• Applied Microscopy
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• v.8 no.1
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• pp.81-90
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• 1978

Introduction of electron microscope in biological and medical sciences change the concept of functional and morphologic unit of biological phenomena from the cell to subcellular unit, and it formulated the basis for molecular biology and pathology. Until recently, electron microscopy has mainly been applied to basic research works. However, practical clinical application of electron microscopy is being actively tried. The major clinical fields in which electron microscopy is helpful or even essential include viral diseases, metabolic diseases, glomerular diseases and in the identification of certain types of neoplasms. A brief introduction of characteristics of each conditions are made to encourage more active application of electron microscopy in clinical medicine.

• Archives of Pharmacal Research
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• v.29 no.6
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• pp.431-458
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• 2006

As we approach the completion of the first 25 years of the human immunodeficiency virus(HIV) epidemic, there have been dramatic improvements in the care of patients with HIV infection. These have prolonged life and decreased morbidity. There are twenty currently available antiretrovirals approved in the United States for the treatment of this infection. The medications, including their pharmacokinetic properties, side effects, and dosing are reviewed. In addition, the current approach to the use of these medicines is discussed. We have included a section addressing common comorbid conditions including hepatitis B and C along with tuberculosis.

• IMMUNE NETWORK
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• v.23 no.1
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• pp.11.1-11.11
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• 2023

Memory T cells that mediate fast and effective protection against reinfections are usually generated upon recognition on foreign Ags. However, a "memory-like" T-cell population, termed virtual memory T (T_VM) cells that acquire a memory phenotype in the absence of foreign Ag, has been reported. Although, like innate cells, T_VM cells reportedly play a role in first-line defense to bacterial or viral infections, their protective or pathological roles in immune-related diseases are largely unknown. In this review, we discuss the current understanding of T_VM cells, focusing on their distinct characteristics, immunological properties, and roles in various immune-related diseases, such as infections and cancers.

• Osong Public Health and Research Perspectives
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• v.9 no.6
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• pp.334-339
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• 2018

Objectives: Human rhinoviruses (HRVs) are the major cause of the common cold. Currently there is no registered, clinically effective, antiviral chemotherapeutic agent to treat diseases caused by HRVs. In this study, the antiviral activity of dexamethasone (DEX) against HRV1B was examined. Methods: The anti-HRV1B activity of DEX was assessed by sulforhodamine B assay in HeLa cells, and by RT-PCR in the lungs of HRV1B-infected mice. Histological evaluation of HRV1B-infected lungs was performed and a histological score was given. Anti-HRV1B activity of DEX via the glucocorticoid receptor (GCR)-dependent autophagy activation was assessed by blocking with chloroquine diphosphate salt or bafilomycin A1 treatment. Results: In HRV1B-infected HeLa cells, treatment with DEX in a dose-dependent manner, resulted in a cell viability of > 70% indicating that HRV1B viral replication was reduced by DEX treatment. HRV1B infected mice treated with DEX, had evidence of reduced inflammation and a moderate histological score. DEX treatment showed antiviral activity against HRV1B via GCR-dependent autophagy activation. Conclusion: This study demonstrated that DEX treatment showed anti-HRV1B activity via GCR-dependent autophagy activation in HeLa cells and HRV1B infected mice. Further investigation assessing the development of topical formulations may enable the development of improved DEX effectiveness.

• The Korea Journal of Herbology
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• v.36 no.1
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• pp.97-102
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• 2021

Objectives : Virus infection through the respiratory tract causes various inflammatory diseases such as pneumonia, cystic fibrosis, and obstructive pulmonary disease, causing enormous social damage. Therefore, it is very important to develop a treatment and prevention of infectious diseases. In this study, we investigated the effect of water extracts of Liriope muscari (WELM), known to improve lung function, on the inflammatory response of lung carcinoma cell line A549 cells induced by the viral double stranded RNA mimetic Polyinosinic:polycytidylic acid (Poly I:C). Methods : The cell viability by WELM treatment was analyzed using MTS assay in A549 cells. After inducing an inflammatory response to WELM-treated A549 cells with Poly I:C, the degree of apoptosis was confirmed through bright field microscopy. Interferon beta (IFN-β) mRNA expression level in A549 cells was analyzed by quantitative reverse transcription PCR (qRT-PCR). Results : WELM treatment has no significant effect on cell viability of A549 cells. We confirmed that pre-treatment of WELM effectively reduces the Poly I:C-induced apoptotic cell death in A549 cells. In addition, it was confirmed that the mRNA expression level of IFN-β, a pro-inflammatory cytokine increased by Poly I:C treatment, was significantly suppressed by WELM treatment in A549 cells. Conclusions : These results provide the evidence that WELM is effective at inhibiting inflammation on respiratory viral infections and suggest that Liriope muscari might be a valuable natural substance in the prevention and treatment of infectious diseases.

• Pediatric Infection and Vaccine
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• v.29 no.2
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• pp.110-117
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• 2022

Herpes zoster (HZ) has been reported in immunocompetent children who received the varicella vaccine. In vaccinated children, HZ can be caused by vaccine-strain or by wild-type varicella-zoster virus (VZV). Like wild-type VZV, varicella vaccine virus can establish latency and reactivate as HZ. We report two cases of HZ in otherwise healthy 16- and 14-month-old boys who received varicella vaccine at 12 months of age. They presented with a vesicular rash on their upper extremities three to four months after varicella vaccination. In one case, a swab was obtained by abrading skin vesicles and VZV was detected in skin specimens by polymerase chain reaction. The VZV open-reading frame 62 was sequenced and single nucleotide polymorphism analysis confirmed that the virus from skin specimen was vaccine-strain. This is the first HZ case following varicella vaccination confirmed to be caused by vaccine-strain VZV in the immunocompetent children in Korea. Pediatricians should be aware of the potential for varicella vaccine virus reactivation in vaccinated young children.

• IMMUNE NETWORK
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• v.23 no.4
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• pp.33.1-33.13
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• 2023

Vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been acknowledged as an effective mean of preventing infection and hospitalization. However, the emergence of highly transmissible SARS-CoV-2 variants of concern (VOCs) has led to substantial increase in infections among children and adolescents. Vaccine-induced immunity and longevity have not been well defined in this population. Therefore, we aimed to analyze humoral and cellular immune responses against ancestral and SARS-CoV-2 variants after two shots of the BNT162b2 vaccine in healthy adolescents. Although vaccination induced a robust increase of spike-specific binding Abs and neutralizing Abs against the ancestral and SARS-CoV-2 variants, the neutralizing activity against the Omicron variant was significantly low. On the contrary, vaccine-induced memory CD4⁺ T cells exhibited substantial responses against both ancestral and Omicron spike proteins. Notably, CD4⁺ T cell responses against both ancestral and Omicron strains were preserved at 3 months after two shots of the BNT162b2 vaccine without waning. Polyfunctionality of vaccine-induced memory T cells was also preserved in response to Omicron spike protein. The present findings characterize the protective immunity of vaccination for adolescents in the era of continuous emergence of variants/subvariants.

• Research in Plant Disease
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• v.10 no.4
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• pp.231-240
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• 2004

In the year of 2002 annual nationwide survey of virus diseases occurring in the pepper fields and greenhouses in Korea, the distribution and the incidence of viral diseases was investigated. The pepper samples from both greenhouses (155 samples) and open fields (227 samples) were collected and further analyzed to detect eleven different viruses by RT-PCR. The results indicate that no sample collected from both greenhouse and open field seems to be infected by TMV, RMV, PVY, AMV, and TSWV. On the other hand, CMV, BBWV2, PepMoV, PMMoV, TMGMV and ToMV are readily identified from greenhouse and open field samples by RT-PCR. The infection rates of the collected samples between greenhouse and open field are largely different. Comparing with 10% of virus-infected pepper samples grown in greenhouse, approximately one third of pepper samples collected from open field are infected. The mixed-infection rates in the virus-infected greenhouse and open field samples are 16% and 61%, respectively. The dominant virus occuring in greenhouse is PMMoV, indicating that virus-infected seed stocks and infected plant debris in the growing area may be important sources of inocula. On the other hand, both CMV and BBWV2 are dominant viruses in open field. This may indicate that the migration of viruliferous insect vectors into pepper fields may be the most important source of inoculum. Also, the survey shows that BBWV2 is newly immerging virus to be controlled in Korea. The discrepancies on the distribution and the occurrence of viral diseases between field and greenhouse may provide a fact that the accumulation and distribution of inoculum by successive cultivation and the migration of viruliferous vectors into growing areas are likely to be important factors to determine the incidence of viral diseases. Therefore, the further studies on epidemiology and the consideration of new breeding program of pepper are essential to minimize virus diseases.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.383-390
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• 2016

Mesenchymal stem cells (MSCs) are multipotent stem cells that can be differentiated into a variety of cell types, including adipocytes, osteoblasts, chondrocytes, β-pancreatic islet cells, and neuronal cells. MSCs have been reported to exhibit immunomodulatory effects in many diseases. Many studies have reported that MSCs have distinct roles in modulating inflammatory and immune responses by releasing bioactive molecules. Exosomes are cell-derived vesicles present in biological fluids, including the blood, urine, and cultured medium of cell cultures. In this study, we investigated the immunomodulatory effects of mouse adipose tissue-derived MSCs (mAD-MSCs), cultured medium (MSC-CM) of mAD-MSCs, and mAD-MSC-derived exosomes (MSC-Exo) on lipopolysaccharide (LPS)-induced RAW 264.7 cells. We observed that the expression levels of IL-1β, TNF-α, and IL-10 were significantly increased in LPS-stimulated RAW 264.7 cells compared to those in LPS-unstimulated RAW 264.7 cells. Additionally, these values were significantly (p < 0.05) decreased in mAD-MSCs-RAW 264.7 cell co-culture groups, MSC-CM-treated groups, and MSC-Exo-treated groups. MSCs can modulate the immune system in part by secreting cytokines and growth factors. We observed that immunomodulatory factors such as IL-1β, TNF-α, and IL-10 were secreted by mAD-MSCs under co-culturing conditions of mAD-MSCs with activated RAW 264.7 cells. In addition, mAD-MSC-derived exosomes exhibited similar immunomodulatory effects in activated RAW 264.7 cells. Therefore, our results suggest that mAD-MSCs have an immunomodulatory function through indirect contact.

• Parasites, Hosts and Diseases
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• v.58 no.5
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• pp.589-592
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• 2020

Cyclospora cayetanensis is an apicomplexan protozoan and is one of the most common pathogens causing chronic diarrhea worldwide. Eight stool samples with diarrheal symptom out of 18 Korean residents who traveled to Nepal were obtained, and examined for 25 enteropathogens including 16 bacterial species, 5 viral species, and 4 protozoans in stool samples as causative agents of water-borne and food-borne disease. Only C. cayetanensis was detected by nested PCR, and 3 PCR-positive samples were sequenced to confirm species identification. However, the oocysts of C. cayetanensis in fecal samples could not be detected by direct microscopy of the stained sample. As far as we know, this is the first report of a group infection with C. cayetanensis from a traveler visiting Nepal, and the second report of a traveler's diarrhea by C. cayetanensis imported in Korea.