• Journal of the korean society of oceanography
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• 제37권2호
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• pp.58-65
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• 2002

The study of microbial communities in sediments is impaired by the lack of reliable extraction methods. This study reports on the efficiency of recovery of a method for extracting bacteria, protists and diatoms from sandy sediments using a modified decant/fix method. The best extractions were achieved after fixation with a microtubule stabilising fixative and subsequent sonication for 80 seconds. We estimate that the efficiencies of recovery of bacteria and mixed heterotrophic flagellates were $96.4{\pm}3.5\%$ and $96.9{\pm}4.6\%$, respectively. Diatoms were recovered with an efficiency of 38-83% and varied considerably from species to species. This study suggests that the decant/fix method is effective in extracting small cells such as bacteria and heterotrophic flagellates, and that the efficiency of recovery of the method varies due to cell length and different types of organisms. When microbial carbon biomass had been underestimated by up to 32%, with much of that relating to larger cells such as microalgae and ciliates. We note that the corrected abundances may be still a subset of the total numbers present.

• 한국어류학회지
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• 제20권2호
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• pp.112-116
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• 2008

2005년 1월부터 2005년 12월까지 동대만의 잘피밭에서 채집된 산호해마(4.1~10.4 cm SL)의 식성을 조사하였다. 산호해마의 주요 먹이는 옆새우류였으며, 그 외, 카프렐라류, 주걱벌레붙이류, 요각류, 곤쟁이류 및 잘피 등을 소량 섭식하였다. 산호해마는 모든 체장에서 옆새우류를 주로 섭식하였으며, 작은 크기(<4.5 cm SL)에서는 요각류도 섭식하였다. 또한 성장함에 따라 섭식하는 먹이생물의 크기는 증가하였으나, dietary breadth는 서서히 감소하는 양상이었다.

• BMB Reports
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• 제44권1호
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• pp.1-10
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• 2011

Inter-cellular communication via diffusible small molecules is a defining character not only of multicellular forms of life but also of single-celled organisms. A large number of bacterial genes are regulated by the change of chemical milieu mediated by the local population density of its own species or others. The cell density-dependent "autoinducer" molecules regulate the expression of those genes involved in genetic competence, biofilm formation and persistence, virulence, sporulation, bioluminescence, antibiotic production, and many others. Recent innovations in recombinant DNA technology and micro-/nano-fluidics systems render the genetic circuitry responsible for cell-to-cell communication feasible to and malleable via synthetic biological approaches. Here we review the current understanding of the molecular biology of bacterial intercellular communication and the novel experimental protocols and platforms used to investigate this phenomenon. A particular emphasis is given to the genetic regulatory circuits that provide the standard building blocks which constitute the syntax of the biochemical communication network. Thus, this review gives focus to the engineering principles necessary for rewiring bacterial chemo-communication for various applications, ranging from population-level gene expression control to the study of host-pathogen interactions.

• Advances in Traditional Medicine
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• 제7권3호
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• pp.286-289
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• 2007

Heracleum nepalense D Don. (Umbelliferae) is a small shrub having high glabrescent stem found in stream banks in Sikkim. Various medicinal properties which include antidiarrhoeal, antiseptic, anti-influenzal etc. have been attributed for this plant in the traditional system of medicine in Sikkim. In present investigation the methanol extract of roots of Heracleum nepalense was subjected for its effectiveness against both Gram-positive and Gram-negative bacteria causing diarrhoea. The roots extract was tested for its minimum inhibitory concentration (MIC) against both Gram-positive and Gram-negative organisms causing diarrhoea. Further, the zones of inhibition produced by the crude extract against few sensitive strains was measured and compared with those of standard antibiotic ciprofloxacin. It is evident that the methanol extract is very active against the bacteria causing diarrhoea at low concentrations. The antibacterial efficacy of the root extract was found to decrease in the following order against different tested bacterial strains like Shigella dysenteriae, Escherichia coli, Shigella boydii, Vibrio cholerae, Salmonella typhimurium.

• 한국수산과학회지
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• 제30권5호
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• pp.896-902
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• 1997

1994년 1월부터 1994년 12월까지 광양만 대도주변 잘피밭에서 채집된 실고기의 식성을 조사하였다. 실고기는 요각류 (Copepoda)와 잘피의 엽상체에 부착하여 서식하는 단각류 (Amphipoda)의 일종인 옆새우류 (Gammaridea)를 주로 섭이하였으며, 그 외, 카프렐라류 (Caprellidea), 주걱벌레붙이류 (Tanaidacea), 곤쟁이류 (Mysidacea) 등을 소량 섭이하였다. 실고기는 성장함에 따라 섭이된 먹이생물 조성의 변동이 뚜렷하였다. 어린 실고기는 요각류를 주로 섭이하였으나, 체장이 증가하면서 옆새우류를 주로 섭이하였다. 먹이생물의 조성은 계절에 따라 변화되었는데, 봄철에는 요각류가, 여름철과 가을철에는 옆새우류가 주로 섭이되었다.

• Fisheries and Aquatic Sciences
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• 제14권4호
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• pp.333-337
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• 2011

A new and a unique Brachionus rotifer was found in Hwajinpo coastal lagoon in Gangwon Province, South Korea. This Brachionus certainly originated from the wild rather than from aquaculture stations because Hwajinpo coastal lagoon has been under rigorous control as a military protected area and therefore could not have been contaminated by aquaculture stations. The new strain was identified as Brachionus rotundiformis based upon its morphological characteristics. The parthenogenetic female of this new rotifer strain typically shows characters similar to those of B. rotundiformis, such as the pot shape of the body, rounded dorsal plate compared with flattened ventral plate, elliptical mictic egg, four frontal spines, six pointed occipital spines, non-nodal foot, two toes, trophi typical of the Brachionus genus with five uncus plates resembling comb teeth, one wide symmetrical manubrium and ramus, and no stiffened spine as is seen in freshwater Brachionus rotifers. Moreover, its lorica was rather small in size compared with other common rotifer strains that serve as live-food organisms (Guam, Thai, and Bali strains). This new and unique Korean brackish rotifer, a B. rotundiformis strain, was therefore named the National Fisheries Research and Development Institute (NFRDI) $N^{\circ}1$ rotifer strain.

• Journal of Plant Biotechnology
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• 제37권1호
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• pp.57-66
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• 2010

Programmed cell death systems are important for an active type of cell deaths. Among them, a type of programmed cell death, autophagy is activated in cancer cells in response to multiple stresses and has been demonstrated to promote tumor cell survival and drug resistance. Thus, in the area of cancer, over the time frame form around the 1940s to date, of the 155 small molecules, 73% are other than "synthetic", with 47% actually being either "natural products" or "directly derived therefrom". Autophagy has multiple physiological functions in multicellular organisms, including protein degradation and organelle turnover. Genes and proteins that constitute the basic machinery of the autophagic process were first identified in the yeast system and some of their mammalian orthologues have been characterized as well. Numerous oncogenes, including Akt1, Bcl-2, NF1, PDPK1, class I PI3K, PTEN, and Ras and oncosuppressors, inculuding Bec-1, Bif-1, DAPK-1, p53 and UVRAG suppress or promote the autophagy pathway. Regulation of autophagy in tumors is governed by similar principles of the normal cells, only in a much more complicated manner, given the frequently observed abnormal PI3K activation in cancer and the multitude of interactions between the PI3K/AKT/mTOR pathway and other cell signaling cascades, often also deregulated in tumor cells. Autophagy induction by some anticancer agents underlines the potential utility of its induction as a new cancer treatment modality of development for natural medicines.

• Tuberculosis and Respiratory Diseases
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• 제83권2호
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• pp.132-140
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• 2020

In human immunodeficiency virus (HIV)-infected patients, Pneumocystis jirovecii pneumonia (PCP) is a well-known opportunistic infection and its management has been established. However, PCP is an emerging threat to immunocompromised patients without HIV infection, such as those receiving novel immunosuppressive therapeutics for malignancy, organ transplantation, or connective tissue diseases. Clinical manifestations of PCP are quite different between patients with and without HIV infections. In patients without HIV infection, PCP rapidly progresses, is difficult to diagnose correctly, and causes severe respiratory failure with a poor prognosis. High-resolution computed tomography findings are different between PCP patients with HIV infection and those without. These differences in clinical and radiological features are due to severe or dysregulated inflammatory responses that are evoked by a relatively small number of Pneumocystis organisms in patients without HIV infection. In recent years, the usefulness of polymerase chain reaction and serum β-D-glucan assay for rapid and non-invasive diagnosis of PCP has been revealed. Although corticosteroid adjunctive to anti-Pneumocystis agents has been shown to be beneficial in some populations, the optimal dose and duration remain to be determined. Recent investigations revealed that Pneumocystis colonization is prevalent and that asymptomatic carriers are at risk for developing PCP and can serve as the reservoir for the spread of Pneumocystis by airborne transmission. These findings suggest the need for chemoprophylaxis in immunocompromised patients as well as infection control measures, although the indications remain controversial. Because a variety of novel immunosuppressive therapeutics have been emerging in medical practice, further innovations in the diagnosis and treatment of PCP are needed.

• 한국어류학회지
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• 제20권1호
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• pp.45-53
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• 2008

2005년 1월부터 2005년 12월까지 동대만의 잘피밭에서 채집된 돌팍망둑의 식성을 조사하였다. 돌팍망둑의 주요 먹이는 어류 및 새우류였으며, 그 외, 곤쟁이류, 단각류 (옆새우류 및 카프렐라류), 요각류, 두족류, 갯지렁이류 및 게류등이 소량 섭식되었다. 돌팍망둑은 초기에는 요각류와 단각류를 많이 섭식하였으나, 성장함에 따라 어류와 새우류의 섭식율이 점차 증가하였다. 돌팍망둑은 계절에 관계없이 새우류 및 어류를 주로 섭식하였다. 체장별 및 계절별 dietary breadth는 전체적으로 낮게 나타났다.

• 한국식품저장유통학회지
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• 제14권6호
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• pp.688-694
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• 2007

To evaluate the human risk of long-term intake of genetically modified (GM) rice, we carried out RT-PCR of housekeeping genes. Housekeeping genes, which show highly uniform expression in living organisms during various stages of development and under different environmental conditions, were normalized by RT-PCR. We assessed the expression of 10 common housekeeping genes (18s rRNA, 25S rRNA, UBC, UBQ5, UBQ10, ACT11, GAPDH, eEF-$1{\alpha}$, ${\beta}$-TUB, GAPDH, ${\beta}$-actin, B2m, G6pd2, Gyk, Gus, Hprt, Cyclophlin A, Tfrc, ${\alpha}$-tubulin and RPL13A) in the liver, stomach, small intestine, large intestine, kidney and spleen of mice fed GM or non-GM rice. We found no significant differences in the expression of housekeeping genes between the two groups of mice.