• Parasites, Hosts and Diseases
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• v.37 no.3
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• pp.149-156
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• 1999

Pneumocystis carinii is pulmonary pathogen of immunocompromised humans or other mammals. Its infection results from activation of organism involves in latent infection or form new infection through the air. Almost all children are known to be infected within 2 to 4 years of birth, though prenatal transplacental transmission has not yet been demonstrated. In this study we observed experimental P.carinii infection in neonatal rats, thus investigating the possibility of transplacental vertical transmission by Diff-Quik staining of the lung impression smears and in-sity hybridization for lung sections. The postive rate of P.carinii infection in immunosuppressed maternal rats was 100%, but that in normal maternal rats was 0%. Cystic forms of P.carinii were observed in three of six 1-week old neonatal rats born of heavily infected mothers, but none of them was positive by in-situ hybridization. Five weeks after birth, cystic forms were detected in four neonatal rats. In the lobes of the lungs, no predilection site of P.carinii was recognized. Counts of cystic forms on smears and the reactivity of in-situ hbridization in the lungs of neonatal rats 0 were signficantly lower than in maternal rats. The present findings suggest that P.carinii is rarely transmitted through the placenta and proliferates less successfully in the lungs of neonatal rats than in mothers.

• Korean Journal of Veterinary Research
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• v.50 no.2
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• pp.139-143
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• 2010

A 2-month-old male Jeju native black calf with respiratory distress was died and requested to the Veterinary Pathology Laboratory of Jeju National University for diagnosis. Grossly, lungs were focally attached to the pleura and heart with fibrin. Purple red sublobar consolidations were distributed in both apical and cardiac lobes of lungs. Histopathologically, diffuse severe bronchointerstitial pneumonia characterized by multifocal necrotizing bronchiolitis, formation of numerous multinucleated syncytial cells in bronchiolar and alveolar lumens, and diffuse alveolar wall thickening were observed in lungs. Eosinophilic intracytoplasmic inclusions were observed in bronchiolar epithelial cells and syncytial cells. According to reverse transcriptase polymerase chain reaction (RT-PCR), bovine respiratory syncytial virus (BRSV) was detected in the lung of calf. Based on the histopathologic findings and RT-PCR, this calf was diagnosed as BRSV infection. In our best knowledge, this is the first case of BRSV infection in Jeju native black calf.

• Toxicological Research
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• v.30 no.3
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• pp.205-210
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• 2014

Didecyldimethylammonium chloride (DDAC) is used for various purposes, such as a fungicide for coolants, an antiseptic for wood, and disinfectant for cleaning. Despite the increasing likelihood of DDAC inhalation, available data on its toxicity from inhalation are scarce. Therefore, this study was aimed at confirming the toxicity of DDAC after inhalation exposure for 2 wk. Male Sprague-Dawley rats were exposed to approximately $0.15mg/m^3$, $0.6mg/m^3$, and $3.6mg/m^3$ DDAC aerosols in whole-body exposure chambers. After DDAC exposure for 2 wk, effects of DDAC on body weight, blood, bronchoalveolar lavage (BAL), and the lungs were verified. The mass median aerodynamic diameter of DDAC aerosols was $1.86{\mu}m$ and the geometric standard deviation was 2.75. The concentrations of DDAC aerosols for the low, medium, and high groups were $0.15{\pm}0.15mg/m^3$, $0.58{\pm}0.40mg/m^3$, and $3.63{\pm}1.56mg/m^3$, respectively. Body weight gain was significantly influenced by DDAC exposure. In the high group, a body weight decrease of 2.6 g was observed, whereas a 25.8 g increase was observed in the normal control group after the first 3 days. The low and medium groups showed 23.3 g and 20.4 g increases, respectively, after the first 3 days. Decreases in body weight were recovered during the next 4 days. In contrast, no changes were noted in hematological and blood biochemistry parameters after DDAC exposure. Furthermore, only mild effects were observed on bronchoalveolar cell differentiation counts and cell damage parameters in the BAL fluids of the medium and high groups. Although inflammatory cell infiltration and interstitial pneumonia were partially observed, fibrosis was not found in the lungs of the medium and high groups. In conclusion, body weight gain and the lungs were mainly affected by DDAC exposure. The no-observed-adverse-effect level (NOAEL) for DDAC was determined as $0.15mg/m^3$.

• Korean Journal of Veterinary Service
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• v.44 no.2
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• pp.103-111
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• 2021

Actinobacillus (A.) pleuropneumoniae is the etiological agent of a porcine pleuropneumonia and have great economic importance to the global swine industry. For recent 5 years, a total of 50 pleuropneumonia cases of 24 pig farms were selected from pig lungs submitted to the College of Veterinary Medicine, Jeju National University using polymerase chain reaction (PCR) analysis. Collected lungs were fixed in 10% neutral phosphate-buffered formalin and processed for histological examination. Serotypes of A. pleuropneumoniae in pneumonic lesions were analyzed by PCR methods. And the antimicrobial susceptibility of A. pleuropneumoniae isolates was determined by a disc diffusion test. Grossly, unilateral distribution of hemorrhagic or necrotic pneumonic lesions was more common than bilateral distribution in lungs. In peracute or acute cases, histopathologic changes were characterized by necrosis, hemorrhage, neutrophils infiltration, vascular thrombosis, widespread edema and fibrinous exudates. Following the acute response, macrophage infiltration, marked fibrosis around zonal necrotic areas, and marked fibrous pleuritis were characteristic in chronic cases. A total of 50 pleuropneumonia were associated with A. pleuropneumoniae serotype 5 in 46 cases (92%), serotype 2 in 3 cases (6%), and both 2 and 5 in 1 case (2%). More than 90% of collected isolates showed high sensitivity to ceftiofur, amoxicillin, and colistin. However, ampicillin, penicillin, and tylosin showed low susceptibility. The results of this study demonstrated that A. pleuropneumoniae serotype 5 was predominant at porcine pleuropneumonia cases in Jeju.

• Microbiology and Biotechnology Letters
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• v.50 no.2
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• pp.310-318
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• 2022

The fruits of Paulownia tomentosa (Thunb.) (PT) Steud. have been reported to exert a variety of biological activities. A previous study confirmed that compounds isolated from PT fruits (PTF) exerted anti-inflammatory effects on TNF-α-stimulated airway epithelial cells. However, there is no report on the protective effects of PTF on acute lung injury (ALI). Here, we examined the ameliorative effects of PTF in an experimental animal model of lipopolysaccharide (LPS)-induced ALI. In ALI mice, increased levels of inflammatory cell influx were confirmed in the lungs of mice, and an increase of microphage numbers, TNF-α, IL-6 and MCP-1 production and protein content were detected in mouse bronchoalveolar lavage fluid. However, these increases were significantly reversed with PTF pretreatment. In addition, PTF inhibited the increased expression of iNOS and COX-2 in the lungs of ALI mice. Furthermore, the upregulation of MAPK and NF-κB activation was decreased in the lungs of ALI mice by PTF. In the in vitro experiment, PTF pretreatment exerted an anti-inflammatory effect by inhibiting the secretion of nitric oxide, TNF-α and IL-6 in LPS-stimulated RAW264.7 macrophages. Collectively, these results indicated that PTF has ameliorative effects on airway inflammation in an experimental animal model of ALI.

• Journal of Korean Neurosurgical Society
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• v.65 no.5
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• pp.680-687
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• 2022

Objective : The influence of moderate-to-severe traumatic brain injury (TBI) on acute pulmonary injury is well established, but the association between acute pulmonary injury and mild TBI has not been well studied. Here, we evaluated the histological changes and fluctuations in inflammatory markers in the lungs to determine whether an acute pulmonary inflammatory response occurred after mild TBI. Methods : Mouse models of mild TBI (n=24) were induced via open-head injuries using a stereotaxic impactor. The brain and lungs were examined 6, 24, and 72 hours after injury and compared to sham-operated controls (n=24). Fluoro-Jade B staining and Astra blue and hematoxylin staining were performed to assess cerebral neuronal degeneration and pulmonary histological architecture. Quantitative real-time polymerase chain reaction analysis was done to measure inflammatory cytokines. Results : Increased neuronal degeneration and the mRNA expression of interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-10, and transforming growth factor (TGF)-β were observed after mild TBI. The IL-6, TNF-α, and TGF-β levels in mice with mild TBI were significantly different compared to those of sham-operated mice 24 hours after injury, and this was more pronounced at 72 hours. Mild TBI induced acute pulmonary interstitial edema with cell infiltration and alveolar morphological changes. In particular, a significant infiltration of mast cells was observed. Among the inflammatory cytokines, TNF-α was significantly increased in the lungs at 6 hours, but there was no significant difference 24 and 72 hours after injury. Conclusion : Mild TBI induced acute pulmonary interstitial inflammation and alveolar structural changes, which are likely to worsen the patient's prognosis.

• Journal of Cardiovascular Imaging
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• v.31 no.4
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• pp.191-199
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• 2023

BACKGROUND: Assessment of left ventricular (LV) function plays a pivotal role in the management of patients with valvular heart disease, including those caused by rheumatic heart disease. Noninvasive LV pressure-strain loop analysis is emerging as a new echocardiographic method to evaluate global LV systolic function, integrating longitudinal strain by speckle-tracking analysis and noninvasively measured blood pressure to estimate myocardial work. The aim of this study was to characterize global LV myocardial work efficiency in patients with severe rheumatic mitral stenosis (MS) with preserved ejection fraction (EF). METHODS: We retrospectively included adult patients with severe rheumatic MS with preserved EF (> 50%) and sinus rhythm. Healthy individuals without structural heart disease were included as a control group. Global LV myocardial work efficiency was estimated with a proprietary algorithm from speckle-tracking strain analyses, as well as noninvasive blood pressure measurements. RESULTS: A total of 45 individuals with isolated severe rheumatic MS with sinus rhythm and 45 healthy individuals were included. In healthy individuals without structural heart disease, the mean global LV myocardial work efficiency was 96% (standard deviation [SD], 2), Compared with healthy individuals, median global LV myocardial work efficiency was significantly worse in MS patients (89%; SD, 4; p < 0.001) although the LVEF was similar. CONCLUSIONS: Individuals with isolated severe rheumatic MS and preserved EF, had global LV myocardial work efficiencies lower than normal controls.

• Molecules and Cells
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• v.45 no.12
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• pp.896-910
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• 2022

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible and potentially fatal virus. So far, most comprehensive analyses encompassing clinical and transcriptional manifestation have concentrated on the lungs. Here, we confirmed evident signs of viral infection in the lungs and spleen of SARS-CoV-2-infected K18-hACE2 mice, which replicate the phenotype and infection symptoms in hospitalized humans. Seven days post viral detection in organs, infected mice showed decreased vital signs, leading to death. Bronchopneumonia due to infiltration of leukocytes in the lungs and reduction in the spleen lymphocyte region were observed. Transcriptome profiling implicated the meticulous regulation of distress and recovery from cytokine-mediated immunity by distinct immune cell types in a time-dependent manner. In lungs, the chemokine-driven response to viral invasion was highly elevated at 2 days post infection (dpi). In late infection, diseased lungs, post the innate immune process, showed recovery signs. The spleen established an even more immediate line of defense than the lungs, and the cytokine expression profile dropped at 7 dpi. At 5 dpi, spleen samples diverged into two distinct groups with different transcriptome profile and pathophysiology. Inhibition of consecutive host cell viral entry and massive immunoglobulin production and proteolysis inhibition seemed that one group endeavored to survive, while the other group struggled with developmental regeneration against consistent viral intrusion through the replication cycle. Our results may contribute to improved understanding of the longitudinal response to viral infection and development of potential therapeutics for hospitalized patients affected by SARS-CoV-2.

• Journal of Veterinary Clinics
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• v.6 no.2
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• pp.307-318
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• 1989

In recent years much attention has been paid to swine respiratory infection caused by Pasteurella(P) multocida with rapid expansion of pork Industry in Korea. The present study was performed to observe the etiologic situation of P. multocida infection by bacteriological, serological(serotyping) and pathological examinations with the lungs respectively. In addition antibiotic susceptibility test was carried out against the isolated strains of P. multocida. The results obtained are as follows : 1. Eighteen strains(12.8％) wert isolated from the 140 cases of swine lungs examined, and biological and biochemical characteristics of the isolates were the sam as those in the references of other workers, whereas some differences were observed in sugar fermentation and enzyme activity according to the strain of isolates. 2. Capsular serotyping performed on 18 P. multocida revealed that 13 strains(72.2％) were A type and 5 strains(27.8％) were D type, respectively. 3. When serotyping was performed against somatic antigen on 18 strains capsular types of which were identified as described above 9(50％), 3(16.7％) and 4(22.2％) strains belong to 1:A, 3:A and 2:D, respectively, but untypable 2 strains(11.1％) were observed. 4. Antibiotic susceptibility test by employing disc method for 24 kinds of drugs revealed that 15 kinds of antibiotics were sensitive to 18 strains of P. multocida isolated such as ampicillin(l00％), penicillin(100％), cloxacillin(56％), piperacillin(70％), cefotaxime(30%), minocycline(60％), chloramphenicol(95％), erythromycin(39％), kanamycin(17％), gentamicin(70%), amikasin(30%), colistin(78％) and nalidixic acid(5％), respectively, but resistant to 9 kinds of antibiotics such as sulpenicillin, cefazolin, cephalothin, cefametazol, cefoperazone, kitasamycin, oleandomycin. lincomycin and bacitracin. 5. Pathological features of 60 cases of swine lungs indicated that pneumonic .lesions were observed in 38 cases(63.3％) examined by macroscopic finding, in which lesions of 8 cases(13.4％) would correspond to those of mycoplasmal infection, and 30 cases(50％) were similar to viral infection by histopathological finding, whereas 22 cases(36.7％) were considered to be normal by ecropsy or histopathological finding.

• Parasites, Hosts and Diseases
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• v.32 no.3
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• pp.171-176
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• 1994

Wistar rats were induced of Pneumowstis cayinii infection by injection with methyl-prednisolone to correlate the cyst counts and numbers of nuclei. Seven sections of the lungs were examined by impression smears and also whole lung homogenates were screened for nucleus counting for each rat. At the first week of the experiment, all of the Impression smears except one were cyst negative but trophic forms were counted around 106. At the third week, the cysts appeared one per 20 Immersion oil lens fields. The nuclei were on the order of 107 at this period, and this amount of Pc is regarded as the limit of cyst detection on Impression smears. When the nuclei were over 109 in the lungs, the cysts were counted about 50 in 20 microscopic fields. The organisms were distributed in the lungs without any predilection focus. The present data suggest that the trophic forms, proliferate first and the cysts appear later in the lungs.