• International Journal of Stem Cells
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• v.17 no.1
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• pp.30-37
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• 2024

The lung is a complex organ comprising a branched airway that connects the large airway and millions of terminal gas-exchange units. Traditional pulmonary biomedical research by using cell line model system have limitations such as lack of cellular heterogeneity, animal models also have limitations including ethical concern, race-to-race variations, and physiological differences found in vivo. Organoids and on-a-chip models offer viable solutions for these issues. Organoids are three-dimensional, self-organized construct composed of numerous cells derived from stem cells cultured with growth factors required for the maintenance of stem cells. On-a-chip models are biomimetic microsystems which are able to customize to use microfluidic systems to simulate blood flow in blood channels or vacuum to simulate human breathing. This review summarizes the key components and previous biomedical studies conducted on lung organoids and lung-on-a-chip models, and introduces potential future applications. Considering the importance and benefits of these model systems, we believe that the system will offer better platform to biomedical researchers on pulmonary diseases, such as emerging viral infection, progressive fibrotic pulmonary diseases, or primary or metastatic lung cancer.

• Korean Journal of Veterinary Research
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• v.64 no.3
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• pp.29.1-29.8
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• 2024

The liver is a defense against infections due to its strategic location between the gastrointestinal and systemic circulations. In dogs and cats, infectious hepatitis encompasses a range of contagious diseases affecting the liver either directly or as part of a broader systemic infection, including bacterial, mycobacterial, viral, fungal, protozoal, parasitic, and rickettsial diseases. Catechins possess well-recognized natural antioxidant properties. This study investigated their therapeutic potential for applications in hepatology, evaluating whether catechins reduce hepatic inflammation in rats repeatedly exposed to carbon tetrachloride (CCl₄). Sprague-Dawley rats were given catechin 50 (C50) or 100 (C100) mg/kg body weight orally daily for 3 days. This treatment was given with or without concurrent intraperitoneal injections of CCl₄. Phosphate-buffered saline served as the vehicle control, while silymarin administered at 100 mg/kg was used as the positive control. Gross examination revealed significant enlargement, edema, and darker tissue in CCl₄-induced livers treated with vehicle. Additionally, spotty discoloration was observed on the surface. Kupffer cell activation suppressed the expression of inflammatory mediators, including inducible nitric oxide synthase (iNOS), in groups co-treated with catechin and CCl₄; this effect was reversed when catalase replaced catechin in CCl₄-injured rats. Catechin alleviates hepatic inflammation in rats repeatedly exposed to CCl₄; it also modulates the activation of Kupffer cells and monocytes. These results should lead to new treatments for liver inflammation in veterinary practice.

• Clinical and Experimental Pediatrics
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• v.52 no.11
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• pp.1234-1240
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• 2009

Purpose:Enteroviruses (EVs) are commonly known to cause infection, especially in infants and children. This report presents an overview of enterovirus epidemiology in central Korea. Methods:From the spring of 2005 to the autumn of 2006, we collected the cerebrospinal fluid (CSF) and stool samples from the pediatric patients with a febrile illness or suspected meningitis who were admitted to hospitals in central Korea. In order to test for EVs, cell lines were derived from pretreated susceptible specimen, and the cytopathic effects were observed. Seminested real time-polymerase chain reaction (RT-PCR) and direct sequencing were performed for genotypic and phylogenetic analyses. Results:Of the 305 patients examined, 51 (16.7%) tested positive for EV. Of these 51 patients, 44 showed the following serotypes: Echovirus (ECV) 18 (18 cases, 35.2%), Coxsackievirus B (CVB) 5 (13 cases, 25.4%), ECV25 (5 cases, 9.8%), ECV9 (4 cases, 7.8%), ECV5 (3 cases, 5.8%), and EV74 (1 case, 1.9%). In 2005, between June and August, ECV18 and CVB5 were mostly responsible for the enteroviral infections among the patients in central Korea. In 2006, between July and August, ECV25 was mostly the cause of enteroviral infection. Conclusions:There is a need for continuous surveillance of enteroviral infection and its clinical manifestations, particularly for EV74, which was first identified in Korea.

• Korean Journal of Veterinary Research
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• v.38 no.4
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• pp.756-762
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• 1998

The purpose of this study was to investigate the confirmation and prevalence of porcine cytomegalovirus (PCMV) infection of pigs in Korea using enzyme-linked immunosorbent assay (ELISA). Four hundred-eighty one sera tested were collected from the areas of Kyonggi, Kangwon, Chungcheong, Cholla, Gyongsang and Cheju during the year of 1991 to 1997 except 1994. PCMV antigen, OF-1 strain, for ELISA, was prepared 19-PFT-F cell line originated from porcine fallopian tube. Positive control was used by sera made from the specific pathogen free piglets which were infected with OF-1 strain. Three hundred-sixty seven of 481 sera (76.3%) were positive against PCMV. Antibody titers of these seropositives were classified by 129 (26.8%) cases in more than 1 : 12,800, 77 (16.0%) in 1 : 6,400, 76 (15.8%) in 1 : 3,200, 44 (9.2%) in 1 : 1,600, and 41 (8.5%) in 1 : 800, respectively. Also, the seropositive pigs were divided by 87.4% (76/87) in older than 6 month-old, 73.9% (238/322) in 2~6-month old, and 73.6% (53/72) in less than 2-month old, respectively. Regional prevalence rate of PCMV infection in Korea showed 89.7% (70/78) in Chungchong, 79.8/% (83/104) in Cholla, 79.4% (143/180) in Kyonggi, 79.3% (42/53) in Gyongsang, 50% (15/30) in Kangwon, and 38.9% (14/36) in Cheju area, respectively. In the sera collected in 1991, seropositive rate was appeared as 90.2% (37/41). From 1992 to 1997 except 1994, the average infection rate to PCMV was 77.5%. Consequently, these results confirmed that PCMV in Korean piggeries was introduced at least before the year of 1991. More importantly, PCMV infection has been prevailing nation-wide in pig herds in Korea.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.4
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• pp.227-235
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• 2013

Purpose: High risk human papillomavirus (HPV) is the main source of cervical cancer, nearly up to 100%. Because there are no affordable data regarding the incidence of HPV in different sites of oral cavity, the purpose of this study is to review the previous article and to find out about the incidence and types of HPV in specific areas of oral cavity. Methods: We examined a total of 106 patients with oral cavity cancer for HPV detection. Available DNA chip (MY-HPV chip kit$^{(R)}$, Mygene Co., Korea) was used for the detection of low risk HPV types (6, 11, 34, 40, 42, 43, 44) and high risk HPV types (16, 18, 31, 33, 35, 39, 45, 51, 52, 54, 56, 58). Patients were previously diagnosed as invasive cancer of oral cavity. Specimen used for HPV detection was extracted from the main mass during resection and were tested for HPV type, performed by a DNA chip method. Results: Histologic results showed that there were squamous cell carcinomas, mucoepidermoid carcinomas, cystadenocarcinomas, leiomyosarcoma and etc. Among HPV positive cancer, 2 patients showed positive for high risk HPV type 16, 3 patients showed positive for low risk HPV type 6 and the other 2 patients were positive for other types of HPV. Of the 7 patients with HPV positive, 4 patients were on the tongue, 3 on the lower gingiva. Conclusion: Most of the HPV positive cancers were on the tongue in our study. Cervical cancer of HPV infection is reported to be increasing in our society and because HPV infection largely spreads by sexual contact, the incidence of oral cancer with HPV infection is greatly assumed to be on the increase, simultaneously. Because the incidence of HPV on specific areas of oral cavity among oral cancer patients is not identified, more studies are ongoing.

• Parasites, Hosts and Diseases
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• v.23 no.1
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• pp.58-72
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• 1985

A histopathological study was carried out on the duodenum of mice and rats experimentally infected by F. seoulensis. Each mouse was infected with 500 metacercariae and killed after 1, 2, 3 days, 1 and 2 weeks from infection. Each rat was given 1, 000 metacercariae and was examined after 1, 2 and 4 weeks from infection. The duodenal tissue sections of mice and rats were stained with hematoxylin eosin, and PAS stained for the rats of 1 week group. The pathological findings are summarized as below. 1. There were no differences in mucosal findings between the mice and the rats, and between the location of duodenum, 1 and 5 em distal to the pylorus. 2. Each worm embraced a villus exclusively with its foliate fore body which was inserted into the intervillous spaces. The fluke pinched villous epithelia using its oral and ventral suckers. The tribocytic organ destroyed the villous epithelia deeply up to the stroma after 3 days from infection. 3. Apparent villous changes were observed in the mice after 3 days from infection. Villous changes were shortening, widening, blunting or fusion. The villous stroma showed edema, microscopic hemorrhage, capillary congestion, dilatation of lymphatics and inflammatory cell infiltration. The cells were lymphocytes, plasma cells, eosinophils and giant cells. Rarely submucosal and trans:nural inflammation was encountered.

• Parasites, Hosts and Diseases
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• v.26 no.1
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• pp.45-54
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• 1988

To observe the clinical course and intestinal histopathology in heavy infection of Fibricola seoulensis, an experimental study was performed in mice. Clinical, experimental infection with 1, 000 metacercariae. On the 11th day after infection, the mice began to die and all of the infected mice were dead by the 16th day. The infected mice showed gradual weight loss. Occult blood was detected after the 10th day. Diarrhea accurred after the 9th day and was recognized in all of the infected mice on the 12th day. Hemoglobin and mean corpuscular hemoglobin decreased significantily after the 12th day, and mean corpuscular hemoglobin concentration decreased in all infected mice. The histopathological changes were more marked in the duodenum than in the jejunum or ileum. Major changes were villous atrophy and crypt hyperplasia, with decreased villus/crypt ratio, inflammatory cell infiltration and stromal edema. The present results suggest that the cause of death of mice heavily infected with F. seoulensis should be malnutrition and severe fluid loss due to malabsorption, together with intestinal bleeding.

• Parasites, Hosts and Diseases
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• v.50 no.3
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• pp.243-247
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• 2012

Ascaris suum eggs are inactivated by composting conditions; however, it is difficult to find functional changes in heat-treated A. suum eggs. Here, unembryonated A. suum eggs were incubated at $20^{\circ}C$, $50^{\circ}C$, and $70^{\circ}C$ in vitro, and the gene expression levels related to viability, such as eukaryotic translation initiation factor 4E (IF4E), phosphofructokinase 1 (PFK1), and thioredoxin 1 (TRX1), and to apoptosis, such as apoptosis-inducing factor 1 (AIF1) and cell death protein 6 (CDP6), were evaluated by real-time quantitative RT-PCR. No prominent morphological alterations were noted in the eggs at $20^{\circ}C$ until day 10. In contrast, the eggs developed rapidly, and embryonated eggs and hatched larvae began to die, starting on day 2 at $50^{\circ}C$ and day 1 at $70^{\circ}C$. At $20^{\circ}C$, IF4E, PFK1, and TRX1 mRNA expression was significantly increased from days 2-4; however, AIF1 and CDP6 mRNA expression was not changed significantly. IF4E, PFK1, and TRX1 mRNA expression was markedly decreased from day 2 at $50^{\circ}C$ and $70^{\circ}C$, whereas AIF1 and CDP6 mRNA expression was significantly increased. The expressions of HSP70 and HSP90 were detected for 9-10 days at $20^{\circ}C$, for 3-5 days at $50^{\circ}C$, and for 2 days at $70^{\circ}C$. Taken together, incremental heat increases were associated with the rapid development of A. suum eggs, decreased expression of genes related to viability, and earlier expression of apoptosis-related genes, and finally these changes of viability- and apoptosis-related genes of A. suum eggs were associated with survival of the eggs under temperature stress.

• Parasites, Hosts and Diseases
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• v.53 no.3
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• pp.321-327
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• 2015

A 50-year-old male visited the outpatient clinic and complained of fever, poor oral intake, and weight loss. A chest X-ray demonstrated streaky and fibrotic lesions in both lungs, and chest CT revealed multifocal peribronchial patchy ground-glass opacities with septated cystic lesions in both lungs. Cell counts in the bronchoalveolar lavage fluid revealed lymphocyte-dominant leukocytosis, and further analysis of lymphocyte subsets showed a predominance of cytotoxic T cells and few T helper cells. Video-assisted wedge resection of the left upper lobe was performed, and the histologic examination was indicative of a Pneumocystis jirovecii infection. Trimethoprim-sulfamethoxazole (TMP-SMX) was orally administered for 3 weeks; however, the patient complained of cough, and the pneumonia was aggravated in the follow-up chest X-ray and chest CT. Molecular studies demonstrated mutations at codons 55 and 57 of the dihydropteroate synthase (DHPS) gene, which is associated with the resistance to TMP-SMX. Clindamycin-primaquine was subsequently administered for 3 weeks replacing the TMP-SMX. A follow-up chest X-ray showed that the pneumonia was resolving, and the cough was also alleviated. A positive result of HIV immunoassay and elevated titer of HCV RNA indicated HIV infection as an underlying condition. This case highlights the importance of careful monitoring of patients with P. jirovecii pneumonia (PCP) during the course of treatment, and the molecular study of DHPS mutations. Additionally, altering the anti-PCP drug utilized as treatment must be considered when infection with drug-resistant P. jirovecii is suspected. To the best of our knowledge, this is the first case of TMP-SMX-resistant PCP described in Korea.

• Pediatric Infection and Vaccine
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• v.24 no.1
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• pp.54-59
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• 2017

Purpose: Urinary tract infection (UTI) is the most common serious bacterial infection in infants younger than 3 months of age. Lumbar puncture is routinely performed to evaluate febrile young infants for sepsis. However, there is no clear consensus on the use of routine lumbar puncture to diagnose concomitant meningitis in infants with UTI. We evaluated the prevalence of coexisting bacterial meningitis and sterile cerebrospinal fluid (CSF) pleocytosis in young infants with UTI. Methods: We retrospectively reviewed the medical records of 85 infants with UTI, aged from 29 to 99 days, who were admitted to Daegu Catholic University Medical Center from January 2013 to May 2016. We included 80 patients who had undergone lumbar puncture. Demographic features, clinical features, and laboratory findings were analyzed. Patients were divided into two groups based on the presence of sterile CSF pleocytosis and we compared these groups and assessed the differences between them. Results: Of the 80 UTI patients enrolled, 34 (43%) had sterile CSF pleocytosis. None had bacterial meningitis, and CSF polymerase chain reaction for enterovirus was positive in two patients without CSF pleocytosis. There were no significant differences between the two groups with regards to age, body temperature, peripheral white blood cell count, urinalysis, and duration of hospital stay. Conclusions: Though sterile CSF pleocytosis is common in young UTI patients, coexisting bacterial or viral meningitis is very rare. Indications for lumbar puncture in these patients depend on clinical condition.