• The Korean Journal of Physiology
• /
• v.22 no.2
• /
• pp.189-206
• /
• 1988

The effects of ouabain on the contractile and electrical activities were investigated in the isolated preparations of guinea-pig taenia coli, and compared with those of vanadate. Spontaneous contractions were recorded with force transducer, and electrical activites were measured by use of suction electrode, or single sucrose-gap technique. The contractions were induced by the electrical stimulation for 5 seconds every 1 minute with alternating current (60 Hz, 3.0 V/cm) through the platinum electrodes located in parallel with the long axis of the preparation. All experiments were performed in tris-buffered Tyrode solution which was aerated with $100%{\;}O_2$ and kept at $35^{\circ}C$. The results obtained were as follows: 1) Responses of spontaneous contractions to ouabain were concentration-dependent; $10^{-7}M$ ouabain caused a rise of basal tone. Above the concentration of $10^{-6}M$ ouabain, an initial increase followed by a decrease in tension was observed. 2) A continuous spike discharge was induced by the administration of $10^{-7}M$ ouabain. Above $10^{-6}M$ ouabain, a transient initial increase followed by a decrease in spike frequency and amplitude was produced, and finally membrane potential was sustained at a certain level without a spike discharge. 3) The characteristic response to $10^{-7}M$ ouabain was not blocked by the pretreatment with $10^{-7}M$ atropine. 4) The electrically induced contractions were completely suppressed at the concentration of $2{\times}10^{-7}M$ ouabain. These contractions were blocked more rapidly in paralled with the increase in ouabain concentration. 5) Effects of vanadate on the spontaneous activities were quite different from those of ouabain; $10^{-6}M$ vanadate increased the amplitude of contractions and $10^{-5}M$ vanadate increased slightly both amplitude and frequency of spontaneous contractions. $10^{-4}M$ vanadate showed irregular phasic contractions superimposed on the increased basal tone. 6) $10^{-5}M$ vanadate depolarized the membrane potential and shortened the interval between the bursts of spike discharge, whereas $10^{-4}M$ vanadate induced continuous spike discharge with membrane depolarization. 7) Vanadate caused a characteristic inhibitory response to the contractions induced by electrical stimulation; An initial rapid inhibition of tension development and then gradual recovery to a certain level. From the above results, the following conclusions could be made: 1) The rise of basal tone at $10^{-7}M$ ouabain is due to continuous spike discharge without a silent period. The continuous spike discharge is likely to be associated with a slight membrane depolarization caused by the blockage of Na pump. 2) The biphasic response induced by above $10^{-6}M$ ouabain seems to occur by the different mechanisms. The initial increase in tension is associated with depolarization along with an increase in spike frquency, whereas the subsequent relaxation occurs through a non-electrical mechanism. 3) The characteristic response to $10^{-7}M$ ouabain is resulted not from the action on intrinsic nerve terminal, but from its direct action on the membrane of smooth muscle cells. 4) The phasic contractions superimposed on the increased basal tone at the concentration of $10^{-4}M$ vanadate is resulted from the continuous spike discharge with membrane depolarization, of which mechanism remains unknown. 5) The inhibitory action of ouabain on the electrically induced contractions suggests that the increasein intracellular Na in some way inhibits the electrically induced $Ca^{2+}$ influx. The mechanism of vanadate action on the induced contractions remains unknown.

• Korean Journal of Agricultural Science
• /
• v.5 no.2
• /
• pp.136-144
• /
• 1978

A series of experiments over three years was planned for practical application of rhizobia in farms and grass lands in Korea. This is the report for the studies of the first year mainly on the isolation and characterization of rhizobial strains, and on the assessment of their nodulation abilities and nitrogen fixation capacities. 1. Total number of 88 strains for soybean group and 22 st ra ins for pea and vetch group was isolated from nodules which were taken from legumes grown in Daekwanyong, Cheju and various places in Korea. 2. Morphological and cultural characteristics of the strains were studied, and attempts were also made to investigate their antigenic properties and to demonstrate lysogenic strains in these groups. The results were : i) the isolates varied in cultural characteristics on yeast mannitol broth and agar, and in degree of congo reel absorption ; ii) similarities in their antigenic properties were found between/among the strains: G-3/G-9/D216, G-20/G-52 in soybean group; iii) no lysogeny was found in the strains of these groups. 3. Plant infection tests by test tube and bottle method in light room were carried out to elucidate the ability of the strains to nodulate specific legumes and of the capacity of such nodules to fix atmospheric nitrogen. The isolates were grouped into non- invasive, ineffective, or effective to the legumes. Those strains which produced effective nodules, supporting similar level of growth as nitrate control, were: P-3, 4 and 8 in pea and vetch group; G-23, 27, and, D-216 in soybean group.

• Journal of Chest Surgery
• /
• v.37 no.7
• /
• pp.547-552
• /
• 2004

Recently, autologous bone marrow cell transplantation (CTx) for angiogenesis and myogenesis in ischemic myocardium has been extensively investigated to improve heart functions. This study was designed to evaluate the effects of CTx with off-pump coronary artery bypass grafting (OPCAB) in patients who were not feasible for complete revascularization. Material and Method: Four male patients underwent CTx and OPCAB simultaneously. Bone marrow was aspirated from iliac bone. Mean 1.5 ${\times}$ 10$^{9}$ mononuclear cells including mean 6.7 ${\times}$ 10$^{6}$ CD34 + cells and 3.7 ${\times}$ 10$^{6}$ AC133 + cells were obtained and concentrated with 10 cc. These cells were transplanted into non-graftable ischemic myocardium after OPCAB. The heart function of all patients were evaluated using the MIBI scan, echocardiogram and MRI preoperatively. The effects of CTx was evaluated using MIBI scan and echocardiogram at 1 month postoperatively. Result: An average of 2 grafts were bypassed to left anterior descending artery territory. Other territories were transplanted with isolated mononuclear cell. All patients had uncomplicated postoperative course. After 1 month follow up, there were improvement in symptom, ejection fraction (from 49% to 55%) on echocardiogram and myocardial perfusion on MIBI scan in all patients. Conclusion: These preliminary data showed improvement of heart function and myocardial perfusion and also showed the feasibility and safety of combined therapy with OPCAB and CTx in ischemic myocardium. However, the effectiveness of CTx alone cannot be readily assessed. Further randomized, controlled studies are required to evaluate the effectiveness of CTx alone.

• Korean Journal of Organic Agriculture
• /
• v.25 no.4
• /
• pp.843-859
• /
• 2017

The JK-1 isolate which was the best producer of indole-3-acetic acid and carotenoid among the 388 strains isolated from 28 wetlands in Jeju, was identified to be Rhodopseudomonas palustirs belongs to a typical group of non sulfur purple bacteria based on 16S sRNA sequencing. This study investigated the effect of different cultural conditions of pH, temperature, agitation, light and aeration on growth, IAA and carotenoid production of photosynthetic bacterium JK-1 for optimization of IAA and carotenoid production. It was found that growth, IAA, carotenoid, and bacteriochlorophyll production with light (3,000~3,500 Lux) and agitation (100 rpm) showed better results than those with dark/static or dark/agitation (100 rpm) in anaerobic conditions. The optimal pH, temperature and agitation speed for cell growth were 7, $30^{\circ}C$, 150 rpm, for IAA production were 9, $30^{\circ}C$, 150rpm and for carotenoid production were 6, $25^{\circ}C$, 50 rpm, cultured for 72 h under anaerobic light, respectively. The growth and IAA production were high in aerobic culture compared with anaerocic culture, whereas carotenoid and bacteriochlorophyll content were decreased extremely in aerobic condition (0.5~1 vvm). Subsequently, the optimal culture conditions for JK-1 were selected with pH 7, $30^{\circ}C$ and 100 rpm under anaerobic light and the effect on plant growth was tested by pot assay. Inoculation of JK-1 with 3% (v/v) level caused increase in shoot and root dry weigh that varied from 20%~58% to 40%~28% in young radish in camparison to uninoculated treatment at 50 days of growth. The study suggests that the JK-1 isolate may serve as efficient biofertilizer inoculants to promote plant growth.

• Korean Journal of Plant Tissue Culture
• /
• v.27 no.6
• /
• pp.423-428
• /
• 2000

In 1997 when cloned sheep Dolly and soon after Polly were born, it had become head-line news because in the former the nucleus that gave rise to the lamb came from cells of six-year-old adult sheep and in the latter case a foreign gene was inserted into the donor nucleus to make the cloned sheep produce human protein, factor IX, in e milk. In the last few years, once the realm of science fiction, cloned mammals especially in livestock have become almost commonplace. What the press accounts often fail to convey, however, is that behind every success lie hundreds of failures. Many of the nuclear-transferred egg cells fail to undergo normal cell divisions. Even when an embryo does successfully implant in the womb, pregnancy often ends in miscarriage. A significant fraction of the animals that are born die shortly after birth and some of those that survived have serious developmental abnormalities. Efficiency remains at less than one % out of some hundred attempts to clone an animal. These facts show that something is fundamentally wrong and enormous hurdles must be overcome before cloning becomes practical. Cloning researchers now tent to put aside their effort to create live animals in order to probe the fundamental questions on cell biology including stem cells, the questions of whether the hereditary material in the nucleus of each cell remains intact throughout development, and how transferred nucleus is reprogrammed exactly like the zygotic nucleus. Stem cells are defined as those cells which can divide to produce a daughter cell like themselves (self-renewal) as well as a daughter cell that will give rise to specific differentiated cells (cell-differentiation). Multicellular organisms are formed from a single totipotent stem cell commonly called fertilized egg or zygote. As this cell and its progeny undergo cell divisions the potency of the stem cells in each tissue and organ become gradually restricted in the order of totipotent, pluripotent, and multipotent. The differentiation potential of multipotent stem cells in each tissue has been thought to be limited to cell lineages present in the organ from which they were derived. Recent studies, however, revealed that multipotent stem cells derived from adult tissues have much wider differentiation potential than was previously thought. These cells can differentiate into developmentally unrelated cell types, such as nerve stem cell into blood cells or muscle stem cell into brain cells. Neural stem cells isolated from the adult forebrain were recently shown to be capable of repopulating the hematopoietic system and produce blood cells in irradiated condition. In plants although the term$\boxDr$ stem cell$\boxUl$is not used, some cells in the second layer of tunica at the apical meristem of shoot, some nucellar cells surrounding the embryo sac, and initial cells of adventive buds are considered to be equivalent to the totipotent stem cells of mammals. The telomere ends of linear eukaryotic chromosomes cannot be replicated because the RNA primer at the end of a completed lagging strand cannot be replaced with DNA, causing 5' end gap. A chromosome would be shortened by the length of RNA primer with every cycle of DNA replication and cell division. Essential genes located near the ends of chromosomes would inevitably be deleted by end-shortening, thereby killing the descendants of the original cells. Telomeric DNA has an unusual sequence consisting of up to 1,000 or more tandem repeat of a simple sequence. For example, chromosome of mammal including human has the repeating telomeric sequence of TTAGGG and that of higher plant is TTTAGGG. This non-genic tandem repeat prevents the death of cell despite the continued shortening of chromosome length. In contrast with the somatic cells germ line cells have the mechanism to fill-up the 5' end gap of telomere, thus maintaining the original length of chromosome. Cem line cells exhibit active enzyme telomerase which functions to maintain the stable length of telomere. Some of the cloned animals are reported prematurely getting old. It has to be ascertained whether the multipotent stem cells in the tissues of adult mammals have the original telomeres or shortened telomeres.

• Radiation Oncology Journal
• /
• v.19 no.4
• /
• pp.389-396
• /
• 2001

Purpose : To detect differentially expressed genes in the patients with uterine cervical cancer during the radiation therapy. Materials and Methods : In patients with biopsy proven uterine cervical cancer, we took tumor tissue just before radiation therapy and at 40 minutes after external irradiation of 1.8 Gy. Total RNAs isolated from non-irradiated and irradiated tumor tissue samples were analyzed using the differential-display reverse transcription-polymerase chain reaction (DDRT-PCR). Complementary DNA (cDNA) fragments corresponding to differentially expressed messenger RNAs(mRNAs) were eluted, and cloned. The differential expression of the corresponding mRNAs was confirmed by reverse northern blot. Differentially expressed cDNA bands were sequenced. Nucleotide sequence data were analyzed in the Gene Bank and EMBL databases via the BLAST network sewer to identify homologies to known genes or cDNA fragments. Expression pattern of down-regulated clone was examined using RT-PCR in S patients undergoing radiotherapy. Results : We identified 18 differentially expressed bands by DDRT-PCR, which were eluted and cloned. There were 10 up-regulated clones and 1 down-regulated clone in reverse northern blot. One cDNA fragment had homology to chemokine receptor CXCR4, four were identified as Human ESTs in the EMBL database in EST clones. Down-regulated CxCa-11 was also down regulated in all patients. Conclusion : Using the DDRT-PCR, we have identified 10 up-regulated and 1 down-regulated clone(s) in the patients with uterine cervical cancer during the radiation therapy. The clinical relevance and the functions of these genes will be further investigated.

• Journal of Chest Surgery
• /
• v.35 no.7
• /
• pp.511-516
• /
• 2002

Background: This study was undertaken in infant patients with isolated ventricular septal defect(VSD) to determine the effect of surgical closure on ventricular systolic time interval, as a parameter for ventricular performance, by echocardiography. Material and Method: Thirty patients were enrolled. Mean age of patients at operation was 6.5$\pm$3.2 months and all patients had non-restrictive VSD. We checked the left atrium/aorta(LA/Ao) ratio, left ventricle ejection fraction(EF), left ventricular systolic time interval(LVSTI), and right ventricular systolic time interval(RVSTI). Echocardiographic studies were done before surgical correction and postoperative periods(postopl: within 2 weeks, postop2: between 4 and 6 months, postop3: between 1 and 2 years). Result: LA/Ao ratio decreased significantly at immediate postoperative period compared to preoperative period and sustained during further follow-up period(from 1.74$\pm$0.37 to 1.36$\pm$0.24＊, 1.32$\pm$0.22＊, and 1.27$\pm$0.19＊, p<0.01). LV EF had not changed during follow-up periods(from 65.1$\pm$7.0 to 62.3$\pm$9.5, 62.8$\pm$5.7, and 64.1$\pm$6.9). LVSTI decreased significantly at postop2 and sustained during further follow-up period (from 0.46$\pm$0.13 to 0.46$\pm$0.11, 0.37$\pm$0.08＊, and 0.34$\pm$0.07＊, p<0.01). RVSTI decreased significantly at postop3(0.33$\pm$0.08 to 0.32$\pm$0.08, 0.31$\pm$0.07, and 0.27$\pm$0.05＊, p<0.01). Conclusion: We found that right and left ventricular systolic time intervals had decreased over the period of 1 year after surgical correction of VSD. Therefore, it is necessary to observe the change of ventricular function during that period.

• Clinical and Experimental Pediatrics
• /
• v.46 no.1
• /
• pp.42-50
• /
• 2003

Purpose : The acute respiratory distress syndrome(ARDS), an acute form of severe alveolar-capillary injury evolving after a direct or indirect lung insult is thought to be a common cause of respiratory failure though not many clinical studies on the subject have been made yet. Methods : Between January 1992 and December 2001, we conducted a retrospective study on 33 children who fulfilled the definition of the ARDS recommended by the American-European Consensus Conference in 1994. Results : A total of 33 patients(20 boys and 13 girls) were selected. Their age ranged from 4 months to 12 years with seven children younger than 1 year. The overall mortality rate was 78.8% and no significant difference was noted based on age or sex. Concerning seasonal variation, incidence of the ARDS increased in spring, especially in May(21.2%). Pneumonia(66.7%) was found to be the most common risk factor of the ARDS followed by sepsis(24.2%) and aspiration(3.0%). In immune compromised children(six cases), including a recipient of bone marrow transplantation, the mortality rate was 100%. Compared with children with multiple organ failure recording a 83.3% mortality rate, those with isolated respiratory failure, showed a lower mortality rate of 33.3%, although stastistically insignificant. Between survivor and non-survivor groups, significant differences were shown in hematocrit, $PaO_2$, $PaCO_2$, PEEP, and $PaO_2/FiO_2$ on the seventh day after the onset of the ARDS. Conclusion : According to our study, respiratory failure proved to have a great effect on mortality rate in the ARDS. More aggressive intervention and further studies on this subject should be done to improve the survival rate.

• Pediatric Infection and Vaccine
• /
• v.11 no.1
• /
• pp.90-100
• /
• 2004

Objective : Urinary tract infection(UTI) is a frequent serious bacterial infection in young infants. The clinical presentation may be non-specific and variable, depends on factors such as the age and the level of infection. Children with renal involvement may be at risk of permanent renal damage. Experimental studies have shown that renal lesions caused by acute febrile UTI may be prevented or diminished by early diagnosis and treatment. Therefore, it is important to find a method that can permit early diagnosis and identification of patients who are at risk for progressive renal damage. We designed this study to identify related factors in culture positive UTI infants, and also to identify related factors in culture negative UTI infants, who are febrile with pyuria, by using renal imaging and functional studies including renal sonography, DMSA scan and VCUG. Methods : Retrospectively analyzed the medical records of 136 febrile infants with pyuria over 2 years(from January 2001 to February 2003). Urine culture was done in all cases, and regardless of urine culture findings, renal imaging study was done if symptomatic UTI suspected. Results : Total 57 organisms were isolated in 53 patients. E. coli was the most common organism(86%), followed by E. faecalis, M. morganii, Proteus species, P. aeruginosa, S. aureus and E. fergusonii. Most of the isolates had high sensitivity on cephalosporins or amikacin and had low sensitivities on aminopenicillins. Abnormal acute phase DMSA scan or VCUG findings were seen in both urine culture positive and negative group without statistical differences(P>0.05). In febrile infants with pyuria, fever over 48 hours, older age and high CRP related to abnormal acute phase DMSA scan findings regardless urine culture results. Conclusion : 1st or 3rd generation cephalosporins with amikacin could be the first choice of treatment for UTI. Febrile infants with positive urine culture dose mean urinary tract infection but not acute pyelonephritis which directly relates to cortical damage which could be confirmed by acute phase DMSA scan. Even cases with negative urine culture findings, acute pyelonephritis should be concerned in febrile infants with pyuria who are older than 3 months of age, has fever over 48 hours or high CRP level. And in such cases, acute phase DMSA scan and VCUG should be evaluated for early treatment and long term prognosis.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.35 no.4
• /
• pp.321-326
• /
• 2015

This study was performed to analyze the resident microbial flora and the effects of probiotic inoculation on the fermentation characteristics of whole grain naked barley (Hordeum Vulgare L.) with the goal of evaluating the possibility of utilization as fermented feedstuff. Naked barley grains were harvested 35 days after heading, and the microbial flora was analyzed using MALDI-TOF mass spectrometer. After inoculation of commercial microbes to the naked barley grain (BT), the pH and number of bacteria, such as aerobic bacteria, lactic acid bacteria, yeast and E. coli, were measured and compared with the non-inoculated control (BC). A total of 122 colonies was isolated from the naked barley grain and the most popular bacteria species was Staphylococcus xylosus (n = 30, 24.59%). The pH value decreased more rapidly in BT than in BC, and was significantly lower after 7 days of fermentation at $4.33{\pm}0.02$ and $4.83{\pm}0.01$, respectively. The number of aerobic bacteria, lactic acid bacteria and yeast showed an increasing trend within the first 7 days of fermentation, however, their numbers decreased at 28 and 42 days of fermentation. The population of lactic acid bacteria in BT was higher than in BC, but there was no significant different at 7 days of fermentation, with respective levels of $9.24{\pm}0.20$ and $9.01{\pm}0.10logCFU/g$ (p>0.05). The initial number of E. coli was very high in the naked barley grain but subsequently decreased significantly. After 7 days of fermentation, E. coli was not detected in either BT or BC samples. From these results, it appears that the fermentation of naked barley grain proceeded adequately after 7 days, and that fermentation contributes to the safety of naked barley grain during storage.