• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.22 no.3
• /
• pp.143-154
• /
• 2016

The purpose of this study was investigated the quality changes before and after harvesting, storage and, processing of onion. Experiments were carried out to compare the effect on the characteristics of the postharvest from preharvest factors using onion. This experiment had identified the characteristics of harvested onions after cultivating with several preharvest factors such as the light and water conditions. These tests were conducted in an onion growth in the field, storage, and processing of fresh-cut during a laboratory periods of 2 years. In first year, onion cultivars ('Kars' and 'Pop') were produced under stable or unstable environment conditions, these onions were stored at low temperature(0?). Measurement was evaluated by the growth amount after harvesting, and the fresh weight loss and respiration rate during storage. According to different culture conditions and storage temperatures, it was investigated the properties of the fresh-cut onion. Growth of onion was varied depending on the cultivars and culture conditions. The amount of growth on 'Kars' and 'Pop' onions were decreased by excessive soil water conditions with shading. These influences were found the morphological differences resulting for the cell tissue of onion being rough and large. Onion cultivated in excessive soil water with shading affected the degree of its respiration rate and fresh weight loss during storage. Ones in excessive soil water with shading were higher than the control in fresh weight loss and respiration rate, respectively. However fresh-cut onion could not investigated to clarify the difference due to effects of cultivation condition and storage temperature on some measure items such as electrolyte leakage and microbial number change. There was a change of only electrolyte leakage depending on the storage temperature, rather than cultivated conditions before harvesting factor. The results showed that the onion grown on in the good environment was represented to a good quality produce even after harvesting.

• Korean Journal of Plant Tissue Culture
• /
• v.24 no.1
• /
• pp.1-35
• /
• 1997

Fertilized egg, by successive cell divisions, differentiates into different tissues and organs with various structures and functions. Different cells and tissues contain different proteins, products of selective gene expression. Not all the genes in any genomes are equally active, temporal and spatial gene expression being the general rule. Present paper attempts to review the tanscriptional mechanisms or the initiations of transcription from several angles. In some of the organisms the genes in the process of transcription or the genes in the inactive state can be seen under the light microscope. Some bands of Drosophila polytene chromosomes may exhibit a swollen or puff appearance under certain conditions. A puff, unfolded or decondensed form of chromomere, represents sets of intense transcriptional activity or RNA synthesis. The heterochromatic X chromosome whose genes remain inactive in the female mammals can be visualized as a dark staining structure called Barr body, Configuration of chromatin differs between transcribed and nontranscribed chromatin. Modification to the chromatin facilitates RNA synthesis. The movement of large polymerase molecule along the DNA would probably be facilitated if some modifications of the chromatin configuration is effected. Methylation of cytosines in CG sequences is associated with inactive genes. Methylation can play a role in determination of mammalian cells during embryogenesis. Demethylation is necessary for the gene to be expressed during development A histone modification that is also known to be correlated with transcriptional capacity of chromatin is acetylation of the lysine residues of the core histones. Chromatin containing a high level of histone acetylation is very sensitive to DNase 1. For the transcription to occur TBP must first bind to the TATA box. Another TF, TF IIB, then binds to the promoter-TBP complex, facilitating the access of RNA polymerase to the transcription initiation site. As recently as eight years ago researchers assumed that histones were irrelevant to the regulation of gene expression. Histones combine with the DNA to form nucleosome of the chromatin. Histones are vital participant in gene regulation. Histone and basal factors compete for access to TATA box. When DNA is exposed to basal factors before histones are introduced, the basal factors assemble on TATA boxes preventing the access of histones, allowing transcription to occur, for transcription to begin, activator protein at the upstream activation sequence or enhancer must interact with the tail of histone H4 at TATA box and cause the histone role particle to dissociate from the TATA box leading to partial breakup of the histone core particle and allowing the basal factors to bind to the TATA box. New concept of genomic flux in contrast to the old concept of static genome has been developed based on the powerful new molecular techniques. Genomic changes such as repetitive DNAs and transposable elements, it is assumed but not yet proved, may affect some of the developmental patterns that characterize particular cells, tissues, organs, and organisms. In the last decade or so remarkable achievement have been made in the researches of the structures and functions of TFs and the specific target sequences located in promoters or enhancers where these TFs bind. TFs have independent domains that bind DNA and that activate transcription. DNA binding domain of TFs serves to bring the protein into the right location. There are many types of DNA binding domains. Common types of motifs can be found that are responsible for binding to DNA. The motifs are usually quite short and comprise only a small part of the protein structure. Steroid receptors have domains for hormone binding, DNA binding, and activating transcription. The zinc finger motif comprises a DNA binding domain. Leucine zipper consist of a stretch of amino acids with a leucine residue in every seventh position Two proteins form a dimer because they interact by means of leucine zippers on similar α-helical domain. This positions their DNA binding basic domains for interaction with the two halves of a DNA sequence with dyad symmetry of TGACTCA, ACTGAGT.

• Korean Journal of Environmental Biology
• /
• v.17 no.4
• /
• pp.481-492
• /
• 1999

The observations on the spatio-temporal distribution and seasonal fluctuations of phytoplankton community were carried out in Deukryang Bay of the Korean Southwestern Sea from June 1992 to April 1993. A total of 75 species of phytoplankton belonged to 47 genera was identified. In Deukryang Bay seasonal succession in dominant species; P. alata, G. flaccida, S. costatum, L. danicus and N. longissima in summer, St. palmeriana, Ch. curvisetus and B. paxillifera in autunm, S. costatum, Ch. curvisetus, E. zodiacus and Pn. pungens in winter, and As. glacialis, As. kariana, N. pelagica, Th. nitzschioides and S. costatum in spring, were very marked, that is to say, the communities structure of phytoplankton in Deukryang Bay appeared to be various species composition and it was occupied with diatoms all the year round. Phytoplankton standing crops fluctuated with an annual mean of $1.4{\times}10^5 cells/1 between the lowest value of 2.6{\times}10^3 cells/1 in July and the highest value of 1.0{\times}10^6 cells/1$ by S. costatum in January. Densities of the phytoplankton cell number by the samples of Deukryang Bay ranged from $2.6{\times}10^3cells/1 to 1.2{\times}10^5 cells/1 with the mean value of 3.6{\times}10^4cells/1 in summer, from 6.0{\times}10^3cells/1 to 2.6{\times}10^5 cells/1 with mean of 1.5{\times}10^5 cells/1 in autumn, from 1.3{\times}10^4cells/1 to 1.0{\times}10^6 cells/1 with mean 3.5{times}10^5 cells/1 in winter, and from 4.8{\times}10^3cells/1 to 6.0{\times}10^5 cells/1 with mean of 1.6{\times}10^5 cells/1$ in autumn. That is to say, phytoplankton standing crops was large in low temperature seasons, on the other hand small in high temperature seasons. Chlorophyll $\alpha$ concentration fluctuated between 0.l9 $\mu$g/l and 12.3 $\mu$g/l in March. in Deukryang Bay seasonal flucturation in chi-$\alpha$ concentration was not marked. Especially, chl-$\alpha$ concentration in the water around Deukryang Island located in the middle part of Deukryang Bay showed patchy distributions with a very high concentration. And chl-$\alpha$ concentration was high during a year. Therefore, phytoplankton production in Deukryang Bay could be very high year-round.

• Journal of Chest Surgery
• /
• v.31 no.8
• /
• pp.739-748
• /
• 1998

Background: It has been well documented that transient occlusion of the coronary artery causes myocardial ischemia and finally cell death when ischemia is sustained for more than 20 minutes. Extensive studies have revealed that ischemic myocardium cannot recover without reperfusion by adequate restoration of blood flow, however, reperfusion can cause long-lasting cardiac dysfunction and aggravation of structural damage. The author therefore attempted to examine the effect of postischemic reperfusion on myocardial ultrastructure and to determine the rationales for recanalization therapy to salvage ischemic myocardium. Materials and methods: Young Holstein-Friesian cows(130∼140 Kg body weight; n=40) of both sexes, maintained with nutritionally balanced diet and under constant conditions, were used. The left anterior descending coronary artery(LAD) was occluded by ligation with 4-0 silk snare for 20 minutes and recanalized by release of the ligation under continuous intravenous drip anesthesia with sodium pentobarbital(0.15 mg/Kg/min). Drill biopsies of the risk area (antero-lateral wall) were performed at just on reperfusion(5 minutes), 1-, 2-, 3-, 6-, 12-hours after recanalization, and at 1-hour assist(only with mechanical respiration and fluid replacement) after 12-hour recanalization. The materials were subdivided into subepicardial and subendocardial tissues. Tissue samples were examined with a transmission electron microscope (Philips EM 300) at the accelerating voltage of 60 KeV. Results: After a 20-minute ligation of the LAD, myocytes showed slight to moderate degree of ultrastructural changes including subsarcolemmal bleb formation, loss of nuclear matrix, clumping of chromatin and margination, mitochondrial destruction, and contracture of sarcomeres. However, microvascular structures were relatively well preserved. After 1-hour reperfusion, nuclear and mitochondrial matrices reappeared and intravascular plugging by polymorphonuclear leukocytes or platelets was observed. However, nucleoli and intramitochondrial granules reappeared within 3 hours of reperfusion and a large number of myocytes were recovered progressively within 6 hours of reperfusion. Recovery was apparent in the subepicardial myocytes and there were no distinct changes in the ultrastructure except narrowed lumen of the microvessels in the later period of reperfusion. Conclusions: It is likely that the ischemic myocardium could not be salvaged without adequate restoration of coronary flow and that the microvasculature is more resistant to reversible period of ischemia than subendocardium and subepicardium. Therefore, thrombolysis and/or angioplasty may be a rational method of therapy for coronarogenic myocardial ischemia. However, it may take a relatively longer period of time to recover from ischemic insult and reperfusion injury should be considered.

• Journal of Food Hygiene and Safety
• /
• v.23 no.3
• /
• pp.264-270
• /
• 2008

Phytic acid(PA) (Inositol hexaphosphate, $IP_6$) is a naturally occurring polyphosphorylated carbohydrate that is present in substantial amounts in almost all plants and mammalian cells. Recently PA has received much attention for its role in anticancer activity. In the present study, the preventive effects of PA on colon carcinogenesis were investigated. Six-week old Fisher 344 male rats were fed a AIN-93G purified diet and PA(0.5% or 2% PA in water) for 8 weeks. The animals received two ($1^{st}\;and\;2^{nd}$ week) injections of azoxymethane(AOM, 15 mg/kg b.w.) to induce colonic aberrant crypt foci(ACF). After sacrifice, the total numbers of aberrant crypts(AC) and ACF in colonic mucosa were examined after staining with methylene blue. Blood and serum were analyzed with a blood cell differential counter and an automatic serum analyzer. AOM induced the total numbers of $142.3{\pm}22.3$ ACF/colon and $336.6{\pm}55.1$ AC/colon. PA at the doses of 0.5 and 2% decreased the numbers of ACF and AC/colon in a dose-dependent manner. The numbers of ACF/colon and AC/colon by PA at the dose of 0.5% were $124.4{\pm}28.5\;and\;302.7{\pm}67.3$, respectively. PA at the dose of 2% significantly decreased the ACF and AC numbers to $109{\pm}18.1\;and\;254.8{\pm}50.6$, respectively(p<0.01). Especially, 2% PA significantly reduced the number of large ACF(${\geq}4$ AC/ACF) from $26.8{\pm}6.2$ ACF/colon to $15{\pm}6.7$ ACF/colon(p<0.01). Although some parameters in blood counts and serum chemistry were changed compared with the control, no specific toxicity was found. These findings suggest that phytic acid can be a chemopreventive agent for colon carcinogenesis resulting from inhibition of the development of ACF in the F344 rat.

• Journal of Yeungnam Medical Science
• /
• v.9 no.2
• /
• pp.288-301
• /
• 1992

The objective of the present study was to identify the characteristics of phospholipase C (PLC) isozymes purified from bovine brain and to investigate their interrelationship with G protein. The purified PLC isozymes ${\beta}$, ${\gamma}$ and ${\delta}$ were obtained and the characteristics of PLC activity on various concentrations of free $Ca^{2+}$ were observed. The activity of PLC was increased with increasing $Ca^{2+}$ concentration and the activity PLC ${\delta}$ was increased higher in the presence of phosphatidyl choline(PC) than in the abscence of PC. For vesicle formation as the structure of cell membrane, cholic acid and deoxycholic acid as detergent on phosphatidylinositol bisphosphate($PIP_2$) substrate containing PC were used, and then the activity of PLC isozymes were increased with increasing concentration of cholate, from 0.2% to 1% and were increased slightly in deoxycholate. In the $PIP_2$ containing phospholipid and glycolipid as brain extract, the activity of PLC isozymes were checked in 0.2%-1% cholic acid. The activities of PLC isoyzmes were continuously increased up to 1% cholic acid. The quantitation of PLC isozymes from several bovine organs by radioimmunoassay was made. Brain was the most sufficient organ in terms of amount of PLC ${\beta}$and ${\delta}$. A large amount of PLC ${\delta}$ was existed in adrenal gland. The binding capacity of GTPrS and G protein was observed and other observations of the binding effect of GTPrS-G protein and PLC monoclonal Ab-Protein A from tissue homogenate with PLC were made. From the observation the binding capacity was revealed the range of 0.11%-1.49%. The effects of each type of G protein on the percent activity of purified PLC isozymes were observed. From the observation, activities of isozymes were increased in $Go{\alpha}$ & Gmix, and the activities of PLC ${\beta}$ and ${\delta}$ were increased in $G{\beta}{\gamma}$ and $Gi{\alpha}$. Activities of PLC ${\beta}$ and ${\gamma}$ were decreased in $Gt{\alpha}$ but PLC ${\delta}$ increased.

• The Korean Journal of Physiology
• /
• v.2 no.1
• /
• pp.23-30
• /
• 1968

Tissue homogenates of 12 kinds of human cancer tissues were incubated separately in medium containing $C^{14}-1-glucose$ and $C^{14}-6-glucose$ as a substrate in order to observe the oxidative pathway of glucose in the tumor tissues. At the end of 3 hours incubation in the Dubnuff metabolic shaking incubator, respiratory $CO_2$ samples trapped by alkaling which was placed in the center well of incubation flask were analysed for total $CO_2$ production rates and their radioactivities. The tissue homogenate samples after incubation were analyzed for their concentrations of glucose, lactate and pyruvate. Calculations were made on the glucose consumption rate and accumulation rates of lactate and pyruvate. Fractionation of oxidative pathway of glucose was carried out by calculating $C^{14}O_2 yields from C-1 and C-6 carbon of glucose. The following results were obtained. 1. In 12 kinds of human cancer, total $CO_2$ production rates were less than $8{\mu}M/gm$ except 2 cases. These lower values impressed that oxidative metabolism in the tumor tissues generally inhibited as compared with that in normal tissues. On the other hand, fractions of $CO_2$ derived from glucose to total $CO_2$ production rates (RSA) were less than 10% in every case. These facts showed that oxidation of glucose into $CO_2$ was remarkably inhibited in the tumor tissues. 2. Factions of glucose disappeared into $CO_2\;(RGD_{CO_2})$, lactate $(RGD_L)$, pyruvate $(RGD_P)$ to glucose consumption rates were as follows. $RGD_{CO_2}$ were less than 2% in cases of in this experiment and $RGD_L$ showed more than 5% except in 2 cases. These facts showed that anaerobic degradation of glucose into 3 carbon compounds was easily proceeded but further degradation into $CO_2$ via the TCA cycle was greatly inhibited resulting in accumulation of lactate. There are large variation in values of $RGD_P$ in different kinds of tumor tissue but relatively higher values in $RGD_{CO_2}$ were obtained in the tumor tissues as compared with those of normal tissues. 3. The oxidative pathway of glucose in tumor tissues were analyzed from the values of RSA which were obtained in $C^{14}-1\;and\;C^{14}-6-glucose$ incubation experiments. It was found that 3% of $CO_2$ derived from glucose were oxidized via the principal EMP-TCA cycle and the remainder were via alternate pathway such as HMP in the liver cancer and values in other cancer tissues were as follows; 4% in the tongue cancer, 6% in the colon cancer, 6% in the lung cancer, 9% in the stomach cancer, 11% in the ovarian cancer, 12% in the neck tumor, 22% in the uterine cancer, 22% in the bladder tumor, 32% in the spindle cell sarcoma and 65% in the brain tumor. These values except later 2 cases showed less than 30% which is the lowest value among the normal tissues. Even in the brain tumor in which showed highest value in the tumor group. It is reasonable to suppose that this fraction was remarkably decreased because values in normal brain tissue was more than 90%. From the above data, it was concluded that in tumor tissues, oxidation of glucose via TCA cycle was greatly inhibited but correlation between degree of inhibited oxidation of glucose via TCA cycle and malignancy of tumor were not clarified in this experiments.

• Microbiology and Biotechnology Letters
• /
• v.41 no.4
• /
• pp.407-415
• /
• 2013

In this study, we investigated the antioxidant activities on HaCaT and the whitening effects on B16F1 melanoma cells of Dendropanax morbifera leaf extract. In an antioxidative activity assay using HaCaT cells, the ethyl acetate ($50{\mu}g/ml$) and aglycone fractions ($25{\mu}g/ml$) of the D. morbifera leaf extract didn't exhibit any characteristics of cytotoxicity. When HaCaT cells were exposed to a single large dose ($800mJ/cm^2$) of UVB, the extracts protected the cells against UVB radiation. When HaCaT cells were treated with 10 mM $H_2O_2$ and $4{\mu}M$ rose bengal, the ethyl acetate ($6.25{\sim}50{\mu}g/ml$) and aglycone ($6.25{\sim}25{\mu}g/ml$) fractions protected the cells against oxidative damage in a concentration dependent manner. When the whitening effects of D. morbifera leaf extract were tested in melanoma B16/F1 cells treated with the a-melanocyte stimulating hormone (${\alpha}$-MSH), the extracts inhibited ${\alpha}$-MSH-stimulated intra/extracellular melanogenesis in a concentration dependent manner. The inhibitory effects of the ethyl acetate and aglycone fractions of D. morbifera leaf extract were 21% and 44% at $25{\mu}g/ml$, respectively. Both are more effective than arbutin (15% at $25{\mu}g/ml$) which is known as a whitening agent. These results indicate that fractions of the D. morbifera leaf can function as cell protectants and natural antioxidants in biological systems, particularly skins exposed to UV radiation by quenching and/or scavenging $^1O_2$ and other ROS, and protecting cells against ROS. In addition, fractions of the D. morbifera leaf can be applied to new whitening cosmetics because of their inhibitory effects on ${\alpha}$-MSH stimulated melanogenesis in B16F1 melanoma cells.

• Tuberculosis and Respiratory Diseases
• /
• v.47 no.2
• /
• pp.172-183
• /
• 1999

Background: Nitric oxide is a short-lived effector molecule derived from L-arginine by the nitric oxide synthase(NOS). Nitric oxide plays a role in a number of physiologic and pathophysiologic functions including host defense, edema formation, and regulation of smooth muscle tone. Some kinds of cells including macrophage are known to produce large quantities of nitric oxide in response to inflammatory stimuli such as interleukin-$1\beta$(IL-$1\beta$), tumor necrosis factor-$\alpha$(TNF-$\alpha$), interferon-$\gamma$(IFN-$\gamma$) and lipopolysaccharide(LPS). Reactive oxygen species are also known to be important in the pathogenesis of acute cell and tissue injury such as acute lung injury model Methods: Using the RA W264.7 cells, we have examined the ability of oxidant hydrogen peroxide($H_2O_2$) to stimulate nitric oxide production and inducible NOS mRNA expression. Also, we have examined the effects of NOS inhibitors and antioxidants on $H_2O_2$ induced nitric oxide production. Results: Stimulation of RAW264.7 cells with combinations of 100 ng/ml IL-$1\beta$, 100 ng/ml TNF-$\alpha$, and 100 U/ml IFN-$\gamma$ or 100 U/ml IFN-$\gamma$ and $1{\mu}g/ml$ LPS induced the synthesis of nitric oxide as measured by the oxidation products nitrite($NO_2^-$) and nitrate($NO_3^-$). Addition of $250 {\mu}M-2$ mM $H_2O_2$ to the cytokines significantly augmented the synthesis of $NO_2^-$ and $NO_3^-$(p<0.05). When cells were incubated with increasing concentrations of $H_2O_2$ in the presence of IL-$1\beta$, TNF-$\alpha$ and IFN-$\gamma$ at constant level, the synthesis of $NO_2^-$ and $NO_3^-$ was dose-dependently increased(p<0.05). $N^G$-nitro-L-arginine methyl ester(L-NAME), dose dependently, significantly inhibited the formation of $NO_2^-$ and $NO_3^-$ in cells stimulated with LPS, IFN-$\gamma$ and $H_2O_2$ at constant level(p<0.05). Catalase significantly inhibited the $H_2O_2$-induced augmentation of cytokine-induced $NO_2^-$ and $NO_3^-$ formation(p<0.05). But, boiled catalase did not produce a significant inhibition in comparison with the native enzyme. Another antioxidant 2-mercaptoethanol and orthophenanthroline dose-dependently suppressed $NO_2^-$ and $NO_3^-$ synthesis(p<0.05). Northern blotting demonstrated that H:02 synergistically stimulated the cytokine-induced iNOS mRNA expression in RA W264.7. Conclusion: These results suggest that $H_2O_2$ contributes to inflammatory process by augmenting the iNOS expression and nitric oxide synthesis induced by cytokines.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.20 no.3
• /
• pp.151-157
• /
• 2015

Recent laboratory studies have documented that mixotrophic dinoflagellates Dinophysis spp. and heterotrophic dinoflagellate Oxyphysis oxytoxoides share a common prey, i.e. the mixotrophic ciliate Mesodinium rubrum. Nonetheless, very little is known about the population dynamics and species interactions among these protists in natural environments. To investigate the interactions between the dinoflagellate predators and their ciliate prey in the field, we took the samples twice a day from 26 July to 28 August, 2011 at a fixed station in Masan Bay and analyzed their abundances. During this study, salinity was highly variable, ranging from 5 to 28, due to the periodic input of rainfalls to the sampling station. Water temperature was on average $26.5^{\circ}C$ until 20 August and thereafter was about $21^{\circ}C$ by the end of the sampling period. The ciliate M. rubrum occurred persistently throughout the sampling period, ranging from 13 to $492\;cells\;mL^{-1}$. Cell densities of D. acuminata and O. oxytoxoides ranged from undetectable level to $19,833\;cells\;L^{-1}$ and from undetectable level to $100,333\;cells\;L^{-1}$, respectively. The high abundance of D. acuminata mostly followed the blooming of the ciliate M. rubrum, but it often did not peak even during heavy blooms of the prey, probably due to sensitivity to large salinity fluctuation and also presumably overlapped grazing by other mixotrophic dinoflagellates. The abundance of O. oxytoxoides was detected only when water temperature was lower than $24^{\circ}C$, indicating that water temperature is an important environmental factor to control the population dynamics of the dinoflagellate species.