the eastern paleotropic region, where a higher number of local endemic foliicolous lichens have been reported. So far, there are a total of six known foliicolous lichen taxa from South Korea; S. concreta, S. macrocarpa, S. melanobapha, S. nemathora, S. smaragdula, and S. subelegans from Jeju Island. So far, the genus Strigula is the only known representative of the foliicolous lichen flora in South Korea. Among the recorded species, S. concreta, S. smaragdula, and S. subelegans are abundant and widespread. Japan, the closest area to Jeju Island, has the same distribution pattern of foliicolous lichens, with S. smaragdula, S. melanobapha, and S. subtilissima. Pollen studies conducted by Chung reported that changes in vegetation on Jeju Island, due mainly to deglacial warming and the influence of geographical change, resulted from sea-level rises. In general, all of the foliicolous lichens observed so far were restricted to the southernmost part of South Korea, particularly Jeju Island. Island might be influenced by its geographical setting. One reason could be the close dispersal distances of spores and vegetative propagules from areas such as the southern part of Japan and eastern part of China, where more foliicolous lichens can be found. Thor et al. also showed that the southern part of Japan harbors more foliicolous lichens than the northern part. Considering that China is close to Jeju Island, many foliicolous lichens, including S. concreta, S. macrocarpa, S. nemanthora, and S. smaragdula, have been reported from Yunnan province, the southernmost part of China. Geographically, this province is far away from Jeju Island. In other provinces, such as Shandong, Jiangsu, Shanghai, and Zhejiang, which are closer to Jeju Island, no foliicolous lichens have been recorded so far. Therefore, the chance of spores and propagules coming from such closer areas is questionable. Thus, the location of origin of ancestors of foliicolous lichens of South Korea and the time and means of their invasion of this island is controverisial. The current study would lead the way to finding answers to the above mentioned questions.

• Radiation Oncology Journal
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• v.33 no.2
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• pp.109-116
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• 2015

Purpose: To analyze prognostic factors for locoregional recurrence (LRR), distant metastasis (DM), and overall survival (OS) in cervical cancer patients who underwent radical hysterectomy followed by postoperative radiotherapy (PORT) in a single institute. Materials and Methods: Clinicopathologic data of 135 patients with clinical stage IA2 to IIA2 cervical cancer treated with PORT from 2001 to 2012 were reviewed, retrospectively. Postoperative parametrial resection margin (PRM) and vaginal resection margin (VRM) were investigated separately. The median treatment dosage of external beam radiotherapy (EBRT) to the whole pelvis was 50.4 Gy in 1.8 Gy/fraction. High-dose-rate vaginal brachytherapy after EBRT was given to patients with positive or close VRMs. Concurrent platinum-based chemoradiotherapy (CCRT) was administered to 73 patients with positive resection margin, lymph node (LN) metastasis, or direct extension of parametrium. Kaplan-Meier method and log-rank test were used for analyzing LRR, DM, and OS; Cox regression was applied to analyze prognostic factors. Results: The 5-year disease-free survival was 79% and 5-year OS was 91%. In univariate analysis, positive or close PRM, LN metastasis, direct extension of parametrium, lymphovascular invasion, histology of adenocarcinoma, and chemotherapy were related with more DM and poor OS. In multivariate analysis, PRM and LN metastasis remained independent prognostic factors for OS. Conclusion: PORT after radical hysterectomy in uterine cervical cancer showed excellent OS in this study. Positive or close PRM after radical hysterectomy in uterine cervical cancer correlates with poor prognosis even with CCRT. Therefore, additional treatments to improve local control such as radiation boosting need to be considered.

• Tuberculosis and Respiratory Diseases
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• v.51 no.3
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• pp.281-288
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• 2001

Background : The most common anterior mediastinal tumors originate from the thymus. Among them, thymic carcinomas occur as an early local invasion and wide spread metastases. However, when squamous cell carcinoma in the thymus or mediastinum is identified, an occult primary lung cancer must be excluded because the histologic types resemble those found more typically in the lung. CD5 and cytokeratin immunohistochemical staining is useful in evaluating biopsy samples from those tumors. Squamous cell carcinoma of an unknown primary origin in the mediastinum is a rare occurrence and there are only a handful of case reports. Here we describe a case with an anterior mediastinal mass of squamous cell carcinoma with unknown primary origin. A resection of the mediastinal mass without an association with the lung was performed. Immunohistochemical stallings were positive using cytokeratin 13, and negative using CD5 and cytokeratin 7. This was followed by chemotherapy for presumed thymic carcinoma.

• Radiation Oncology Journal
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• v.12 no.2
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• pp.191-199
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• 1994

Purpose : This study was undertaken to show the clinical results of combined radiotherapy and hyperthermia in primary hepatoma Materials and Methods : Between December 1989 and March 1993, 50 patients with hepatomas were treated by combined radiotherapy and hyperthermia. Among them, we analyzed retrospectively 33 patients who received the complete course of treatment. The ages of the patients ranged from 36 to 75(mean age: 55.5 years). Twenty-six patients ($78.8\%$) were men, and 7 ($21.2\%$ were women. According to Child's classification, nine patients ($27.3{\%}$) were A group, 9 ($27.3\%$) were B group, 15 ($45.4\%$) were C group. Radiation therapy was done by a 6 MV and 15 MV linear accelerator. Patients were treated with daily fractions of 150-180 cCy to doses of 2550 cGy -4950 cGy (median : 3000 cGy). Local hyperthermia was done by 8 MHZ RF capacitive heating device (Cancermia. Green Cross Co., Korea), 50-60 min/session, 1-2 sessions/wk, and 8.5 sessions (median number)/patient. We analyzed the prognostic factors including age, sex, tumor type, Child's classification, $\alpha$-fetoprotein, liver cirrhosis, ascites, portal vein invasion, esophageal varix, number of hyperthermia, chemotherapy, total bilirubin level, Karnofsky perfomance status. Results : The overall 1-year survival was $24.2\%$, with a mean survival of 10months. Of 33 patients, tumor regression (PR+MR) was seen in $30.4\%$, no response was seen in $52.2\%,\;17.4\%$ patient was progressed. In patients who had tumor regression, the overall 1-year survival was $42.1\%$ with a mean survival of 14 months. Factors influencing the survival were sex (p=0.05), tumor type (p=0.0248), Child's classification (p=0.0001), liver cirrhosis (p=0.0108), ascites (p=0.0009), and Karnofsky perfomance status (p=0.0028). Complications developed in 28 patients, including 18 hot pain,5 fat necrosis, 3 transient fever, 2 nausea and vomiting. Conclusion : In this study, the results suggests that combined radiotherauy and hyperthermia may improve the survival rate of hepatoma.

• Radiation Oncology Journal
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• v.32 no.1
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• pp.7-13
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• 2014

Purpose: To evaluate the results of postoperative radiotherapy in patients with extra-hepatic bile duct cancer (EHBDC) and identify the prognostic factors for local control and survival. Materials and Methods: Between January 2001 and December 2010, we retrospectively reviewed the cases of 70 patients with EHBDC who had undergone curative resection and received postoperative radiotherapy. The median radiation dose was 50.4 Gy (range, 41.4 to 54 Gy). The resection margin status was R0 in 30 patients (42.9%), R1 in 25 patients (35.7%), and R2 in 15 patients (21.4%). Results: The 5-year rates of overall survival (OS), event-free survival (EFS), and locoregional control (LRC) for all patients were 42.9%, 38.3%, and 61.2%, respectively. The major pattern of failure was distant relapses (33 patients, 47.1%). A multivariate analysis showed that the postradiotherapy CA19-9 level, radiation dose (${\geq}50$ Gy), R2 resection margins, perineural invasion, and T stage were the significant prognostic factors for OS, EFS, and LRC. OS was not significantly different between the patients receiving R0 and R1 resections, but was significantly lower among those receiving R2 resection (54.6%, 56.1%, and 7.1% for R0, R1, and R2 resections, respectively). Conclusion: In patients with EHBDC who had undergone curative resection, a postoperative radiotherapy dose less than 50 Gy was suboptimal for OS and LRC. Higher radiation doses may be needed to obtain better LRC. Further investigation of novel therapy or palliative treatment should be considered for patients receiving R2 resection.