Characterization of Severe Acute Respiratory Syndrome Coronavirus 2Stability in Multiple Water Matrices

The advent of the global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) necessitates a thorough study of the stability and transmissibility in the environment. We characterized the stability of SARS-CoV-2 in three water matrices: fresh, tap, and seawater. The minimum infective dose of SARS-CoV-2 in Vero cells was confirmed to be 10 3 PFU/mL. The stability of SARS-CoV-2 varied according to the water matrix: infective SARSCoV-2 was undetectable after treatment with fresh water and seawater, but remained detectable for 2 days in tap water, when starting with an initial concentration of 10 4 PFU/mL. When the starting concentration was increased to 10 5 PFU/mL, a similar trend was observed. In addition, viral RNA persisted longer than infectious virus in all water matrices. This study was conducted in stagnant water containing a significantly high titer of virus, thus, human-to-human transmission of SARS-CoV-2 through the actual aquatic environment is expected to be rare.

Organoids as a New In Vitro Model of Human Norovirus Infection

Human noroviruses (HuNoVs) are the main causative viral agents in epidemic and endemic acute gastroenteritis worldwide. Despite their impact on the global economic and health burden, developing effective control measures to prevent and treat norovirus gastroenteritis remains a difficult problem to solve. One of the major reasons for this problem is the lack of affordable small animal models and a robust and reproducible In Vitro cell culture system for the propagation of this poorly characterized RNA virus. Recently, the development of a 3-dimensional culture system using pluripotent stem cells to mimic the native small intestine has led to the discovery of new strategies for the cultivation of this virus. In this review, we describe a human stem cell-derived intestinal organoid model that led to the development of the currently available HuNoV In Vitroculture systems that support replication of the virus, and provide helpful insights into HuNoV biology and vaccine and therapeutic development.

Organoids as a New In Vitro Model of Human Norovirus Infection

Human noroviruses (HuNoVs) are the main causative viral agents in epidemic and endemic acute gastroenteritis worldwide. Despite their impact on the global economic and health burden, developing effective control measures to prevent and treat norovirus gastroenteritis remains a difficult problem to solve. One of the major reasons for this problem is the lack of affordable small animal models and a robust and reproducible In Vitro cell culture system for the propagation of this poorly characterized RNA virus. Recently, the development of a 3-dimensional culture system using pluripotent stem cells to mimic the native small intestine has led to the discovery of new strategies for the cultivation of this virus. In this review, we describe a human stem cell-derived intestinal organoid model that led to the development of the currently available HuNoV In Vitroculture systems that support replication of the virus, and provide helpful insights into HuNoV biology and vaccine and therapeutic development.

Distribution of Pathogenic Vibrio Species in the Coastal Seawater of South Korea (2017–2018)

OBJECTIVES: Pathogenic Vibrio species are widely distributed in warm estuarine and coastal environments, and can infect humans through the consumption of raw or mishandled contaminated seafood and seawater. For this reason, the distribution of these bacteria in South Korea was investigated.METHODS: Seawater samples were collected from 145 coastal area points in the aquatic environment in which Vibrio species live. Environmental data (i.e., water temperature, salinity, turbidity, and atmospheric temperature) was collected which may help predict the distribution of the species (data not shown). Seawater samples were filtered, and incubated overnight in alkaline peptone water, at 37°C. Using species-specific polymerase chain reaction methods, screening tests were performed for the hlyA, ctxA, vvhA, and tlh genes. Clones of pathogenic Vibrio species were isolated using 3 selective plating media.RESULTS: In 2017, total seawater isolation rates for Vibrio vulnificus, Vibrio cholerae (non-pathogenic, non-O1, non-O139 serogroups), and Vibrio parahaemolyticus were 15.82%, 13.18%, 65.80%, respectively. However, in 2018 isolation rates for each were 21.81%, 19.40%, and 70.05%, respectively.CONCLUSION: The isolation rates of pathogenic Vibrio species positively correlated with the temperature of seawater and atmosphere, but negatively correlated with salinity and turbidity. From 2017 to 2018, the most frequent seawater-isolated Vibrio species were V. parahaemolyticus (68.10 %), V. vulnificus (16.54%), and non-toxigenic V. cholerae (19.58%). Comprehensive monitoring, prevention, and control efforts are needed to protect the public from pathogenic Vibrio species.

Serological and Molecular Detection of Toxoplasma gondii and Babesia microti in the Blood of Rescued Wild Animals in Gangwon-do (Province), Korea

Infections of Toxoplasma gondii and Babesia microti are reported in many wild animals worldwide, but information on their incidence and molecular detection in Korean wild fields is limited. In this study, the prevalence of T. gondii and B. microti infection in blood samples of 5 animal species (37 Chinese water deer, 23 raccoon dogs, 6 roe deer, 1 wild boar, and 3 Eurasian badgers) was examined during 2008–2009 in Gangwon-do (Province), the Republic of Korea (=Korea) by using serological and molecular tests. The overall seropositivity of T. gondii was 8.6% (6/70); 10.8% in Chinese water deer, 4.3% in raccoon dogs, and 16.7% in roe deer. PCR revealed only 1 case of T. gondii infection in Chinese water deer, and phylogenic analysis showed that the positive isolate was practically identical to the highly pathogenetic strain type I. In B. microti PCR, the positive rate was 5.7% (4/70), including 2 Chinese water deer and 2 Eurasian badgers. Phylogenetic analysis results of 18S rRNA and the β-tubulin gene showed that all positive isolates were US-type B. microti. To our knowledge, this is the first report of B. microti detected in Chinese water deer and Eurasian badger from Korea. These results indicate a potentially high prevalence of T. gondii and B. microti in wild animals of Gangwon-do, Korea. Furthermore, Chinese water deer might act as a reservoir for parasite infections of domestic animals.

Prevalence of Clonorchis sinensis Infection among Residents along 5 Major Rivers in the Republic of Korea

Clonorchis sinensis is currently the most important parasite affecting public health problems in the Republic of Korea. We investigated the prevalence of C. sinensis infection among residents living along 5 major rivers in Korea. A total of 42,562 individual stool samples were collected from 37 localities and examined using the formalin-ether sedimentation technique. Helminth eggs were detected in 4,052 (9.5%) residents and 3,586 (8.4%) were infected with C. sinensis. The egg positive rate of C. sinensis in Nakdong, Seomjin, Geum, Yeongsan, and Han River was 11.7%, 9.9%, 6.5%, 3.1%, and 1.0%, respectively. The overall prevalence of clonorchiasis by sex was 11.2% in males and 6.2% in females. The age-prevalence was the highest in the 50-59 years band. It has been reconfirmed that the endemicity of clonorchiasis is higher in southern areas of Korea, especially along Nakdong and Seomjin Rivers. A combination of continuous control programs with health education initiatives is urgently required in these highly endemic areas of clonorchiasis in Korea.

Trigonelline protects the cardiocyte from hydrogen peroxide induced apoptosis in H9c2 cells

OBJECTIVE@#To elucidate the key parameters associated with hydrogen peroxide induced oxidative stress and investigates the mechanism of trigonelline (TG) for reducing the H2O2 induced toxicity in H9c2 cells.@*METHODS@#Cytotoxicity and antioxidant activity of TG was assessed by EZ-CYTOX kit. RNA extraction and cDNA synthesized according to the kit manufacture protocol. Apoptosis was measured by the Flowcytometry, general PCR and qPCR.@*RESULTS@#It was found that the TG significantly rescued the morphology of the H9c2 cells. Treatment of cells with TG attenuated H2O2 induced cell deaths and improved the antioxidant activity. In addition, TG regulated the apoptotic gene caspase-3, caspase-9 and anti-apoptotic gene Bcl-2, Bcl-XL during H2O2 induced oxidative stress in H9c2 cells. These results were comparable with quercetin treatment. For evident, flow cytometer results also confirmed the TG significantly reduced the H2O2 induced necrosis and apoptosis in H9c2 cells. However, further increment of TG concentration against H2O2 could induce the necrosis and apoptosis along with H2O2.@*CONCLUSIONS@#It is suggested that less than 125 μ M of TG could protect the cells from H2O2 induced cell damage by down regulating the caspases and up regulating the Bcl-2 and Bcl-XL expression. Therefore, we suggest the trigonelline could be useful for treatment of oxidative stress mediated cardiovascular diseases in future.

Toxoplasma gondii Infection Suppresses House Dust Mite Extract-Induced Atopic Dermatitis in NC/Nga Mice

PURPOSE: Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan parasite that infects humans and animals via congenital or postnatal routes, and it is found worldwide. Modulation of the immune system by parasite infection is proposed to suppress allergic inflammation. Growing evidences have shown that interleukin (IL)-10-producing regulatory B cells (B(regs)) and CD4+CD25+FoxP3+ regulatory T cells (T(regs)) induced by parasite infection play a critical role in allergic or autoimmune diseases because these cells regulate negatively cellular immune responses and inflammation. Currently, the role of IL-10-producing regulatory B cells in host immune response during T. gondii infection is unknown. In this study, we investigate whether T. gondii infection can suppress the development of unrelated atopic dermatitis (AD)-like lesions. METHODS: AD is a chronically relapsing inflammatory skin disease accompanied by severe itching; for this, we used NC/Nga mice, a well-known experimental model of systemic AD. Repeated exposure to Dermatophagoides farinae crude extract (DfE), known as a major environmental allergen, evokes AD-like skin lesions in NC/Nga mice under specific pathogen-free conditions. NC/Nga mice were intraperitoneally infected with 10 cysts of T. gondii. RESULTS: T. gondii infection significantly ameliorated AD-like skin lesions in NC/Nga mice. The subpopulation of B(regs) and T(regs) in the AD mice was expanded in the course of T. gondii infection. In addition, T. gondii infection inhibited Th2 and enhanced Th1 immune response in the DfE-treated AD mice. CONCLUSIONS: We have experimentally demonstrated for the first time that T. gondii infection ameliorated AD-like skin lesions in a mouse model of AD. Our study could in part explain the mechanisms of how parasite infection prevents the development of allergic disorder. Therefore, these immunemechanisms induced by T. gondii infection may be beneficial for the host in terms of reduced risk of allergic immune reactions.

Trigonelline protects the cardiocyte from hydrogen peroxide induced apoptosis in H9c2 cells

Objective: To elucidate the key parameters associated with hydrogen peroxide induced oxidative stress and investigates the mechanism of trigonelline (TG) for reducing the H2O2 induced toxicity in H9c2 cells. Methods: Cytotoxicity and antioxidant activity of TG was assessed by EZ-CYTOX kit. RNA extraction and cDNA synthesized according to the kit manufacture protocol. Apoptosis was measured by the Flowcytometry, general PCR and qPCR. Results: It was found that the TG significantly rescued the morphology of the H9c2 cells. Treatment of cells with TG attenuated H2O2 induced cell deaths and improved the antioxidant activity. In addition, TG regulated the apoptotic gene caspase-3, caspase-9 and anti-apoptotic gene Bcl-2, Bcl-XL during H2O2 induced oxidative stress in H9c2 cells. These results were comparable with quercetin treatment. For evident, flow cytometer results also confirmed the TG significantly reduced the H2O2 induced necrosis and apoptosis in H9c2 cells. However, further increment of TG concentration against H2O2 could induce the necrosis and apoptosis along with H2O2. Conclusions: It is suggested that less than 125 μ M of TG could protect the cells from H2O2 induced cell damage by down regulating the caspases and up regulating the Bcl-2 and Bcl-XL expression. Therefore, we suggest the trigonelline could be useful for treatment of oxidative stress mediated cardiovascular diseases in future.

Molecular Detection and Seroprevalence of Babesia microti among Stock Farmers in Khutul City, Selenge Province, Mongolia

Babesiosis is an emerging tick-borne disease in humans worldwide; however, little is known about the frequency of infection or prevalence of this disease in other parts of the world, excluding North America. In this study, we aimed to investigate Babesia microti infection frequency in a human population in Mongolia. One hundred blood samples were collected from stock farmers living in Khutul city of Selenge province, Mongolia. The sera and DNA from blood samples were evaluated for the presence of B. microti infection by using indirect fluorescent antibody (IFA) tests and PCR. The positive detection rates obtained using the IFA tests and PCR assays were 7% and 3%, respectively. This study is the first to detect of B. microti infections based on antibody seroprevalence or PCR assays for the presence of B. microti DNA in a Mongolian population.

Rhamnogalacturonan II is a Toll-like receptor 4 agonist that inhibits tumor growth by activating dendritic cell-mediated CD8+ T cells

We evaluated the effectiveness of rhamnogalacturonan II (RG-II)-stimulated bone marrow-derived dendritic cells (BMDCs) vaccination on the induction of antitumor immunity in a mouse lymphoma model using EG7-lymphoma cells expressing ovalbumin (OVA). BMDCs treated with RG-II had an activated phenotype. RG-II induced interleukin (IL)-12, IL-1beta, tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) production during dendritic cell (DC) maturation. BMDCs stimulated with RG-II facilitate the proliferation of CD8+ T cells. Using BMDCs from the mice deficient in Toll-like receptors (TLRs), we revealed that RG-II activity is dependent on TLR4. RG-II showed a preventive effect of immunization with OVA-pulsed BMDCs against EG7 lymphoma. These results suggested that RG-II expedites the DC-based immune response through the TLR4 signaling pathway.

Prevalence of Toxoplasma gondii Infection in Household Cats in Korea and Risk Factors

Several epidemiological surveys have reported the prevalence of Toxoplasma gondii infection in stray cats in Korea, but little information is available on T. gondii infection in household cats. The aim of the present study was to assess the prevalence and risk factors of T. gondii infection among household cats reared in Seoul, Korea. A total of 474 blood samples were collected from clinically healthy household cats. All samples were tested using ELISA and PCR. The risk factor analysis was based on a questionnaire filled out by the owners. The overall positive rate for ELISA and PCR assays was 2.2% (10/437) and 2.1% (10/474), respectively. With regard to the origin of cats, the positive rates among cats adopted from the animal shelter and veterinary clinic for stray cats were significantly different (P<0.05). Our study demonstrated that the positive rate of T. gondii infection in household cats was low and that this low prevalence was assumed to be associated with keeping the cats indoors and restriction of eating raw food and uncooked meat. Therefore, we suggest that the owners check the origin of the cats prior to adoption to prevent infection of other animals, including humans.

Detection of Ocular Toxoplasma gondii Infection in Chronic Irregular Recurrent Uveitis by PCR

Toxoplasma gondii is a zoonotic parasite resulting in human infections and one of the infectious pathogens leading to uveitis and retinochoroiditis. The present study was performed to assess T. gondii infection in 20 ocular patients with chronic irregular recurrent uveitis (20 aqueous humor and 20 peripheral blood samples) using PCR. All samples were analyzed by nested PCR targeting a specific B1 gene of T. gondii. The PCR-positive rate was 25% (5/20), including 5% (1) in blood samples, 25% (5) in aqueous humor samples, and 5% (1) in both sample types. A molecular screening test for T. gondii infection in ocular patients with common clinical findings of an unclear retinal margin and an inflammatory membrane over the retina, as seen by fundus examination, may be helpful for early diagnosis and treatment.

Prevalence of Enterobius vermicularis among Preschool Children in Muan-gun, Jeollanam-do, Korea

We assessed the prevalence of Enterobius vermicularis infection and changes in the egg positive rate (EPR) over 1-year time, using the adhesive cellophane-tape perianal swab method in 2,347 preschool children in Muan-gun, Jeollanam-do, Republic of Korea in 2008 and 2009. The overall EPR for E. vermicularis was 4.1% in 2008 and 4.5% in 2009. A study population of 389 children was repeatedly examined for 2 years. Within this group, the EPR in 2009 was twice higher than in 2008, and the EPR of the group of 5-7-year-old children was significantly higher than that of other age groups. Moreover, in the group of 5-7-year-old children in 2009, the rates of positive and negative conversion were significantly higher and lower, respectively, than in other age groups. Conclusively, enterobiasis was prevalent during 2008-2009 among preschool children in Muan-gun, Jeollanam-do, and the increased EPR in 2009 was due to an increase in newly acquired infections among 5-7-year-old children.

Comparison of Egg Positive Rates of Enterobius vermicularis among Preschool Children in Three Korean Localities

This survey was performed to investigate and compare egg positive rates (EPRs) of Enterobius vermicularis among preschool children in 3 Korean localities (Chuncheon-si, Inje-gun, and Paju-si) in 2008. A total of 7,048 preschool children were examined. Overall, the total EPR was 4.0%; the EPR was the highest in Chuncheon-si (5.6%), followed by Inje-gun (4.5%) and Paju-si (3.4%). The EPR of boys (4.9%) was higher than that of girls (3.1%). The EPR significantly increased with age, with the highest observed in 5~7-year-olds. These findings demonstrate that E. vermicularis infection is widely prevalent among preschool children in Chuncheon-si, Inje-gun, and Paju-si, Republic of Korea.

The Effect of Hyaluronic Acid on the Invasiveness of Malignant Glioma Cells : Comparison of Invasion Potential at Hyaluronic Acid Hydrogel and Matrigel

OBJECTIVE: Hyaluronidase (HAse), a degrading enzyme of hyaluronic acid (HA), is highly expressed in patients with malignant glioma. The purpose of this study was to verify whether HAse is related to the invasion of glioma cells. We also investigated if glioma cells with higher mobility in 2-dimensioal (2-D) method have also higher mobility at 3-dimensional (3-D) environment. METHODS: Malignant glioma cell lines (U87MG, U251MG, U343MG-A, and U373MG) were used, and their HAse expressions were evaluated by HA zymography. The migration ability was evaluated by simple scratch technique. The invasiveness of each cell lines was evaluated by Matrigel invasion assay and HA hydrogel invasion assay. In HA hydrogel invasion assay, colonies larger than 150 micrometer were regarded as positive ones and counted. Statistical analysis of migration ability and invasion properties of each cell lines was performed using t-test. RESULTS: In scratch test to examine migration ability of each cell lines, U87MG cells were most motile than others, and U343MG-A least motile. The HAse was expressed in U251MG and U343MG-A cell lines. However, U87MG and U373MG cell lines did not express HAse activity. In Matrigel invasion assay, the cell lines expressing HAse (U251MG and U343MG-A) were more invasive in the presence of HA than HAse deficient cell lines (U87MG and U373MG). In HA hydrogel invasion assay, the HAse-expressing cell lines formed colonies more invasively than HAse-deficient ones. CONCLUSION: Malignant Glioma cells expressing HAse were more invasive than HAse-deficient ones in 3-dimensional environment. Therefore, it might be suggested that invasion of malignant gliomas is suppressed by inhibition of HAse expression or HA secretion. Additionally, the ability of 2-D migration and 3-D invasion might not be always coincident to each other in malignant glioma cells.

The Risk Factors Associated with Surgical Site Infection after an Abdominal Operation

PURPOSE: Surgical site infection (SSI) is the most common nosocomial infection in surgical patients, and this accounts for 38% of all patients with nosocomial infections. Despite the advances in techniques and knowledge to prevent infection, SSI remains a significant source of postoperative morbidity and mortality, and it results in a prolonged hospital stay and increased cost. This study aims to assess the incidence of SSI and to identify the risk factors associated with SSI for patients who undergo abdominal operation. METHODS: The data on 347 abdominal operations that were done under general anesthesia from 1 August 2005 to 31 July 2006 was collected and reviewed. RESULTS: The overall incidence of SSI was 4.9%. Comorbidity was the independent risk factor for the development of SSI (P=0.011). The development of SSI was related with the American Society of Anesthesiologists (ASA) preoperative assessment score (P=0.025). The duration of the operation had a statistically significant association with an increased risk of SSI on univariate analysis. The wound classification was not associated with SSI. Staphylococcus aureus was the most frequently isolated organism, and all of the cases were methcillin-resistant Staphylococcus aureus. CONCLUSION: This study demonstrate that comorbidity is a significant independent risk factor for SSI.

Detection of Human Papilloma Virus DNA in Seborrheic Keratosis of Korean Skin

BACKGROUND: DNA of epidermodysplasia verruciformis(EV)-associated human papillomaviruses (HPVs) has been detected in benign and malignant skin tumors and other proliferative diseases of epithelial origin. The objective of this study was to determine the association of EV-associated HPV DNA in nongenital seborrheic keratoses(SK) in Korean patients. SUBJECTS AND METHODS: Forty biopsy specimens were collected from patients with nongenital SK and cutaneous SCC and controls. All tissue samples were examined by PCR. RESULTS: By polymerase chain reaction(PCR), EV-associated HPV DNA was detected in 15 of 40 nongenital SK(37.5%) compared with 1 of 40 cutaneous squamous cell carcinomas(SCC) samples and 3 of 40 healthy controls. Detected viruses in SK included HPV 20(n=6), HPV 23 (n=2). The rest tested positive for HPV 5, 16, 17, 22, 25, 37, and RTRX4. CONCLUSION: Our findings suggest that EV-associated HPV may be involved in the pathogenesis of nongenital SK of Asian skin.

A Case of Generalized Vitiligo Associated with Interstitial Deletion of Chromosome 13q

No abstract available.

A Case of Metastatic Calcinosis Cutis / 대한피부과학회지

Metastatic calcinosis is a common feature of chronic renal failure. Its first manifestations are bone demineralization and non-visceral and/or visceral calcification with mostly mural deposits in arteries and arterioles. It is initially characterized by hyperphosphatemia followed by secondary or tertiary hyperparathyroidism. Cutaneous involvement is a rare complication. We present the case of 46-year-old man with end-stage renal disease accompanied by secondary hyperparathyroidism. He developed solitary erythematous nodule on the left first thumb and on tissue examination, there were small deposits of calcium in the dermis. His secondary hyperparathyroidism attributed to parathyroid multinodular hyperplasia was corrected by total parathyroidectomy and elevated laboratory abnormalities were normalized.