• 한국식품과학회지
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• 제54권2호
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• pp.203-208
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• 2022

본 연구에서는 글루텐 분해능을 가지는 유산균을 선별하기 위해 전통식품인 젓갈을 이용하였다. 선별된 균주는 API, 16S rRNA sequencing과 현미경을 통해 간균의 형태를 갖는 Lactobacillus paracasei로 동정되었고 이를 GLU70으로 명명하기로 하였다. MRS 배지에서 GLU70의 생육특성을 조사한 결과, 6시간부터 12시간까지 대수기이며 12시간 이후부터 정지기임을 확인하였다. 이렇게 동정된 GLU70을 글루텐이 함유된 MRS배지에서 시간별로 배양하였을 때 대수기인 12시간 이후부터 24시간 이전까지 글루텐 분해가 가속화되었고, 48시간에서 최대 45% 정도의 분해율을 나타내었다. 또한 GLU70이 유산균으로서 적합하기 위해서 가져야하는 내산성, 내담즙성, 내열성에 대한 분석을 실시하였다. 많은 연구에서 Lactobacillus 종이 pH 2.5 이상에서는 균의 생존율이 높았지만, 그 이하에서는 거의 생존하지 않는다고 보고하고 있다 (Shin 등, 1999). 이에 따라 분리한 GLU70에서도 유사하게 pH 2.0에서는 균이 사멸하였고 pH 3.0부터 약 84%의 생존율을 보였고 많은 연구들과 유사한 결과를 가지는 것을 통해 우수한 내산성을 가지는 것을 확인하였다. 내담즙성의 경우 oxgall이 0.3% 함유된 배지에서 성장할 수 있을 정도의 내성을 가져야 한다는 연구결과와 비교하였을 때 GLU70은 담즙에 대하여 매우 강한 내성을 가지고 있다고 보기는 어렵다. 또한 내열성에 대한 연구결과에서는 50℃ 이상의 온도에서는 사멸하였으나 30℃에서는 높은 생존율을 나타냈다. 또한 분리된 GLU70이 실제 밀가루 반죽에서 감소하는 글루텐 함량을 분석하였을 때 12 h 배양한 배양상등액을 넣어 25℃에서 24 h 동안 발효한 밀가루 반죽에서 가장 높은 분해력을 확인하였다. 또한 밀가루 반죽의 발효 온도에 따른 글루텐 분해율을 타 균주와 비교하여 GLU70의 우수성을 판단하고자 하였다. GRAS 인정 유산균 11종과 GLU70을 각각 밀가루 반죽에 넣은 후 25℃와 35℃에서 발효하였다. 그 결과 GLU70이 타 균주들과 비교하였을 때 모든 온도에서 반죽이 흘러내리는 등의 이상현상 없이 50% 이상의 매우 높은 글루텐 분해율을 보였다. 이를 통해 GLU70이 향후 식품 산업에 다양한 활용 가능성을 지니며 글루텐 저감화 밀가루 제조 등에 적용하기에 적합하다고 제시된다.

• Reproductive and Developmental Biology
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• 제29권2호
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• pp.101-108
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• 2005

Tumor necrosis factor-related apoptosis inducing ligand (TRAIL) is a well-known inducer of apoptotic cell death in many tumor cells. 1RAIL is expressed in human placenta, and cytotrophoblast cells express 1RAIL receptors. However, the role of TRAIL in human placentas and cytotrophoblast cells is not. well understood. In this study a trophoblast cell line, JEG-3, was used as a model system to examine the effect of TRAIL. on key intracellular signaling pathways involved in the control of trophoblastic cell apoptosis and survival JEG-3 cells expressed receptors for 1RAIL, death receptor (DR) 4, DR5, decoy receptor (OcR) 1 and DeR2. Recombinant human TRAIL (rhTRAIL) did not have a cytotoxic effect determined by MIT assay and did not induce apoptotic cell death determined by poly-(ADP-ribose) polymerase cleavage assay. rhTRAIL induced a rapid and transient nuclear translocation of nuclear $factor-{\kappa}B(NF-{\kappa}B)$ determined by immunoblotting using nuclear protein extracts. rhTRAIL rapidly activated extracellular signal-regulated protein kinase (ERK) 1/2 as determined by immnoblotting for phospho-ERK1/2. However, c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (p38MAPK) and Akt (protein kinase B) were not activated by rhTRAIL. The ability of 1RAIL to induce $NF-{\kappa}B$ and ERK1/2 suggests that interaction between TRAIL and its receptors may play an important role in trophoblast cell function during pregnancy.

• Clinical and Experimental Reproductive Medicine
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• 제39권4호
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• pp.153-160
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• 2012

Objective: The aim of this study was to compare vitrification optimization of mouse embryos using electron microscopy (EM) grid, cryotop, and thin plastic strip (TPS) containers by evaluating developmental competence and apoptosis rates. Methods: Mouse embryos were obtained from superovulated mice. Mouse cleavage-stage, expanded, hatching-stage, and hatched-stage embryos were cryopreserved in EM grid, cryotop, and TPS containers by vitrification in 15% ethylene glycol, 15% dimethylsulfoxide, 10 ${\mu}g/mL$ Ficoll, and 0.65 M sucrose, and 20% serum substitute supplement (SSS) with basal medium, respectively. For the three groups in which the embryos were thawed in the EM grid, cryotop, and TPS containers, the thawing solution consisted of 0.25 M sucrose, 0.125 M sucrose, and 20% SSS with basal medium, respectively. Rates of survival, re-expansion, reaching the hatched stage, and apoptosis after thawing were compared among the three groups. Results: Developmental competence after thawing of vitrified expanded and hatching-stage blastocysts using cryotop and TPS methods were significantly higher than survival using the EM grid (p<0.05). Also, apoptosis positive nuclei rates after thawing of vitrified expanded blastocysts using cryotop and TPS were significantly lower than when using the EM grid (p<0.05). Conclusion: The TPS vitrification method has the advantages of achieving a high developmental ability and effective preservation.

• Journal of Microbiology and Biotechnology
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• 제27권5호
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• pp.1010-1022
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• 2017

Hybrid histidine kinase is part of a two-component system that is required for various stress responses and pathogenesis of pathogenic fungi. The Tco1 gene in human pathogen Cryptococcus neoformans encodes a hybrid histidine kinase and is important for pathogenesis. In this study, we identified a Tco1 homolog, UmTco1, in the maize pathogen Ustilago maydis by bioinformatics analysis. To explore the role of UmTco1 in the survival of U. maydis under environmental stresses and its pathogenesis, ${\Delta}umtco1$ mutants were constructed by allelic exchange. The growth of ${\Delta}umtco1$ mutants was significantly impaired when they were cultured under hyperosmotic stress. The ${\Delta}umtco1$ mutants exhibited increased resistance to antifungal agent fludioxonil. In particular, the ${\Delta}umtco1$ mutants were unable to produce cytokinesis or conjugation tubes, and to develop fuzzy filaments, resulting in impaired mating between compatible strains. The expression levels of Prf1, Pra1, and Mfa1, which are involved in the pheromone pathway, were significantly decreased in the ${\Delta}umtco1$ mutants. In inoculation tests to the host plant, the ${\Delta}umtco1$ mutants showed significantly reduced ability in the production of anthocyanin pigments and tumor development on maize leaves. Overall, the combined results indicated that UmTco1 plays important roles in the survival under hyperosmotic stress, and contributes to cytokinesis, sexual development, and virulence of U. maydis by regulating the expression of the genes involved in the pheromone pathway.

• 한국수산과학회지
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• 제50권2호
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• pp.153-159
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• 2017

We examined changes in the physiological responses of gray mullet Mugil cephalus exposed to acidic seawater (pH 6.0, 6.5, 7.0) and normal seawater (pH 8.0, control) for 15 days. As pH decreased, survival rate and body weight also decreased. Levels of aminotransferase, total protein and triglycerides also differed significantly with changes in pH, presumably due to stress caused by exposure to acidic water. The level of osmotic pressure was significantly higher in the pH 6.0 group than in other groups. Superoxide dismutase was significantly higher in the pH 6.5 and 7.0 groups than in the pH 8.0 group, and glutathione level was lowest in the pH 6.0 group. We conclude that decreasing the pH level of seawater induces a stress response in fish, damaging their ability to control their hematological and osmotic pressure. Antioxidant enzymes are generally sensitive to osmotic stress; in this study, antioxidant activity significantly changed with pH level. These results indicate that physiological stress induced by exposure to acidification reduces survival rates and inhibits growth in M. cephalus.

• Parasites, Hosts and Diseases
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• 제55권5호
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• pp.505-512
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• 2017

Toxoplasma gondii cathepsin C proteases (TgCPC1, 2, and 3) are important for the growth and survival of T. gondii. In the present study, B-cell and T-cell epitopes of TgCPC1 were predicted using DNAstar and the Immune Epitope Database. A TgCPC1 DNA vaccine was constructed, and its ability to induce protective immune responses against toxoplasmosis in BALB/c mice was evaluated in the presence or absence of the adjuvant ${\alpha}-GalCer$. As results, TgCPC1 DNA vaccine with or without adjuvant ${\alpha}-GalCer$ showed higher levels of IgG and IgG2a in the serum, as well as IL-2 and $IFN-{\gamma}$ in the spleen compared to controls (PBS, pEGFP-C1, and ${\alpha}-GalCer$). Upon challenge infection with tachyzoites of T. gondii (RH), $pCPC1/{\alpha}-GalCer$ immunized mice showed the longest survival among all the groups. Mice vaccinated with DNA vaccine without adjuvant (pCPC1) showed better protective immunity compared to other controls (PBS, pEGFP-C1, and ${\alpha}-GalCer$). These results indicate that a DNA vaccine encoding TgCPC1 is a potential vaccine candidate against toxoplasmosis.

• 한국축산식품학회지
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• 제34권2호
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• pp.230-237
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• 2014

This study was designed to find the most suitable method and wall material for microencapsulation of the Lactobacillus plantarum to maintain cell viability in different environmental conditions. To improve the stability of L. plantarum, we developed an encapsulation system of L. plantarum, using water-in-oil emulsion system. For the encapsulation of L. plantarum, corn starch and glyceryl monostearate were selected to form gel beads. Then 10% (w/v) of starch was gelatinized by autoclaving to transit gel state, and cooled down at $60^{\circ}C$ and mixed with L. plantarum to encapsulate it. The encapsulated L. plantarum was tested for the tolerance of acidic conditions at different temperatures to investigate the encapsulation ability. The study indicated that the survival rate of the microencapsulated cells in starch matrix was significantly higher than that of free cells in low pH conditions with relatively higher temperature. The results showed that corn starch as a wall material and glycerol monostearate as a gelling agent in encapsulation could play a role in the viability of lactic acid bacteria in extreme conditions. Using the current study, it would be possible to formulate a new water-in-oil system as applied in the protection of L. plantarum from the gastric conditions for the encapsulation system used in chicken feed industry.

• Asian Pacific Journal of Cancer Prevention
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• 제14권10호
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• pp.5579-5587
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• 2013

Research indicates that a small population of cancer cells is highly tumorigenic, endowed with the capacity for self-renewal, and has the ability to differentiate into cells that constitute the bulk of tumors. These cells are considered the "drivers" of the tumorigenic process in some tumor types, and have been named cancer stem cells (CSC). Epithelial-mesenchymal transition (EMT) appears to be involved in the process leading to the acquisition of stemness by epithelial tumor cells. Through this process, cells acquire an invasive phenotype that may contribute to tumor recurrence and metastasis. CSC have been identified in human head and neck squamous cell carcinomas (HNSCC) using markers such as CD133 and CD44 expression, and aldehyde dehydrogenase (ALDH) activity. Head and neck cancer stem cells reside primarily in perivascular niches in the invasive fronts where endothelial-cell initiated events contribute to their survival and function. Clinically, CSC enrichment has been shown to be enhanced in recurrent disease, treatment failure and metastasis. CSC represent a novel target of study given their slow growth and innate mechanisms conferring treatment resistance. Further understanding of their unique phenotype may reveal potential molecular targets to improve therapeutic and survival outcomes in patients with HNSCC. Here, we discuss the state-of-the-knowledge on the pathobiology of cancer stem cells, with a focus on the impact of these cells on head and neck tumor progression, metastasis and recurrence due to treatment failure.

• 대한핵의학회:학술대회논문집
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• 대한핵의학회 2002년도 춘계학술대회 및 총회
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• pp.17-24
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• 2002

Recurrence of colorectal cancer after apparently curative resection remains common, with reported relapse rates of up to 40%. Because complete resection of solitary metastases or local recurrence may improve long-term survival, surgical management of such cases has become increasingly aggressive but has led to only modest survival benefit. The limitations of current approaches based on structural imaging are well documented, with over half of the patients who are thought suitable for curative surgery being found to have unresectable disease at operation. Therefore, better preoperative assessment is crucial. The increasing use of FDG-PET as an oncologic staging investigation has significantly improved the assessment of patients with suspected colorectal cancer recurrence. Several studios show that substantial and largely appropriate changes in patient management occur, often soaring patients the significant morbidity and mortality associated with aggressive but futile therapies while also saving scarce community resources. Nevertheless, the clinical relevance of these findings has still been questioned. The utility of PET in routine clinical practice will likely depend on its ability to provide incremental information compared with CT in selected patients rather than to serve as a replacement for CT. In conclusion, in patients with suspected recurrent or metastatic colorectal carcinoma, FDG-PET should be performed (1) when there is rising carcinoembryonic antigen levels in the absence of a known source, (2) to increase the specificity of structural imaging when there is an equivocal lesion, and (3) as a screening method for the entire body in the preoperative staging before curative resection of recurrent disease.

• 대한한방종양학회지
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• 제9권1호
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• pp.99-108
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• 2003

Recently, the proportion of the population older has increased rapidly. As the aged population is increasing, the prevalence of malignancy rises with age, too. We believe that the potential benefits of approach to cancer care in the elderly are self-evident. In order to investigate the characteristics of cancer in the elderly, we reviewed literature related with the biology of the aged with cancer. The elderly undergo age-related changes in their physiology which may result in altered tolerance to disease and to the requirements of the management of illness. The possible reasons for the increased prevalence of cancer in the elderly are a longer potential duration of exposure to carcinogens, a reduced ability of repair DNA and reduced host defences against malignancy. In general, cancer patients in the elderly have a shorter survival. Because it is impossible to offer the active treatment of cancer in the elderly. Also, they have the problems that the psychosocial change and reduce of physiological function such as absorption, metabolism and excretion. We hope that other groups will further research cancer in the elderly in future.