• Title/Summary/Keyword: Lethal concentration

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Solvent Fractionation of Fig Leaves and its Antimicrobial Activity (무화과 잎의 용매분획 및 항미생물 활성)

  • Kang, Seong-Kuk;Chung, Hee-Jong
    • Applied Biological Chemistry
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    • v.38 no.4
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    • pp.289-292
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    • 1995
  • Fig leaves were extracted with methanol and then fractionated with ethyl acetate and various buffers to get active fractions, and their antimicrobial activities in each fraction were determined. Acidic fraction and phenolic fraction of fig leaves showed strong antimicrobial activities, but the basic fraction and neutral fraction did not show any activities. The degree of antimicrobial activities in phenolic fraction against tested bacteria were higher than those in acidic fraction, but these against yeasts and mold were almost equivalent to those in acidic fraction. Especially, phenolic fraction showed the strongest activities against Staphylococcuns aureus and Pseudomonas aeruginosa. Although there were some differences among microorganisms, minimum inhibition concentrations(MIC) in acidic and phenolic fractions against tested microorganisms were 0.05 to 0.1 g eq./ml and 0.01 to 0.25 g eq./ml, on the basis of fresh sample weight, respectively. Minimum lethal concentrations(MLC) in acidic and phenolic fractions were 0.25 to 2.00 g eq./ml and 0.05 to 1.50 g eq./ml, respectively. These supposed the antimicrobial activities in phenolic fraction were generally higher than those in acidic fraction and also phenolic fraction had lower MIC and MLC values than acidic fraction.

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Effects of Cryoprotectants on Survival and Hatching of Black Seabream, Acanthopagrus schlegeli Embryos (감성돔, Acanthopagrus schlegeli 배의 생존과 부화에 미치는 동해방지제의 영향)

  • 임한규;장영진;조필규
    • Journal of Aquaculture
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    • v.16 no.4
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    • pp.262-266
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    • 2003
  • In order to develop a method for the cryopreservation of fish embryos, the determination of optimal concentrations of dimethyl sulfoxide (DMSO), ethylene glycol and glycerol as individual cryoprotectants was performed by using the early embryos of black seabream, Acanthopagrus schlegeli. Optimal concentrations of cryoprotectants were assessed in terms of effects on mortality, median lethal concentration and hatching rate of embryos. The mortality of black seabream embryos immersed in cryoprotectants was related to the concentrations of cryoprotectants and immersion times. The toxicity to embryos was lower in order of DMSO, < ethylene glycol, < glycerol. The results from the mortality, median lethal concentration and hatching rate evaluations suggest that DMSO was the most effective cryoprotectant for black seabream embryos followed by ethylene glycol, and suitable concentrations of DMSO and ethylene glycol were 2.0∼2.25M and 1.0∼1.78M, respectively, with 20 minutes of immersion time.

Biodiesel - derive d Pentaerythritol Lubricant Oil Bases Earthworm Using Toxicity Test (지렁이를 이용한 바이오디젤 유래 펜타에리쓰리톨계 윤활유 베이스의 환경 독성 테스트)

  • Jung Haeyoung;Park Wanseon;Kim Eui Yong;Chae Hee Jeong
    • Proceedings of the KAIS Fall Conference
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    • 2004.06a
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    • pp.311-314
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    • 2004
  • Toxicity test fur various synthetic lubricant oil bases derived from biodiesel was carried out. The earthworms(Eisenia fetida) were maintanied in artificial soil consisting of sand for 14 days. Eisenia fetida was cultivated at temperature of $20{\pm}2^{\circ}C$, pH 6.0 $\pm$ 0.5 and moisture of $31\~37\%$. Pentaerythritol(PE) lubricant oil base was tested for acute toxicities to Eisenia fetida. The earthworms were exposed to each lubricant oil with various concentrations of lubricant oil base. After 14 days, the number of surviving earthworms and thier weight alteration during the test period was determined. $LC_{50}$(lethal concentration when $50\%$ of the population were killed) pentaerythritol was determined to be 1,555 mg/kg soil dry weight.

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Short-term behavioral responses and tolerance limits of red seabream Pagrus major fingerlings following sudden low salinity exposure (급격한 저염분 노출에 따른 참돔 Pagrus major 치어의 단기 행동반응 및 내성 한계에 관한 연구)

  • Sung Jin Yoon
    • Korean Journal of Environmental Biology
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    • v.39 no.4
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    • pp.495-506
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    • 2021
  • In this study, using a continuous behavior measurement technique, the short-term behavioral responses and tolerance limits of red seabream Pagrus major fingerlings to sudden exposure to low salinity in a controlled environment were observed. The activity of the fingerlings suddenly exposed to 21.4, 17.3, and 9.8 psu increased temporarily at the initial exposure to show irregular swimming behavior, but then recovered a stable activity pattern through rapid salinity adaptation. However, the organisms suddenly exposed to 7.3 and 4.3 psu could not withstand the salinity stress, and their swimming behavior was severely disturbed and all individuals died within 48 hours. The findings suggest that red seabream underwent a temporary salinity stress process at the beginning of the exposure to concentrations of 10.0 psu or higher. At these concentrations, osmotic control was possible within at least 11 hours, so stable metabolic activity was also possible. However, organisms suddenly exposed to concentrations below 5.0 psu exceeded the tolerance to low salinity and the sublethal limit. In red seabream exposed to this concentration range, severe behavioral and metabolic disturbances were observed, and death was observed due to osmotic control failure. In conclusion, a salinity range of 5.0 to 10.0 psu can be predicted to correspond to a concentration range in which the osmotic control ability of the red seabream fingerlings is lost, and sub-lethal reactions occur.

Assessment of acute inhalation toxicity of citric acid and sodium hypochlorite in rats

  • Jinhee Kim;Chul-Min Park;Su Hyun Choi;Mi Jin Yang;Ju-Yeon Lee;Byung-Suk Jeon;Hyun-Ok Ku;Min-Seok Kim
    • Journal of Veterinary Science
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    • v.24 no.2
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    • pp.22.1-22.12
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    • 2023
  • Background: Citric acid (CA) and sodium hypochlorite (NaOCl) have been used to disinfect animals to protect them against avian influenza and foot-and-mouth disease. Objectives: We performed a good laboratory practice (GLP)-compliant animal toxicity study to assess the acute toxic effects of CA and NaOCl aerosol exposure in Sprague-Dawley rats. Methods: Groups of five rats per sex were exposed for 4 h to four concentrations of the two chemicals, i.e., 0.00, 0.22, 0.67, and 2.00 mg/L, using a nose-only exposure. After a single exposure to the chemicals, clinical signs, body weight, and mortality was observed during the observation period. On day 15, an autopsy, and then gross findings, and histopathological analysis were performed. Results: After exposure to CA and NaOCl, body weight loss was observed but recovered. Two males died in the CA 2.00 mg/L group and, two males and one female died in the 2.00 mg/L NaOCl group. In the gross findings and histopathological analysis, discoloration of the lungs was observed in the CA exposed group and inflammatory lesions with discoloration of the lungs were observed in the NaOCl exposed group. These results suggest that the lethal concentration 50 (LC50) of CA is 1.73390 mg/L for males and > 1.70 mg/L for females. For NaOCl, the LC50 was 2.22222 mg/L for males and 2.39456 mg/L for females. Conclusions: The Globally Harmonized System is category 4 for both CA and NaOCl. In this study, the LC50 results were obtained through a GLP-based acute inhalation toxicity assessment. These results provide useful data to reset safety standards for CA and NaOCl use.

The Effects of Lead(II) Nitrate on the Embryo Development in Native Amphibians (질산납이 한국산 무미양서류의 배아발달에 미치는 영향)

  • Lee, Hae-Bum;Ko, Sun-Kun
    • Korean Journal of Environmental Biology
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    • v.35 no.4
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    • pp.706-714
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    • 2017
  • An investigation of the effects of Pb for domestic anuran embryos were evaluated with the Frog Embryo Teratogenesis Assay; Xenopus (FETAX). Depending on the species, the difference between the embryo size and the embryonic development time was determined. As a result, mortality and malformation rates were increased, malformation patterns were changed and larval body length were decreased in a dose dependent manner of the Pb. The half maximal lethal concentration ($LC_{50}$) of the Bufo gargarizans, Hyla japonica, Rana nigromaculata and Bombina orientalis were 0.58, 0.49, 0.52, $0.54mg\;L^{-1}$, respectively. The half maximal effective concentration ($EC_{50}$) of the Bufo gargarizans, Hyla japonica, Rana nigromaculata and Bombina orientalis were 0.35, 0.74, 0.30, $0.29mg\;L^{-1}$, respectively. The teratogenic index (TI) were 1.66 in the Bufo gargarizans, 1.81 in the Hyla japonica, 1.73 in the Rana nigromaculata and 1.86 in the Bombina orientalis, respectively. Therefore, the Pb seems likely to have a teratogenic effect in all four species' embryonic development. The Bombina orientalis was the most sensitive to the Pb. This means that the difference between the different species, even if they have all been exposed to the same concentration of pollutants depending on the species. The result above show that the Pb acts as a teratogenic agent in the development of the four domestic frog species.

Helicobactericidal Activity of Cissus quadrangularis L. Variant I

  • Austin, Anoop;M, Jegadeesan;R., Gowrishankar
    • Natural Product Sciences
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    • v.10 no.5
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    • pp.217-219
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    • 2004
  • Cissus quadrangularis L. variant I (Family: Vitaceae), the common variant with square stem is widely used for peptic ulcer disorders (PUD) in traditional medicine. Aerial parts were collected during flowering and vegetative seasons and analysed. Aqueous (hot and cold) and solvent extracts (acetone, chloroform and ethanol) were screened for their anti-Helicobacter pylori (Hp) activities. Among them chloroform extract was observed to recover bioactive principles markedly with low minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC). MIC was $30\;{\mu}g$ in both samples and MLC was $35\;{\mu}g$ for vegetative and $30\;{\mu}g$ for flowering seasons, respectively. Extracts from samples collected during flowering season were better than thse of vegetative season.

Antiprotozoal Activity of Deacetylated Chitosan Oligosaccharide (dp 2-8) on Trichomonas vaginalis

  • Shin, Woon-Seob;Kil, Jun-Cheul;Park, Gab-Man
    • Journal of Microbiology and Biotechnology
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    • v.16 no.12
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    • pp.1984-1989
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    • 2006
  • Deacetylated chitosan oligosaccharide (COS) had effective antiprotozoal activity against Trichomonas vaginalis (Minimal Inhibitory Concentration, MIC 0.25%), whereas 80% acetylated cas showed no antiprotozoal activity (MIC > 1 %). an the other hand, 80% acetylated cas showed growth stimulatory activity against the protozoa. When T. vaginalis was treated with 98% deacetylated COS at 0.25% concentration, the viability of the protozoa was rapidly decreased within 15 min, and the protozoa completely died within 40 min. Ultrastructural changes of trichomonads treated with COS included a loss of defined nuclear membrane and endoplasmic reticulum membranes, an increase in the number of free ribosome, vacuolation, and ultimately lysis of the cell membrane. These results indicate that deacetylated COS can be used as an antitrichomonal agent, although its lethal mechanism is not known.

Chitosan for the Removal of Mercury, Hg (수중에서 카이토산에 의한 수은 제거)

  • Seok, Kyu-Jin
    • Journal of Aquaculture
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    • v.5 no.2
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    • pp.177-182
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    • 1992
  • Experiments were conducted with goldfish exposed to various levels of mercuric chloride(control group) and mercuric chloride with chitosan (experimental group). Dilutions of these two solutions were made in the concentration ranges 0.6 to 1.0 $mg/{\ell}$ and 1.2 to 2.0 $mg/{\ell}$, respectively. Fifty percent lethal concentration of mercuric chloride($LC_{50}$) for 48 hours with the species was between 0.6 and 0.7 $mg/{\ell}$. Exposure of goldfish to mercury produced a marked, dose-dependent mortality with elevation of concentration (P<0.05). However, at each concentration of mercuric chloride treated with chitosan, mortality decreased significantly compared to control group (P<0.05).

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Anti-inflammatory Effects of Gagamtunong-san (가감투농산(加減透膿散)의 항염작용에 대한 실험적 연구)

  • Kim, Sang-Jin;Yoo, Dong-Youl
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.22 no.1
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    • pp.100-107
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    • 2008
  • The purpose of this research was to investigate the anti-inflammatory effects of Gagamtunong-san(GTNS) which has been medicated the patient such as mastitis. The results were as follows. The cytotoxicity on mouse lung fibroblast Cells(mLFC) was not served at all concentration of GTNS. GTNS in RAW264.7 cell inhibited $IL-1{\beta}$, IL-6, $TNF-{\alpha}$, COX-2 and NOS-II mRNA genes expression in a concentration-dependent manner. Specially GTNS inhibited NOS-II production very significantly at 100 ${\mu}g/ml$. GTNS inhibited NO production significantly in a concentration-dependent manner. GTNS inhibited ROS production in a concentration-dependent manner. GTNS inhibited $IL-1{\beta}$, IL-6 and $TNF-{\alpha}$ production significantly in serum of acute anti-inflammation-induced mice. GTNS increased the survival rate from the 3rd day on LPS-induced lethal endotoxemia. These results suggest that Gagamtunong-san(GTNS) can be useful in treating a lot of women mammary diseases caused by inflammation such as acute and chronic mastitis.