• Title/Summary/Keyword: LD 50

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Target Strength of Schlegel′s Black Rockfish (Sebastes schlegeli)and Red Seabream (Pagrus major) (조피볼락과 참돔의 표적 강도에 관한 연구)

  • 손창환;황두진
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.38 no.2
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    • pp.119-128
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    • 2002
  • This study investigates dorsal aspect target strength with fish size, tilt angle and frequency characteristics for the schlegel's black rockfish(Sebastes achlegeli) and the red seabream (Pagrus major). This study was carried out on free swimming fish in a cage in order to obtain acoustic data of the biomass estimation using the scientific echo sounder. The results obtained from this study are summarized as follows; 1 The coefficients of the schlegel's black rockfish and the red seabream using maximum TS with fish length were expressed -63.7dB and -62.6dB at a frequency of 38kHz, -64.4dB and -65.4dB at 120kHz, and -62.4dB and -65.0dB at 200kHz, respectively. 2. The coefficients of the schlegel\`s black rockfish and the red seabream using averaged TS with fish length were expressed -68.4dB and -67.9dB at a frequency of 38kHz, -73.4dB and -72.7dB at 120kHz, and -70.BdE and -73.4dB at 2001Hs, respectively. 3. The coefficients of the schlegel's black rockfish and the red seabream using maximum TS with body weight were expressed -52.0dB and -50.9dB at a frequency of 38kHz, -52.7dB and -53.7dB at 120kHz, and -50.7dB and -53.3dB at 200kHz, respectively. 4. The coefficients of the schlegel's black rockfish and the red seabream using averaged TS with body weight were expressed -56.7dB and -56.2dB at a frequency of 38kHz, -61.7dB and -61.0dB at 120kHz, and -59.ldE and -61.6dB at 200kHz, respectively. 5. Varying the tiIt angle of the two red seabream from -26$^{\circ}$to +25$^{\circ}$, the variation width of target strength expressed smaller at a frequency of 38kHz than at 120kHz and expressed about 3~6dB higher head up than head down at 120kHz.

Studies on the Interactions of $M_1-,M_2-receptors$ with Nicotinic Receptors in Rabbit Sympathetic Ganglia (가토 교감신경절에서 무스카린성 수용체 아형과 니코틴성 수용체의 상호작용에 대한 연구)

  • Kim, Jong-Keun;Rhu, Choon-Sik;Kang, Sam-Suk
    • The Korean Journal of Pharmacology
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    • v.28 no.2
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    • pp.171-179
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    • 1992
  • Effects of a $M_1$ receptor antagonist, pirenzepine, a $M_2$ receptor antagonist, AF-DX116, and a nicotinic receptor antagonist, mecamylamine on the pressor responses to preganglionic sympathetic nerve stimulation (PNS) and McN-A-343 and DMPP in spinal (pithed) rabbits were investigated, in order to elucidate a functional role of $M_1$, $M_2$ and nicotinic receptors in ganglionic transmission. Pirenzepine and AF-DX116 selectively inhibited the McN-A-343-induced pressor response in chlorisondamine-treated rabbit and the BCh-induced bradycardia, respectively. Electrical stimulations of preganglionic sympathetic outflow at T8 level produced increases in blood pressure. Pirenzepine $(3\;{\mu}g/kg)$ significantly inhibited the PNS-induced pressor response and the degree of inhibition was not changed by increasing the doses to $100\;{\mu}g/kg$. AF-DX116 $(100\;{\mu}g/kg)$ had no effect on the PNS-induced pressor response. Mecamylamine inhibited the PNS-induced pressor response in a dose-dependent manner. The inhibitory action of mecamylamine was significantly augmented by combined-treatment with pirenzepine $(30\;{\mu}g/kg)$ but AF-DX116 $(100\;{\mu}g/kg)$ did not affect the inhibitory action of mecamylamine. McN-A-343 and DMPP elicited pressor response in the spinal rabbit. Pirenzepine and AF-DX116 dose-dependently inhibited the McN-A-343-induced pressor response but they did not affect DMPP-induced pressor response. Mecamylamine inhibited both pressor responses induced by McN-A-343 and DMPP. These results suggest that not only nicotinic receptors but also $M_1$ receptors play a facilitatory role in ganglionic transmission but $M_2$ receptors do not contribute the transmission in spinal (pithed) rabbits.

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Spatial Variation Analysis of Soil Characteristics and Crop Growth across the Land-partitioned Boundary II. Spatial Variation of Soil Chemical Properties (구획경계선(區劃境界線)의 횡단면(橫斷面)에 따른 토양특성(土壤特性)과 작물생육(作物生育)에 관한 공간변이성(空間變異性) 분석연구 II. 토양(土壤) 화학성(化學性)의 공간변이성(空間變異性))

  • Park, Moo-Eon;Yoo, Sun-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.22 no.4
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    • pp.257-264
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    • 1989
  • In order to study spatial variability of soil chemical properties across the land-partitioned boundary on Hwadong silt clay loam soil (Fine clayey, mixed, mesic family of Aquic Hapludalfs) in the experimental fie ld of the wheat and Barley Research Institute in Suwon, all measured data were analyzed by means of kriging, fractile diagram, smooth frequency distribution, and autocorrelation. Sampling for soil chemical property analysis was made at 225 intersections of 15x 15 grid with 10m interval from three soil depths (0-10cm, 25-35cm, 50-60cm) in the seven patitioned fields. 1. The coefficient of variance (CV) of various chemical properties varied from 5.4 to 72.7%. Soil pH was classified into the low variation group with CV smaller than 10%, while the other chemical properties belonged to the medium variation group with C.V. between 10 and 100% 2. The approximate number of soil samples for the determination of various chemical properties with error smaller than 10% were two for pH, ten for CEC, 15 for exchangeable Ca, 32 for total nitrogen content, 39 for exchangeable Mg, 40 for exchangeable K, 61 for exchangeable Na, 82 for organic matter content, 212 for available phosphate,. 3. Smooth frequency distribution and fractile diagram showed that available phosphate was in log-normal distribution while others were in normal distribution. 4. Serial correlation analysis revaled that the soil chemical properties had spatial dependence between two nearest neighbouring grid points. Autocorrelation analysis of chemcial properties measured between the serial grid points in the direction of south to north following land-partitioned boundary showed that the zone of influence showing stationarity ranged from 20 to 50m. In the direction of east to west accross land-partitioned boundary, the autocorrelogram of many chemical properies showed peaks with the periodic interval of 30m, which were similar to the partitioned land width. This reveals that the land-partitioned boundary causes soil variability.

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Characteristics of New Microsporidia S80 Isolated from Silkworm, Bombyx mori L. in Korea (가잠(家蠶)으로부터 분리(分離)된 새로운 Microsporidia S80의 특성(特性))

  • Lim, Jong Sung;Cho, Sae Yun
    • Current Research on Agriculture and Life Sciences
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    • v.1
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    • pp.67-83
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    • 1983
  • The new microsporidia S80 isolated from, Bombyx mori L. in Korea showed ovoid in the morphology of the spores and the size were measured $2.9{\pm}0.28{\mu}$ in length and $1.7{\pm}0.29{\mu}$ width. No other microsporidian spore like this has not been so far isolated from Silkworm. The length of the polar filament extruded in hydrogen peroxide ($H_2O_2$) at $30^{\circ}C$ was $26{\mu}$ of a round cytoplasm on the top. The spores were partly stained with Giemsa, Safranin-O and Gram as the same staining properties as Nosema bombycis, Microsporidia K 79 and other microsporidian spores. The fine structures were observed under scanning eleceron microscope through ultrathin sectioning. The spore wall was composed of three layers ; the thin exospore of an electron dense rippled layer, the thick electron lucent endospore which was thinning considerably at the polar filament insertion point, and the inner limiting membrane. Polar cap present at the sporeapex, with a long polar filament of 12-13 coils, subtending angle of $60^{\circ}$ to spore axis, which is tubular made up of a multilayered and are a benes core, light ring structure enclosing the dance core, the dark ring structure enclosing the inner light ring structure and the other than and light ring structure bounded from cytoplasm. Lamellate polaroplast occupied the anterior part of the spore, and the two neclei with dense nucleoplasm bounded by a double nuclear envelope were cited in the slight downer middle portion of spore. From the characteristics of the shape, size and fine structures, it is certain to reason the Microsporidia S80 belong to the phylum Microspora, class Microspora, order Microsporida, order Microsporida. The shape of two nuclei cited seems to be genus Nosema, but in the classification for the suborder it should be defined wheather pansporoblasts be formed or not and for the genis especial attempts have been made to define the characters which distinguish the disporous genera in the life cycle. Survey through the infection of the bad cocoons during 1980 to 1982 in South Korea the areas contaminated with new microsporidia were revealed 5 provinces of Kyung-Gi, Kang-Won, Chung-Nam and Chun-Nam. Pathological effects inoculated per os at second instar larvae of silkworm, the LD 50 was $7.1{\times}10^7/ml$ as lower pathogenecity than that of Nosema bombycis Naegeli of $1.2{\times}10_7/ml$. While on the other hand the inoculation of the microsporidia at fourth instar larvae lowerd the whole cocoon weight and cocoon shell weight and significant at 1% level. The microsporidia S80 defined it can not be transmitted transovarially from the result of predictive and collective examination of 21 egg batches from the infected female moth.

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Mite-Control Activities of Active Constituents Isolated from Pelargonium graveolens Against House Dust Mites

  • Jeon, Ju-Hyun;Kim, Hyung-Wook;Kim, Min-Gi;Lee, Hoi-Seon
    • Journal of Microbiology and Biotechnology
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    • v.18 no.10
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    • pp.1666-1671
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    • 2008
  • The mite-control activities of materials obtained from Pelargonium graveolens oil against Dermatophagoides farinae and D. pteronyssinus were examined using an impregnated fabric disk bioassay and were compared with those shown by commercial benzyl benzoate and N,N-diethyl-m-toluamide (DEET). Purification of the biologically active constituents from P. graveolens oil was done by silica gel chromatography and high performance liquid chromatography. The structures of the active components were analyzed by EI/MS, $^{1}H$-NMR, $^{13}C$-NMR, $^{1}H-^{13}C$ COSY-NMR, and DEPT-NMR spectra, and were identified as geraniol ($C_{10}H_{18}O$, MW 154.25, trans-3,7-dimethyl-2,6-octadien-l-ol) and $\beta$-citronellol ($C_{10}H_{20}O$, MW 156.27, 3,7-dimethyl-6-octen-l-o1). Based on the $LD_{50}$ values, the most toxic compound was geraniol (0.26${\mu}g/cm^{2}$), followed by $\beta$-citronellol (0.28${\mu}g/cm^{2}$), benzyl benzoate (10.03${\mu}g/cm^{2}$), and DEET (37.12${\mu}g/cm^{2}$) against D. farillae. In the case of D. pteronyssinus, geraniol (0.28${\mu}g/cm^{2}$) was the most toxic, followed by $\beta$-citronellol (0.29${\mu}g/cm^{2}$), benzyl benzoate (9.58${\mu}g/cm^{2}$), and DEET (18.23${\mu}g/cm^{2}$). These results suggest that D. farinae and D. pteronyssinus may be controlled more effectively by the application of geraniol and $\beta$-citronellol than benzyl benzoate and DEET. Furthermore, geraniol and $\beta$-citronellol isolated from P. graveolens could be useful for managing populations of D. farinae and D. pterollyssinus.

Therapeutic Strategy for the Prevention of Pseudorabies Virus Infection in C57BL/6 Mice by 3D8 scFv with Intrinsic Nuclease Activity

  • Lee, Gunsup;Cho, SeungChan;Hoang, Phuong Mai;Kim, Dongjun;Lee, Yongjun;Kil, Eui-Joon;Byun, Sung-June;Lee, Taek-Kyun;Kim, Dae-Hyun;Kim, Sunghan;Lee, Sukchan
    • Molecules and Cells
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    • v.38 no.9
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    • pp.773-780
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    • 2015
  • 3D8 single chain variable fragment (scFv) is a recombinant monoclonal antibody with nuclease activity that was originally isolated from autoimmune-prone MRL mice. In a previous study, we analyzed the nuclease activity of 3D8 scFv and determined that a HeLa cell line expressing 3D8 scFv conferred resistance to herpes simplex virus type 1 (HSV-1) and pseudorabies virus (PRV). In this study, we demonstrate that 3D8 scFv could be delivered to target tissues and cells where it exerted a therapeutic effect against PRV. PRV was inoculated via intramuscular injection, and 3D8 scFv was injected intraperitoneally. The observed therapeutic effect of 3D8 scFv against PRV was also supported by results from quantitative reverse transcription polymerase chain reaction, southern hybridization, and immunohistochemical assays. Intraperitoneal injection of 5 and $10{\mu}g$ 3D8 scFv resulted in no detectable toxicity. The survival rate in C57BL/6 mice was 9% after intramuscular injection of 10 $LD_{50}$ PRV. In contrast, the 3D8 scFv-injected C57BL/6 mice showed survival rates of 57% ($5{\mu}g$) and 47% ($10{\mu}g$). The results indicate that 3D8 scFv could be utilized as an effective antiviral agent in several animal models.

Efficacy of Physostigmine and Procyclidine as Combinational Prophylactics of Organophosphate Poisoning (Physostigmine과 procyclidine으로 구성된 복합예방제의 유기인제 해독효능)

  • Hur, Gyeung-Haeng;Choen, Ki-Cheol;Phi, Taek-San;Kim, Jae-Cheon;Hong, Dea-Sik;Park, Hoon;Jung, Chang-Hee;Lee, Yong-Han;Kim, Yun-Bae
    • Biomolecules & Therapeutics
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    • v.9 no.1
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    • pp.33-39
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    • 2001
  • Antidotal efficacy of combinational prophylactics composed of physostigmine plus procyclidine, alone or in combination with antidotes such as atropine plus 2-pralidoxime or atropine plus HI-6, was evaluated in rats. Physostigmine (0.1 mg/kg) plus procyclidine (3 mg/kg), pretreated subcutaneously 30 min prior to subcutaneous exposure to organophosphates of militarily importance, exerted protection ratios of 7.2, 6.5, 4.0, 2.9 and 8.0 fold for tabun, saris, soman, cyclosarin and V-agent, respectively. In comparison, low effects (1.7 fold for soman and 1.3 fold for cyclosarin) were achieved with the traditional antidotes atropine (17.4 mg/kg) plus 2-pralidoxime (30 mg/kg) administered intramuscularly immediately after organophosphate, in contrast to high effects (5.5 fold for soman and 160.0 fold for cyclosarin) with atropine (17.4 mg/kg) plus HI-6 (125 mg/kg), although the protection ratio markedly decreased when treatment of antidotes was delayed. Note- worthy, the combinational prophylactics markedly potentiated the effects of antidotes to higher than 5.0 fold in all cases. In addition, the combinational prophylactics fully prevented the seizures and excitotoxic brain injuries induced by a high dose (100 mg/kg, 1.3 LD$_{50}$) of soman. Taken together, it is suggested that the prophylactics composed of physostigmine and procyclidine, in combination with posttreatment antidotes, could be a promising regimen for the prevention of lethality, seizures and brain injuries induced by organophosphates possessing diverse properties.s.

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Acute Toxicity and Four-week Intravenous Toxicity Studies of Intralipidos (Intralipidos에 대한 급성독성 및 4주간 정맥 내 반복투여 독성시험)

  • Li, Guang-Xun;Che, Jeong-Hwan;Kang, Byeong-Cheol;Lee, Won-Woo;Ihm, Jong-Hee;Jung, Ji-Yun;Yi, Beoung-Hi;Nam, Jeong-Seok;Park, Jae-Hak;Lee, Yong-Soon
    • Toxicological Research
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    • v.14 no.3
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    • pp.443-452
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    • 1998
  • This sutdy was carried out to investigate the acute toxicity and foru-week intravenous toxicity of the intralipidos in rats and rabbits. The acute toxicity study of Intralipidos was performed in Spragur-Dawley (SD) rats. Intralipidos was administered by intravenous to maximum dose 200 ml/kg. $LD_{50}$ of intralipidos was found 139.5ml/kg and 153.8ml/kg in male female SD rats. Four-week toxicity of intralipidos using New Zealand White Rabbit and SD rats. The Rabbit and Rats were administered by intravenous seven days per week for 28 days, with dosage of 15, 6, 2 ml/kg/day and 20, 6, 2ml/kg/day, respectively. Animals treated with intralipidos did not cause any death and show any clinical signs. They did not show any significant changes of body weight, feed uptake and water consumption. They were not significantly different from the control group in urinalysis, ocular examination hematological, serum biochemical value and histopathological examination. Therefore, Intralipidos was not indicated to have any toxic effect in the Rabbits and Rats, when it was administrated by intravenous below the dosage 15ml/kg/day and 20 ml/kg/day for four weeks.

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Single and Four-Week Repeated Oral Toxicity Study of Antidiabetic Herb Extract Microcapsule in Sprague-Dawley Rats (항당뇨 한약추출고형물의 Sprague-Dawley 랫드를 이용한 단회 및 4주 반복투여 독성시험)

  • Kim, Young-Chul;Kim, Hye-Jeong;Kong, Min-Kyu;Lim, Ae-Kyoung;Kwon, Mi-Hwa;Kim, Kil-Soo;Lee, Gee-Dong
    • Toxicological Research
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    • v.23 no.1
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    • pp.87-96
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    • 2007
  • Single and repeated-dose toxicity of anti-diabetic herb extract microcapsule (ADHEM) were evaluated according to Toxicity Test Guidelines of Korea Food and Drug Administration using Sprague-Dawley rats. For single-dose toxicity test, kneading ADHEM with sterilized water were administered orally once at dose levels of 0 and 2,000 mg/kg and examined for 14 days. No dead animals, clinical signs and abnormal necropsy findings were observed and also no significant difference in body weights was found. Therefore, the $LD_{50}$ of ADHEM was considered to be higher than 2,000 mg/kg in both male and female rats. For repeated-dose toxicity test, ADHEM were mixed with powder fodder and administerd orally for 28 days at dose levels of 0, 500, 1000 and 2000 mg/kg/day. No dead animals, clinical signs and significant difference in body weights were found. In hematology and serum biochemistry, all values were included within the normal ranges. In relative organ weights, kidney or liver were significantly increased in the 500, 1000 or 2000 mg/kg/day male groups, uterus was significantly increased in the 500 mg/kg/day female group and left adrenal glands were significantly decreased in the 2000 mg/kg/day female group. In histopathological examinations, vacuolation and microgranuloma in the liver, chronic progressive nephropathy and inflammation in the kidney were observed in the 500, 1000 or 2000 mg/kg/day both male and female groups. Therefore, the no observed adverse effect level (NOAEL) of ADHEM was considered to be lower than 500 mg/kg/day in both male and female rats.

p53 Nuclear Accumulation as a Possible Biomarker for Biological Radio-dosimetry in Oral Mucosal Epithelial Cells

  • Kim, Youn-Young;Kim, Jong-il;Kim, Jin;Yook, Jong-In;Kim, The-Hwan;Son, Young-Sook
    • BMB Reports
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    • v.34 no.2
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    • pp.123-129
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    • 2001
  • Cellular response to ionizing radiation is affected by cell types, radiation doses, and post-irradiation time. Based on the trypan blue dye exclusion assay in normal oral mucosal cells (OM cells), a 48 h post-irradiation was sufffcient and an adequate time point for the evaluation of radiation sensitivity Its $LD_{50}$ was approximately 1.83 Gy To investigate possible biomarkers useful for the biological radiodosimetry of normal epithelial cells (p53, c-fos, cyclin D1, cdc-2, pRb) EGF receptor phosphorylation and Erk activation were evaluated at different radiation doses and different post-irradiation times. From 0.5 Gy, p53 was accumulated in the nucleus of basal cells of the OM raft culture at 4 h post-irradiation and sustained up to 24 h post-irradiation, which suggests that radiation-induced apoptosis or damage repair was not yet completed. The number of p53 positive cells and biosynthesis of p53 were correlated with radiation doses. Both cyclin D1 and c-fos were only transiently induced within 1 h post-irradiation. Cyclin D1 was induced at all radiation doses. However, cfos induction was highest at 0.1 Gy, approximately 7.3 fold more induction than the control, whose induction was reduced in a reverse correlation with radiation dose. The phosphorylation pattern of cdc-2 and pRb were unaffected by radiation. In contrast to A431 tails overexpressing the EGF receptor approximately 8.5 fold higher than normal epithelial, the OM cells reduced the basal level of the EGF receptor phosphorylation in a radiation dose dependent fashion. In conclusion, among radiation-induced biomolecules, the p53 nuclear accumulation may be considered for the future development of a useful marker far biological radiodosimetry in normal epithelial tissue since it was sustained for a longer period and showed a dose response relationship. Specific c-fos induction at a low dose may also be an important finding in this study It needs to be studied further for the elucidation of its possible connection with the low dose radio-adaptive response.

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