• Journal of Microbiology and Biotechnology
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• v.22 no.10
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• pp.1343-1349
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• 2012

Most of the Helicobacter pylori strains containing the cag pathogenicity island (PAI) have been associated with more severe gastric disease in infected humans. The cag PAI is composed of 27 proteins, and some of the components are required for CagA translocation into host cells as well as induction of proinflammatory cytokines, such as interleukin-8 (IL-8); however, the exact function of most of the components remains unknown or poorly characterized. In this study, we demonstrated that CagT (HP0532), which is an essential structural component of the cag PAI apparatus, plays an important role in the translocation of CagA into host epithelial cells. In addition to being located on the bacterial surface, CagT is also partially localized in the inner membrane, where it acts as a chaperone-like protein and promotes CagA translocation. However, CagT secretion was not detected by immunoprecipitation analysis of cell culture supernatants. Meanwhile, CagT was related to the introduction of IL-8 of the host cell. These results suggest that CagT is expressed on both the inner and outer bacterial membranes, where it serves as a unique type IV secretion system component that is involved in CagA secretion and cag PAI apparatus assembly.

• Korean Journal of Microbiology
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• v.52 no.4
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• pp.406-414
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• 2016

Among 6 leu codons, CUG is the most frequently used codon in E. coli. It is recognized by leu-tRNA(CAG) encoded by four genes scattered on two chromosomal loci (leuT and leuPQV ). In the process of constructing a strain with no functional leu-tRNA (CAG) gene on chromosome, we made two mutant strains separately, one on leuPQV locus (${\Delta}leuPQV$), and the other on leuT locus [$leuT^*$(GAG)], where the anticodon of leuT was changed from CAG to GAG, thereby altering its recognition codon from CUG to CUC. We attempted to combine these two mutations by transduction using $leuT^*$(GAG) strain as a donor and ${\Delta}leuPQV$ strain as a recipient. Large and small colonies appeared from this transduction. From PCR and DNA sequencing, large colony was confirmed to be the reciprocal recombinant as expected, but the small colonies contained both mutant $leuT^*$(GAG) and wild type leuT (CAG) genes in the cell. This heterozygous diploid strain did not show any unusual morphology under microscopic observation, but, interestingly, it showed a linear growth curve in rich medium with much slower growth rate than wild type cell. It always formed homogenous small colonies in the selection medium, but, when there was no selection, it readily segregated into $leuT^*$(GAG) and leuT (CAG). From these observations, we suggested that the strain with both $leuT^*$(GAG) and leuT (CAG) genes was not a partial diploid (merodiploid), but a full diploid cell having two different chromosomes. We proposed a model explaining how such a heterozygous diploid cell was formed and how and why its growth showed a linear growth curve.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.12 no.2
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• pp.140-149
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• 2009

Purpose: Helicobacter pylori infection is probably acquired in childhood and persists as an asymptomatic infection for decades in most individuals. It is unclear why only a minority of those infected develop a clinical manifestation, even in childhood, such as peptic ulcer disease. H. pylori infection activates local immune responses and causes lymphocyte infiltration in the gastric mucosa. We have previously reported that both T and B cells in the lamina propria play important roles in the local immune response of H. pylori-infected children. The aim of this study was to investigate the association between H. pylori genotypes and gastric mucosal lymphocytes. Methods: Twenty-five H. pylori-infected children (10 with peptic ulcer disease and 15 with gastritis) were enrolled in this study. We investigated the genotypes (cagA, cagE, vacA, and babA2) and evaluated the association with clinical manifestations, histopathology, and gastric mucosal lymphocytes. Results: The prevalence of cagA, cagE, vacA s1m1, and babA2 was 80%, 60%, 84%, and 88%, respectively. The most prevalent (68%) combination of cagA, vacA, and babA2 genotypes was cagA+/vacA s1m1+/babA2+. H. pylori genotypes were not associated with clinical manifestations, histopathology, or gastric mucosal lymphocytes. Conclusion: There was no association between the cagA, cagE, vacA, or babA2 status and gastric mucosal lymphocytes. The role of the host immune response in relation to H. pylori genotypes and disease potential in children needs further studies.

• Korean Journal of Adult Nursing
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• v.19 no.5
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• pp.47-55
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• 2007

Purpose: The purpose of this study was to determine the effect of supportive nursing care on the level of knowledge and compliance with sick-role behavior in patients with coronary artery disease after coronary angiography (CAG). Methods: A quasi-experimental research was performed with 81 subjects with coronary artery disease who were admitted for CAG to a cardiovascular department. Among the selected subjects, 40 of them were assigned to experimental group and the rest of them were assigned to control group by convenience. Supportive nursing care was implemented twice by a researcher. Results: 1. The mean score of knowledge related to coronary artery disease was higher in the group who received supportive nursing care than that of the control group (t=2.259, p=.027). 2. The mean score of compliance of sick role behavior was higher in the group who received supportive nursing care than that of the control group (t=4.580, p=.001). Conclusion: The supportive nursing care after CAG was effective in increasing the knowledge level and compliance of sick-role behavior in patients with coronary artery disease. Further studies would be recommended to identify long-term effectiveness of supportive care on patients' outcomes.

• Journal of Microbiology and Biotechnology
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• v.33 no.12
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• pp.1543-1551
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• 2023

The recently published high-resolution R388 T4SS structure provides exciting new details about the complete complex of T4SS, including the components making up the stalk and arches, numerous symmetry mismatches between regions of the complex, and an intriguing interpretation of the closed stalk and radial symmetry of the inner membrane complex, which is related to pilus biogenesis assembly. However, there are a few unidentified densities in the electron microscopy map and portions of the identified component sequences for which the structure is not yet known. It is also unclear how well this minimized DNA-transporting T4SS predicts the structure of other T4SSs, such as expanded systems and those that transport proteins rather than DNA. In this review, we evaluate what can be inferred from the recent high-resolution structure of the R388 T4SS with respect to the Cag and Dot/Icm systems. These systems were selected because, given what is currently known about these systems, we expect them to present most structural differences compared to the R388 T4SS structure. Furthermore, we discuss bacterial physiology and diversity, the T4SS structures and their variations between different bacterial species. These insights may prove beneficial for researchers who elucidate the structure and functions of T4SS in different bacterial species.

• The Korean Journal of Mycology
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• v.23 no.3 s.74
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• pp.202-208
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• 1995

This study describes the effects of several components on PCR amplification used for RAPD. We used different concentrations of reaction components to obtaine discrete and reproducible PCR products from Pleurotus cornucopiae. The optimum concentrations of reaction components were found to be 80 ng of template DNA, 30 pmole of 10-mer primer, $200\;{\mu}M$ dNTP, 2mM $MgCl_2$, 50 mM KCl, 10 mM Tris-HCl(pH 9.0), 0.1% Triton X-100, 1.5 unit of Taq DNA polymerase (promega) in $50\;{\mu}l$ reaction volume. The optimum annealing temperature was $35^{\circ}C$. These results proved to be valuable for characterization of Pleurotus spp.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.5
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• pp.362-368
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• 2008

Purpose: It is well known that lung to heart ratio (LHR) is one of the high risk findings in TI- 201 myocardial perfusion SPECT. We evaluated the clinical efficacy of LHR to identify severe coronary artery disease in adenosine stress Tc-99m tetrofosmin gated myocardial perfusion SPECT (gSPECT). Materials and Methods: The study population was 157 patients who underwent both adenosine stress Tc-99m gSPECT and coronary angiography (CAG) within one month. According to the results of CAG and gSPECT LHR and the incidence of increased LHR were compared. Results: Among 53 patients with normal coronary arteries increased LHR was found in 2 patients (3.8%) and 0 in 44 patients (0%) with one vessel disease, 2 in 27 with two vessel disease (7.4%) and 8 in 33 with triple vessel disease (24.2%). Significant differences were found in LHR between subgroups of summed stress score, summed rest score and LV ejection fraction (LVEF). There were weak negative correlation between LHR and LVEF and weak positive correlation between LHR and SSS and SRS. Conclusion: Increased LHR had higher incidence in patients with triple vessel disease, severe LV dysfunction and/or extensive perfusion defect than those of normal group. Although its sensitivity might be low to identify severe coronary artery disease, LHR could be helpful in abnormal myocardial perfusion SPECT to stratify risk and prognosis.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7635-7638
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• 2014

Background: The aim of this study was to investigate the value of serum gastric markers to differentiate between patients with precancerous lesions and nonatrophic chronic gastritis. Materials and Methods: Serum samples of 128 patients with dyspepsia who were candidates for endoscopic examination were tested for pepsinogen (PG I and PG II), PG I/II ratio, gastrin 17(G-17), anti-Helicobacter pylori (anti-H pylori ) and anti-CagA antibodies. Two sample t-tests, chi-square tests and Pearson's correlation analyses were used for analysis using SPSS (version 20). Results: PGI, PG I/II ratio values were decreased significantly in the precancerous lesion group (0.05, 0.001 respectively). The frequency of H pylori infection was significantly (p=0.03) different between the two groups ofthe study. Conclusions: We suggest PGI and the PG I/II ratio as valuable markers for screening of premalignant gastric lesions.

• Microbiology and Biotechnology Letters
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• v.49 no.3
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• pp.440-448
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• 2021

Helicobacter pylori (H. pylori) establishes long-term infections associated with severe gastric diseases such as peptic ulceration and gastric cancer. Exposure to an antibacterial agent can help regulate the expression levels of its pathogenic genes. In this study, we analyzed the transcriptional changes in H. pylori genes induced by β-caryophyllene. We used next-generation sequencing (NGS) to analyze RNA expression changes, and reverse transcription-polymerase chain reaction (RT-PCR) was performed as required to verify the results. The NGS results showed that 30 out of 1,632 genes were expressed differentially by β-caryophyllene treatment. Eleven genes associated with DNA replication, virulence factors, and T4SS components were significantly downregulated. RT-PCR confirmed that treatment reduced the expression levels of 11 genes. RT-PCR showed the reduced expression of 11 genes (dnaE, dnaN, holB, gyrA, cagA, vacA, secA, flgE, virB2, virB4, and virB8) following β-caryophyllene treatment. These results suggest that β-caryophyllene can modulate various H. pylori pathogenic determinants and be a potential therapeutic agent for H. pylori infection.

• The Journal of the Korean Society for Microbiology
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• v.34 no.6
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• pp.519-532
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• 1999

Helicobacter pylori is a causative agent of type B gastritis and plays a central role in the pathogenesis of gastroduodenal ulcer and gastric cancer. To elucidate the host-parasite relationship of the H. pylori infection on the basis of molecular biology, we tried to evaluate the genomic diversity of H. pylori. An ordered overlapping bacterial artificial chromosome (BAC) library of a Korean isolate, H. pylori 51 was constructed to set up a genomic map. A circular physical map was constructed by aligning ApaI, NotI and SfiI-digested chromosomal DNA. When the physical map of H. pylori 51 was compared to that of unrelated strain, H. pylori 26695, completely different restriction patterns were shown. Fifteen known genes were mapped on the chromosome of H. pylori 51 and the genetic map was compared with those of strain 26695 and J99, of which the entire genomic sequences were reported. There were some variability in the gene location as well as gene order among three strains. For further analysis on the genomic diversity of H. pylori, when comparing the genomic structure of 150 H. pylori Korean isolates with one another, genomic macrodiversity of H. pylori was characterized by several features: whether or not susceptible to restriction digestion of the chromsome, variation in chromosomal restriction fingerprint and/or high frequency of gene rearrangement. We also examined the extent of allelic variation in nucleotide or deduced amino acid sequences at the individual gene level. fucT, cagA and vacA were confirmed to carry regions of high variation in nucleotide sequence among strains. The plasticity zone and strain-specific genes of H. pylori 51 were analyzed and compared with the former two genomic sequences. It should be noted that the H. pylori 51-specific sequences were dispersed on the chromosome, not congregated in the plasticity zone unlike J99- or 26695-specific genes, suggesting the high frequency of gene rearrangement in H. pylori genome. The genome of H. pylori 51 shows differences in the overall genomic organization, gene order, and even in the nucleotide sequences among the H. pylori strains, which are far greater than the differences reported on the genomic diversity of H. pylori.