• Fisheries and Aquatic Sciences
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• v.27 no.9
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• pp.614-621
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• 2024

Channel catfish (Ictalurus punctatus), an introduced species in Vietnam, is widely cultured in the Northern provinces. The off-white grub disease in Channel catfish, caused by metacercariae of Dollfustrema bagarii (Digenea: Bucephalidae) lodged in internal organs, often results in heavy economic losses. Up to the present, there have been no specific guidelines for preventing and treating this disease. Here, we explore the potential treatment of infected channel catfish through the injection of Ivermectin. We evaluated the tolerance of channel catfish to the drug and determined the optimal dosage for treating off-white grubs disease. Healthy fish weighing 180-200 g received dosages of up to 3.250 mg/kg of body weight. The median lethal dose (LD₅₀) throughout a 24-hour period was 0.808 mg/kg body weight, with a confidence interval ranging from 0.583 to 1.118 mg/kg body weight. The infected fish used for treatment testing ranged in weight from 400 to 500 g. The value for the 24-hour median effective dose (ED₅₀) was 0.253 mg, and the appropriate therapeutic injection ranged from 0.300 to 0.700 mg per kg of body weight. Flowing the histopathological alterations, after the metacercariae were shriveled and died, the immune cells cleaned and eliminated them from fish.

• Korean Journal of Microbiology
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• v.29 no.1
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• pp.25-33
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• 1991

Antiviral activities of papaverine and nucleoside analogs, 9-[(1,3-dihydroxy-2-propoxy)methyl]guanine (DHPG) and acyclovir, against human cytomegalovirus (HCMV) infection were compared in vitro. Papaverine and DHPG were effective in reducing infectious HCMV yields with $ED_{50}{\s}$ (effective dose 50: the concentraion at which 50% of virus yields was obtained) of approximately 1.02 and $0.45{\mu}{\M}$, respectively; while acyclovir was less effective with an $ED_{50}$ of about $10.4{\mu}{\M}$The relative cytotoxicity of these drugs was evaluated under the same conditions used to measure infectious HCMV yields. Papaverine and DHPG demonstrated little cellular toxicity as measured by their effect on the viability of confluent cells at concentrations in the range of those demonstrating potent inhibition of HCMV replication. Similarly, protein synthesis was largely unaffected by these drugs in stationary mock-infected cells as measured by the incorporation of isotopically labelled amino acids. In contrast, cellular DNA synthesis was invariably reduced in the presence of either drug. HCMV-specific DNA synthesis was also strongly inhibited by papaverine and DHPG.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.115-115
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• 2002

The anti-diarrhea and spasmolytic activities of Soonkijangquebo (SKJQB), a Korean herbal anti-diarrhea formulation, were subjected to pharmacological evaluation. SKJQB, at a dose of 50\ulcorner200 mg/kg, inhibited castor oil-induced diarrhea in mice. The median effective dose (ED50) of the anti-diarrhea effect was 93 mg/kg.(omitted)

• Parasites, Hosts and Diseases
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• v.49 no.1
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• pp.17-23
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• 2011

The aim of this study was to assess the cytotoxic effects of various concentrations of miltefosine on Leishmania major (MRHO/IR/75/ER) and L. tropica (MHOM/IR/02/Mash10) promastigotes and to observe the programmed cell death features. The colorimetric MTT assay was used to find L. major and L. tropica viability and the obtained results were expressed as 50% inhibitory concentration (IC50). Also, 50% effective doses (ED50) for L. major and L. tropica amastigotes were also determined, Annexin-V FLUOS staining was performed to study the cell death properties of miltefosine using FAGS analysis. Qualitative analysis of the total genomic DNA fragmentation was performed by agarose gel electrophoresis. Furthermore, to observe changes in cell morphology, promastigotes were examined using light microscopy. In both strains of L. major and L. tropica, miltefosine induced dose-dependent death with features of apoptosis, including cell shrinkage, DNA laddering, and externalization of phosphatidylserine. The IC50 was achieved at 22 ${\mu}M$ and 11 ${\mu}M$ for L. major and L. tropica after 48 hr of incubation, respectively. ED50 of L. major and L. tropica amastigotes were 5.7 ${\mu}M$ and 4.2 ${\mu}M$, respectively. Our results indicate that miltefosine induces apoptosis of the causative agent of cutaneous leishmaniasis in a dose-dependent manner. Interestingly, L. major did not display any apoptotic changes when it was exposed to miltefosine in concentrations sufficient to kill L. tropica.

• Journal of the Korean Chemical Society
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• v.42 no.4
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• pp.378-382
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• 1998

A Quantitative Structure-Activity Relationship of 1-phenylcyclohexyl amine(PCA) and dexoxadral as a receptor has been investigated using semiempirical PM3 MO and Hyper Chem calculation. A set of 19 analogues of PCA was chosen for the study using a selection procedure aimed at minimizing the interparameter correlations, while ensuring that the frontier orbital covered the maximum possible range of LogP. The results show that the FOS and LogP is a good structural parameter to predict the maximum electroshock effective dose ($MES\;ED_{50}$) and toxicity dose ($TD_{50}$) for PCA derivatives.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1114-1119
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• 2012

This study was conducted to assess the microbial toxicity of ionic silver solution ($Ag^+N$) and silver nanoparticle suspension ($Ag^0NP$) based on the Microtox bioassay. In this test, the light inhibition of luminescent bacteria was measured after 15 and 30 min exposure to aqueous solutions and soils spiked with a dilution series of $Ag^+N$ and $Ag^0NP$. The resulting dose-response curves were used to derive effective concentration (EC25, $EC_{50}$, EC75) and effective dose ($ED_{25}$, $ED_{50}$, $ED_{75}$) that caused a 25, 50 and 75% inhibition of luminescence. In aqueous solutions, $EC_{50}$ value of $Ag^+N$ after 15 min exposure was determined to be < $2mg\;L^{-1}$ and remarkably lower than $EC_{50}$ value of $Ag^0NP$ with $251mg\;L^{-1}$. This revealed that $Ag^+N$ was more toxic to luminescent bacteria than $Ag^0NP$. In soil extracts, however, $ED_{50}$ value of $Ag^+N$ with 196 mg kg-1 was higher than $ED_{50}$ value of $Ag^0NP$ with $104mg\;kg^{-1}$, indicating less toxicity of $Ag^+N$ in soils. The reduced toxicity of $Ag^+N$ in soils can be attributed to a partial adsorption of ionic $Ag^+$ on soil colloids and humic acid as well as a partial formation of insoluble AgCl with NaCl of Microtox diluent. This resulted in lower concentration of active Ag in soil extracts obtained after 1 hour shaking with $Ag^+N$ than that spiked with $Ag^0NP$. With longer exposure time, EC and ED values of both $Ag^+N$ and $Ag^0NP$ decreased, so their toxicity increased. The toxic characteristics of silver nanomaterials were different depending on existing form of Ag ($Ag^+$, $Ag^0$), reaction medium (aqueous solution, soil), and exposure time.

• Applied Biological Chemistry
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• v.44 no.4
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• pp.269-272
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• 2001

This study was carried out to investigate the antifungal activities of the extracts from various parts of three pinus species, P. densiflora, P. rigida and P. koraiensis to pathogenic fungus Collectotrichum gloeosporioides. The EtOAc fraction from the bark of P. koraiensis stem and root showed 98.8 and 100% of activity, respectively to the fungus. Median effective doses $(ED_{50})$ of above two fractions were 469 and 588 ${\mu}g/ml$, respectively in the bioassay with the fungus. $ED_{50}$ of the EtOAc fraction from the bark of P. koraiensis stem against Alternaria brassicicola and Fusarium oxysporum was 533 and 2,277 ${\mu}g/ml$, respectively. This means that the fraction was more sensitive to the C. gloeosporioides and A. brassicicola than the fungus F. oxysporum. The EtOAc fraction from the leaves of P. densiflord showed 39.6% of activity to C. gloeosporioides, but all the fractions from the leaves of two species showed no activity. The active compounds in the bark of P. koraiensis stem and root are being identified.

• Journal of The Korean Society of Clinical Toxicology
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• v.14 no.1
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• pp.9-15
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• 2016

Purpose: In most emergency department (ED), sedation is required before carrying out an invasive procedure on a pediatric patient. In the ED setting, it is essential to determine the optimal dose and administration route of CH for successful sedation. The aim of this study was to determine the optimal dose of CH for an invasive procedure and to examine the effectiveness of the drug's different administration routes. Furthermore, in this study, we performed simple survey using questionnaire which composed of Likert-scale to evaluate satisfaction of medical staffs in ED with administration routes. Methods: This study was conducted prospectively. The study participants were pediatric patients under 8 years old who visited the ED in two tertiary hospitals in South Korea within a period of 12 months. Results: Overall, 300 patients were included in this study. The age, sex, and weight of the patients were not shown to influence the sedation time. Chloral hydrate dosage is the independent factor to influence the both sedation and discharge time (p<0.01). In the comparison of the groups, groups 1, 2, and 5 showed no significant difference. On the other hand, groups 3 and 4 were shown to be statistically significantly different from group 1. Conclusion: Up to 100 mg/kg CH is safe to use in the emergency department for pediatric patients, but the initial dose of 50 mg/kg for oral administration should be considered in advance because it can provide safe and effective sedation with a lower possibility of causing an adverse effect.

• The Korean Journal of Pain
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• v.18 no.2
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• pp.118-123
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• 2005

Background: A nerve ligation injury may produce a tactile allodynia. The effects of intrathecally delivered lamotrigine on allodynia induced due to fifth and sixth lumbar spinal nerves ligation in rats, using lumbar intrathecal catheters were examined. Methods: Sprague-Dawley rats (body weight 160-180 g) were prepared by tightly ligating the fifth and sixth left lumbar spinal nerves, with the implantation of a chronic intrathecal catheter for drug administration. Mechanical allodynia and allodynic threshold were measured using von Frey filaments and the updown method, respectively. After the baseline hind paw withdrawal thresholds had been obtained, lamotrigine (10, 30, 100 and $300{\mu}g$) was administered intrathecally. Thereafter, the dose-response curves and 50% effective dose ($ED_{50}$) were obtained. Motor dysfunction was assessed by observing the righting/stepping reflex responses and abnormal weight bearing. Results: Intrathecal administration of lamotrigine produced a dose-dependent antiallodynic action ($ED_{50}=61.7{\mu}g$). Mild motor weakness was observed with $300{\mu}g$ lamotrigine, but no severe motor impairment was found. Conclusions: It is suggested that intrathecal lamotrigine could produce moderate antagonism of mechanical allodynia at the spinal level in a rat neuropathic pain model with minimal motor weakness.

• The Korean Journal of Pain
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• v.25 no.1
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• pp.1-6
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• 2012

Background: Curcumin has been reported to have anti-inflammatory, antioxidant, antiviral, antifungal, antitumor, and antinociceptive activity when administered systemically. We investigated the analgesic efficacy of intrathecal curcumin in a rat model of inflammatory pain. Methods: Male Sprague Dawley rats were prepared for intrathecal catheterization. Pain was evoked by injection of formalin solution (5%, $50{\mu}l$) into the hind paw. Curcumin doses of 62.5, 125, 250, and $500{\mu}g$were delivered through an intrathecal catheter to examine the flinching responses. The $ED_{50}$ values (half-maximal effective dose) with 95% confidence intervals of curcumin for both phases of the formalin test were calculated from the dose-response lines fitted by least-squares linear regression on a log scale. Results: In rats with intrathecal administration of curcumin, the flinching responses were significantly decreased in both phases. The slope of the regression line was significantly different from zero only in phase 2, and the $ED_{50}$ value (95% confidence interval) of curcumin was $511.4{\mu}g$ (23.5-1126.5). There was no apparent abnormal behavior following the administration of curcumin. Conclusions: Intrathecal administration of curcumin decreased inflammatory pain in rats, and further investigation to elucidate the precise mechanism of spinal action of curcumin is warranted.