• Korean Journal of Veterinary Research
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• v.24 no.2
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• pp.137-147
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• 1984

Cells with an epithelioid morphology were isolated from the rabbit myometrium and were grown in culture. The cells had a doubling time of 53 hours when grown in the presence of 10% fetal calf serum in Basal Eagle's medium with 3mM glutamine. In the presence of estrogen plus insulin, doubling time was reduced to 40 hours. Creatine kinase activity upon reaching confluency was determined to be 0.019 unit per mg protein. Approximately 30% of the activity was extractable only in high ionic strength buffer. Cells also contained plasminogen activator with a specific activity of 140 CTA units per million cells. Creatine kinase was mainly BB form. The cells contained a cross reactive protein against bovine smooth muscle uterine anti-myosin.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8387-8390
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• 2016

Background: Treatment of biochemical failure after radical prostatectomy for prostate cancer is largely empirically based. The use of PSA kinetics has been used as a guide to determine local or systemic treatment of biochemical failure. We here compared PSA kinetics with detection of bone marrow micrometastasis as methods to determine local or systemic relapse. Materials and Methods: A transversal study was conducted of men with biochemical failure, defined as a serum PSA >0.2ng/ml after radical prostatectomy. Consecutive patients having undergone radical prostatectomy and with biochemical failure were enrolled and clinical and pathological details were recorded. Bone marrow biopsies were obtained from the iliac crest and touch prints made, micrometastasis (mM) being detected using anti-PSA. The clinical parameters of total serum PSA, PSA velocity, PSA doubling time and time to biochemical failure, age, Gleason score and pathological stage were registered. Results: A total of 147 men, mean age $71.6{\pm}8.2years$, with a median time to biochemical failure of 5.5 years (IQR 1.0-6.3 years) participated in the study. Bone marrow samples were positive for micrometastasis in 98/147 (67%) of patients at the time of biochemical failure. The results of bone marrow micrometastasis detected by immunocytochemistry were not concordant with local relapse as defined by PSA velocity, time to biochemical failure or Gleason score. In men with a PSA doubling time of < six months or a total serum PSA of >2,5ng/ml at the time of biochemical failure the detection of bone marrow micrometastasis was significantly higher. Conclusions: The detection of bone marrow micrometastasis could be useful in defining systemic relapse, this minimally invasive procedure warranting further studies with a larger group of patients.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.5
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• pp.100-108
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• 2010

An autocorrelation method is used in pitch estimation. Autocorrelation values in time and frequency domains, which have different characteristics, correspond to the pitch period and fundamental frequency, respectively. We utilize an integrated autocorrelation method in time and frequency domains. It can remove the errors of pitch doubling and having. In the time and frequency domains, pitch period and fundamental frequency have reciprocal relation to each other. Especially, fundamental frequency estimation ends up as an error because of the resolution of FFT. To reduce these artifacts, interpolation methods are applied in the integrated autocorrelation domain, which decreases pitch errors. Moreover, only for the pitch candidates found in a time domain, the corresponding frequency-domain autocorrelation values are calculated with reduced computational complexity. Using linear interpolation, we can decrease the required number of FFT coefficients by 8 times. Thus, compared to the conventional methods, computational complexity can be reduced by 9.5 times.

• Radiation Oncology Journal
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• v.19 no.2
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• pp.163-170
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• 2001

Purpose : The measurement of radiation survival using a clonogenic assay, the established standard, can be difficult and time consuming. In this study, We have used the MTT assay, based on the reduction of a tetrazolium salt to a purple formazan precipitate by living cells, as a substitution for clonogenic assay and have examined the optimal condition for performing this assay in determination of radiation sensitivity. Materials and Methods : Four human cancer cell lines - PCI-1, SNU-1066, NCI-H630 and RKO cells have been used. For each cell line, a clonogenic assay and a MTT assay using Premix WST-1 solution, which is one of the tetrazolium salts and does not require washing or solubilization of the precipitate were carried out after irradiation of 0, 2, 4, 6, 8, 10 Gy. For clonogenic assay, cells in $25\;cm^2$ flasks were irradiated after overnight incubation and the resultant colonies containing more than 50 cells were scored after culturing the cells for $10\~14$ days. For MTT assay, the relationship between absorbance and cell number, optimal seeding cell number, and optimal timing of assay was determined. Then, MTT assay was performed when the irradiated cells had regained exponential growth or when the non-irradiated cells had undergone four or more doubling times. Results : There was minimal variation in the values gained from these two methods with the standard deviation generally less than $5\%$, and there were no statistically significant differences between two methods according to t-test in low radiation dose (below 6 Gy). The regression analyses showed high linear correlation with the $R^2$ value of $0.975\~0.992$ between data from the two different methods. The optimal cell numbers for MTT assay were found to be dependent on plating efficiency of used cell line. Less than 300 cells/well were appropriate for cells with high plating efficiency (more than $30\%$). For cells with low plating efficiency (less than $30\%$), 500 cells/well or more were appropriate for assay. The optimal time for MTT assay was after 6 doubling times for the results compatible with those of clonogenic assay, at least after 4 doubling times was required for valid results. In consideration of practical limits of assay (12 days, in this study) cells with doubling time more than 3 days were inappropriate for application. Conclusion : In conclusion, it is found that MTT assay can successfully replace clonogenic assay of tested cancer cell lines after irradiation only if MTT assay was undertaken with optimal assay conditions that included plating efficiency of each cell line and doubling time at least.

• The Transactions of the Korea Information Processing Society
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• v.3 no.4
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• pp.877-882
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• 1996

The effects of periodic and chaotic behaviour in the Bonhoeffer-Van der Pol (BVP) oscillation of the nerve membrane driven by a periodic stimulating current A1 coswtare investigated through hardware implementation.For hardware implementation of the BVP model. real element values were escaled with computer simulation results to determine the parameter real value.As the parameter A1 varied in the range 0 to 1.3, the BVP model showed an ordinary and reversed period-doubling cascade and a chaotic state. At the low driving amplitude ofa1 the period-doubling showed and at the high driving amplitude of A1 the chaotic state occured. To analyse the BVP model for chaotic behaviour Phase Plane, Time series are used to verify that properties.

• Journal of Ginseng Research
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• v.10 no.1
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• pp.27-35
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• 1986

This study was devised to observed the growth inhibition and change of disaccharidase activities of human colon cancer cells cultured in medium containing the ginseng extract. Three species of human colon cancer cell lines, HRT-18, HCT-48 and HT-29, were used for the experiment. The activities of sucrease, lactase, maltase and trehalase in the cancer cells were determined. The results obtained are summarized as follows; 1. The doubling times of the HRT-18, HT-29 and HCT-48 were about 20,22 and 24 hours, respectively. 2. The growth rates of the HRT-18 and HCT-48 in culture medium containing the ginseng extract were inhibited gradually according to increase of the concentration of ginseng extract and extension of the incubation time. 3. The activities of disaccharidase in HRT-18 and HCT-48 cultured in the medium containing the ginseng extract were increased compared with control group as follows;

• Microbiology and Biotechnology Letters
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• v.26 no.4
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• pp.303-308
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• 1998

A bacterial strain which utilizes phenol under denitrifying condition was isolated from the industrial waste water collected from the Chong-ju Industrial Complex. The strain was identified as Pseudomonas species from the morphological, physiological, and biochemical characteristics and designated as HL100. The strain can utilize phenol as the sole source of carbon and energy when nitrate is provided as the terminal electron acceptor. The isolated strain completely degraded 3 mM of phenol within 110 hour with concomitant reduction of nitrate to nitrite. The observed maximum doubling time was 20 hours. Under appropriate condition, complete reduction of nitrate to atmospheric N$_2$ was observed indicating that the isolated strain could perform complete steps of denitrification. The strain showed optimal growth at pH 7.0 and temperature of 37$^{\circ}C$ under denitrifying phenol-degrading condition. The strain can also utilize toluene as the sole carbon and energy source under the same growth condition. However, no growth was detected on xylene and benzene.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7575-7582
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• 2015

Cyclin E, a key coordinator of the G1 to S transition in the cell cycle, may be deregulated in several malignancies, including breast cancer. The most significant aberration in cyclin E is its elastase mediated proteolytic cleavage into tumor specific low molecular weight isoforms (LMW-Es). LMW-Es are biochemically hyperactive and biologically drive tumorigenesis in transgenic mouse models. Additionally, expression of LMW-Es has been correlated with poor survival in breast cancer cases. Here we determine whether expression of LMW-Es in a breast cancer cell line that is naturally devoid of these deregulated forms would alter their progression through each phase of the cell cycle. The results revealed that LMW-Es expression resulted in an increased doubling time, concomitant with a predominant increase in the population in the S phase of the cell cycle. Moreover, downregulation of p53 in LMW-Es cells resulted in additional shortening of the doubling time and enrichment of cells in the S and G2/M phases of the cell cycle. Furthermore, expression of LMW-Es sensitized cells to ${\beta}$-estradiol (E2) mediated growth and changed expression patterns of estrogen receptor and Bcl-2. Intriguingly, expression of LMW-Es could surpass anti-apoptotic effects raised by p53 upregulation. Taken together these studies suggest that overexpression of LMW-Es in collaboration with p53 loss results in altered g rowth properties of MCF-7 cells, enhancing the oncogenic activity of these ER positive breast cancer cells.

• Journal of Microbiology and Biotechnology
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• v.9 no.5
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• pp.604-612
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• 1999

A puc-deleted cell of Rhodobacter sphaeroides grows with a doubling time longer than 160 h under light-limiting photoheterotrophic (3 Watts [W]/㎡) conditions due to an absence of the peripheral light-harvesting B800-850 complex. A spontaneous fast-growing mutant, R. sphaeroides SK101, was isolated from the puc-deleted cells cultured photoheterotrophically at 3 W/㎡. This mutant grew with an approximately 40-h doubling time. The growth of the mutant, however, was indistinguishable from its parental strain during photoheterotrophic growth at 10 W/㎡ as well as during aerobic growth. The membrane of SK101 grown aerobically did not reveal the presence of any spectral complex, while the amounts of the B875 complex and photosynthetic pigments of SK101 grown anaerobiclly in the dark with dimethylsulfoxide (DMSO) were the same as those of the parental cell. These results indicate that the oxygen control of the photosynthetic complex formation remained unaltered in the mutant. The B875 complex of SK101 under light-limiting conditions was elevated by 20％ to 30％ compared with that of the parental cell, which reflected the parallel increase of the bacteriochlorophyll and carotenoid contents of the mutant. When the puc was restored in SK101, the B875 complex level remained unchanged, but that of the B800-850 complex increased. The mutated phenotype of SK101 was complemented with orfQ encoding a putative bacteriochlorophyll-mobilizing protein. Accordingly, it is proposed that the mutated OrfQ of SK101 should have an altered affinity towards the assembly factor specific to the most peripheral light-harvesting complex, which could be either the B875 or the B800-850 complex.

• Korean Journal of Animal Reproduction
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• v.25 no.3
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• pp.219-225
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• 2001

To establish rabbit Embryonic Stem (ES) cells, rabbit one-cell embryos were collected and cultured in vitro to blastocysts. Blastocysts were co-cultured with mouse embryonic fibroblasts (MEF), rabbit embryonic fibroblasts (REF) or 570 cells expressing LIF (SNL). Although rabbit ES cells were isolated with low efficiencies, total 8 ES cell lines were kept in vitro with normal colony shape. The MEF was the best feeder for rabbit ES cell isolation in regard to growth rate and undifferentiated morphology. The doubling time of rabbit ES cells in MEF was about 84 hours and the undifferentiated morphology was maintained following passing and freezing processes. These rabbit ES cells were differentiated into embryoid body following the culture in the uncoated dishes, indicating that they were undifferentiated stem cells.