• Archives of Pharmacal Research
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• v.28 no.6
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• pp.722-729
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• 2005

With the aim to improve the specificity and to reduce the cytotoxicity of polyethylenimine (PEI), we have synthesized the conjugates of the branched PEI (25 kDa) with transferrin. The trans-ferrin-PEI (TP) conjugates with five compositions were synthesized using periodate oxidation method and confirmed by FT-IR spectroscopy and gel permeation chromatography. The free amine contents of TP conjugates, which were able to condense and deliver DNA, increased as the amount of PEI increased. TP/DNA polyplexes were characterized by measuring gel elec-trophoresis, ethidium bromide fluorescence quenching, particle size and zeta potential of complexes. Complete complexation of the polyplexes was observed above the N/P ratio of 5 in TP/DNA, and above 3 in PEI/DNA, respectively. The zeta potential of the complexes decreased as the amount of transferrin in TP conjugates increased. Transfection efficiency of TP conjugates was evaluated in HeLa cell and Jurkat cell systems. Among the five compositions of TP conjugates, TP-2 system mediated a higher $\beta$-galactosidase gene expression than PEI system in Jurkat cell which was known to express elevated numbers of transferrin receptors. From the results of the cell viability based on MTT assay, TP conjugates showed lower cytotoxicity com-pared with the PEI system. We expect that the TP conjugate can be used efficiently as a non-viral gene delivery vector.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.44-45
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• 2006

Gene therapy holds great promise for treating various forms of diseases with a genetic origin including cystic fibrosis, different forms of cancer, and cardiovascular disorders. The clinical use of gene therapy treatments is however restricted, mainly because of the absence of safe and efficient gene delivery technologies. In our group, with an aim of developing efficient and nontoxic polymeric gene delivery systems, several novel types of polymeric gene carriers have been designed, synthesized, and evaluated. Herein, I will mainly present our recent work on low molecular weight linear PEI-PEG-PEI triblock copolymers, degradable hyperbranched poly(ester amine)s, and reduction-sensitive poly(amido amine)s.

• Journal of Veterinary Clinics
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• v.28 no.1
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• pp.1-6
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• 2011

We are aim to evaluate antimicrobial effects of the extract of Galla rhois (GR) on the health status and performance of growing and finishing pigs. This study was conducted on the growing and finishing pigs (n = 200) for 130 days in a swine husbandry. The animals were divided with two groups; GR treated group (n = 100) and commercial diet feeding group (n = 100). GR treated animals had provided with commercial diet adding the extract of GR as 0.2%. During the study period, we compared clinical signs, weight increase rate, diet consumption amount, fecal scores, gross findings, necropsy findings, histopathological findings between the treated group and non treated group. After necropsy, bacteria isolation and PCR analysis were conducted with the clinical samples. As the results of this long-term clinical trial, GR showed the antimicrobial effects on respiratory disease and diarrhea. We were identified that GR had the anti-bacterial and anti-viral effects.

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.735-742
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• 2013

Peptide nucleic acids (PNAs) that bind to complementary nucleic acid sequences with extraordinarily high affinity and sequence specificity can be used as antisense oligonucleotides against microRNAs, namely antagomir PNAs. However, methods for efficient cellular delivery must be developed for effective use of PNAs as therapeutic agents. Here, we demonstrate that antagomir PNAs can be delivered to hepatic cells by complementary DNA oligonucleotide and cationic liposomes containing galactosylated ceramide and a novel cationic lipid, DMKE (O,O'-dimyristyl-N-lysyl glutamate), through glycoprotein-mediated endocytosis. An antagomir PNA was designed to target miR-122, which is required for translation of the hepatitis C virus (HCV) genome in hepatocytes, and was hybridized to a DNA oligonucleotide for complexation with cationic liposome. The PNA-DNA hybrid molecules were efficiently internalized into hepatic cells by complexing with the galactosylated cationic liposome in vitro. Galactosylation of liposome significantly enhanced both lipoplex cell binding and PNA delivery to the hepatic cells. After 4-h incubation with galactosylated lipoplexes, PNAs were efficiently delivered into hepatic cells and HCV genome translation was suppressed more than 70% through sequestration of miR-122 in cytoplasm. PNAs were readily released from the PNA-DNA hybrid in the low pH environment of the endosome. The present study indicates that transfection of PNA-DNA hybrid molecules using galactosylated cationic liposomes can be used as an efficient non-viral carrier for antagomir PNAs targeted to hepatocytes.

• Korean Journal of Clinical Pharmacy
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• v.27 no.3
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• pp.150-160
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• 2017

Background: Recently, a fixed combination of grazoprevir and elbasvir (GE) has been introduced to the arsenal of chemotherapeutics to fight against this virus. The study aimed to provide information on the efficacy and safety of GE for the treatment of HCV infection by performing a meta-analysis of literature data. Methods: PubMed and EMBASE database searches were conducted. Among the literature retrieved, pivotal Phase III clinical studies were analyzed. Statistical analysis of the data was performed by RevMan. Results: Four pivotal Phase III clinical studies compared the efficacy and safety of GE. When HCV patients were treated with GE for 12 weeks, the sustained virologic response, defined as the viral RNA level below the lower limit of quantification at 12 weeks after the cessation of therapy (SVR12), was 94.7%. The clinical advantage of GE involves its use by patients with cirrhosis and/or renal failure without dose adjustment. If the genotype (GT) of the causative virus was GT1a with NS5A polymorphism or GT4 with resistance to peginterferon/ribavirin, treatment with GE plus ribavirin for 16 weeks resulted in a better outcome compared to treatment with GE alone for 12 weeks. Adverse events reported during the four clinical studies were 71.09% in the GE arms and it was 76.61% in the non-GE arms, with the most frequent events being mild central nervous system symptoms. Conclusion: GE was generally safe and effective for the treatment of HCV infection. However, since HCV mutates very rapidly and becomes resistant to antiviral agents, long-term monitoring should be mandatory.

• Journal of Plant Biotechnology
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• v.1 no.1
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• pp.61-68
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• 1999

Rapid accumulation of reactive oxygen species (ROS) and their toxic reaction products with lipids and proteins significantly contributes to the damage of crop plants under biotic and abiotic stresses. We have identified several stress activated alfalfa genes, including the gene of the alfalfa ferritin and a novel NADPH-dependent aldose/aldehyde reductase enzyme. Transgenic tobacco plants that synthesize alfalfa ferritin in vegetative tissues-either in its processed form in chloroplast or in the cytoplasmic non-processed form-retained photosynthetic function upon free radical toxicity generated by paraquat treatment and exhibited tolerance to necrotic damage caused by viral and fungal infections. We propose that by sequestering intracellular iron involved in generation of the very reactive hydroxyl radicals through a Fenton reaction, ferritin protects plant cells from oxidative damage. Our preliminary results with the other stress-inducable alfalfa gene (a NADPH-dependent aldo-keto reductase) indicate, that the encoded enzyme may play role in the stress response of the plant cells. These studies reveal new pathways in plants that can contribute to the increased stress resistance with a potential use in crop improvement.

• The Plant Pathology Journal
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• v.24 no.3
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• pp.289-295
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• 2008

RNA-RNA interactions and the dynamic RNA conformations are important regulators in virus replication in several RNA virus systems and may also involved in the regulation of many important virus life cycle phases, including translation, replication, assembly, and switches in these important stages. The 5' non-translated region of Potato virus X(PVX) contains multiple cis-acting elements that facilitate various viral processes. It has previously been proposed that RNA-RNA interactions between various RNA elements present in PVX RNA genome are required for PVX RNA accumulation(Hu et al., 2007; Kim and Hemenway, 1999). This model was based on the potential base-pairing between conserved sequence elements at the upstream of subgenomic RNAs(sgRNAs) and at the 5' and 3' end of RNA genome. We now provide more evidence that RNA-RNA base-pairing between elements present at the 5' end and upstream of each sgRNA is required for efficient replication of genomic and subgenomic plus-strand RNA accumulation. Site-directed mutations introduced at the 5' end of plus-strand RNA replication defective mutant(${\Delta}12$) increasing base-pairing possibility with conserved sequence elements located upstream of each sgRNAs restored genomic and subgenomic plus-strand RNA accumulation and caused symptom development in inoculated Nicotiana benthamiana plants. Serial passage of a deletion mutant(${\Delta}8$) caused more severe symptoms and restored wild type sequences and thus retained possible RNA-RNA base-pairing. Altogether, these results indicate that the RNA element located at the 5' end of PVX genome involved in RNA-RNA interactions and play a key role in high-level accumulation of plus-strand RNA in vivo.

• Journal of Veterinary Clinics
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• v.22 no.4
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• pp.365-370
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• 2005

Enzootic pneumonia caused by Mycoplasma hyopneumoniae is responsible for major economic losses in pig herds of world wide. Mycoplasma hyopneumoniae can also act as a primary pathogen of porcine respiratory disease complex followed by bacterial or viral infection. This study was carried out to investigate the prevalence of mycoplasmal pneumonia of slaughtered pigs in Jeju for two years. The lungs and sera of 214 cases were examined for gross and microscopic lesions of the lungs, immunohistichemistry test for Mycoplasma hyopneumoniae antigen and enzyme-linked immunohistichemistry assay (ELISA) for serum antibody titer. Pulmonary consolidation was observed in the lungs of 163 pigs $(76.1\%)$ with average gross lesion score of $6.0\%$., Bronchointerstitial pneumonia was most frequently observed $(78.5\%)$. The incidence of pulmonary consolidation was decreased in vaccinated pigs compared to that of non-vaccinated pigs. The rate of consolidation in the lungs was significantly decreased in the vaccinated pigs (P<0.05). Antigen of Mycoplasma hyopneumoniae was identified by immunohistichemistry test in the lungs of 174 pigs $(81.3\%)$. ELISh antibodies to Mycoplasma hyopneumoniae were detected in 154 pigs $(72.0\%)$. These results showed the prevalence of swine pneumonia and the incidence of Mycoplasma hyopneumoniae in slaughtered pigs of Jeiu province. We expect that these results would be helpful for the control of swine mycoplasmal pneumonia and porcine respiratory disease complex in Jeju.

• Journal of Mushroom
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• v.4 no.2
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• pp.53-56
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• 2006

The enormous production of spores by the fruitbodies in the cultivation of oyster mushrooms (Pleurotus ostreatus) is develop an allergy with symptoms similar to an "extrinsic allergic alveolitis (EEA)". the sporeless strain would noy only benefit health of mushroom workers but also reduce the risk of viral infections on the mushroom farms. For the development of a sporeless strain of P. ostreatus we used strain ASI 2069. This non-commercial strain is completely nonsporulating. We have recovered both nuclear types of strain ASI 2069 as monokaryons (hereafter referred to as neohaplonts) by protoplasting the mycelium. Crosses between neohaplonts and SSI's(single spore isolates) obtained from a sporulating commercial strain ASI 2180 yielded fruitbodies that isolated 128 strains. 13 excellent strains are selected from 30 bred strains by quality of fruitbodies and spore number. Among 13 excellent strains, G192 strain is chose finally to high yield and sporelessness.

• Parasites, Hosts and Diseases
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• v.51 no.3
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• pp.335-341
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• 2013

Balamuthia mandrillaris is one of the 4 amebas in fresh water and soil that cause diseases in humans. Granulomatous amebic encephalitis (GAE), caused by B. mandrillaris, is a rare but life-threatening condition. A 4-year-old, previously healthy, Thai girl presented with progressive headache and ataxia for over a month. Neuroimaging studies showed an infiltrative mass at the right cerebellar hemisphere mimicking a malignant cerebellar tumor. The pathological finding after total mass removal revealed severe necrotizing inflammation, with presence of scattered amebic trophozoites. Cerebrospinal fluid (CSF) obtained from lumbar puncture showed evidence of non-specific inflammation without identifiable organisms. A combination of pentamidine, sulfasalazine, fluconazole, and clarithromycin had been initiated promptly before PCR confirmed the diagnosis of Balamuthia amebic encephalitis (BAE). The patient showed initial improvement after the surgery and combined medical treatment, but gradually deteriorated and died of multiple organ failure within 46 days upon admission despite early diagnosis and treatment. In addition to the case, 10 survivors of BAE reported in the PubMed database were briefly reviewed in an attempt to identify the possible factors leading to survival of the patients diagnosed with this rare disease.