• Journal of Microbiology and Biotechnology
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• v.20 no.10
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• pp.1450-1456
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• 2010

Accurate and rapid diagnosis of Pandemic Influenza A/H1N1 2009 virus (H1N1 2009) infection is important for the prevention and control of influenza epidemics and the timely initiation of antiviral treatment. This study was conducted to evaluate the performance of several diagnostic tools for the detection of H1N1 2009. Flocked nasopharyngeal swabs were collected from 254 outpatients of suspected H1N1 2009 during October 2009. This study analyzed the performances of the RealTime Ready Inf A/H1N1 Detection Set (Roche), Influenza A (H1N1) Real-Time Detection Kit (Bionote), Seeplex Influenza A/B OneStep Typing Set [Seeplex Reverse Transcriptase PCR (RT-PCR)], BinaxNow Influenza A & B Test Kit [Binax Rapid Antigen Test (RAT)], and SD BIOLINE Influenza Ag kit (SD RAT). Roche and Bionote real-time RT-PCR showed identical results for the H1N1 2009 hemagglutinin gene. Compared with real-time RT-PCR, the sensitivities and specificities were 83.7% and 100% for Seeplex RT-PCR, 64.5% and 94.7% for Binax RAT, and 69.5% and 100% for SD RAT. The sensitivities of Seeplex RT-PCR, Binax RAT, and SD RAT in patients aged over 21 years were 73.7%, 47.4%, and 57.9%, respectively. The sensitivities of Seeplex RT-PCR, Binax RAT, and SD RAT on the day of initial symptoms were mostly lower (68.8%, 56.3%, and 31.3%, respectively). In conclusion, multiplex RT-PCR and RAT for the detection of H1N1 2009 were significantly less sensitive than real-time RT-PCR. Moreover, a negative RAT may require more sensitive confirmatory assays, because it cannot be ruled out from influenza infection.

• Journal of Life Science
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• v.34 no.7
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• pp.493-499
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• 2024

Antimicrobial peptides are antimicrobial substances inherent in animals and plants, with strong antibacterial activity even in small amounts and with various other functions such as antiviral and antioxidant actions. Plants can be grown with just water and sunlight, allowing for their mass production at low costs. However, transforming a chloroplast into one that produces antimicrobial peptides, rather than growing plants, increases the amount of protein expression and minimizes contamination of the ecosystem because gene transfer by pollen does not occur. In that context, using transgenic plant chloroplasts to produce recombinant proteins increases protein degradation and reduces the solubility of proteins. To solve this problem, we fused SUMO, a fusion protein, with a recombinant protein. We also used a 6xHis tag to purify the fusion protein. The antimicrobial peptide stomoxyn is an antibacterial substance found in stable flies. Stomoxyn has an α-helix structure and is amphiphilic, which allows it to dissolve bacterial cell membranes. In this study, we constructed a transformation vector to express stomoxyn in both plant chloroplasts and Escherichia coli and used this vector to confirm the expression of stomoxyn in E. coli. The expression of the protein was then confirmed in E. coli using a transformation vector. The expressed stomoxyn was purified by nickel column and SUMOase treatment, and its antibacterial activity was confirmed using an agar diffusion assay. The EGFP gene was used to ensure that the transformed vector was inserted into the chloroplast.

• Anatomy and Cell Biology
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• v.57 no.3
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• pp.408-418
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• 2024

Vitamin C is a well-known antioxidant with antiviral, anticancer, and anti-inflammatory properties based on its antioxidative function. Aptamin C, a complex of vitamin C with its specific aptamer, has been reported to maintain or even enhance the efficacy of vitamin C while increasing its stability. To investigate in vivo distribution of Aptamin C, Gulo knockout mice, which, like humans, cannot biosynthesize vitamin C, were administered Aptamin C orally for 2 and 4 weeks. The results showed higher vitamin C accumulation in all tissues when administered Aptamin C, especially in the spleen. Next, the activity of natural killer (NK) cells were conducted. CD69, a marker known for activating for NK cells, which had decreased due to vitamin C deficiency, did not recover with vitamin C treatment but showed an increasing with Aptamin C. Furthermore, the expression of CD107a, a cell surface marker that increases during the killing process of target cells, also did not recover with vitamin C but increased with Aptamin C. Based on these results, when cultured with tumor cells to measure the extent of tumor cell death, an increase in tumor cell death was observed. To investigate the signaling mechanisms and related molecules involved in the proliferation and activation of NK cells by Aptamin C showed that Aptamin C treatment led to an increase in intracellular STAT3 activation. In conclusion, Aptamin C has a higher capability to activate NK cells and induce tumor cell death compared to vitamin C and it is mediated through the activation of STAT3.

• Journal of Life Science
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• v.30 no.3
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• pp.221-229
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• 2020

Distylium racemosum is an evergreen tree growing wild on Jeju Island, which has been reported to exert biological activity. Obesity is induced by genetic, metabolic, environmental, and other factors. Among these, certain bacterial and viral infections have been shown to cause obesity, which is known as infectobesity. Human adenovirus (HAdV)-36 is one of the viruses that are known to cause infectobesity in humans. Unlike extensive research on preventing obesity and developing anti-obesity drugs, little research has been conducted specifically on the prevention and treatment of infectobesity. Therefore, this study aimed to evaluate the effects of phytochemicals from D. racemosum on the replication of HAdV-36. A549 cells infected with HAdV-36 were treated with an ethyl acetate fraction of a D. racemosum leaf extract (DRE), and the virus titer was calculated based on the hemagglutination (HA) titer. The results showed a concentration-dependent inhibitory effect of DRE treatment on HA titers. DRE treatment was also found to inhibit the cytopathic effects of the virus and the expression of viral genes. Quercitrin was identified as the constituent of DRE exerting an inhibitory effect on HAdV-36 replication. This study shows that DRE can be used as a candidate substance for the development of treatment for HAdV-36 infections. In addition, this study provides a basis to further investigate DRE for the development of anti-infectobesity medication.

• Journal of Life Science
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• v.24 no.10
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• pp.1132-1136
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• 2014

A yellow-colored pigment is found in turmeric, or Curcuma longa L. (Zingiberaceae), a perennial herb distributed mainly throughout tropical and subtropical regions. C. longa has potent antiviral, antimutagenic, anti-inflammatory, anticancer, and antioxidant properties. However, pharmacological mechanisms of ethanol extract derived from C. longa remain poorly understood. The aim of this study was to investigate the potential acute toxicity of C. longa (Curcuma longa L.) extract in BALB/c mice administered a single oral dose of 0, 20, 200, and 2,000 mg/kg by gavage. After the administration of the agent, signs of toxicity were observed every hour for the first 6 hr and every day for 14 days. No mortality, abnormal clinical signs, or pathological changes were observed compared to a control group, and there were no differences in the body weights of the control and treatment groups. Biological serum activities were not significantly changed in the treatment group compared to the control group. These results indicate that a single oral administration of C. longa extract does not exert any toxic effects at a dose of 2,000 mg/kg body weight and that the $LD_{50}$ of C. longa extract is greater than 2,000 mg/kg body weight. Accordingly, C. longa appears to have potential in various functional agents or foods, without toxicity.

• Microbiology and Biotechnology Letters
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• v.40 no.4
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• pp.396-402
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• 2012

The chemical composition, anti-porcine epidemic diarrhea virus (PEDV) activity and antimicrobial activity of Artemisia dubia essential oil were evaluated in this study. Fifty eight compounds from A. dubia essential oil were identified through analysis by gas chromatography-mass spectrometry (GC-MS). The major constituents of the oil were camphor (17.18 %), germacrene-D (15.70%), trans (${\beta}-$) racaryophyllene (6.79%), ene thujones (6.57%), 1, 8-cineole (5.94%) and camphene (5.08%). The essential oil was evaluated for antiviral activity against PEDV in Vero cells using a cytopathic effect (CPE) reduction method. The oils actively inhibited PEDV replication with a 50% inhibitory concentration ($IC_{50}$) of 43.7 ${\mu}^3/mL$. The 50% cytotoxicity concentration ($CC_{50}$) of the oils was over 100 ${\mu}/mL$ and the derived therapeutic index was >2.3. Similar analysis of the ribavirin revealed that they have a relatively weaker efficacy when compared to the oils. The antimicrobial activity of the essential oil against 5 microorganisms was evaluated by the disc diffusion method. The essential oil exhibited antimicrobial activity against 5 tested microorganisms with a clear zone of 8-22 mm. Among the tested microorganisms, Streptococcus pyogenes was the most sensitive and Candida albicans the least. Therefore, in can be concluded that essential oils of A. dubia may have interesting applications for microbial control or the control of PEDV-derived diseases.

• Journal of Microbiology and Biotechnology
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• v.28 no.11
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• pp.1928-1936
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• 2018

Recently, human infections caused by severe fever with thrombocytopenia syndrome virus (SFTSV), which can lead to fatality, have dramatically increased in East Asia. With the unavailability of vaccines or antiviral drugs to prevent and/or treat SFTSV infection, early rapid diagnosis is critical for prevention and control of the disease. Here, we report the development of a simple, rapid and sensitive portable detection method for SFTSV infection applying reverse transcription-loop mediated isothermal amplification (RT-LAMP) combined with one-pot colorimetric visualization and electro-free reaction platform. This method utilizes a pocket warmer to facilitate diagnosis in a resource-limited setting. Specific primers were designed to target the highly-conserved region of L gene of SFTSV. The detection limit of the RT-LAMP assay was approximately $10^0$ viral genome copies from three different SFTSV strains. This assay exhibited comparable sensitivity to qRT-PCR and 10-fold more sensitivity than conventional RT-PCR, with a rapid detection time of 30 to 60 minutes. The RT-LAMP assay using SFTSV clinical specimens has demonstrated a similar detection rate to qRT-PCR and a higher detection rate compared to conventional RT-PCR. Moreover, there was no observed cross-reactive amplification of other human infectious viruses including Japanese Encephalitis Virus (JEV), Dengue, Enterovirus, Zika, Influenza and Middle East Respiratory Syndrome Coronavirus (MERS-CoV). This highly sensitive, electro- and equipment-free rapid colorimetric visualization method is feasible for resource-limited SFTSV field diagnosis.

• Clinical and Experimental Pediatrics
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• v.49 no.10
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• pp.1086-1092
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• 2006

Purpose : Refractory status epilepticus(RSE) is a serious neurological emergency in children. The mortality is high and the neurological outcome is not good. This study aimed to evaluate the clinical significance of cerebrospinal fluid(CSF) pleocytosis in refractory status epilepticus in children. Methods : From January 1999 to January 2006, 25 out of 37 children with refractory status epilepticus had spinal tapping. We retrospectively analyzed the data from these children's medical records. We compared the results between groups with and without CSF pleocytosis, and between a group with first seizure and a group with epilepsy. Result : Six out of 25 children had CSF pleocytosis. The group without CSF pleocytosis had a higher mortality rate and required higher doses of antiepileptic drugs as compared with the group with CSF pleocytosis. The group with CSF pleocytosis had much worse neurologic segualae. However, except for the children with CNS infection, the overall prognosis between the group with and without CSF pleocytosis was not significantly different. All children with CSF pleocytosis came in with first seizures. Conclusion : In children with RSE, a CSF study must be perfomed as soon as possible to exclude the possibility of CNS infection. A CSF study is even more important in cases of first seizure or CNS infection suspected. Mild CSF pleocytosis without evidence of infection does not seem to affect the prognosis, so physicians should therefore be more cautious in selecting antibacterial or antiviral agents for it.

• Journal of Life Science
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• v.28 no.1
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• pp.50-57
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• 2018

Millettia erythrocalyx, a species of plant in the Fabaceae family, is widely distributed in the tropical and subtropical regions of the world, such as the Indies, China, and Thailand. The antiviral activity of flavonoids from M. erythrocalyx has been reported; however, the antioxidative and anticancer activities of M. erythrocalyx remain unclear. In this study, we evaluated the antioxidative and anticancer effects of ethanol extract of M. erythrocalyx (EEME) and the molecular mechanism of its anticancer activity in human hepatocellular carcinoma HepG2 cells. EEME exhibited significant antioxidative effects, with a concentration at 50% inhibition ($IC_{50}$) value of $2.74{\mu}g/ml$, as measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay; moreover, it inhibited cell proliferation in a dose-dependent manner in HepG2 cells. Cell cycle analyses showed that EEME induced HepG2 cell accumulation in the subG1 phase in a dose-dependent manner. EEME also induced apoptosis of HepG2 cells, with increases in apoptotic cells and apoptotic bodies, as detected by Annexin V and 4,6-diamidino-2-phenylindole (DAPI) staining, respectively. Treatment with EEME resulted in increased expression of First apoptosis signal (Fas), a death receptor, and Bcl-2-associated X protein (Bax), a proapoptotic protein, and the activation of caspase-3, 8, and 9, resulting in the cleavage of poly (Adenosine diphosphate-ribose) polymerase (PARP). Collectively, these results suggest that EEME may exert an anticancer effect in HepG2 cells by inducing apoptosis via both the intrinsic and extrinsic pathways.

• Pediatric Infection and Vaccine
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• v.27 no.3
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• pp.198-204
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• 2020

Cytomegalovirus (CMV) disease is rare in children who receive anticancer chemotherapy and have no history of stem cell transplantation (SCT). We report a case of CMV retinitis that developed during maintenance chemotherapy for acute leukemia. A 7-year-old boy developed decreased visual acuity and persistent pancytopenia during maintenance chemotherapy. Laboratory investigations initially showed significant CMV antigenemia (51 positive cells/200,000 leukocytes); however, antiviral therapy was not deemed necessary in this patient who had no history of SCT. CMV antigenemia worsened to 170 positive cells/200,000 leukocytes over 3 weeks. Ophthalmological examination revealed multiple bilateral retinal infiltrates and granular lesions. He was diagnosed with CMV retinitis and was treated with a 4-week course of intravenous ganciclovir and intravitreal injection of ganciclovir 6 times, followed by a 1-month course of orally administered valganciclovir. A CMV antigenemia assay showed negative results, and follow-up fundoscopy revealed lesser retinal infiltration after the sixth intravitreal ganciclovir injection. Future studies should focus on the development of standardized screening methods and preemptive therapeutic strategies for CMV disease in high-risk children.