• The Korean Journal of Physiology and Pharmacology
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• v.1 no.4
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• pp.413-423
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• 1997

The importance of the kidney in the development of hypertension was first demonstrated by Goldblatt and his colleagues more than fifty years ago. Many hormones and other regulatory factors have been proposed to play a major role in the development of hypertension. Among these factors angiotensia II (ANG II) is closely involved in renal hypertension development since it directly regulates $Na^+$ reabsorption in the renal proximal tubule. Thus the aim of the present study was to examine signaling pathways of low dose of ANC II on the $Na^+$ uptake of primary cultured rabbit renal proximal tubule cells (PTCs) in hormonally defined seum-free medium. The results were as follows: 1) $10^{-11}$ M ANG II has a significant stimulatory effect on growth as compared with control. Alkaline phosphatase exhibited significantly increased activity. However, leucine aminopeptidase and ${\gamma}-glutamyl$ transpeptidase activity were not significant as compared with control. In contrast to $10^{-11}$ M ANG II stimulated $Na^+$ uptake $(108.03{\pm}2.16% of that of control)$, $10^{-9}$ M ANG II inhibited ($92.42{\mu}2.23%$ of that of control). The stimulatory effect of ANG II on $Na^+$ uptake was amiloride-sensitive and inhibited by losartan (ANG II receptor subtype 1 antagonist) and not by PD123319 (ANG II receptor subtype 2 antagonist). 2) Pertussis toxin (PTX) alone inhibited $Na^+$ uptake by $85.52{\pm}3.52%$ of that of control. In addition, PTX pretreatment prevented the AMG II-induced stimulation of $Na^+$ uptake. 8-Bromoadenosine 3',5'-cyclic monophosphate (8-Br-cAMP), forskolin, and isobutylmethylxanthine (IBMX) alone inhibited $Na^+$ uptake by $88.79{\pm}2.56,\;80.63{\pm}4.38,\;and\;84.47{\pm}4.74%$ of that of control, respectively, and prevented the ANG II-induced stimulation of $Na^+$ uptake. However, $10^{-11}$ M ANG II did not stimulate cAMP production. 3) The addition of 12-O-te-tradecanoylphorbol-13-acetate (TPA, 0.01 ng/ml) to the PTCs produced significant increase in $Na^+$ uptake ($114.43{\pm}4.05%$ of that of control). When ANG II and TPA were added together to the PTCs, there was no additive effect on $Na^+$ uptake. Staurosporine alone had no effect on $Na^+$ uptake, but led to a complete inhibition of ANG II- or TPA-induced stimulation of Na'uptake. ANG II treatment resulted in a $111.83{\mu}4.51%$ increase in total protein kinase C (PKC) activity. In conclusion, the PTX-sensitive PKC pathway is the main signaling cascade involved in the stimulatory effects of ANG II on $Na^+$ uptake in the PTCs.

• Animal Bioscience
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• v.35 no.3
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• pp.367-376
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• 2022

Objective: The highly pathogenic avian influenza virus (HPAIV) is a threat to the poultry industry as well as the economy and remains a potential source of pandemic infection in humans. Antiviral genes are considered a potential factor for HPAIV resistance. Therefore, in this study, we investigated gene expression related to cytokine-cytokine receptor interactions by comparing resistant and susceptible Ri chicken lines for avian influenza virus infection. Methods: Ri chickens of resistant (Mx/A; BF2/B21) and susceptible (Mx/G; BF2/B13) lines were selected by genotyping the Mx dynamin like GTPase (Mx) and major histocompatibility complex class I antigen BF2 genes. These chickens were then infected with influenza A virus subtype H5N1, and their lung tissues were collected for RNA sequencing. Results: In total, 972 differentially expressed genes (DEGs) were observed between resistant and susceptible Ri chickens, according to the gene ontology and Kyoto encyclopedia of genes and genomes pathways. In particular, DEGs associated with cytokine-cytokine receptor interactions were most abundant. The expression levels of cytokines (interleukin-1β [IL-1β], IL-6, IL-8, and IL-18), chemokines (C-C Motif chemokine ligand 4 [CCL4] and CCL17), interferons (IFN-γ), and IFN-stimulated genes (Mx1, CCL19, 2'-5'-oligoadenylate synthase-like, and protein kinase R) were higher in H5N1-resistant chickens than in H5N1-susceptible chickens. Conclusion: Resistant chickens show stronger immune responses and antiviral activity (cytokines, chemokines, and IFN-stimulated genes) than those of susceptible chickens against HPAIV infection.

• Tuberculosis and Respiratory Diseases
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• v.69 no.1
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• pp.24-30
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• 2010

Background: A novel 2009 influenza A (H1N1) virus emerged and disseminated to all over the world. There are few reports on the clinical characteristics of patients with complications. We describe the clinical features of pneumonia in adult patients hospitalized, who have novel influenza infection. Methods: There were 43 adult patients enrolled into the study with pneumonia of 528 hospitalized patients confirmed influenza A (H1N1) virus infection by real-time reverse transcriptase polymerase chain reaction testing, between 24 August 2009 and 31 January 2010. The clinical data of patients with pneumonia were collected retrospectively. Results: There were 22 of 43 (51.2%) influenza patients with pneumonia that had higher risk factors for complications. Compared to 28 patients with influenza A (H1N1) viral pneumonia and 15 patients, who had isolated bacteria from cultures, those with mixed viral and bacterial pneumonia were significantly more likely to have unilobar consolidations on chest radiographs (53.3 vs. 10.7%, p<0.01) and higher scores of pneumonia severity index (PSI; 90 [66~100] vs. 53 [28~90], p=0.04). Six patients required mechanical ventilation support in an Intensive Care Unit and were more likely to have dyspnea (83.3 vs. 29.3%, p=0.02) and low levels of $PaO_2$ (48.3 [37.0~70.5] vs 64.0 [60.0~74.5] mm Hg, p=0.02) and high levels of pneumonia severity index (PSI) score (108.0 [74.5~142.8] vs. 56.0 [40.5~91.0], p=0.03). Conclusion: The majority of pneumonia patients infected with novel influenza improved. Chest radiographic findings of unilobar consolidations suggest that mixed pneumonia is more likely. Initial dyspnea, hypoxemia, and high levels of PSI score are associated with undergoing mechanical ventilation support.

• Tuberculosis and Respiratory Diseases
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• v.70 no.5
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• pp.397-404
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• 2011

Background: To evaluate chest CT findings of pandemic influenza A/H1N1 pneumonia without co-infection. Methods: Among 56 patients diagnosed with pandemic influenza A/H1N1 pneumonia, chest CT was obtained in 22 between October 2009 and Februrary 2010. Since two patients were co-infected with bacteria, the other twenty were evaluated. Predominant parenchymal patterns were categorized into consolidation, ground glass opacity (GGO), and mixed patterns. Distribution of parenchymal abnormalities was assessed. Results: Median age was 46.5 years. The CURB-65 score, which is the scoring system for severity of community acquired pneumonia, had a median of 1. Median duration of symptoms was 3 days. All had abnormal chest x-ray findings. The median number of days after the hospital visit that Chest CT was performed was 1. The reasons for chest CT performance were radiographic findings unusual for pneumonia (n=13) and unexplained dyspnea (n=7). GGO was the most predominant pattern on CT (n=13, 65.0%). Parenchymal abnormalities were observed in both lungs in 13 cases and were more extensive in the lower lung zone than the upper. Central and peripheral distributions were identified in ten and nine cases, respectively. One showed diffuse distribution. Peribronchial wall thickening was found in 16 cases. Centrilobular branching nodules (n=7), interlobular septal thickening (n=4), atelectasis (n=1), pleural effusion (n=5), enlarged hilar and mediastinal lymph nodes (n=6 and n=7) were also noted. Conclusion: Patchy and bilateral GGO along bronchi with predominant involvement of lower lungs are the most common chest CT findings of pandemic influenza A/H1N1 pneumonia.

• Journal of Microbiology and Biotechnology
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• v.26 no.11
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• pp.1972-1982
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• 2016

Influenza A virus is a single-stranded RNA virus with a genome of negative polarity. Owing to the antigenic diversity and cross concrete shift, an immense number of novel strains have developed astronomically over the years. The present work deals with the codon utilization partialness among five different influenza A viruses isolated from human hosts. All the subtypes showed the homogeneous pattern of nucleotide utilization with a little variation in their utilization frequencies. A lower bias in codon utilization was observed in all the subtypes as reflected by higher magnitudes of an efficacious number of codons. Dinucleotide analysis showed very low CpG utilization and a high predilection of A/T-ending codons. The H5N1 subtype showed noticeable deviation from the rest. Codon pair context analysis showed remarkable depletion of NNC-GNN and NNT-ANN contexts. The findings alluded towards GC-compositional partialness playing a vital role, which is reflected in the consequential positive correlation between the GC contents at different codon positions. Untangling the codon utilization profile would significantly contribute to identifying novel drug targets that will pacify the search for antivirals against this virus.

• Journal of Gastric Cancer
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• v.2 no.1
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• pp.12-19
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• 2002

Purpose: The H. pylori cagA gene, vacA gene and iceA gene are considered to be important virurence factors that have been implicated in the development of gastric adenocarcinoma. It was reported that the presence of IS605 elements may be responsible for rearrangements and lead to partial or total deletions of the cag pathogenicity island (PAI) and the virulence of cag PAI may be changed. However, different results regarding the association between these virulence factors and clinical disease have been reported from different geographic regions. This study evaluated the relationship between H. pylori virulence factors such as cagA, vacA, iceA, IS605 and gastric adenocarcinoma. Materials and Methods: H. pylori isolates were obtained from 54 infected patients (24 cases of gastric adenocarcinoma, 30 cases of control). H. pylori isolates were identified by PCR with ureC gene and 16S rRNA. PCR was performed to examine cagA, vacA, iceA and IS605 genotypes. Results: Significant difference was found in the negative rates of cagA between gastric adenocarcinoma group and control ($62.5\%\;vs.\;33.3\%$ P=0.033). No significant difference was found in the prevalence of iceA, vacA between gastric adenocar cinoma and control. The genotype of cagA+ vacA s1-m1 iceA1 was predominant in H. pylori isolates irrespective of the clinical outcome. IS605 in PAI was not found in gastric adenocarcinoma gruop and control. The positive rates of IS605 in genome were $33.3\%$ in gastric adenocarcinoma group and $36.7\%$ in control (P>0.05). In gastric carcinoma, the positive rate of $cagA^{+}/IS605$ was lower than in control ($12.5\%\;vs\;40.0\%$, P=0.025) and the positive rate of cagA-/IS605 was higher than in control ($54.2\%\;vs\;23.3\%$, P=0.02). Conclusion: H. pylori virulence factors had not related significantly with gastric adenocarcinoma. Further study is needed to examine the specificity of H. pylori strains.

• Tuberculosis and Respiratory Diseases
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• v.70 no.1
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• pp.28-35
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• 2011

Background: The aim of the study was to describe the characteristics, treatments, and outcomes of critically ill patients with pandemic Influenza A/H1N1 2009 at a major medical center in Korea. Methods: This retrospective observational study examined critically ill adult patients with pandemic Influenza A/H1N1 2009, who were admitted to the AMC between August and December 2009. Results: 27 patients with confirmed pandemic Influenza A/H1N1 2009 were admitted to the intensive care unit (ICU) at the Asan Medical Center (AMC). The median age (IQR) was 59 years (41~67), and 66.7% of the patients were older than 51 years. A total of 81.5% of the patients had 2 or more co-morbidities. The median time (IQR) from symptom onset to presentation was 2 days (1~4), and the median time from presentation to ICU admission was 0 days (0~1.5). All patients received oseltamivir (300 mg/day) and 13 patients received triple combination therapy (oseltamivir, amantadine, ribavirin). Twelve patients required mechanical ventilation on the first day of ICU admission. A total of 6 patients (22.2%) died within 28 days of admission. The patients who died had significantly higher acute physiology and chronic health evaluation (APACHE) II and sequential organ failure assessment (SOFA) scores at presentation. There were no significant differences in age, co-morbidities, or antiviral regimens between survivors and non-survivors. Conclusion: Critical illness related to pandemic Influenza A/H1N1 2009 was common in elderly patients with chronic co-morbidities. All patients were given high-dose oseltamivir or triple combination antiviral therapy. Nonetheless, patients with critical illnesses associated with pandemic Influenza A/H1N1 2009 had a death rate of 22.2%.

• Journal of Life Science
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• v.28 no.8
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• pp.962-968
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• 2018

Type A influenza virus is circulating in wild birds and can infect wide ranges of hosts such as humans, pigs, domestic birds, and other mammals. Many subtypes of avian influenza viruses are circulating in aquatic birds. Most avian influenza viruses found in aquatic birds are low pathogenic avian influenza viruses. Highly pathogenic avian influenza viruses have been found in waterfowls since 2005. It is known that H5 and H7 subtypes of avian influenza viruses can be mutated into highly pathogenic avian influenza viruses in domestic poultry. In this study, we isolated novel reassortant H7N7 avian influenza virus from the fecal materials of migratory birds in the Western part of South Korea in 2016, and analyzed the sequences of all its eight genes. The genetic analysis of our isolate, A/waterfowl/Korea/S017/2016 (H7N7) indicates that it was reassortant avian influenza virus containing genes of both avian influenza viruses of wild birds and domestic ducks. Phylogenetic analysis showed that our isolate belongs to Eurasian lineage of avian influenza virus. Since avian influenza viruses continue to evolve, and H7-subtype avian influenza virus can mutate into the highly pathogenic avian influenza viruses, which cause the great threat to humans and animals, we closely survey the infections in both wild birds, and domestic poultry, and mammals.

• Biomolecules & Therapeutics
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• v.13 no.1
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• pp.20-25
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• 2005

The present study was performed to evaluate antiarrhythmic effects of KR-32570, a novel inhibitor of sodium hydrogen exchanger subtype-1 (NHE-1), in rat arrhythmia induced by focal ischemia and reperfusion. During ischemia, KR-32570 significantly decreased the number of premature ventricular contraction (PVC) from 152.0 times to 75.5, 52.4 and 20.0 times for 0.1, 0.3 and 1.0 mg/kg, respectively (p<0.05) and the duration of ventricular tachycardia (VT) from 88.1 s to 35.8, 7.7 and 1.3 s, respectively(p<0.05) in anesthetized rats subjected to 10-min coronary occlusion of coronary artery. Similarlt to ischemia-induced arrhythmia, KR-32570 significantly decreased reperfusion-induced arrhythmia including PVC (41.3, 21.5, 11.3 and 6.6 times at vehicle, 0.1, 0.3 and 1.0 mg/kg, respectively, p<0.05) and VT (100.5, 64.2, 25.8 and 25.2 s, respectively, p<0.05), and VF (86.9, 27.5, 6.9 and 0 s, respectively, p<0.05). Moreover, KR-32570 dose-dependently decreased the incidence of mortality occurring after reperfusion (41, 27, 18 and 0% at vehicle, 0.1, 0.3, 1.0 mg/kg, respectively). These results suggest that KR-32570 has a potent antiarrhythmic effect in rat arrhythmia induced by ischemia and reperfusion.

• Tuberculosis and Respiratory Diseases
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• v.68 no.3
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• pp.162-167
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• 2010

Background: To date, there are few data on the risk factors for severe cases and deaths associated with the 2009 pandemic H1N1 influenza A. Here, we describe the clinical and epidemiologic characteristics of patients hospitalized for pneumonia and identify those factors associated with the development of major complications (MC). Methods: We reviewed the medical records of 41 cases of pneumonia admitted to a university-affiliated tertiary hospital between Aug 26 and Dec 10, 2009, and who had confirmed H1N1 influenza A based on real-time reverse transcriptase-polymerase-chain-reaction assay. There were 7,962 patients that fit these criteria. We compared the clinical features and demographic characteristics of patients who developed MC to with those who did not develop MC. Results: During the study period, 10 patients developed MC (required admission to the intensive care unit, n=10; required ventilator therapy, n=6; death, n=4). Patients with MC were significantly older than those without MC and more frequently had underlying medical conditions (90.0% vs 41.9%, p-value <0.01). In the patients with developed MC, the median $PaO_2/FiO_2$ ratio of 230.0 (145.0~347.3) at admission and pneumonia severity index (PSI) score of 141.5 (88.3~158.5) were higher than patients without MC. However, no differences were observed in laboratory findings or in viral shedding between the 2 groups. Conclusion: In hospitalized pneumonia patients of 2009 H1N1 influenza, old age, a history of malignancy, initial hypoxemia, $PaO_2/FiO_2$ ratio, and PSI score appear to be risk factor significantly related to developing MC. These findings might be the basis to influence strategies for admitting patients to an intensive or intermediate care unit and for pre-emptive antiviral therapy.