Experimental studies on hemorrhagic shock

의학과/박사[한글] [영문] Part Ⅰ. Hemorrhagic Shock and Cardiac Catecholamines It is generally known that vasoconstriction is a prominent feature of the early stage of hemorrhagic shock in experimental animals, and that this is a protective mechanism mediated through the sympathetic nervous system to maintain a blood supply to vital organs. Freeman et al.(1938), however, pointed out that, although animals with intact sympathetic nervous system were able to compensate more readily to acute hemorrhage than completely sympathectomized animals, the mortality rate was greater in intact than in sympathectemized animals if the hemorrhagic hypotension was prolonged. This concept was supported by many other workers (Gope, 1911; Pillcher et al., 1914; Bayliss, 1923). Furthermore, it has also been shown that the adrenergic blocking agent such as dibenamine can protect from the lethal effects of hemorrhagic hypotension (Wiggers et al., 1950;Levy et al., 1954; Lillehei et al., 1964). These observations lead to the proposal that decrease in sympathetic nervous system response might be pertinent for a decrease in mortality following hemorrhagic shock. In contrast to the above reports, Chien and Hitzig (1960) determined the amount of blood withdrawal which produced death in 50% of intact and sympathectomized dogs and concluded that the presence of the sympathetic nervous system increased the tolerance to hemorrhage shock. Although there is controversial reports concerning the effects of sympathetic nervous system on hemorrhagic shock, it is obvious that the adrenergic neurotransmitter, i.e. catecholamines play an important role in the lethal effects of hemorrhage. In addition, Park(1961) demonstrated that myocardial catecholamines were significantly reduced during hemorrhagic hypotension. Coleman and Glaviano(1963) also showed that catecholamines in the heart, spleen, brain, and liver were markedly decreased during relationship between the endogenous tissue catecholamines and hemorrhagic shock. The present experiment, therefore, was designed to explore the role of cardiac catecholamines in the mortality of hemorrhagic shock. Healthy albino male rabbits, weighing approximately 2.0kg, were anesthetized with urethane (0.4g/kg) given intravenously. A carotid artery was exposed and was directly connected to a mercury manometer for continuous recording of changes in arterial blood pressure on smoked drum. The other carotid artery was also exposed in order to withdraw blood. Endotracheal intubation was employed so that a free air-way maintained at all times and heparin (3.0-5.0mg/kg) was injected intravenously to prevent blood coagulation. Initial 10.0ml of blood per kg of animal weight was rapidly withdrawn and thereafter 2.0ml/kg of blood was withdrawn at an interval of 10 minutes until the animal died. 1. Following the initial bleeding of 10.0ml/kg in normal rabbits, the mean arterial pressure was rapidly dropped to 60mmHg from 110mmHg. Thereafter, the blood pressure was gradually reduced until death. The average survival time and total bleeding volume for these animals were 84 minutes and 28.0ml/kg, respectively. Examination of the cardiac catecholamines soon after death revealed average 1.18μg/g, which is significantly smaller than that of normal(1.68μg/kg). 2. The injection of norepinephrine (2.0mg/kg) markedly elevated the concentration of myocardial catecholamines in rabbits. At the end of one hour after injection of norepinephrine, the animals were subjected to hemorrhagic shock by the procedure described previously. The average survival time for these animals was 62minutes, indicating that pretreatment of norepinephrine hasten the death due to hemorrhagic shock. The average bleeding volume was 18.0ml/kg and the cardiac catecholamine concentration was 1.21μg/g which is not significantly different from the control animals. 3. The intraperitoneal injection of reserpine (3.0mg/kg) depletes almost completely the cardiac catecholamines of rabbits within 24 hours. At the end of 24 hours after the injection of reserpine, the animals were subjected to hemorrhagic shock. The total bleeding volume taken until death was 30.0ml/kg. The average survival time for those rabbits was 101 minutes which is significantly longer than that observed in control animals.restrictio

Streptomyces albidoflavus SMF301에서 蛋白質分解酵素의 生成과 菌體分化와의 相關關係에 관한 定量的 硏究

Thesis (doctoral)--서울대학교 대학원 :미생물학과,1998.Docto

Trends in microbial genomic research in Korea

미생물을 이용한 국내 유전체 연구의 동향분석과 해양미생물연구의 동향을 파악22othe

Direct electron transfer between frhAGB-encoding hydrogenase and TrxR in a non-methanogenic hyperthermophilic archaeon

Previously, a gene cluster homologous to the frhAGB-encoding F420-reducing hydrogenase (Frh) was identified in a non-methanogen Thermococcus onnurineus NA1. The heterotrimeric enzyme complex exhibited hydrogenase activity with methyl viologen, FMN or FAD as electron acceptor, but not with deazaflavin coenzyme F420, implicating that it has a role distinct from that of homologues from methanogens. Herein, we describe that Frh from T. onnurineus NA1 can reduce thioredoxin reductase (TrxR). In the course of understanding the role of TrxR in T. onnurineus NA1, we employed protein-protein interaction tools and some protein bands, of which one band was identified as a protein coded by frhG afterwards, were pulled down with TrxR in the immunoprecipitation experiment using an antibody of TrxR. The relationship between the hydrogenase and TrxR was further investigated, and TrxR could be reduced directly by Frh, coupled with H2 oxidation in the absence of any other electron carriers. Subsequently, the reduced TrxR by Frh relayed cascade of electron transfer to a sulfur response regulator, SurR. The mechanism behind the phenomena will be discussed.en, FMN or FAD as electron acceptor, but not with deazaflavin coenzyme F420, implicating that it has a role distinct from that of homologues from methanogens. Herein, we describe that Frh from T. onnurineus NA1 can reduce thioredoxin reductase (TrxR). In the course of understanding the role of TrxR in T. onnurineus NA1, we employed protein-protein interaction tools and some protein bands, of which one band was identified as a protein coded by frhG afterwards, were pulled down with TrxR in the immunoprecipitation experiment using an antibody of TrxR. The relationship between the hydrogenase and TrxR was further investigated, and TrxR could be reduced directly by Frh, coupled with H2 oxidation in the absence of any other electron carriers. Subsequently, the reduced TrxR by Frh relayed cascade of electron transfer to a sulfur response regulator, SurR. The mechanism behind the phenomena will be discussed.2

Formate Energy Metabolism in Thermococcus onnurineus NA1

The tripartite modular organization of group 4 hydrogenase could be found in many archaeal genomes, however, there is no report to unveil the physiological role of multisubunit monovalent cation/proton antiporter participating in mediating the electron relay of the respiratory chain to date. Here, we try to address the identity of chemiosmotic ion to couple formate oxidation to ATP synthesis in the anaerobic respiratory mechanism of formate oxidation. Additionally, the physiological role of the multisubunit monovalent cation/proton antiporter related with ATP synthesis was considered.the electron relay of the respiratory chain to date. Here, we try to address the identity of chemiosmotic ion to couple formate oxidation to ATP synthesis in the anaerobic respiratory mechanism of formate oxidation. Additionally, the physiological role of the multisubunit monovalent cation/proton antiporter related with ATP synthesis was considered.1

Method for preparing a carboxylic acid using nitrilase RMN2

본 발명은 신규한 나이트릴레이즈 및 이의 용도에 관한 것으로, 보다 구체적으로, 본 발명은 서열번호 1, 서열번호 3, 서열번호 5 및 서열번호 7로 이루어진 군에서 선택되는 아미노산 서열로 나타내는 나이트릴레 이즈를 나이트릴 기질과 반응시키는 단계를 포함하는 카르복실산을 제조하는 방법, 및 상기 나이트릴레이 즈를 포함하는 카르복실산 제조용 생촉매 조성물에 관한 것이다

수소생산성 개선 우수고세균 개발 및 실증연구

Thermococcus onnurineus NA1 was isolated from a deep-sea hydrothermal vent. It was shown that T. onnurineus NA1 is capable of producing H2 under anaerobic growth conditions supplemented with CO, formate, or starch. The polyphasic approach by employing transcriptomic, proteomic and metabolomic tools allowed us to understand how the strain regulates the metabolism upon the presence of one carbon substrates coupled with H2 production. Currently, we are trying to enhnace H2 productivity by the combination of genetic and process engineering tools, and H2 production rate of the engineered strains was significantly enhanced on CO or by-product gas of steel-mill process. Recently, H2 production from CO has been demonstrated at the pilot scale bioreactor. The result and future prospect would be duscussed.y employing transcriptomic, proteomic and metabolomic tools allowed us to understand how the strain regulates the metabolism upon the presence of one carbon substrates coupled with H2 production. Currently, we are trying to enhnace H2 productivity by the combination of genetic and process engineering tools, and H2 production rate of the engineered strains was significantly enhanced on CO or by-product gas of steel-mill process. Recently, H2 production from CO has been demonstrated at the pilot scale bioreactor. The result and future prospect would be duscussed.2

Improvement of 2,3-butanediol production from CO gas by random mutagenesis of Clostridium sp. AWRP

Some acetogenic bacteria has the ability to use carbon monoxide (CO) using the Wood-Ljungdahl pathway. Biological conversion of CO using acetogens offers benefits of utilizing industrial waste gases containing CO and generating valuable fuels such as ethanol, butanol and 2,3-butanediol. In this study, we screened 2,3-butanediol-producing microbes among various environmental samples and isolated a new strain, Clostridium sp. AWRP from a wetland. This strain is able to produce acetate, ethanol and 2,3-butanediol as major metabolites using CO. To improve 2,3-butanediol production, the wild-type strain was modified by random mutagenesis technology. After treatment of cells with N-methyl-N-nitro-N-nitrosoguanidine (NTG), mutants with better growth than the wild-type strain under high CO partial pressure were selected. They showed different growth and metabolite production patterns. Among them, a few mutants were identified to have improved CO consumption and 2,3-butanediol production. Here, we describe effective strategies for selection of CO-utilizing 2,3-butanediol producers through enrichment processes during isolation and mutagenesis.els such as ethanol, butanol and 2,3-butanediol. In this study, we screened 2,3-butanediol-producing microbes among various environmental samples and isolated a new strain, Clostridium sp. AWRP from a wetland. This strain is able to produce acetate, ethanol and 2,3-butanediol as major metabolites using CO. To improve 2,3-butanediol production, the wild-type strain was modified by random mutagenesis technology. After treatment of cells with N-methyl-N-nitro-N-nitrosoguanidine (NTG), mutants with better growth than the wild-type strain under high CO partial pressure were selected. They showed different growth and metabolite production patterns. Among them, a few mutants were identified to have improved CO consumption and 2,3-butanediol production. Here, we describe effective strategies for selection of CO-utilizing 2,3-butanediol producers through enrichment processes during isolation and mutagenesis.2