• Radiation Oncology Journal
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• v.19 no.2
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• pp.171-180
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• 2001

Purpose : Expression of TIMP, intrinsic inhibitor of MMP, is regulated by signal transduction in response to genotoxins and is likely to be an important step in metastasis, angiogenesis and wound healing after ionizing radiation. Therefore, we studied radiation mediated TIMP expression and its mechanism in head and neck cancer cell lines. Materials and Methods : Human head and neck cancer cell lines established at Asan Medical Center were used and radiosensitivity $(D_0)$, radiation cytotoxicity and metastatic potential were measured by clonogenic assay, n assay and invasion assay, respectively. The conditioned medium was prepared at 24 hours and 48 hours after 2 Gy and 10 Gy irradiation and expression of TIMP protein was measured by Elisa assay with specific antibodies against human TIMP. hTIMP1 promoter region was cloned and TIMP1 luciferase reporter vector was constructed. The reporter vector was transfected to AMC-HN-1 and -HN-9 cells with or without expression vector Ras, then the cells were exposed to radiation or PMA, PKC activator. EMSA was peformed with oligonucleotide (-59/-53 element and SP1) of TIMP1 promoter. Results : $D_0$ of HN-1, -2, -3, -5 and -9 cell lines were 1.55 Gy, 1.8 Gy, 1.5 Gt, 1.55 Gy and 2.45 Gy respectively. n assay confirmed cell viability, over $94\%$ at 24hrs, 48hrs after 2 Gy irradiation and over 73% after 10 Gy irradiation. Elisa assay confirmed that cells secreted TIMP1, 2 proteins continuously. After 2 Gy irradiation, TIMP2 secretion was decreased at 24hrs in HN-1 and HN-9 cell lines but after 10 Gy irradiation, it was increased in all cell lines. At 48hrs after irradiation, it was increased in HN-1 but decreased in HN-9 cells. But the change in TIMP secretion by RT was mild. The transcription of TIMP1 gene in HN-1 was induced by PMA but in HN-9 cell lines, it was suppressed. Wild type Ras induced the TIMP-1 transcription by 20 fold and 4 fold in HN-1 and HN-9 respectively. The binding activity to -59/-53, AP1 motif was increased by RT, but not to SP1 motif in both cell lines. Conclusions : We observed the difference of expression and activity of TIMPs between radiosensitive and radioresistant cell line and the different signal transduction pathway between in these cell lines may contribute the different radiosensitivity. Further research to investigate the radiation response and its signal pathway of TIMPs is needed.

• Magazine of the Korean Society of Agricultural Engineers
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• v.21 no.4
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• pp.99-107
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• 1979

In order to investigate the utilization of industrial waste and briquette ash for concrete production, briquette ash was used as fine aggregate for mortar production and three different kinds mortars were produced by mixing carbide and bottom aches with cement. These products were compared with mortar, produced by standard sand, in the respects of compressive, tensil and bending strengths. Further study on the economic aspect of utilization of briquette ash is needed but the results obtained from our preliminary study are summarized as follows : 1. The compressive strengths at the age of seven days of mortars, made of one to two ratios of cement to briquette ash, (cement+carbide ash) to briquette ash and(cement+bottom ash) to briquette ash were 70%, 61% and 58%, respectively, of the mortar made of standard sand. The compressive strengths of those mortars at the age of 28 days were 56%, 49% and 48% of the mortar made standard sand. 2. The compressive strengths at the age of seven days of the mortar made of one to two ratios of cement to briquette ash, (cement+carbide ash) to briquette ash and (cement+bottom ash) to briquette ash were 84%, 73%, and 70% of the mortar which was produced according to Korean Standard Value. The compressive strengths of those mortars at the age of 28 days were 85%, 73% and 73% of the mortar of the Korean Standard value. 3. The tensil strengths at the age of seven days of the mortars made of one to two ratios of cement to briquette ash, (cement+carbide ash) to briquette ash, and (cement+bottom ash) to briquette ash were 64%, 36%, and 36%, respectively, of the mortar of standard sand. The tensil strengths of those mortars at the age of 28 days were 70%, 47%, and 39%, respectively, of the standard mortar. The mortars made of one to two ratios of cement to briquette ash at the age of seven and 28 days were higher than the mortars of Korean Standard. The other mortars were 61 to 62% at the age of seven days and 75 to 90% at the age of 28 days of the Korean Standard mortar, respectively. 4. The bending strengths at the age of seven days of mortar made of one to two ratios of cement to briquette ash, (cement+carbide ash) to briquette ash, and (cement+bottom ash) to briquette ash were 46%, 53% and 50% of the mortar of standard sand. The bending strengths of those mortars at the age of 28 days were 90%, 77% and 69%, respectively of the mortar of standard sand. 5. The mortar of briquette ash which was lower in strengths compared with the mortar of cement have shown possibility of its secondary products of cement and concrete. The uses of briquette ash and industrial waste as construction materials would contribute toward solving various pollution problems caused by industrial wastes and saving labor costs needed to cleaning up. Furthermore, the effective use of briquette ash would greatly save the aggregate resources.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.534-539
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• 2006

In the ozone disinfection unit process of a piston type batch reactor with continuous ozone analysis using a flow injection analysis (FIA) system, the CT values for 1 log inactivation of Cryptosporidium parvum by viability assays of DAPI/PI and excystation were $1.8{\sim}2.2\;mg/L{\cdot}min$ at $25^{\circ}C$ and $9.1mg/L{\cdot}min$ at $5^{\circ}C$, respectively. At the low temperature, ozone requirement rises $4{\sim}5$ times higher in order to achieve the same level of disinfection at room temperature. In a 40 L scale pilot plant with continuous flow and constant 5 minutes retention time, disinfection effects were evaluated using excystation, DAPI/PI, and cell infection method at the same time. About 0.2 log inactivation of Cryptosporidium by DAPI/PI and excystation assay, and 1.2 log inactivation by cell infectivity assay were estimated, respectively, at the CT value of about $8mg/L{\cdot}min$. The difference between DAPI/PI and excystation assay was not significant in evaluating CT values of Cryptosporidium by ozone in both experiment of the piston and the pilot reactors. However, there was significant difference between viability assay based on the intact cell wall structure and function and infectivity assay based on the developing oocysts to sporozoites and merozoites in the pilot study. The stage of development should be more sensitive to ozone oxidation than cell wall intactness of oocysts. The difference of CT values estimated by viability assay between two studies may partly come from underestimation of the residual ozone concentration due to the manual monitoring in the pilot study, or the difference of the reactor scale (50 mL vs 40 L) and types (batch vs continuous). Adequate If value to disinfect 1 and 2 log scale of Cryptosporidium in UV irradiation process was 25 $mWs/cm^2$ and 50 $mWs/cm^2$, respectively, at $25^{\circ}C$ by DAPI/PI. At $5^{\circ}C$, 40 $mWs/cm^2$ was required for disinfecting 1 log Cryptosporidium, and 80 $mWs/cm^2$ for disinfecting 2 log Cryptosporidium. It was thought that about 60% increase of If value requirement to compensate for the $20^{\circ}C$ decrease in temperature was due to the low voltage low output lamp letting weaker UV rays occur at lower temperatures.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.2
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• pp.103-110
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• 1986

The experiments were carried out to study the influence of meteorological factors and cutting management on dry matter accumulation and net energy value in orchardgrass (Dactlylis glomerata L.) cv. Potomac and Baraula, perennial ryegrass (Lolium perenne L.) cv. Reveille and Semperweide and meadow fescue (Festuca pratensis Huds.) cv. Cosmos 11 and N.F.G.. The field trials were designed as a split plot design with three cutting regimes of 6-7 cuts at grazing stage, 4-5 cuts at silage stage and 3 cuts at hat stage in Korea and West Germany from 1975 to 1979. The results obtained are summarized as follows: 1. Productivity of orchardgrass, perennial ryegrass and meadow fescue were mainly affected by cutting systems and meteorological factors, especially air temperature, rainfalls, solar radiation and their interactions. In West Germany, cutting frequency was to be found asan most important factor influenced to dry matter yield and net energy value. 2. Orchardgrass, taken as average of all experimental sites in Korea, produced high yield of 875 kg/10 a in dry matter, which was as much as 32% and 27% higher than those of perennial ryegrass and meadow fescue, respectively. The annual dry matter yields of orchardgrass from 1976 to 1977 were shown a little variation. Dry matter yields in Freising and Braunschweig in West Germany were increased in all grass species continuously. 3. Orchardgrass, perennial ryegrass and meadow fescue showed different response to cutting frequency. The highest dry matter yields were found under 3 cuts at hay stage for orchardgrass and 4-5 cuts at silage stage for perennial ryegrass and meadow fescue. In West Germany, dry matter yields, as average of all grass species under different cutting systems, were 1326 kg, 1175 kg and 1098 kg/10a for 3 cuts, 4-5 cuts and 6-7 cuts, respectively. 4. Chemical composition and net energy concentration of temperate grasses were influenced by cutting managements. The highest yields of digestible crude protein were obtained under 6-7 cuts at grazing stage both in Korea and West Germany. In net energy yields, 3 cutting system produced the highest yield with 694 (orchardgrass), 665 (perennial ryegrass) an 623 kStE/10 a (meadow fescue). However, frequent cutting at grazing and silage stage produced higher yields than 3 cuts at hay stage in Cheju, Suweon and Taekwalyong.

• Applied Biological Chemistry
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• v.27
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• pp.29-46
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• 1984

To utilize several species of hard wood as raw materials of feed products, fermentation characteristics of cellulosic substrates to single cell protein was investigated, and results were summarized as follows. Among the microorganisms investigated, Tricoderma viride was selected as one of the most cellulolytic. Mixed culture of fungi did not show a synergistic effect on cellulose degradation. When the fungi were cultured at $28^{\circ}C$ for 7 days in a medium containing wheat bran 25 g, cellulose 0.25 g, proteose peptone 0.025 g and tween 800.025 g, cellulotic activities on carboxy methyl cellulose and filter paper reached maximum at 12 hr. The alkali treatment resulted in increased degradation of substrate from 13 to 18% when treated with enzymes for 12h, and reducing sugar formation increased with decreased size of substrates. Glucose was a very good feedback inhibitor of the enzyme from T.viride than that of xylose. When the substrate was rehydrolyzed, hydrolysis rate was 31% to reducing sugars within 12 hr. Quantative anlysis with HPLC showed the ratio of glucose to xylose in sugar syrups as 1.77 to 1. For the purpose of producing cellulosic-single cell protein from the sawdust of mulberry tree, 15 strains of xylose-assimilating yeast were isolated from 42 samples of rotten woods and compost soils and examined for their ability to utilize xylose. Then three strains were selected by their strong xylose-assimilating activities. The cultivative condition, the growth characteristics, and protein and nucleic acid productivities of three strains were investigated. The results obtained were, 1. Wood hydrolysate of mulberry tree was assimilated by 5 strains of CHS-2, CHS-3, ST-40, CHS-12 and CHS-13. 2. The optimum initial pH and temperature for the growth of strain CHS-13 were 4.4 and $30^{\circ}C$. 3. The specific growth rate of strain CHS-13 was $0.23h^{-1}$ and generation time was 3.01 hrs at the optimum condition. 4. CHS-13 strain assimilated 81 % of sugar in wood hydrolysate. 5. CHS-13 strain was identified as Candida guilliermondii var. guilliermondii 6. When the CHS-13 strain was cultured in the wood hydrolysate containing yeast extract, L-protein content was increased with yeast extract concentration. 7. The L-protein and nucleic acid yields from wood hydrolysate were 0.73 mg/ml and $4.92{\times}10^{-2}\;mg/ml$ respectively. 8. An optimal nucleic acid content of CHS-13 strain was observed in the medium containing 0.2% of yeast extract.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.5
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• pp.549-556
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• 2006

The purpose of this study was to assess the effects of mulberry leaf extract supplement on blood glucose, glycated hemoglobin ($HbA_{1C}$) and serum lipids in type II diabetic patients, and also to assess safety in liver function after mulberry leaf extract supplement. The study was a randomized placebo-controlled trial and total 23 type II diabetic patients were divided into a MLE group taking 1,000 mg mulberry leaf extract supplement per day as experimental group and a placebo group taking 1,000 mg cellulose Powder supplement per day for 12 weeks. After 2 weeks of wash-out period, fasting blood glucose, $HbA_{1C}$, serum lipid levels and liver function test were analyzed before and after treatment of 12 weeks. The general baseline characteristics, nutrient intake and life style factors of study subjects were similar between two groups during intervention. The concentrations of fasting blood glucose and $HbA_{1C}$ (p<0.05) decreased significantly after mulberry leaf extract supplement in MLE group, while there were no changes found in placebo group. We also found it showed that mulberry leaf extract supplement for 12 weeks decreased significantly (p<0.05) the fasting blood glucose in poor fasting blood glucose group and $HbA_{1C}$ concentration in poor $HbA_{1C}$ group. The concentrations of LDL-cholesterol (p<0.05) and triglyceride (p<0.01) decreased significantly in MLE group after 12 weeks of taking the supplement, while there were no changes found in placebo group. The mulberry leaf extract supplement for 12 weeks didn't show hepatotoxicity. These results suggested that mulberry leaf extract supplement could be effective in improving fasting blood glucose and $HbA_{1C}$ levels in the diabetic patients, specially having high concentrations of fasting blood glucose and $HbA_{1C}$ among type II diabetic patients.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.399-415
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• 1999

From bacteria to mammalian cells, one of the most important mediators of intracellular signal transduction mechanisms which regulate a variety of intracellular processes is free calcium. In salivary acinar cells, elevation of intracellular calcium concentration ($[Ca^{2+}]_i$) is essential for the salivary secretion induced by parasympathetic stimulation. However, in addition to $[Ca^{2+}]_i$, gap junctions which couple individual cells electrically and chemically have also been reported to regulate enzyme secretion in pancreatic acinar cells. Since the plasma membrane of salivary acinar cells has a high density of gap junctions, and these cells are electrically and chemically coupled with each other, gap junctions may modulate the secretory function of salivary glands. In this respect, I planned to investigate the role of gap junctions in the modulation of salivary secretion and $[Ca^{2+}]_i$, using mandibular salivary glands of rats. In order to measure the salivary flow rate, fluid was collected from the cannulated duct of the isolated perfused rat mandibular glands at 2 min intervals. $[Ca^{2+}]_i$, was measured from the cells loaded with fura-2 by spectrofluorometry. The results obtained were as follows: 1. CCh-induced salivary secretion was reversibly inhibited by 1 mM octanol, a gap junction blocker. 2. CCh-induced increase in $[Ca^{2+}]_i$, was also reversed by the application of 1 mM octanol. 3. Octanol did not block the initial increase in $[Ca^{2+}]_i$ caused by CCh, which suggested that the reduction of $[Ca^{2+}]_i$, caused by gap junction blockade was not resulted from the inhibition of $Ca^{2+}$ release from intracellular $Ca^{2+}$ stores. 4. Addition of octanol during stimulation with $1{\mu}M$ thapsigargin, a potent microsomal ATPase inhibitor, reduced $[Ca^{2+}]_i$, to the basal level. This suggested that inhibition of gap junction permeability closed plasma membrane $Ca^{2+}$ channels. 5. 2,5-di-tert-butyl-1,4-benzohydroquinone (TBQ) generated $[Ca^{2+}]_i$ oscillations resulting from periodic influx of $Ca^{2+}$ via plasma membrane. The TBQ-induced $[Ca^{2+}]_i$ oscillations were stopped by the application of 1mM octanol which implicated that gap junctions modulate the permeability of plasma membrane $Ca^{2+}$ channels. 6. Glycyrrhetinic acid, another well known gap junction blocker, also inhibited CCh-induced salivary secretion from rat mandibular glands. These results suggested that gap junctions play an important role in the modulation of fluid secretion from the rat mandibular glands and this was probably due to the inhibition of $Ca^{2+}$ influx through the plasma membrane $Ca^{2+}$ channels.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.377-398
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• 1999

Calcium fluoride, created by topical fluoride application, is the reservoir for fluoride ion regulated by pH in the oral environment. Therefore, the amount and the maintenance of calcium fluoride have an important role in preventing dental caries. The aim of this study is to evaluate the effect of Nd:YAG laser irradiation on the generation of calcium fluoride and the acid resistance of tooth enamel. The bovine anterior permanent teeth were prepared (n=276), and divided into following groups : no treatment (control) fluoride application alone, laser irradiation alone, laser irradiation after fluoride application, and fluoride application after laser irradiation. And each group was subdivided based on the application time of 1.23% acidulated phosphate fluoride (APF) (5 min and 30 min) and the irradiation energy of Nd:YAG laser ($20J/cm^2\;and\;40J/cm^2$). In case of fluoride application, each group was divided according to KOH treatment. Twenty three treatment conditions were made for this experiment and twelve specimens were assigned to each treatment condition. In each treatment condition, ten specimens were used for chemical analysis and two specimens were observed under SEM. In groups without treating KOH, fluoride content and the depth of enamel dissolved were measured using enamel biopsy technique. In groups with treating KOH, the amount of calcium fluoride was measured by the treatment with 1 M KOH for 24 hours and enamel biopsy was performed after KOH treatment. The results were analyzed by the fluoride content and the depth of enamel dissolved by enamel biopsy, amount and thickness of calcium fluoride, and the surface structures of enamel. The results are as follows: 1. In groups without treating KOH, the fluoride content of removed enamel showed a positive relationship with the energy density of laser when the laser irradiated before fluoride application 2. In groups without treating KOH, the depth of enamel dissolved decreased more with the combined laser and fluoride treatment than with laser or fluoride treatment, except for the case of $20J/cm^2$ laser irradiation after 5 minute fluoride application (p<0.05). 3. The amount of calcium fluoride did not increased by laser treatment with no statistical significance(p>0.05). 4. The particle size of calcium fluoride increased in case of fluoride treatment after laser irradiation, compared with fluoride application alone. In case of laser treatment after fluoride application, the particle size of calcium fluoride increased and some of the particles fused as well. 5. There were no significant differences in the fluoride content of dissolved enamel between groups without treating KOH and control group, except for the case of laser irradiation after treatment of APF for 30 minutes (p>0.05). 6. In groups with treating KOH, depth of removed enamel in the groups of combined treatment with laser and fluoride was shallower than that in fluoride application groups (p<0.05). 7. In groups without treating KOH, the relationship between fluoride content and the depth of enamel dissolved showed more negative (Spearman correlation coefficient: -0.6281) than in groups with treating KOH (Spearman correlation coefficient: -0.3792). The greater amount of calcium fluoride could be found in case where there was a significant differences of the depth of enamel dissolved between groups with and without treating KOH. From these results, it can be concluded that laser seems to be a little effects on the amount of calcium fluoride formation, but has some effect on the lowering the solubility of calcium fluoride. As the combined treatment of laser and fluoride application showed more effective acid-resistant property, more extended recall period for fluoride application can be achieved with this combined treatment in the clinic.

• The Korean Journal of Air & Space Law and Policy
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• v.20 no.1
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• pp.9-43
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• 2005

The Korean government established her first "National Space Program" in 1996, and revised it in 2000 and 2005. As embedded in the National Space Program, Korea aims to become one of the world's top countries in space technology by 2010. All of 13 satellites are planned to be put into orbit as schematized, which include 7 multi-purpose satellites, 4 science satellites and 2 geostationary orbit satellites. The Space Center in Korea is to be built at Woinara-Do, Bongrae-Myon, Koheung-Goon, Junlanam Province on the southern coast of the Korean peninsular. The first phase of the construction of the space center will be finished by 2007 for launch of KSLV-l. This will make Korea be the 13th advanced country in space development having a launching site in the world. The "Space Center" will serve as the infrastructure for the development of space technology and related technology, and plan to launch a low earth orbit satellite in 2007. A second science satellite made in Korea will be launched from the space center by 2007. From 2010, the center will be operated on a commercial basis operating launch facilities for low-to mid-altitude orbit satellites. Since the 'Aircraft Industry Promotion Act' was replaced by the 'Aerospace Industry Development Promotion Acf of 1987, this Act had been amended seven times from 1991 year to 2004. Most of developed countries has been enacted the space law including the public or private items such as an (1)DSA, (2)Russia, (3)the United Kingdom, (4)Germany, (5)France, (6)Canada, (7)Japan, (8)Sweden, (9)Australia, (10)Brazil, (11)Norway, (12)South Africa, (13)Argentina, (14)Chile, (15)Ukrainian etc. As the new Space Exploration Promotion Act was passed by the resolution of the Korean Congress on May 3, 2005, so the Korean government has made the public proclamation the abovementioned Act on May 31, this year. This Act takes effect on December 1, 2005 after elapsing six months from the date of promulgation. The main contents of Space Exploration Promotion Act of 2005 is as the following (1)establishing a basic plan for promoting space exploration, (2)establishment and function of national space committee, (3)procedure and management of domestic and international registration of space objects, (4)licensing of launch by space launch vehicles, (5)lability for damages caused by space accidents and liability insurance, (6) organizing and composition of the space accident investigation committee, (7)Support of non-governmental space exploration project, (8)Requesting Support and Cooperation of Space Exploration, (9)Rescue of Astronauts and Restitution of Space Objects, etc.. In oder to carry out successfully the medium and long basic plan for promoting space exploration and to develope space industry in Korea, I think that it is necessary for us to enlarge and to reorganize the function and manpower of the Space Technology Development Division of the Ministry of Science & Technology and the Korea Aerospace Research Institute. Korea has been carrying out its space program step by step according to the National Space Program. Korea also will continually strengthen the exchange and cooperation with all the countries in the world under the principle of equality, friendship relations and mutual benefits. Together with all other peoples around the globe, Korea will make due contribution towards the peaceful utilization of space resources and promotion of human progress and prosperity.

• Tuberculosis and Respiratory Diseases
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• v.42 no.3
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• pp.361-369
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• 1995

Background: A number of different weaning techniques can be employed such as spontaneous breathing trial, Intermittent mandatory ventilation(IMV) or Pressure support ventilation(PSV). However, the conclusive data indicating the superiority of one technique over another have not been published. Usually, a conventional spontaneous breathing trial is undertaken by supplying humidified $O_2$ through T-shaped adaptor connected to endotracheal tube or tracheostomy tube. In Korea, T-tube trial is not popular because the high-flow oxygen system is not always available. Also, the timing of extubation is not conclusive and depends on clinical experiences. It is known that to withdraw the endotracheal tube after weaning is far better than to go through any period. The tube produces varying degrees of resistance depending on its internal diameter and the flow rates encountered. The purpose of present study is to evaluate the effectiveness of weaning and extubation following a 60 minutes spontaneous breathing trial with simple oxygen supply through the endotracheal tube. Methods: We analyzed the result of weaning and extubation following a 60 minutes spontaneous breathing trial with simple oxygen supply through the endotracheal tube in 18 subjects from June, 1993 to June, 1994. They consisted of 9 males and 9 females. The duration of mechanical ventilation was from 38 hours to 341 hours(mean: $105.9{\pm}83.4$ hours). In all cases, the cause of ventilator dependency should be identified and precipitating factors should be corrected. The weaning trial was done when the patient became alert and arterial $O_2$ tension was adequate($PaO_2$ > 55mmHg) with an inspired oxygen fraction of 40%. We conducted a careful physical examination when the patient was breathing spontaneously through the endotracheal tube. Failure of weaning trial was signaled by cyanosis, sweating, paradoxical respiration, intercostal recession. Weaning failure was defined as the need for mechanical ventilation within 48 hours. Results: In 19 weaning trials of 18 patients, successful weaning and extubation was possible in 16/19(84.2 %). During the trial of spontaneous breathing for 60 minutes through the endotracheal tube, the patients who could wean developed slight increase in respiratory rates but significant changes of arterial blood gas values were not noted. But, the patients who failed weaning trial showed the marked increase in respiratory rates without significant changes of arterial blood gas values. Conclusion: The result of present study indicates that weaning from mechanical ventilation following a 60 minutes spontaneous breathing with $O_2$ supply through the endotracheal tube is a simple and effective method. Extubation can be done at the same time of successful weaning except for endobronchial toilet or airway protection.