• Journal of Sericultural and Entomological Science
• /
• v.10
• /
• pp.35-40
• /
• 1969

Various formulae for estimation of spring leaf production in mulberry trees were calculated and obtained. Four varieties of mulberry trees were used as the materials, and four characters, namely branch length (X$_1$), node number (X$_2$), branch diameter (X$_3$) and branch number per stock (X$_4$) were studied. The formulae to estimate the leaf yield of spring mulberry trees are as follows: 1. $Y_1$v$_1$= -26.8939＋50.3950X$_1$＋1.1403X$_2$ $Y_1$v$_2$= -372.1091＋116.6371X$_1$＋0.1984X$_2$ $Y_1$v$_3$= 149.8203＋90.5125X$_1$-0.9775X$_2$ $Y_1$v$_4$= 108, 1496＋59.4533X$_1$＋1.4965X$_2$ Where $Y_1$v$_1$, $Y_1$v$_2$, $Y_1$v$_3$, $Y_1$v$_4$, are showed the estimated yield of the each variety, namely Gaeryang Seuban, Ilchirye, Nosang, and Suwon Sang No. 4, respectively. X$_1$ and X$_2$ denote the measured values of branch length and node number, respectively. 2. $Y_{7}$v$_1$= -54.4411＋32.9869c1.1127X$_2$＋21.7600X$_3$ $Y_{7}$v$_2$= -494.1480-1.8756X$_1$＋0.9788X$_2$＋110.0039X$_3$ $Y_{7}$v$_3$= 143.2836＋29.1779X$_1$＋0.1644X$_2$＋48.4135X$_3$ $Y_{7}$v$_4$= 1243.2549＋1.9454X$_1$＋2.7118X$_2$-75.6669X$_3$ Where $Y_{7}$v$_1$, $Y_{7}$v$_2$, $Y_{7}$v$_3$, $Y_{7}$v$_4$, are the estimated yield of the each variety, namely Gaeryang-Seuban, Ilchirye, Nosang, Suwon Sang No 4, respectively. X$_1$, X$_2$, X$_3$ denote the measured values of each character, branch length, node number, branch diameter and branch number per stock, respectively. 3. $Y_{11}$v$_1$=233.4780＋74.3713X$_1$＋1.2912X$_2$＋39.0420X$_3$-148.9300X$_4$ $Y_{11}$v$_2$=-317.0150＋15.l524X$_1$＋1.0861X$_2$＋156.7973X$_3$-148.3742X$_4$ $Y_{11}$v$_3$=178.7011＋29.8664X$_1$-0.2562X$_2$＋102.4632X$_3$-83.2693X$_4$ $Y_{11}$v$_4$= 264.0062＋47.7742X$_1$＋2.6996X$_2$＋92.8882X$_3$-192.3464X$_4$ Where $Y_{11}$v$_1$, $Y_{11}$v$_2$, $Y_{11}$v$_3$, $Y_{11}$v$_4$, are the estimated yield values of four varieties, and X$_1$, X$_2$, X$_3$, X$_4$, denote the measured values of four characters, namely branch length, node number, branch diameter and branch number per stock, respectively. The estimation method of mulberry spring leaf yield by measurement of some characters, in autumn the year before, could be the better method to determine the leaf yield of mulberry trees without destroying the leaves and without weighting the leaves of mulberry trees than the other methods.

• Journal of Chest Surgery
• /
• v.38 no.5 s.250
• /
• pp.349-356
• /
• 2005

Background: Arterial conduits using in coronary artery bypass grafting (CABG) have been known a great long term patency rates, and improved short and long term clinical outcomes. It has been reported that Off pump CABG has better clinical results than CABG using cardiopulmonary bypass. To evaluate the advantage of arterial conduits over venous conduits and to avoid the adverse effects of cardiopulmonary bypass, we performed total arterial Off pump CABG. Material and Method: From January 2001 to October 2004, Off pump CABG using only arterial conduits was performed on 325 patients with a mean age of $59.3\pm11.9$ years ($36\~83$). Mean ejection fraction was $55.4\pm14.0\%\;(15\~86).$ Angiography showed left main disease or triple-vessel disease in $81.9\%$ of the patients. Indications of using arterial conduits was stenosis $\ge50\%$ of left anterior descending artery, stenosis $\ge80\%$ of branches of left circumflex artery, and stenosis $\ge90\%$ of right coronary artery and its branches. Multi-slice computed tomography was performed on 194 patients to evaluate the short term patency rates. Result: A total of 928 distal anastomoses were performed and the average anastomoses per a patient were $2.86\pm0.78$. There was 1 operative mortality. Postoperative complications were mediastinitis in 6 patients ($1.8\%$), renal failure in 4 patients ($1.2\%$), perioperative myocardial infarction in 3 patients ($0.9\%$), reoperation for bleeding in 3 patients ($0.9\%$). There was no postoperative stroke. Patency rate of arterial conduits was $99.3\%$ (581/585). There were 4 stenoses or competitive flows in 2 radial arteries and 2 right internal mammary arteries. Conclusion: Total arterial Off pump CABG appears to be safe, showing a low surgical mortality and morbidity and excellent short term patency rates of arterial conduits.

• Journal of Chest Surgery
• /
• v.37 no.2
• /
• pp.119-130
• /
• 2004

Decrease in cardiac function after open heart surgery is due to an ischemia induced myocardial damage during surgery, and ischemic preconditioning, a condition in which the myocardial damage does not accumulate after repeated episodes of ischemia but protects itself from damage after prolonged ischemia due to myocytes tolerating the ischemia, is known to diminish myocardial damage, which also helps the recovery of myocardium after reperfusion, and decreases incidences of arrythmia. Our study is performed to display the ischemic preconditioning and show the myocardial protective effect by applying cardioplegic solution to the heart removed from rat. Material and Method: Sprague-Dawley male rats were used, They were fixed on a modified isolated working heart model after cannulation. The reperfusion process was according to non-working and working heart methods and the working method was executed for 20 minutes in which the heart rate, aortic pressure, aortic flow and coronary flow were measured and recorded. The control group is the group which the extracted heart was fixed on the isolated working heart model, recovered by reperfusion 60 minutes after infusion and preserved in the cardioplegic solution 20 minutes after the working heart perfusion and aortic cross clamp, The thesis groups were divided into group I, which ischemic hearts that were hypoxia induced were perfused by cardioplegic solution and preserved for 60 minutes; group II, the cardioplegic solution was infused 45 seconds (II-1), 1 minutes (II-2), 3 minutes (II-3), after the ischemia induction, 20 minutes after working heart perfusion and aortic cross clamp; and group III, hearts were executed on working heart perfusion for 20 minutes and aortic cross clamp was performed for 45 seconds (III-1), 1minute (III-2), 3 minutes (III-3), reperfused for 2 minutes to recover the heart, and then aortic cross clamping was repeated for reperfusion, all the groups were compared based on hemodynamic performance after reperfusion of the heart after preservation for 60 minutes. Result: The recovery time until spontaneous heart beat was longer in groups I, II-3, III-2 and III-3 to control group (p<0.01). Group III-1 (p<0.05) had better results in terms of recovery in number of heart rates compared to control group, and recovered better compared to II-1 (p<0.05). The recovery of aortic blood pressure favored group III-1 (p<0.05) and had better outcomes compared with II-1 (p<0.01). Group III-1 also showed best results in terms of cardiac output (p<0.05) and group III-2 was better compared to II-2 (p<0.05). Group I (p<0.01) and II-3 (p<0.05) showed more cardiac edema than control group. Conclusion: When the effects of other organs are dismissed, protecting the heart by infusion of cardioplegic solution after enforcing ischemia for a short period of time before the onset of abnormal heart beats for preconditioning has a better recovery effect in the cardioplegic group with preconditioning compared to the cardioplegic solution itself. we believe that further study is needed to find a more effective method of preconditioning.

• Journal of Chest Surgery
• /
• v.37 no.10
• /
• pp.817-826
• /
• 2004

Background: Several studies have demonstrated that conventional hypothermic cardiopulmonary bypass (CPB) causes cellular injury, abnormal responses in peripheral vascular beds and increased postoperative bleeding, whereas normothermic CPB provides protection of the hypothermic-induced effects and better cardiac recovery. The present study was prospectively performed to compare the effects of normothermic CPB to those of hypothermic CPB on the inflammatory and hematologic responses during cardiac surgery. Material and Method: Thirty-four adult patients scheduled for elective cardiac surgery were randomly assigned to hypothermic CPB (nasopharyngeal temperature $26～28^{\circ}C,$ n=17) or normothermic CPB (nasopharyngeal $temperature>35.5^{\circ}C,$ n=17) group. In both groups, cold $(4^{\circ}C)$ crystalloid cardioplegia was applied for myocardial protection. Blood samples were drawn from radial artery before (Pre-CPB), 10 minutes after starting (CPB-10) and immediately after ending (CPB-OFF) CPB. Total leukocyte and platelet counts, interleukin-6 (IL-6) level(expressed as percent to the baseline of Pre-CPB), D-dimer level, protein C and protein S activity were measured with the blood samples. The amount of bleeding for postoperative 24 hours and blood transfusion after operation were also assessed. All parameters were compared between the two groups. Result: The total leukocyte counts $(10,032\pm65/mm^3)$ and the increased ratio of IL-6 $(353\pm7.0%)$ at CPB-OFF in the normothermic group were higher than that $(7,254\pm48/mm^3$ and $298\pm7.3%)$ of the hypothermic group(p=0.02 and p=0.03). In the normothermic group, protein C activity $(32\pm3.8%)$ and protein S activity $(35\pm4.1%)$ at CPB-OFF were significantly lower than that $(45\pm4.3%$ and $51\pm3.8%)$ of the hypothermic group (p=0.04 and p=0.009). However, there were no differences in platelet counts and D-dimer concentration. In the normothermic group, the amount of bleeding for postoperative 24 hours $(850\pm23.2$ mL) and requirements for blood transfusion after operation such as packed cell $(1,402\pm20.5$ mL), fresh frozen plasma $(970\pm20.8$ mL) and platelet $(252\pm6.4$ mL) were higher than that $(530\pm21.5$ mL, $696\pm15.7$ mL, $603\pm18.2$ mL and $50\pm0.0$ mL) of the hypothermic group. Conclusion: These results indicate that normothermic CPB with cold crystalloid cardioplegia was associated with higher increase in inflammatory response, hemostatic abnormalities and postoperative bleeding problem than moderate hypothermic CPB.

• Journal of Chest Surgery
• /
• v.35 no.7
• /
• pp.523-529
• /
• 2002

Background: Previous reports present that the early results of coronary artery bypass grafting (CABG) has been improving with the accumulation of surgical experience. We conducted a retrospective analysis of the patients who received CABG to evaluate the recent results of CABG. Material and Method: Between January 1996 and August 2001, 154 patients underwent CABG at Hanyang University Hospital. There were 47 patients(group I) who were operated between 1996 and 1998, and 107 patients(group II) who were operated thereafter. The preoperative diagnosis, operative procedure, mortality, and complications were analyzed retrospectively. Result: There were 35 males and 12 females in group I, and 78 males and 29 females in group II, which shows similar ratio of sexes between the two groups. The average age of patients for group I and group II was $55.9{\pm}6.2$ years and $61.0{\pm}8.0$ years, respectively, showing a significant increase in group II(p<0.05). The average left ventricular ejection fraction(LVEF) for group I and group II was $54.6{\pm}11.8$% and $56.9{\pm}13.0$%, respectively. The number of patients who had previous MI in group I and group II were 13 patients(27.7%) and 14 patients(13.1%), respectively, which shows a significant difference (p<0.05). All procedures were performed using the cardiopulmonary bypass(CPB) and moderate systemic hypothermia. Myocardial protection was achieved using intermittent hypothermic ischemia under ventricular fibrillation state or cold crystalloid cardioplegic solution for most of group I patients, whereas cold blood cardioplegic solution was used for group II patients. The mean CPB times for group I and group II were $149.2{\pm}48.7$ minutes and $113.1{\pm}30.6$ minutes, respectively. The mean aortic cross clamp times for group I and group II were $81.3{\pm}26.5$ minutes $72.2{\pm}23.9$ minutes, respectively. These figures show that CPB and aortic cross clamp times were significantly reduced in group II(p<0.05). The use of the left internal thoracic artery(LITA) was increased from 42%(20/47) for group I to 81% (87/107) for group II. The mean number of grafts also significantly increased from $2.5{\pm}0.6$ for group I to $3.0{\pm}1.1$ for group II(p<0.05). Intra-aortic balloon pump(IABP) was applied in 7 cases in group I and 17 cases in group II. Of these, 28.6%(2/7) and 52.9%(9/17) were broadly applied preoperatively in patients with LVEF<40% or congestive heart failure. The operative mortalities for group I and II were 10.6%(5/47) and 0.9%(1/107), respectively, which shows significant decrease for group II(p.0.05). Conclusion: This report suggest that CABG using CPB can recently be performed more safely in virtue of the accumulation of surgical experience with reduction in CPB and aortic cross clamp times and improved surgical techniques and myocardial protection. And we think that the optimal treatment of patients with left ventricular dysfunction associated with congestive heart failure and the extended application of IABP, especially have contributed to the reduction of operative mortality and morbidity.

• Journal of Food Hygiene and Safety
• /
• v.13 no.4
• /
• pp.441-447
• /
• 1998

This study was performed to investigate the changes of amount of S. typhimurium during cooking processes using pork and japchae (a Korean food which is made from meat, vegetables and noodles), and to support a practical application to develop a hazard analysis critical control point (HACCP) model. The pork was purchased in a retail shop, cut ($0.5\;cm\;{\times}\;10\;cm\;{\times}\;10\;cm$, 25 g), tested for Salmonella contamination (results: negative), inoculated with S. typhimurium ($10^{7}\;CFU/g$), then treated in various conditions related to cooking. Mter thawing for 24 hours in various conditions, the number of S. typhimurium was increased to $10^{10}\;CFU/g$ at a refrigerated temperature ($4~10^{\circ}C$), and to $10^{21}\;CFU/g$ at room temperature ($22~29^{\circ}C$). Mter thawing in a microwave oven for 40 seconds, the number of S. typhimurium increased to $10^{8}\;CFU/g$. During the thawing period, the number of S. typhimurium increased over time. At the refrigerated temperature, the number of the bacteria was $10^{10}\;CFU/g$ after 24 hours, $10^{13}\;CFU/g$ after 48 hours, and $10^{20}\;CFU/g$ after 72 hours. At room temperature the number of bacteria reached $10^{11}\;CFU/g$ in 2 hours, $10^{15}\;CFU/g$ in 4 hours, $10^{16}\;CFU/g$ in 8 hours, $10^{18}\;CFU/g$ in 12 hours, and $10^{21}\;CFU/g$ in 24 hours. Mter cooking in a frying pan (150{\pm}7^{\circ}C$) for 3 minutes, the bacterial count was $10^{16}\;CFU/g$. After cooking in hot water for 20 minutes, the bacterial count was $10^{7}\;CFU/g\;at\;60^{\circ}C,\;10^{6}\;CFU/g\;at\;63^{\circ}C,\;and\;10^{4}\;CFU/g\;at\;65^{\circ}C$. The fried pork was mixed with cooked vegetables, noodles, sesame oil, sesame seeds, and seasonings to make Korean japchae. This process took $10{\pm}2$ minutes. The bacterial count in the japchae increased to $10^{7}\;CFU/g$ from the count of $10^{6}\;CFU/g$ of the fried pork before it was mixed with the other ingredients. These results indicate that the amount of S. typhimurium is effected by various different cooking processes. This study can suggest that pork should be cooked in water at over $65^{\circ}C$ for 20 minutes in order to prevent food poisoning, if the pork is contaminated with S. typhimurium. The presence of S. typhimurium in the raw pork is identified in an HA for japchae, and the primary CCP for japchae is inadequate cooking (cooking method and time/temperature). We need to standardize time-temperature-size and amount of pork in cooking japchae, because pork is usually cooked in ordinary frying pans when we make this food.

• Journal of Food Hygiene and Safety
• /
• v.20 no.2
• /
• pp.118-122
• /
• 2005

Immu-Forte (Dong-Ahm Bio's. Corp., Korea) was evaluated fir its effectiveness as a nonspecific immunostimulator in mice. The effects of Immu-Forte were determined by analysis of cytokines using ELISh and phenotype of leukocyte subpopulations using monoclonal antibodies specific to mouse leukocyte differentiation antigens and flow cytometry. CD4 T cells, CD8 T cells, macrophages, IL-12 and IFN-r in Immu-Forte EX-treated middle dose group increased in 3 months posttreatment and were significantly higher (p<0.05) than that of control at 3 months posttreatment. All T cells, all B cells, macrophages, IL-2, IL-4 and IL-12 in Immu-Forte EX-treated low dose uoup increased in 3 months posttreatment and were significantly higher (p<0.05) than that of control at 3 months posttreatment. In the Immu-Forte soy-treated group, CD4 T cells, IL-2, IL-4 and IL-12 were significantly higher in high dose-treated group, and CD 4 T cell, macrophages, IL-2, IL-4 and IL-12 were significantly higher in middle dose-treated group, and all T cell, IL-2, IL-4 and IL-12 were significantly higher in low dose-treated group. In the Itnmu-Forte A-treated group, macrophages, m cells and IL-12 in high dose-treated group and all T cells, macrophages, NK cells, IL-2, IL-4 and IL-12 in middle dose-treated group and NK cells in low dose-treated group were significantly higher (p<0.05) than that of control at 3 months posttreatment. In the Immu-Forte F-treated Group, all B cells, IL-4 and IL-12 in high dose-treated group and all T cells, aBl B cells, CD 4 T cells, CD8 T cells, macrophage, IL-2, IL-4, IL-12 and IFN-r in middle dose-treated group and NK cells and IL-12 in low dose-treated group were significantly higher (p<0.05) than that of control at 3 months posttreatment. In conclusion, the study has demonstrated that Immu-Forte had an immunostimulatory effect on mice through proliferation and activation of mouse immune cells.

• Korean journal of food and cookery science
• /
• v.6 no.4 s.13
• /
• pp.69-83
• /
• 1990

Gynostemma pentaphyllum Makino is a kind of perennial liana plant belonging to the Cucurbitaceae family. Since it was first discovered and reported to the Japanese academy in 1977, it came to be widely known to China and Southeast Asia areas as well as Japan. In Korea its name began to appear in the first half of 1980's, and it is now being nationwidely cultivated and popularized as tea stuffs. Gynostemma pentaphyllum Makino has remarkably strong propagation power. In addition. since it contains a great quantity of beneficial components, especially saponin it is believed to have excellent medical effects, too. This study was undertaken to examine the value of Gynostemma pentaphyllum Makino as a health-promotint tea, by investigating the components creating the flaver of tea and the saponin ingredient making medical effects as well as by inspecting whether Gynostemma pentaphyllum Makino products show different component arrangements according to their growing districts. As raw materials of the experiment, three kinds of Gynostemma pentaphyllum Makino samples produced in Suwon, Geochang and Uleungdo were taken. To accomplish the formerly stated goals, the contained quantity of the proximate composition, free sugar, reducing sugar, free amino acid, minerals, tannin, caffeine and vitamin C were measured respectively and compared between the samples, while the saponin content was compared with heat extracted from panax ginseng. The results of the experiment are as follows: 1. In the case of the proximate composition, the crude fat content was the highest in the Gymostemma pentaphyllum Makino material from Geochang (1.62%), the second in that from Suwon (1.56%), and the lowest in that from Uleungdo (1.0%). In addition the Geochang: produced sample had the greatest quantity of the crude protein and ash contents: the order of the crude Protein content was the Geochang produced (17.83%), the Suwon-produced (15.87%), and the Uleungdo-produced(12.28%), while that of the ash content was the Geochang-produced (14.80%), the Uleungdo-produced(10.17%), and the Suwon-produced(9.34%). 2. As for the reducing sugar contents, the Suwon-produced scored the highest of the three (3.3%), while the Geochang-produced was 1.3% and the Uleungdo-produced 0.5%. The total content of free sugar was 1.07% (the Suwon-produced), and 0.49% (the Geochang-produced) respectively but the sample from Uleungdo showed almost no free sugar content. The contained quantity of fructose and glucose was the highest among the kinds of free sugar both in the Suwon-produced and in the Geochang-produced. 3. The content of amino acid was the highest in the Suwon-produced(1.41%), the second in the Geochang-produced(1.37%), and the lowest in the Uleungdo-produced(0.53%). In the experiment, sixteen kinds of amino acid were extracted-Asp. Thr. Ser. Glu. Gly. Ala. Val. Het. Ileu. Leu. Tyr. Phe. Lys. His. Arg. Try. All of them except glutamic acid and methionine showed the highest quantity score in the Suwon-produced, while the glutamic acid content was the higest in the Uleungdo-produced and the methionine content in the Geochang-produced. The sequential arrangement of the sixteen contents according to their magnitude ranged from glycine, aspartic acid, and glutamic acid (the highest) to tryptophan, serine and lysine (the lowest). 4. Ten kinds of mineral were detected-Ca, Mn, Cd, K, Na, Pb, Mg, Fe, Zn, Cu. Among them, the content of Cd, Na, Mg, Zn and Fe was the highest in the Geochang-produced and that of K in the Suwon-produced. 5. The Geochang-produced materials contained much a larger quantity of tannin (6.3%) than the Suwon-produced (2.6%). Neither caffeine nor vitamin C was detected in the three kinds of materials. 6. In the case of the saponin content the Geochang-produced showd 2.39%, the Uleungdo-produced 1.77% and the Suwon-produced 1.49% respectively. However, it was found also that the saponin content of Gymostemma pentaphyllum Makino was the same kind as that of panax ginseng.

• Food Science of Animal Resources
• /
• v.27 no.3
• /
• pp.267-276
• /
• 2007

This study was conducted to determine the effect of cryoprotectants (sugar, sorbitol, polyphosphate) on the physico-chemical characteristics of chicken breast surimi manufactured by pH adjustment (pH 11.0) during freezing storage. The final surimi was divided into experimental units to which the following treatments were randomly assigned: C (Alaska pollack surimi: two washings, 4% sugar +5% sorbitol ${\pounds}'$ 0.3% polyphosphate additive): T1 (chicken breast surimi: pH 11.0 adjusted, 0.3% polyphosphate additive): T2 (chicken breast surimi pH 11.0 adjusted, 5% sorbitol +0.3% polyphosphate additive); T3 (chicken breast surimi: pH 11.0 adjusted, 4% sugar +5% sorbitol +0.3% polyphosphate additive). The crude protein content of the control was higher than all treated samples, however the moisture, crude fat and crude ash of T3 were higher than the control (p<0.05). The pH, WHC and collagen content of the control were higher than all of the treated samples, and these values decreased with storage time for all treatments and the control (p<0.05). The cholesterol content of the control was lower than all treated samples, but the myofibrillar protein contents of all treated samples were higher than the control (p<0.05). The cooking loss of T2 was lower than the control and the other two treatments (p<0.05). The $L^*,\;a^*\;and\;b^*$ values of all treated samples were higher than those of the control during freezing storage (p<0.05). The W value of T3 at 1.5 and 3 months of freezing storage was higher than the control and T1 (p<0.05). The myoglobin and met-Mb contents of the control were similar to all treated samples, and the met-Mb content of the control and all treated samples increased with storage time (p<0.05). Immediately after freezing, the hardness of the control was higher than all treated samples, however it was lower after 1.5 and 3 months of frozen storage (p<0.05). The cohesiveness and gumminess of the control were higher than all treated samples immediately after freezing, however the values for T3 were higher than those of the control and the other two treatments during frozen storage for 1.5 and 3 months (p<0.05).

• Tuberculosis and Respiratory Diseases
• /
• v.49 no.4
• /
• pp.486-494
• /
• 2000

Background : The dominant innervation of airway smooth muscle is parasympathetic fibers which are carried in the vagus nerve. Activation of these cholinergic nerves releases acetylcholine which binds to $M_3$ muscarinic receptors on the smooth muscle causing bronchocontraction. Acetylcholine also feeds back onto neuronal $M_2$ muscarinic receptors located on the postganglionic cholinergic nerves. Stimulation of these receptors further inhibits acetylcholine release, so these $M_2$, muscarinic receptors act as autoreceptors. Loss of function of these $M_2$ receptors, as it occurs in animal models of hyperresponsiveness, leads to an increase in vagally mediated hyperresponsiveness. However, there are limited data pertaining to whether there are dysfunctions of these receptors in patients with asthma. The aim of this study is to determine whether there are dysfunction of $M_2$ muscarinic receptors in asthmatic patients and difference of function of these receptors according to severity of asthma. Method : We studied twenty-seven patients with asthma who were registered at Pulmonology Division of Korea University Hospital. They all met asthma criteria of ATS. Of these patients, eleven patients were categorized as having mild asthma, eight patients moderate asthma and eight patients severe asthma according to severity by NAEPP Expert Panel Report 2(1997). All subjects were free of recent upper respiratory tract infection within 2 weeks and showed positive methacholine challenge test ($PC_{20}$<16mg/ml). Methacholine provocation tests were performed twice on separate days allowing for an interval of one week. In the second test, pretreatment with the $M_2$ muscarinic receptor agonist pilocarpine($180{\mu}g$) through inhalation was performed be fore the routine procedures. Results : Eleven subjects with mild asthma and eight subjects with moderate asthma showed significant increase of $PC_{20}$ from 5.30$\pm$5.23mg/ml(mean$\pm$SD) to 20.82$\pm$22.56mg/ml(p=0.004) and from 2.79$\pm$1.51mg/ml to 4.67$\pm$3.53mg/ml(p=0.012) after pilocarpine inhalation, respectively. However, in the eight subjects with severe asthma significant increase of $PC_{20}$ from l.76$\pm$1.50mg/ml to 3.18$\pm$4.03mg/ml(p=0.161) after pilocarpine inhalation was not found. Conclusion : In subjects with mild and moderate asthma, function of $M_2$ muscarinic receptors was normal, but there was a dysfunction of these receptors in subjects with severe asthma. ηlese results suggest that function of $M_2$ muscarinic receptors is different according to severity of asthma.