• Title/Summary/Keyword: Korean studies

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Studies on the Effect of Feeding Pelleted Diets on Energy Metabolism and Nitrogen Retention in Growing Chickens (Pellet사료(飼料)의 급여(給與)가 병아리의 대사(代謝)에너지와 질소축적(窒素蓄積)에 미치는 영향(影響))

  • Park, Chang Sik;Kwon, Soon Ki;Min, Tae Hyuk
    • Korean Journal of Agricultural Science
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    • v.10 no.2
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    • pp.206-211
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    • 1983
  • This study was carried out to compare the feed utilization between pelleted and all-mash diet of similar composition by growing chickens. Day-old broilers (Hubbard) and egg-type chickens(Hy-line) of commercial strain were employed in this experiment. The results obtained were summarized as follows. 1. The chickens fed pelleted diets were heavier than those of birds fed all-mash diets. The Hubbard broilers and Hy-line chickens fed pelleted diets weighed 2,702g and 812g respectively, at 9 weeks of age. In comparison, the Hubbard broilers and Hy-line chickens fed all-mash diets weighed 2,571g and 777g respectively, at 9 weeks of age. 2. The pellet-fed chickens consumed more feeds than birds fed all-mash diets in both types of strain. Feed efficiencies (gain/feed) of Hubbard and Hy-line chickens were 0.38 and 0.26 in pellet feeding groups, and 0.36 and 0.25 in all-mash feeding groups, respectively. The Hy-line chickens fed pelleted diets drank more water than birds fed all-mash diets. 3. Pellet feeding groups produced more dry matter excreta as compared with all-mash feeding groups, reflecting the pattern of feed consumption by these chickens. Nitrogen retention ratio of the Hubbard and Hy-line chickens were 57-67% and 65-73%, respectively. Chickens fed pelleted diets showed 1-4% higher nitrogen retention than chickens fed all-mash diets. 4. The ME/GE ratio of the Hubbard and the Hy-line at 8 weeks of age were 73.4-74.3% and 82.8-83.8%, respectively. Pellet feeding groups showed 1% higher ME/GE ratio than all-mash feeding groups. 5. The dietary productive energy calculated from respiratory quotient was $94.1-102.6kca/kg^{\frac{3}{4}}$ BW/day in pellet feeding groups. The ratios of PE/GE were 41.3-48.9% in pellet feeding groups and 39.0-45.8% in all-mash feeding groups. 6. It appears that pelleting the all-mash diet increases feed consumption and body weight gain of growing chickens. Feed efficiency and energy utilization were also improved by pelleting process. More research work should be done to establish the relationship clearly between feed pelleting and heat increments.

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Studies on Properties of Superplasticized Fly Ash Concrete (고류동화제(高流動化劑)를 사용한 플라이애쉬 콘크리트의 제성질(諸性質)에 관한 연구(硏究))

  • Kim, Seong Wan;Sung, Chan Yong;Cho, Il Ho
    • Korean Journal of Agricultural Science
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    • v.16 no.2
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    • pp.212-224
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    • 1989
  • This paper reports results of an investigation to determine properties of superplasticizered fly ash concrete. The mixture proportions of fly ash were 0, 10, 20 and 30%, by weight of cement, and superplasticizer was added as a percentage of fly ash, 0, 0.6, 12 and 1.8%. To investigate the effective use of the superplasticized fly ash concrete, the basic data were analyzed. The results obtained were summarized as follows : 1. The unit water content was decreased by 1%, 6% and increased by 2% to the ratio of addition of fly ash 10%, 20%, 30%, respectively, but in case of the superplasticized fly ash concrete, it was decreased by 3~16%, 4~14% and 10~17%, at 0.6, 12, and 1.8% dosage of superplasticizer, respectively. 2. In the properties of the fresh fly ash concrete, the slump loss was reduced with the ratio of replacement of fly ash increased, and with times went by. When using superplasticizer in fly ash substituting concrete, the fludity in the concrete was not decreased. 3. The compressive strength of fly ash concrete at early ages was lower than that of ordinary concrete. At the later age of 28 days, the compressive strength with 20% addition of fly ash was increased than that of ordinary concrete. In cased of 10%, 30% addition of fly ash, the compressive strength were reduced. From this, it was proved that the optimum amount of fly ash appears to be about 20%. The compressive strength at all ages of superplasticized fly ash concrete was significantly higher than that of fly ash concrete, with increasing fly ash content. 4. In case of the tensile strength, the effects of the increasing strength with the ages were similar to those of the compressive strtength, and at the later ages was seen a decreasing tendency of strengths. 5. The correlation between compressive and tensile strength of superplasticized fly ash concrete was highly significant. The multiple regression equations of compressive and tensile strength were obtained on a function of the mixture proportion of fly ash and the addition of superplasticizer. The relation between compressive and tensile strength is higher than for ordinary concrete. The strength ratio is 7~11, and it is higher than that of ordinary concrete, 8~10. 6. Bulk density was decreased by 1~3% compared with ordinary concrete with the mixture proportion of fly ash increased, 10~30%, and decreased by 1~2% with the superplasticizer added 0.6~1.8%.

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Experimental studies on the characteristics of the mortar using dispersing agent of cement and high fluid admxiture (시멘트 분산제(分産劑) 및 고류동화제(高流動化劑)를 사용(使用)한 모르터의 제(諸) 성질(性質)에 관(關)한 실험적(實驗的) 연구(硏究))

  • Kim, Seong Wan;Park, In-Gyu
    • Korean Journal of Agricultural Science
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    • v.11 no.1
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    • pp.146-159
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    • 1984
  • This study was the contrast of the compressive strength, the tensile strength, the reducing ratio and the flow of mortar using dispersing agent and high fluid admix. 1. The admix ratio of chemical admixtures espressing maximum strength appeared the same result high fluid admix SP was 0.6%, the dispersing agents LG and C211 were 0.2%, SK was 0.3%, C376 was 0.5%. But two or three times more than standard quantity made the strength's fast lowness, which influenced bad to wateriness and retard the soli-dification. 2. When proper quantity of chemical admixture was used, the increment of compressive strength was as follows. High fluid admix SP was 40.7% and the average increasing rate of dispersing agents(C211 was 19.5%, LG was 19.1%, C376 was 17.9%) was 18.7% more than normal mortar in the codition of 7 days. Also, in the condition of 28 days, high fluid admix SP was about 24.4% and the average of dispersing agents(LG was 21.1%, C211 was 16.4%, SK was 11.1%, C376 was 7.6%) was 14.1%. 3. When proper quantity of chemical admixture was used, the increment of tensile strength was as follows. High fluid admixture SP was 26.6% and the average increasing agents(SK was 16.0%, C376 was 14.7%, LG was 10%, C211 was 5.8%) was 11.6%. Also, in the condition of 28 days, high fluid admix SP was 16.5% and the average increasing rate of dispersing agents(LG was 19.1%, SK was 10.6%, C211 was 10.1%, C376 was 8.7%) was 12.1%. 4. As for the reducing ratio of each dispersing agent, he flow of mortar was less than the slump of concrete. That is; the reducing ratio of concrete was 15% adding each dispersing agent, but the reducing ratio of mortar was in the range of from 5.8% to 13.5% in 1 : 1 mixture, from 7.6% to 14.2% in 1 : 2, from 9.5% to 18.8% in 1 : 3. 5. The fluidity of each chemical admixture was as follows. High fluid admix SP in the condition of 1: 1 and 1 : 2 showed the best result than other dispersing agent and 1 : 3 showed the same result like other agents. Therefore these good dispersing agents were suitable in the prepact concrete construction using intrusion mortar.

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Studies on the Changes of Reproductive Organs, Serum Sex Hormones and Metabolites according to the Gestation Period in Rabbit (가토(家兎)의 임신(姙娠)에 따른 생식기관(生殖器官), 혈중(血中) 성(性)Hormone 및 대사물질(代謝物質)의 변화(變化)에 관(關)한 연구(硏究))

  • Lee, Kyu Seung;Han, Sung Wook;Park, Chang Sik
    • Korean Journal of Agricultural Science
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    • v.9 no.1
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    • pp.303-313
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    • 1982
  • The study was conducted to find out the concentrations of sex hormones and the contents of metabolites in serum, and the changes of weights and tissues on ovary, thyroid gland and adrenal gland according to gestation period in rabbit. The results were summarized as follows: 1. The ovary weights were increased significantly with the time e lapse after gestation and recovered normally at 5 days after parturition. In the histological changes of ovary, the lutein cells were hypertrophied and the secretory granules were increased actively until 3 weeks after gestation, and then a trophied thereafter. 2. The thyroid gland weights at all observation times were higher than those in control group, and the significance was recognized at 1, 3 and 4 weeks after gestation. The histological features of the secretory epithelium were the hyper trophic and columnar condition stimulating the functional state from 1 week after gestation. 3. The adrenal gland weights in experimental group were recognized significantly at 4 weeks after gestation, but showed higher than those in control group at all observation times. The zona fasciculata and zona reticularis of the gland showed the slight hypertrophic condition, but the zona glomeerulosa and adrenal medulla did not find out any particular changes. 4. The serum concentrations of progesterone and LH reached a peak level at 2 weeks and 1 week after geestation respectively, and rapidly began to decline thereafter. 5. The serum concentrations of estradiol-$17{\beta}$ and FSH were not detected below 20.0 pg/ml and 1.3 mIU/ml respectively. 6. The contents of total protein and non-protein nitrogen nitrogen were decreased gradually with the time elapse after gestation, but the significant differences were recognized from 3 weeks. 7. The total lipids were not changed markedly until 3 weeks, but increased significantly at 4 weeks after gestation and at 5 days after parturition. 8. The serum cholesterol tended to be decreased until 3 weeks, but increased at 4 weeks after gestation and at 5 days after parturition. 9. The serum calcium showed a continuous decrease during the gestation period, but the significant differences were recognized at 3 and 4 weeks. The serum phosphorus also had a significant decrease at 4 weeks after gestation.

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Long Term Follow Up of Interferon-alpha Treatment in Children with Chronic Hepatitis B (만성 B형간염 환아에 대한 Interferon-alpha 치료결과의 장기 추적관찰)

  • Baek, Seoung-Yon;Eom, Ji-Hyun;Chung, Ki-Sup
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.6 no.2
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    • pp.140-151
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    • 2003
  • Purpose: We tried to evaluate the long term efficacy and positive predictive factors of interferon-alpha treatment in children with chronic hepatitis B. Methods: The study population included 113 children who received interferon therapy between May 1982 and July 2002 (20 years) for chronic hepatitis B in Department of Pediatrics, Yonsei University College of Medicine. Male to female ratio was 2.3 : 1 and the mean age at diagnosis was $11.1{\pm}4.1$ years old. Response to treatment was defined as normalization of alanine aminotransferase (ALT), disappearance of HBeAg and HBV-DNA Eighty two children responded while 32 did not. Interferon-alpha was given intramuscularly for 6 months at a dosage of $3{\times}10^6$ unit, 3 times weekly. In relapsed cases, lamivudine or interferon retreatment was done. Results: Seroconversion rate was 77.0% in terms of HBeAg, 74.3% in terms of HBV-DNA, and 80.5% in terms of ALT normalization after treatment. Seroconversion rate of both HBeAg and HBV-DNA was 72.6%. Analyzed by life table method, the effect of the treatment had been maintained over 10 years after cessation of therapy. Pre-treatment ALT level was the only significant positive predictive factor of response. Eleven cases (13.4%) relapsed, and 2 out of 3 showed response when treated with lamivudine and 1 out of 3 with interferon retreatment. Conclusion: Interferon-alpha showed significant efficacy in the treatment of chronic hepatitis B in our study. Further studies about the effect of interferon therapy on complications of hepatitis such as hepatocarcinoma, cirrhosis are warranted.

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Effects of Concurrent Chemotherapy and Postoperative Prophylactic Paraaortic Irradiation for Cervical Cancer with Common Iliac Node Involvement (자궁경부암의 근치적 절제술 후 총장골동맥림프절 침범 시 동시항암화학치료와 예방적 대동맥주위림프절 방사선조사의 효과)

  • Han, Tae-Jin;Wu, Hong-Gyun;Kim, Hak-Jae;Ha, Sung-Whan;Kang, Soon-Beom;Song, Yong-Sang;Park, Noh-Hyun
    • Radiation Oncology Journal
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    • v.28 no.3
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    • pp.125-132
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    • 2010
  • Purpose: To retrospectively assess the advantages and side effects of prophylactic Paraaortic irradiation in cervical cancer patients with common iliac nodal involvement, the results for survival, patterns of failure, and treatment-related toxicity. Materials and Methods: From May 1985 to October 2004, 909 patients with cervical carcinoma received postoperative radiotherapy at the Seoul National University Hospital. Among them, 54 patients with positive common iliac nodes on pathology and negative Paraaortic node were included in the study. In addition, 44 patients received standard pelvic irradiation delivered 50.4 Gy per 28 fractions (standard irradiation group), and chemotherapy was combined in 16 of them. The other 10 patients received pelvic irradiation at a dose of 50.4 Gy per 28 fractions in addition to Paraaortic irradiation at 45 Gy per 25 fractions (extended irradiation group). In addition, all of them received chemotherapy in combination with radiation. Follow-up times for pelvic and Paraaortic irradiation ranged from 6 to 201 months (median follow-up time, 58 months) and 21 to 58 months (median follow-up time, 47 months), respectively. Results: The 4-year overall survival, disease free survival, and distant metastasis free survival in the standard irradiation group and extended irradiation group were 67.2% vs. 90.0% (p=0.291), 59.0% vs. 70.0% (p=0.568) and 67.5% vs. 90.0% (p=0.196), respectively. The most common site of first failure for the standard irradiation group was the paraaortic lymph node, while no paraaortic failure was observed in the extended irradiation group. Relatively, hematologic toxicity grade 3 or greater was common in the extended irradiation group (2/10 extended vs. 2/44 standard), while gastrointestinal toxicity of grade 3 or greater was lower (2/10 extended vs. 6/44 standard), and urologic toxicity of grade 3 or greater was observed in the standard irradition group only (0/10 vs. 3/44). Conclusion: Concurrent chemotherapy and prophylactic Paraaortic irradiation in patients with common iliac nodal involvement showed slightly improved clinical outcomes aside from increased hematologic toxicity, which was statistically insignificant. Considering the relatively small number of patients and short follow-up times, additional studies are needed to obtain more conclusive outcomes.

The studies on wrinkle recovery improvement for silk fabrics (견직물의 방추성 개선연구)

  • 김병호;정진영
    • Journal of Sericultural and Entomological Science
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    • no.11
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    • pp.23-29
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    • 1970
  • This experiment is to improve the wrinkle recovery (W.R.) of silk fabrics. The silk fabrics is creased very well, and the crease is the serious defection of it. This experiment is to improve the nature by use of formaldehyde on fabrics. The reagents used were HCl, CH$_3$COOH, CaC$_2$, HCHO, Na$_2$CO$_3$, NH$_4$OH, NaOH and NaHCO$_3$. The silk fabrics was treated, to compare 1 he influence of conditions, by varying the quantities of reagents and the temperature of solution, and the reaction time. The cotton fabrics and the viscose rayon were sunk with the silk at the same condition to be compared the influence. 1) Those of the most suitable temperature to improve for the better W.R. are 75$^{\circ}C$ for silk, 35-45$^{\circ}C$ for cotton, and no particular temperature under 75$^{\circ}C$ for viscose rayon. 2) The W.R. improvements after treated at the temperature of 1) were 11% for silk and 33.4% for cotton. 3) There are the best treating time for every fabrics. They were 60 to 90 min. for viscose rayon when HAC Ras used for solvent. It took, however, 60min. of the best time for silk, 120 min. for cotton, and 40 min. for viscose rayon when acetic anhydride instead of HAC was used. 4) It was possible to improve 16.6% of W.R. for silk at the most suitable treating time, 25.0% for cotton, and 13.3% for viscose rayon. 5) Acetic anhydride was rather more effective to improve W.R. of both silk and viscose rayon than HAC. 6) Treating time was also shorter in case of using acetic anhydride than HAC. 7) The improvement of W.R. were 8.3% for silk at the 10 to 14 ml. of HCHO the best volume, 21. 5% for cotton at 18m!. of HCHO, and 70% of for viscose rayon at 14 to 18ml. of HCHO. 8) The most effective quantity of HCI is 14 ml. for both silk and cotton. The W.R. improvement of silk was 22.2%, and that of cotton 19.5%. 9) The W.R. of 83.3% the best for silk and 61. 6% for cotton were gained when 4.2gr. of NaHCO$_3$ brings down the percent of W.R. for both silk and cotton. 10) The more NaOH and NH$_4$OH as neutralizing agents, the less effectivity of W.R. until the quantities of the reagents are reached to a special range which are 3. 3m!. for silk and 3.3-6.6 ml. for cotton, and then we can see the W.R. increasing as the quantities of reagents are increased. These facts were evident in case of silk and cotton. We can also see with this fact that the reminder of 〔OH$\^$-/〕 neutralizing 〔CH$\^$+/〕in solution makes it possible to treat formaldehyde on fabrics. 11) Low curing temperature was comparatively better for silk, and high temperature better for cotton. 12) The result of this experiment shows that the Improvement of W.R. for silk was possible to 94% which means 22% W.R. increase compared to the untreated silk. This effect also shows that the improvement to W '||'&'||' W (wash and wear) of silk will be possible.

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Studies on the Estimation of Leaf Production in Mulberry Trees IV. Estimation of Spring Leaf Yield by the Measurement of Some Characters (상엽수확고 측정에 관한 연구 제 4보 추기상수각형질의 측정에 의한 익춘 상엽량의 예측)

  • 한경수;장권열;안정준
    • Journal of Sericultural and Entomological Science
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    • v.10
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    • pp.35-40
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    • 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.

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Clinical Analysis of Arteriovenous Fistula in Chronic Renal Failure Patients (만성 신부전 환자에서의 동정맥루 조성술의 임상고찰)

  • Song Chang-Min;Ahn Jae-Bum;Kim In-Sub;Kim Woo-Sik;Shin Yong-Chul;Yoo Hwan-Kuk;Kim Byung-Yul
    • Journal of Chest Surgery
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    • v.39 no.9 s.266
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    • pp.692-698
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    • 2006
  • Background: Owing to the fact that the average life span has increased and the progress in medical science has been made, the number of patients with chronic renal failure (CRF) who have to take hemodialysis (HD) has been going up gradually. Accordingly, it is considered to be as a significant issue to obtain blood vessels which can be used repetitively and supply enough blood flows. Therefore, there have been various kinds of study on an inosculation rate andfactors influencing it following an arteriovenous fistula (AV fistula) and lots of studies are ongoing for the purpose of escalating the inosculation rate. The authors analyzed the effects of short-term result, age, sex, diabetes and hypertension on arteriovenous inosculations in 134 anatomical snuffbox operated subjects among the patients who have taken an AV fistula at this center. Material and Method: Based on 134 patients who underwent an AV fistula at the department of thoracic surgery of this center from July, 2000 to May, 2004, the difference in arteriovenous inosculation rate was compared and analyzed depending or age (discriminated by 65-year-old), sex and the condition of the presence or absence of diabetes and hypertension. Correlation analyses were conducted for each parameter and statistical tests were performed by using SPSS for windows Release 11.0.1, which were determined to be statistically significant if p value was below 0.05. Result: The total number of operations was 169 including 35 of re-operations. The male/female rate was 70 : 64 (52% : 48%). The average age was $56.3{\pm}12.26$ years and there were 33 (24%) old aged patients above 65-year-old; there were 103 (71%) patients with hypertension and 90 (67%) patients with diabetes. Overall arteriovenous inosculation rate was $93{\pm}2.4%,\;91{\pm}2.7%,\;89{\pm}3.0%$ at 6, 12, 24 months, respectively. The arteriovenous inosculation rate of above 65-year-old patient group was $85{\pm}4.8%,\;80{\pm}5.8%,\;80{\pm}5.8%$ and below 64-year-old patient group's was $85{\pm}4.8%,\;80{\pm}5.8%,\;80{\pm}5.8%$ at given time points, respectively, which showed higher inosculation rate in below 64-year-old patient group with a statistical significance (p=0.0034). However, no statistical significance was found between the patients with hypertension and diabetes and the patients with no complication. In addition, there was no statistical significance in inosculation rate between male and female. Conclusion: The arteriovenous inosculation ratewas higher in the treated patient below 64-year-old than in the treated patient above 65-year-old. Thus it is advantageous for increase in long-term inosculation rate to obtain hemodialysis routes at an early age. The conditions of sex and the presence or absence of diabetes and hyper- tension do not make statistically significant effect on the arteriovenous inosculation rate.

Ischemic Preconditioning and Its Relation to Glycogen Depletion (허혈성 전처치와 당원 결핍과의 관계)

  • 장대영;김대중;원경준;조대윤;손동섭;양기민;라봉진;김호덕
    • Journal of Chest Surgery
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    • v.33 no.7
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    • pp.531-540
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    • 2000
  • Baclgrpimd; Recent studies have suggested that the cardioprotective effect of ischemic preconditioning(IP) is closely related to glycogen depletion and attenuation of intracellular acidosis. In the present study, the authors tested this hypothesis by perfusion isolated rabbit hearts with glucose(G) is closely related to glycogen depletion and attenuation of intracellular acidosis. In the present study, the authors tested this hypothesis by perfusion isolated rabbit hearts with glucose(G)-free perfusate. Material and Method; Hearts isolated from New Zealand white rabbits(1.5~2.0 kg body weight) were perfused with Tyrode solution by Langendorff technique. After stabilization of baseline hemodynamics, the hearts were subjected to 45 min global ischemia followed by 120 min reperfusion with IP(IP group, n=13) or without IP(ischemic control group, n=10). IP was induced by single episode of 5 min global ischemia and 10 min reperfusion. In the G-free preconditioned group(n=12), G depletion was induced by perfusionwith G-free Tyrode solution for 5 min and then perfused with G-containing Tyrode solution for 10 min; and 45 min ischemia and 120 min reperfusion. Left ventricular functionincluding developed pressure(LVDP), dP/dt, heart rate, left ventricular end-distolic pressure(LVEDP) and coronary flow (CF) were measured. Myocardial cytosolic and membrane PKC activities were measured by 32P-${\gamma}$-ATP incorporation into PKC-specific peptide and PKC isozymes were analyzed by Western blot with monoclonal antibodies. Infarct size was determined by staining with TTC(tetrazolium salt) and planimetry. Data were analyzed by one-way analysis of variance (ANOVA) and Turkey's post-hoc test. Result ; In comparison with the ischemic control group, IP significantly enhanced functional recovery of the left ventricle; in contrast, functional significantly enhanced functional recovery of the left ventricle; in contrast, functional recovery were not significantly different between the G-free preconditioned and the ischemic control groups. However, the infarct size was significantly reduced by IP or G-free preconditioning(39$\pm$2.7% in the ischemic control, 19$\pm$1.2% in the IP, and 15$\pm$3.9% in the G-free preconditioned, p<0.05). Membrane PKC activities were increased significantly after IP (119%), IP and 45 min ischemia(145%), G-free [recpmdotopmomg (150%), and G-free preconditioning and 45 min ischemia(127%); expression of membrane PKC isozymes, $\alpha$ and $\varepsilon$, tended to be increased after IP or G-free preconditioning. Conclusion; These results suggest that in isolated Langendorff-perfused rabbit heart model, G-free preconditioning (induced by single episode of 5 min G depletion and 10 min repletion) colud not improve post-ischemic contractile dysfunction(after 45-minute global ischemia); however, it has an infarct size-limiting effect.

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