• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.8 no.1
• /
• pp.129-177
• /
• 1970

For the purpose of establishing the systematized technical scheme of the cooperative rice cultivation which has most significant impact to improve rice productivity and the farm management, the author have studied the cultivation practices, and the variation of rice growth and yield between the cooperative rice cultivation and the individual rice cultivation at random selected 18 paddy fields. The author also have investigated through comparative method on the cultivation practices, management, organization and operation scheme of the two different rice cultivation methods at 460 paddy fields. The economic feasibility has been ana lysed and added in this report. The results obtained from this study are summarized as follows; 1. In the nursery, the average amount of fertilizer application, especially, phosphate and potassium, and the frequency of chemicals spray for the disease, insect and pest control at the cooperative rice cultivation are significantly higher than those of the individual rice cultivation. 2. The cultivation techniques of the cooperative rice farming after the transplanting can be characterized by a) the earlier transplanting of rice, b) the denser hills per unit area and the lesser number of seedlings per hill, c) the application of larger quantities of fertilizer including nitrogen, phosphate and potassium, d) more divided application of fertilizers, split doses of the nitrogen and potassium, e) the increased frequencies of the chemicals spray for the prevention of disease, insect and pest damages. 3. The rate of lodging in the cooperative rice cultivation was slightly higher than that of the individual rice cultivation, however, the losses of rice yield owing to the occurrence of rice stem borer and grass leaf roller in the cooperative rice cultivation were lower than that of the individual rice cultivation. 4. The culm length, panicle length, straw weight and grain-straw ratio are respectively higher at the cooperative rice cultivation, moreover, the higher variation of the above factors due to different localities of the paddy fields found at the individual rice cultivation. 5. The number of panicles, number of flowers per panicle and the weight of 1, 000 grains, those contributing components to the rice yield were significantly greater in the cooperative rice cultivation, however, not clear difference in the maturing rate was observed. The variation coefficient of the yield component in the cooperative cultivation showed lower than that or the individual rice cultivation. 6. The average yield of brown rice per 10 are in the cooperative rice cultivation obtained 459.0 kilograms while that of the individual rice cultivation brought 374.8 kilograms. The yield of brown rice in the cooperative rice cultivation increased 84.2 kilogram per 10 are over the individual rice cultivation. With lower variation coefficient of the brown rice yield in the cooperative rice cultivation, it can be said that uniformed higher yield could be obtained through the cooperative rice cultivation. 7. Highly significant positive correlations shown between the seeding date and the number of flowers per panicle, the chemical spray and the number of flowers per panicle, the transplanting date and the number of flowers per panicle, phosphate application and yield, potassium application and maturing rate, the split application of fertilizers and yield. Whilst the significant negative correlation was shown between the transplanting date and the maturing rate 8. The results of investigation from 480 paddy fields obtained through comparative method on the following items are identical in general with those obtained at 18 paddy fields: Application of fertilizers, chemical spray for the control of disease, insects and pests both in the nursery and the paddy field, transplanting date, transplanting density, split application of fertilizers and yield n the paddy fields. a) The number of rice varieties used in the cooperative rice cultivation were 13 varieties while the individual rice cultivation used 47 varieties. b) The cooperative rice cultivation has more successfully adopted improved cultivation techniques such as the practice of seed disinfection, adoption of recommended seeding amount, fall ploughing, application of red soil, introduction of power tillers, the rectangular-type transplanting, midsummer drainage and the periodical irrigation. 9. The following results were also obtained from the same investigation and they are: a) In the cooperative rice cultivation, the greater part of the important practices have been carried out through cooperative operation including seed disinfection, ploughing, application of red soil and compost, the control of disease, insects and pests, harvest, threshing and transportation of the products. b) The labor input to the nursery bed and water control in the cooperative rice cultivation was less than that of the individual rice cultivation while the higher rate of labor input was resulted in the red soil and compost application. 10. From the investigation on the organization and operation scheme of the cooperative rice cultivation, the following results were obtained: a) The size of cooperative rice cultivation farm was varied from. 3 ha to 7 ha and 5 ha farm. occupied 55.9 percent of the total farms. And a single cooperative farm was consisted of 10 to 20 plots of paddies. b) The educational back ground of the staff members involved in the cooperative rice cultivation was superior than that of the individual rice cultivation. c) All of the farmers who participated to the questionaires have responded that the cooperative rice cultivation could promise the increased rice yield mainly through the introduction of the improved method of fertilizer application and the effective control of diseases, insects and pests damages. And the majority of farmers were also in the opinion that preparation of the materials and labor input can be timely carried out and the labor requirement for the rice cultivation possibly be saved through the cooperative rice cultivation. d) The farmers who have expressed their wishes to continue and to make further development of the cooperative rice cultivation was 74.5 percent of total farmers participated to the questionaires. 11. From the analysis of economical feasibility on the two different methods of cultivation, the following results were obtained: a) The value of operation cost for the compost, chemical fertilizers, agricultural chemicals and labor input in the cooperative rice cultivation was respectively higher by 335 won, 199 won, 288 won and 303 won over the individual rice cultivation. However, the other production costs showed no distinct differences between the two cultivation methods. b) Although the total value of expenses for the fertilizers, agricultural chemicals, labor input and etc. in the cooperative rice cultivation were approximately doubled to the amount of the individual rice cultivation, the net income, substracted operation costs from the gross income, was obtained 24, 302 won in the cooperative rice cultivation and 20, 168 won was obtained from the individual rice cultivation. Thereby, it can be said that net income from the cooperative rice cultivation increased 4, 134 won over the individual rice cultivation. It was revealed in this study that the cooperative rice cultivation has not only contributed to increment of the farm income through higher yield but also showed as an effective means to introduce highly improved cultivation techniques to the farmers. It may also be concluded, therefore, the cooperative rice cultivation shall continuously renovate the rice production process of the farmers.

• Journal of Chest Surgery
• /
• v.41 no.6
• /
• pp.679-686
• /
• 2008

Background: Cellular remnants in the bioprosthetic heart valve are known to be related to a host's immunologic response and they can form the nidus for calcification. The extracellular matrix of the decellularized valve tissue can also be used as a biological scaffold for cell attachment, endothelialization and tissue reconstitution. Thus, decellularization is the most important part in making a bioprosthetic valve and biological caffold. Many protocols and agents have been suggested for decellularization, yet there ave been few reports about the effect of a treatment with hypotonic solution prior to chemical or enzymatic treatment. This study investigated the effect of a treatment with hypotonic solution and the appropriate environments such as temperature, the treatment duration and the concentration of sodium dodecylsulfate (SDS) for achieving proper decellularization. Material and Method: Porcine aortic valves were decellularized with odium dodecylsulfate at various concentrations (0.25%, 0.5%), time durations (6, 12, 24 hours) and temperatures ($4^{\circ}C$, $20^{\circ}C$)(Group B). Same the number of porcine aortic valves (group A) was treated with hypotonic solution prior to SDS treatment at the same conditions. The duration of exposure to the hypotonic solution was 4, 7 and 14 hours and he temperature was $4^{\circ}C$ and $20^{\circ}C$, respectively. The degree of decellularization was analyzed by performing hematoxylin and eosin staining. Result: There were no differences in the degree of decellularization between the two concentrations (0.25% 0.5%) of SDS. Twenty four hours treatment with SDS revealed the best decellularization effect for both roups A and B at the temperature of $4^{\circ}C$, but there was no differences between the roups at $20^{\circ}C$. Treatment with hypotonic solution (group A) showed a better ecellularization effect at all the matched conditions. Fourteen hours treatment at $4^{\circ}C$ ith ypotonic solution prior to 80S treatment revealed the best decellularization effect. The treatment with hypotonic solution at $20^{\circ}C$ revealed a good decellularization effect, but his showed significant extracellular matrix destruction. Conclusion: The exposure of porcine heart valves to hypotonic solution prior to SDS treatment is highly effective for achieving decellularization. Osmotic treatment with hypotonic solution should be considered or achieving decellularization of porcine aortic valves. Further study should be carried out to see whether the treatment with hypotonic solution could reduce the exposure duration and concentration of chemical detergents, and also to evaluate how the structure of the extracellular matrix of the porcine valve is affected by the exposure to hypotonic solution.

• Tuberculosis and Respiratory Diseases
• /
• v.58 no.6
• /
• pp.590-599
• /
• 2005

Object : Cigarette smoking is a major cause of mucus hypersecretion, which is a pathophysiological feature of many inflammatory airway diseases. Mucins, which are an important part of the airway mucus, are synthesized from the Muc gene in airway epithelial cells. However, the signaling pathways for cigarette smoke-induced mucin synthesis are unknown. The aim of this study was to determine the signal pathway for smoking induced Muc5ac gene expression. Methods : A549 cells were cultured and transiently transfected with the Muc5ac promoter fragment. These cells were stimulated with 5% cigarette smoke extract (CSE) alone or with CSE after a pretreatment with various signal transduction pathway inhibitors (AG1478, PD98059 and SB203580). The Muc5ac promoter activity was examined using the luciferase reporter system, and the level of phosphorylated EGFR, ERK1/2, p38 MAPK and JNK were all examined using Western blot analysis. Muc5ac mRNA expression was also examined using reverse transcriptase polymerase chain reactions (RT-PCR). Results : 1. The peak level of luciferase activity of the Muc5ac promoter was observed at 5% concentration and after 3 hours of incubation with the CSE. The level of EGFR phosphorylation and the luciferase activity of the transfected cells caused by the CSE were significantly suppressed by AG1478 or PD98059 (P<0.01). 2. CSE phosphorylated ERK1/2 or p38 MAPK but not JNK. The Muc5ac mRNA expression level was increased by the CSE but that was suppressed by PD98059 or AG1478. 3. The CSE-induced phosphorylation of ERK1/2 was blocked by PD98059 and that of p38 MAPK was blocked by either PD98059 or SB203580. Either PD98059 or SB203580 suppressed the luciferase activity of the transfected cells (P<0.0001). Conclusion : The Muc5ac mRNA expression level was increased by the CSE. The increased CSE-induced transcriptional activity was mediated via EGF receptor activation, which led to ERK1/2 and p38 MAPK phosphorylation.

• Tuberculosis and Respiratory Diseases
• /
• v.63 no.3
• /
• pp.235-241
• /
• 2007

Background: Airway mucus hypersecretion plays an important role in the pathogenesis of asthma, and is associated with the induction of MUC5AC expression in airway secretion. The MUC5AC gene is highly polymorphic; however, there are few studies about the association between the polymorphisms of the MUC5AC gene and asthma susceptibility or asthma phenotypes. We have investigated the association of MUC5AC promoter polymorphisms with the risk of asthma and asthma phenotypes. Methods: We determined the genotypes of the MUC5AC promoter (-1274G>A) in 78 asthma patients and in 78 age, sex-matched control individuals in the Korean population. Genomic DNAs from blood were analyzed by PCR and RFLP (restriction fragment length polymorphism) determination. We examined $FEV_1$, total eosinophil count, serum IgE level, $PC_{20}$ and the presence of atopy (by a skin test) in asthma patients. Results: The mean age of the patients was $47.7{\pm}16.1$ years and 38.5% were men, and the mean $FEV_1$ was $84.4{\pm}22.3%$ of predicted in the asthma patients. The -1274G>A polymorphism of the MUC5AC promoter in asthma patients was not significantly different as compared with normal individuals (GG 57.7%, AG 34.6% and AA 7.7% in asthma patients vs. GG 56.4%, AG 38.5% and AA 5.1% in control subject, p = 0.752, Cod). Several clinical parameters in asthma patients such as $FEV_1$, total eosinophil count, serum IgE level, $PC_{20}$ and the presence of atopy, were not associated with the -1274G>A polymorphism of the MUC5AC promoter. Conclusion: The -1274G>A single nucleotide polymorphism (SNP) frequency of the MUC5AC promoter was not associated with asthma in a Korean population.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.7 no.2
• /
• pp.186-196
• /
• 2004

Purpose: Autoimmune hepatitis is a chronic inflammatory liver disease with unknown cause that is characterized by liver histology, circulating autoantibodies and increased levels of immunoglobulin G. Only sporadic reports are available on autoimmune hepatitis in children. The aim of this study was to evaluate the clinical, biochemical, and histological features, and the long-term outcome of autoimmune hepatitis in Korean children. Methods: We reviewed the medical records of 14 children diagnosed as having autoimmune hepatitis at Seoul National University Children's Hospital from 1990 to 2004, and analyzed clinical, biochemical, and histological features, and clinical outcomes. Results: Mean age at diagnosis was 9 years and 11 of the 14 children were female. Six children presented with acute hepatitis-like manifestations. Jaundice and fatigue were the most common symptoms. Other autoimmune diseases accompanied in 6 children. Anti-nuclear antibody was detected in 13 patients and anti-smooth muscle antibody was positive in 8. All 14 patients were type 1 autoimmune hepatitis. The main histologic findings were interface hepatitis, rosette formation, and cirrhosis. Clinical and biochemical features were improved in six patients treated with ursodeoxycholic acid. Eight patients were treated with corticosteroid alone or in combination with azathioprine and five of them are in biochemical remission. Conclusion: Autoimmune hepatitis is an inflammatory liver disease, which has a favorable long-term outcome if it is diagnosed and treated promptly. Therefore, autoimmune hepatitis should be suspected in children with chronic hepatitis of unknown etiology, especially in female patients who show hypergammaglobulinemia or some clinical features of autoimmune disease.

• Tuberculosis and Respiratory Diseases
• /
• v.44 no.5
• /
• pp.1083-1093
• /
• 1997

Background : So far, there have been numerous reports on organ damage due to cryptococcosis, however, cases of lung localization have been infrequently reported. Recently pulmonary cryptococcosis has been reported more frequently than before due to enhanced diagnostic techniques and increased underlying diseases. Method : The author, therefore, analyzed the clinical manifestations of 5 cryptococcosis cases that we experienced at Hanyang University Hospital from 1985 to 1996 and 9 cases reported in Korea from 1984 and 1996 retrospectively. The following results were obtained. Results : Cryptococcosis occurred frequently over sixth decade and the male to female ratio was 3.6 : 1. Underlying diseases included acute rejection after kidney transplantation, rheumatoid arthritis, autoimmune hepatitis, diabetes mellitus and state of bilateral adrenalectomy. Remaining 8 cases had no evidence of an underlying disease. Because the symptoms were subacute & nonspecific, and not improved by conventional antibiotics, 6 patients of 14 pulmonary cryptococcosis patients were treated as pulmonary tuberculosis before correct diagnosis was made. There were three asymptomatic cases. According to the results of CXR, solitary alveolar consolidation was the most common finding(8 cases) followed by diffuse infiltration(5 cases). It also showed pleural effusion, hilar lymphadenopathy and cavity formation that was rarely reported in world literature. The diagnasis was made through fine needle aspiration biopsy in 10 cases, open thoracotomy in 2 cases, transbronchial lung biopsy in 1 case. and thoracentesis with pleural biopsy in 1 case. Only one case showed positive result in sputum stain and culture, serum latex agglutination test for cryptococcus neoformans. Treatment modalities were various such as fluconazole, amphotericin B, flucytosine, ketoconazole, surgery and it's combination. After 1990 year, there was a trend that fluconazole or ketoconazole are more used than other therapeutic modalities. Conclusion : Because the symptoms are subacute & nonspecific and not improved by conventional antibiotics, pulmonary cryptococcosis is likely to misdiagnosis as pulmonary tuberculosis in Korea. Because the diagnosic yield of sputum stain, culture and serologic test for pulmonary cryptococcosis is low, histologic diagnosis is need in most pulmonary cryptococcosis.

• Tuberculosis and Respiratory Diseases
• /
• v.43 no.4
• /
• pp.571-578
• /
• 1996

Background : Long abscess is an accumulation of pus within a destroyed portion of the lung. Antibiotic therapy and postural drainge has proven to be an effective method of treatment for the majority of patients with pyogenic lung abscess. When medical therapy fails, thoracotomy and pulmonary resection are the current therapies. empyema is pus in the pleural space, and this term is deserved for effusions on which the Gram stain of the pleural fluid is positive. Initially, such collection may be drained via chest tribe. Recently, in patients who are judged to be unsuitable for surgery are in poor condition, percutaneous drainage using pig-tail catheter has been performed. We report out experience with 10 cases of lung abscess and 23 cases of empyema who were treated by percutaneous pit-tail catheter drainage. Subjects and Methods : Our study included 10 patients with lung abscess and 23 patients with empyema who were treated by percutaneous pig-tail catheter drainage, from January, 1990, to May, 1996, at Hanyang University then a pig-tail catheter was inserted into the abscess or the site of empyema under fluoroscopic and ultrasonograpic guidance. Following aspiration, the catheter was sutured into the skin, and connected to the suction tip. Catheter drainage was discontinued when the abscess of empyema was resolved in radiologically and clinically. Results : There were 2 cases of lung abscess caused by Staphylococcus aureus and Klebsiella pneumoniae and 14 cases of empyema caused by M. tuberculosis. The others were unknown. The duration of drainage was 1-2 weeks in 7 cases of lung abscess and 14 cases of empyema. In the 29 of 33 patients, percutaneous drainage were carried out successfully 20 of the 29 Gases rapidly improved. Conclusion : Percutaneous drainge is effective and relatively saute for management of lung abscess or empyema refractory to medical therapy or poor candidates for surgical treatment.

• Journal of Life Science
• /
• v.26 no.11
• /
• pp.1313-1319
• /
• 2016

Cancer is a complex disease heterogeneously composed of various types of cells including cancer stem-like cells responsible for relapse and chemoresistance in the tumor microenvironment. The conventional two-dimensional cell culture-based platform has critical limitations for representing the heterogeneity of cancer cells in the three-dimensional tumor niche in vivo. To overcome this insufficiency, three-dimensional cell culture methods in a scaffold-dependent or -free physical environment have been developed. In this study, we improved and simplified the HCT-8 colon cancer cell-based spheroid culture protocol and evaluated the relationship between cancer stemness and responses of chemosensitivity to 5- Fluorouracil (5-FU), a representative anticancer agent against colon cancer. Supplementation with defined growth factors in the medium and the culture dish of the regular surface with low attachment were required for the formation of constant-sized spheroids containing $CD44^+$ and $CD133^+$ colon cancer stem cells. The chemo-sensitivities of $CD44^+$ cancer stem cells in the spheroids were much lower than those of $CD44^-$ non-stem-like cancer cells, indicating that the chemoresistance to 5-FU is due to the stemness of colon cancer cells. Taken together, the inflammation and oncogenic gut environment-sensitive HCT-8 cell-based colon cancer spheroid culture and comparative evaluation using the simplified model would be an efficient and applicable way to estimate colon cancer stemness and pharmaceutical response to anticancer drugs in the realistic tumor niche.

• Journal of Yeungnam Medical Science
• /
• v.13 no.2
• /
• pp.243-250
• /
• 1996

Extravasation of toxic chemotherapeutic agents cause severe skin ulceration and necrosis which often need secondary surgical intervention. Still, there were not established antidote agent in case of extravasation with mitomycin-c. Dimethyl sulfoxide is known as an effective chemical scavenger of toxic hydroxyl free radical and sodium thiosulfate also was demonstrated significant protector from mitomycin-c induced ulceration by a few experimental studies. Author investigated necrotic area of mitomycin-c injected site and compare to the effectiveness of topical treatment with dimethyl sulfoxide and intradermal injection of sodium thiosulfate according to starting times, forty five mice were divided into 3 groups. Control group(n=5) had no treatment after subcutaneous injection of mitomycin-c. Experimental group I and II were 20 mice treated dimethyl sulfoxide and sodium thiosulfate, respectively. Depending on the starting time of treatment, group I and II were subdivided into 1, 2, 3 and 4 as immediate, 6 hours, 12 hours and 24 hours after mitomycin-c injection. Histologic studies of the necrotic area and survival area after treatment were performed using hematoxylin-eosin staining. The mean necrotic area of group I was significantly decreased depending on the starting time of treatment compared with control group(p<0.01). The results means there was no necrosis area which was treated with topical sodium thiosulfate within 6 hours, and it showed also significant decrease of necrosis area within 24 hours. There was also no necrosis area in group II-1 and significant decrease of necrosis area II-2 and III-3. But, effctiveness of intradermal injection of sodium thiosulfate was not found in group II-4 which was started after 24 hours. Hisotolgic findings showed a bland coagulative necrosis without inflammatory changes and no granulation tissue. The significant difference that cytoplasmic loss of subcutaneous fat and decrease number of hair follicles between two groups resulted from the methods of treatment by topical application and intradermal injection. In conclusion, immediate treatments with topical dimethyl sulfoxide or intradermal injection of sodium thiosulfate signifcantly prevents necrosis by extravasation of mitomycin-c.

• Clinical and Experimental Pediatrics
• /
• v.46 no.12
• /
• pp.1224-1229
• /
• 2003

Purpose : Bacterial meningitis is a serious disease, especially in the neonatal period, and it carries a significant degree of mortality and morbidity. Group B streptococcus(GBS) is a common cause of neonatal bacterial meningitis. The purpose of this study was to evaluate the clinical manifestations, treatment results and complications of GBS meningitis. Methods : We analyzed 29 cases retrospectively who had been admitted to the pediatric ward or NICU in Asan Medical Center from May 1990 to January 2002. They had proven GBS in culture or latex agglutination test in CSF. Results : The male to female ratio was 1 : 1.9. There were two cases of early onset type and 27 cases of late onset type. All cases had normal birth weight with full term at delivery. The perinatal predisposing factors were premature rupture of membrane(two cases), and maternal colonization(two cases). The most common presenting symptoms were fever and irritability. Associated diseases were GBS sepsis(21 cases). There was relatively high sensitivity to penicillin derivatives. There were abnormal brain CT or MRI findings in 16 cases(64%), such as infarction, encephalomalatic change, effusion, hydrocephalus, hemorrhage and abscess. The intensive care unit admission rate and the incidence of DIC were higher in the group with complications. Two cases were discharged against advice. Conclusion : We recommend early detection and active treatment in Group B streptococcal meningitis to improve the prognosis.