• Journal of Chest Surgery
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• v.39 no.3 s.260
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• pp.208-213
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• 2006

Background: The prevalence of anastomotic complication is related to anastomotic procedure or site in esophageal cancer operation. We studied the anastomotic leakage and stricture related to the anastomotic procedure & site in patients who received the esophageal resection and reconstruction for esophageal cancer. Material and Method: The anastomotic procedure, site and complication of 321 patients who received the esophageal reconstruction from August 1993 to May 2003 were investigated. Mean age was 64.5$\pm$4.9 (37${\~}$94) years, 300 patients ($93.5\%$) were male and 21 patients were female ($6.5\%$). Result: There were 7 anastomotic leakages ($2.2\%$) and no difference in anastomotic site (cervical anastomosis $4.1\%$, thoracic anastomosis $1.6\%$) and procedure (stapler technique $1.6\%$, semi-staple technique $9.1\%$, hand-sewn technique $0.0\%$). There were 52 anastomotic strictures ($16.2\%$), differences in sites (cervical anastomosis $2.7\%$, thoracic anastomosis $20.2\%$) (p < 0.001) and procedure (stapler technique $20.0\%$, semi-stapler technique $3.0\%$, hand-sewn technique $4.7\%$). And the stapler technique showed higher stricture rate (p < 0.001). Conclusion: Anastomotic technique was less related to anastomotic leakage in esophageal reconstruction for esophageal cancer. However, stapler technique had higher stricture rate than other techniques. Therefore, we suggest that the anastomotic technique be improved to reduce anastomotic stricture.

• Journal of Chest Surgery
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• v.31 no.5
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• pp.466-471
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• 1998

Purpose: The safety and efficacy of minimally invasive techniques in congenital heart surgery were tested in this study. Materal and method: Between July 1997 and November 1997, a total of 46 children were underwent minimally invasive cardiac operations at Seoul National University Children's Hospital. Age and body weight of the patients averaged 34.6${\pm}$41.8 (Range: 1∼148) months and 14.5${\pm}$9.9(Range: 3.0∼40.0) kg, respectively. Twenty eight patients were male. Preoperative surgical indications included 15 atrial septal defects, 25 ventricular septal defects, 1 foreign body in aorta, 3 partial atrioventricular septal defects, 1 total anomalous pulmonary venous connection(cardiac type), and 1 tetralogy of Fallot. After creating a small lower midline skin incision starting as down as possible from the sternal notch, a vertical midline sternotomy extended from xyphoid process to the level of the second intercostal space, where one of the T-, J-, I- or inverted C-shaped lower lying mini-sternotomy was completed with a creation of unilateral right or bilateral trap door sternal opening. A conventional direct aortic and bicaval cannulation was routine. Result: A mean length of skin incision was 6.1${\pm}$1.0(range: 4.0∼9.0) cm. A mean distance between the suprasternal notch and the upper most point of the skin incision was 4.0${\pm}$1.1 (range: 2.0∼7.0) cm. Mean cardiopulmonary bypass time, aortic cross-clamp time, and the operation time were 62.9${\pm}$20.0(range: 28∼147), 29.8${\pm}$12.8(range: 11∼79), and 161.1${\pm}$34.5 (range: 100-250) minutes. A mean total amount of postoperative blood transfusion was 71.0${\pm}$68.1 (range: 0∼267) cc. All patients were extubated mean 11.3${\pm}$13.8(range: 1∼73) hours after operation. A mean total amount of analgesics used was 0.8${\pm}$1.8(range: 0∼9) mg of morphine. The mean duration of stay in intensive care unit and hospital stay were 35.0${\pm}$32.2 (range: 10∼194) hours and 6.2${\pm}$2.0(range: 3∼11) days. There were no wound complications and hospital deaths. Conclusion: This short-term experience disclosed that the minimally invasive technique can be feasibly applied in a selected group of congenital heart disease as well as is cosmetically more attractive approach.

• Journal of Chest Surgery
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• v.31 no.9
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• pp.827-836
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• 1998

Background: Effective cardiopulmonary resuscitation (CPR) should provide acceptable hemodynamics for the vital organs during cardiac arrest and early restoration of spontaneous circulation that guarantees long-term, neurologically intact survival. CPR using heart-lung bypass has been suggested as an option for that use. This study was designed to determine the effectiveness of standard CPR techniques, closed-vs. open-chest CPR, which could be used in the future study verifying the role of heart-lung bypass CPR. Material and Method: By using adult mongrel dogs, closed-chest CPR (CCCPR, n=4) and open-chest CPR (OCCPR, n=5) were compared with respects to hemodynamics, restoration of spontaneous circulation(ROSC), and survival. Ventricular fibrillation-cardiac arrest (VF-CA) was induced by electrical shock in all animals. After 4 minutes of cardiac arrest, basic life support (BLS) was applied for 15 minutes and followed by advanced life support (ALS). ALS was maintained until achi ving ROSC but not longer than 30 minutes regardless of the recovery. Resuscitation procedures in either group were standardized by adopting the protocol of American Heart Association. Result: Prearrest baseline hemodynamic data was not different between two groups. During resuscitation, substantially higher systolic pressure was maintained in OCCPR group than in CCCPR group (45$\pm$15 vs. 33$\pm$11 mmHg during BLS, 83$\pm$36 vs. 44$\pm$15 mmHg during ALS; p=NS). Mean pulmonary arterial pressure went up to the level of mean systemic arterial pressures in CCCPR group and to half of that in OCCPR group, and had kept higher in CCCPR group throughout CPR (32$\pm$10 vs. 22$\pm$4 mmHg during BLS and 32$\pm$15 vs. 24$\pm$10 mmHg during ALS; p=NS). ROSC was obtained in 4 of 5 dogs receiving open-chest CPR and 2 of 4 closed-chest CPR. Prolonged survival was noted in all dogs in OCCPR group (6 to 1440 hours) but not in CCPR group (p<.05). Conclusion: These findings indicate that open-chest CPR can be more effective t maintain hemodynamics during cardiac arrest and to obtain restoration of spontaneous circulation and survival. Further experiment will be designed to compare heart-lung bypass CPR with open-chest CPR.

• Journal of Chest Surgery
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• v.32 no.9
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• pp.799-805
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• 1999

Background: Leakage, stricture formation, and tumor recurrence at the anastomotic site are serious problems after esophagectomy for cancer of the esophagus or cardia. The prevalence of these postoperative complications may be affected by whether an anastomosis is made in the neck or in the chest, therefore a comparison was made between anastomoses made at these two sites. Material and Method: Between 1987 and 1998, 36 patients with cancer of the esophagus underwent transthoracic esophagectomy with cervical(NA, n=20) or thoracic anastomosis(CA, n=16). The tumors were staged postoperatively(stage IIA, n=13; s tage IIB, n=7; stage III, n=16) and were located in the middle thoracic(n=22) or lower thoracic esophagus and cardia(n=14). Result: The overall operative mortality was 8.3%(5% for NA group, 12.5% for CA group). The anastomotic leak rate for the NA group was 15.0% and 12.5% for the CA group. The anastomotic leak rate differed according to the manual(27.3%) or stapled(8.0%) techniques(p < 0.05). The median proximal resection margins in the NA and CA groups were 9.6 cm and 5.8 cm, and the corresponding rates of anastomotic tumor recurrence were 5.3% and 28.6%(p < 0.05). The prevalence of benign stricture formation (defined as moderate/severe dysphagia) was higher in the NA group(36.8%) than in the CA group(21.4%). When an anastomosis was made by the stapled technique, smaller size of the staple increased the prevalence of stricture formation - 41.7% with 25-mm staple and 9.1% with 28-mm staple(p < 0.05). Conclusion: Wider resection margin could decrease the anastomotic tumor recurrence, and the stapled technique could decrease the anastomotic leak. The prevalence of benign stricture was higher in the cervical anastomosis but the anastomotic leak and smaller size(25-mm) of the staple should be considered as risk factors.

• Journal of Chest Surgery
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• v.42 no.6
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• pp.763-769
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• 2009

Background: In the majority of cases, sternal instability and wound infection concomitantly present after a cardiac operation following conventional median sternotomy, and these complications have a major influence on the postoperative course. The aim of this study is to compare the results of the different sternal wiring techniques of sternal infection. Material and Method: Between April 2004 and December 2008, 157 adult patients underwent cardiac in group A, whereas 71 patients who had undergone modified Robicsek sternal wiring were included in group B. The incidences of sternal wound complications in the two groups were assessed. Result: The mean age of the group B patients was older than that of the group A patients ($61{\pm}10$ years vs $57{\pm}13$ years). The incidence of preoperative left ventricular dysfunction (ejection fraction <30%), chronic obstructive pulmonary disease, renal failure requiring dialysis and diabetes mellitus were significantly higher in Group B, whereas the other perioperative risk factors for infection were not significantly different between the two groups. Two patients in group A experienced superficial wound infection, whereas 4 patients in group B displayed superficial wound infection, but the difference was not statistically significant (p=0.255). Yet poststernotomy deep sternal wound infection appeared in 6 patients of group A, whereas none of the patients in group B displayed this malady. Conclusion: The modified Robicsek sternal wiring technique showed greater sternal stability even for the patient with a high risk for infection, and the technique caused a lower incidence of deep sternal wound infection.

• Journal of Korea Water Resources Association
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• v.51 no.10
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• pp.863-874
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• 2018

The purpose of this study is to evaluate the future climate change impact on stream aquatic ecology health of Han River watershed ($34,148km^2$) using SWAT (Soil and Water Assessment Tool) and random forest. The 8 years (2008~2015) spring (April to June) Aquatic ecology Health Indices (AHI) such as Trophic Diatom Index (TDI), Benthic Macroinvertebrate Index (BMI) and Fish Assessment Index (FAI) scored (0~100) and graded (A~E) by NIER (National Institute of Environmental Research) were used. The 8 years NIER indices with the water quality (T-N, $NH_4$, $NO_3$, T-P, $PO_4$) showed that the deviation of AHI score is large when the concentration of water quality is low, and AHI score had negative correlation when the concentration is high. By using random forest, one of the Machine Learning techniques for classification analysis, the classification results for the 3 indices grade showed that all of precision, recall, and f1-score were above 0.81. The future SWAT hydrology and water quality results under HadGEM3-RA RCP 4.5 and 8.5 scenarios of Korea Meteorological Administration (KMA) showed that the future nitrogen-related water quality in watershed average increased up to 43.2% by the baseflow increase effect and the phosphorus-related water quality decreased up to 18.9% by the surface runoff decrease effect. The future FAI and BMI showed a little better Index grade while the future TDI showed a little worse index grade. We can infer that the future TDI is more sensitive to nitrogen-related water quality and the future FAI and BMI are responded to phosphorus-related water quality.

• Journal of Wetlands Research
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• v.17 no.2
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• pp.124-129
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• 2015

In order to get as ecological basic data for river restoration, vegetation investigation was conducted in natural river and analysed it synecological methods, such as ordination cluster. 29 plant communities units were identified and the major dominant plant communites were Quercus mongolica community, Pinus densiflora community, Populus davidiana community, Q. variabilis community and Prunus sargentii community. River vegetations were classified into ravine and gorge forest type and riverine softwood forest type. Ravine and gorge forest was dominanted by hardwood which located in steep slope and in high elevation, and riverine softwood forest by softwood, salix spp. Naturality was an important criterion for the selection of rivers, so many of the selected rivers are located in the upper stream and mid stream rather than the lower stream, where more human intervention is involved. Plant communities were consisted of hardwood forest(44 plots, 92%) and softwood forest(4 plot, 8%), respectively. PCA with total layer data showed 5 groups of communities: Q. mongolica community group, Prunus sargentii community group, Pinus densiflora community group, Prunus sargentii community - Pinus densiflora community group and the rest communities group. PCA with tree layer showed 3 groups: Q. mongolica community group, Prunus sargentii community group, and the rest community group. Cluster analysis also a showed a similar communities group to PCA ordination, but Magnolia sieboldii community and Prunus sargentii community were distinguished from the PCA result. From the result, it can be concluded that the plant communities of riparian be divided into hardwood and softwood forest by statistical techniques. It was appropriate to plant species such as Quercus mongolica, Pinus densiflora, Populus davidiana, Quercus variabilis and Prunus sargentii, at levee zone and high water level. And Sliax spp. were appropriate for planted plants at waterfront and low water level. The herb species to be planted on the floodplain were recommanded in the species composition co-occurred with the woody species.

• Radiation Oncology Journal
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• v.22 no.4
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• pp.254-264
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• 2004

Purpose: This study was carried out to confirm clinical values and limitations of postoperative radiotherapy for hypopharyngeal carcinoma, to evaluate various prognostic factors which may affect to the treatment results and to use these results as fundamental data for making a new treatment strategy. Methods and Materials:. A retrospective analysis was peformed on 64 previously untreated patients with squamous cell carcinoma of the hypopharynx, seen between 1988 and 1999 at Pusan National University Hospital. Most of patients were treated by laryngopharyngectomy and neck dissection followed by conventional fractionated postoperative radiotherapy on surgical bed and cervical nodal areas. Results: The five-year overall survival rate and cause-specific survival rate were 42.2 percent and 51.6 percent, respectively. Univariate analysis of various clinical and pathologic factors confirmed the overall stage, TN-stage, secondary primary cancers, surgical positive margin, nodal extracapsular extension, total radiation doses as significant prognostic factors of hypopharyngeal carcinomas. But in multivariate analysis, TN-stage, surgical positive margin and extracapsular extesion were only statistically significant. Conclusion: In resectable cases of hypopharyngeal carcinoma, combined surgery and postoperative radio-therapy obtained good treatement results, even though sacrificing the function of larynx and pharynx. But in advanced and unresectable cases, with respect to survivals and qualify of life issues, we were able to confirm some limitations of combined therapy. So we recommend that comparative studies of recent various chemo-radiotherapy methods and advanced radiotherapy techniques with these data should be needed.

• Radiation Oncology Journal
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• v.13 no.3
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• pp.215-223
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• 1995

Purpose : The aim of this study was to assess the effectiveness, survival rate and complication of radiation in nasopharyngeal cancer. Materials and Methods : From January 1980 to May 1989. Fifty patients who had nasopharyngeal carcinoma treated with curative radiation therapy at Kosin Medical Center were retrospectively studied. Thirty seven patients($74{\%}$) were treated with radiation therapy alone(Group I) and 13 patients ($26{\%}$) treated with combination of chemotherapy and radiation (Group II). Age distribution was 16-75 years(median : 45.8 years). In histologic type, squamous cell carcinoma was in 30 patients($60{\%}$), undifferentiated carcinoma in 17 patients($34{\%}$), and lymphoepithelioma in 3 patients($6{\%}$). According t AJCC staging system. 4 patients($8{\%}$) were in $T_1$, 13 patients($26{\%}$) in $T_2$. 20 patients($40{\%}$) in $T_3$, 13 patients($26{\%}$) in $T_4$ and 7 patients($14{\%}$) in $N_0$, 6 patients($12{\%}$) $N_1$, 23 patients($46{\%}$) in $N_2$, 14 patients($28{\%}$) in $N_3$. Total radiation dose ranges were 5250-9200cGy(median : 7355 cGy) in Group I and 5360-8400cGy(median : 6758cGy) in Group II Radiotherapy on 4-6MV linear accelerator and/or 6-12MeV electron in boost radiation was given with conventional technique to 26 patients($52{\%}$), with hyperfractionation(115-120cGy/fr., 2times/day) to 16 patients($32{\%}$), with accelerated fractionation(160cGy/fr., 2 times/day) to 8 patients($16{\%}$). In chemotherapy, 5 FU 1000mg daily for 5 consecutive days, pepleomycin 10mg on days 1 and 3, and cisplatin 100mg on day 1 were administered with 3weeks interval, total 1 to 3 cycles(average 1.8cycles) prior to radiation therapy. Follow up duration was 6-140 months(mean : 58 months). Statistics was calculated with Chi-square and Fisher's exact test. Results : Complete local control rates in Group I and II were $75.7{\%},\;69.2{\%} Overall 5 year survival rates in Group I and II were $56.8{\%},\;30.8{\%}$. Five year survival rates by histologic type in Group I and II were $52.2{\%},\;14.3{\%}$ is squamous cell carcinoma and $54.5{\%},\;50{\%}$ in undifferentiated carcinoma. Survival rates in Group I were superior to those of Group II though there were not statistically significant. In both group, survival rates seem to be increased according to increasing total dose of radiation up to 7500cGy, but not increased beyond it. There were not statistically significant differences in survival rates by age, stage, and radiation techniques in both group. Twenty four patients($48{\%}$) experienced treatment failures. Complications were found in 12 patients($24{\%}$). The most common one was osteomyelitis(4 patients, $33.3{\%}$) involving mandible (3 patients) and maxilla(1 patient). Conclusion : Chemotherapy in combination with radiotherapy was found to be not effective to nasopharyngeal cancer and the survival rate was also inferior to that of radiation alone group though it was statistically not significant due to small population in chemotherapy combined group.

• Korean Journal of Veterinary Research
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• v.25 no.1
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• pp.7-17
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• 1985

Many investigators have been pursuing various attempts so far to produce hepatitis B surface antigen(HBsAg) vaccines using the techniques such as isolation from plasma of chronic HBsAg carrier, recombinant DNA technique or preparation of synthetic peptides specific for immunogenic determinants. Hepatitis B virus can not grow on any cell lines by the tissue culture technique at the present time. The plasma of chronic HBsAg carrier is expensive and its source is limited. The HBsAg from the recombinant DNA technique gave still very low yield. Another approach, therefore, has been initiated to develop a synthetic hepatitis B virus vaccine. The possible use of several distinct synthetic vaccines in prophylaxis can be facilitated by availability of full synthetic immunogens. Peptides synthesized for potential application as antiviral vaccines have been mostly tested in the form of conjugates with carrier proteins, although the free synthetic peptide can be immunogenic. To understand basic knowledges on the antigenicity and immunogenicity of a synthetic peptide specific for major immunogenic determinant of HBsAg, a nonapeptide, $H_2N^{139}Cys-Thr-Lys-Pro-Thr-Asp-Gly-^{146}Asn-Aba$ COOH, which corresponds to HBsAg amino acid residues 139 to 147, was synthesized by the Merrifield's solid-phase method with a slight modification. The antigenicity and immunogenicity of this specific synthetic peptide were examined comparing with purified plasma-derived natural HBsAg. The results obtained are as follows; 1. The peptide synthesized showed the identical amino acid composition to the theoretical value. The degree of purification and molecular weight were acertained by methods of high performance liquid chromatography and mass spectrometry. 2. Using m-maleimidobenzoyl-N-hydroxysuccinimide ester as a conjugating agent, the synthetic peptide was conjugated to rabbit albumin and ${\gamma}$-globulin, tetanus and diphtheria toxoids, and keyhole limpet hemocyanin. Their conjugation yields were 8.3, 9.5, 15.8, 13.5, and 11.2%, respectively. 3. The natural HBsAg was purified from plasma of chronic HBsAg carrier. By the electron microscopic observation of the purified natural HBsAg preparation, no Dane particles were observed and the preparation showed negative DNA polymerase activity. 4. Antigenicity of the synthetic peptide and the plasma-derived natural HBsAg was determined by competition radioimmunoassay using $^{125}I$-natural HBsAg. Their 50% inhibitions appeared as $90{\mu}g/ml$ and $0.12{\mu}g/ml$ for the synthetic peptide and the natural HBsAg, respectively. This indicates that the former was about 750-fold less antigenic than the latter. 5. Immunogenicity of the synthetic peptide was determined by administering the peptide-carrier conjugates into rabbits with and without Freund's complete adjuvant. Regardless the carrier proteins and adjuvant, positive immune responses to the synthetic peptide were observed. The higher antibody titers, however, were shown in the groups administered with Freund's complete adjuvant. 6. Immunizing dose 50% in mice of the various peptide-carrier conjugates was 5.47, 6.00, 65.16, 31.25 and $13.03{\mu}g/dose$ for rabbit albumin and ${\gamma}$-globulin, tetanus and diphtheria toxoids, and keyhole limpet hemocyanin, respectively, while the natural HBsAg showed $0.65{\mu}g/dose$. 7. It was postulated that homologous proteins prefer to heterologous ones as the carriers.