Biomedical subjects

Jae-Hoon Lee

Publications and source records attributed to Jae-Hoon Lee.

16 recordsLinked to original sources

PubMed2006

Possible role of light in the maintenance of EIN3/EIL1 stability in Arabidopsis seedlings.

To examine the mechanism of EIN3-mediated gene expression by ethylene, the expression patterns of ethylene-inducible genes by ethylene were monitored in Col-0 and ethylene signaling mutants. In Col-0, the inducibility of ACC oxidase by ethylene in light-grown seedlings was much higher than in dark-grown seedlings. While the expression of ACC oxidase was highly increased by ethylene not only in Col-0 but in ein3-1 under light treatment, this pattern was completely abrogated in etiolated ein3-1 seedlings, suggesting the expression of EIN3-mediated ACC oxidase genes could be affected by light. To check if the level of EIN3 and EIL1 was regulated by light, cell-free degradation assays were performed. This resulted in the rapid degradation of these proteins within 1h after adding dark-grown cell extracts and this degradation was retarded by light-grown extracts. Here, we propose that light may act as a negative regulator in the destabilization of EIN3/EIL1.

Amino Acid Oxidoreductases↗

PubMed2006

A nasal tooth associated with septal perforation: A rare occurrence.

Supernumerary teeth occur in a wide variety of sites, including the palate, mandibular condyle, coronoid process, orbit, maxillary antrum, and nasal cavity. Supernumerary teeth manifest in different ways depending on the site. Reported symptoms and signs associated with supernumerary teeth in the nasal cavity (nasal teeth) include facial pain, external nasal deformities, foul-smelling rhinorrhea, recurrent epistaxis, and oronasal fistula. Very rarely, septal perforation has been reported. We present a case in which eruption of a tooth into the nasal cavity was associated with nasal septal perforation. The tooth was extracted endoscopically.

Humans↗

PubMed2006

Identification of single nucleotide polymorphisms in FOXJ1 and their association with allergic rhinitis.

Forkhead-box J1 (FOXJ1) is a presumed transcription factor that can suppress T cell activity, at least partially, through the repression of NFkappaB activity. Thus, dysregulation of FOXJ1 is thought to be associated with autoimmune diseases and/or other inflammatory diseases. To investigate the association between single nucleotide polymorphisms (SNPs) of human FOXJ1 and allergic rhinitis, we scanned the whole human FOXJ1 gene, including the promoter region, by direct sequencing of DNA from 32 individuals. We identified seven SNPs, three of which (g.-460C>T, g.1805G>T, and g.3375G>C) were chosen for large sample size genotyping (n=713), and to assess the genotype frequencies of these SNPs between controls and allergic rhinitis patients. We also investigated the relationships of each genotype with serum total IgE levels in allergic rhinitis patients, and compared the frequencies of haplotypes constructed by these SNPs between the two groups. Our results suggest that the SNPs g.-460C>T, g.1805G>T and g.3375G>C in the human FOXJ1 gene might be associated with susceptibility to allergic rhinitis (P=0.0184, 0.0076, and 0.0143, respectively). The main haplotype, CGG, also revealed a significant association with allergic rhinitis (P=0.000018). However, no significant association was found between serum total IgE levels and the genotypes of these polymorphisms.

Adult↗

PubMed2005

Functional characterization of NtCEF1, an AP2/EREBP-type transcriptional activator highly expressed in tobacco callus.

Using PCR-select cDNA subtraction, we identified the genes that are predominantly expressed in the shooty callus induced by suppression of the CHRK1 receptor-like kinase gene. One of the identified genes encoded a novel AP2/EREBP-type transcription factor, and it was highly expressed in various types of tobacco callus including the CHRK1 transgenic callus, hence designated as Nicotiana tabacum Callus-Expressing Factor 1 NtCEF1. The NtCEF1-GFP fusion protein was localized in the nucleus. The full length and the C-terminal acidic region of NtCEF1 could function as a transactivator in yeast, when fused to the LexA DNA binding domain. Expression of the NtCEF1 gene was induced by ethylene and by various abiotic stresses. Gel retardation assay revealed that NtCEF1 could bind specifically to the GCC box as well as to the C/DRE motif, albeit less strongly. Interestingly, NtCEF1 overexpression in Arabidopsis resulted in constitutive expression of various ethylene-responsive and defense genes that contain the GCC box in the promoter-but none of the genes containing the upstream C/DRE elements-indicating that NtCEF1 preferentially recognizes the GCC box in vivo. Furthermore, the NtCEF1-overexpressing Arabidopsis plants exhibited enhanced resistance to a bacterial pathogen, Pseudomonas syringae pv. tomato DC3000. Taken together, these results suggest that NtCEF1 is a transcription factor preferentially activating the GCC box-containing defense genes, and that it modulates increased resistance against the biotic stress by activation of the downstream gene expression.

Amino Acid Sequence↗

PubMed2005

TNF-alpha induces the late-phase airway hyperresponsiveness and airway inflammation through cytosolic phospholipase A(2) activation.

BACKGROUND: Late-phase airway hyperresponsiveness (AHR) in asthma is considered the event leading to persistent inflammation in the lungs, but the molecular mechanisms involved in this process are poorly understood. OBJECTIVE: To examine the role of TNF-alpha in the development of a late AHR and airway inflammation in asthma. METHODS: We established a murine model of asthma with not only biphasic AHR to methacholine but also airway eosinophilia. The effect of TNF-alpha blockade was determined by using anti-TNF-alpha antibody and TNF-alpha knockout mice. Cytosolic phospholipase A(2) (cPLA(2)) mRNA expression and activity were assessed by using RT-PCR and 1-stearoyl-2-[1-(14)C] arachidonyl-sn-glycero-3-phosphocholine as the substrate, respectively. RESULTS: TNF-alpha blockade resulted in significant inhibition of the late AHR without affecting the early AHR, and reduction in airway eosinophilia and inflammation. cPLA(2) activity was increased in asthmatic lungs in a TNF-alpha-dependent way, and cPLA(2) inhibitor blocked late AHR and airway eosinophilia. TNF-alpha also stimulated the synthesis of cPLA(2) metabolites such as leukotriene B(4) and platelet-activating factor in the airway. Specific inhibitors of cPLA(2) metabolites inhibited the late AHR and airway eosinophilia. CONCLUSIONS: TNF-alpha is the proximal key cytokine capable of developing late-phase AHR and subsequent airway inflammation through expression/activation of cPLA(2).

Animals↗

PubMed2005

Effect of implant size and shape on implant success rates: a literature review.

Understanding and using biomechanical theories that effect endosseous implant design may improve the performance of implants in varying load conditions and allow the clinician to better apply this information with potentially improved success rates. The following article presents information from English peer-reviewed journals identified by a Medline search covering the years from 1974 through 2004, and attempts to integrate information available in the dental literature and address current controversies and issues in selecting diameter, length, and shapes of dental implants.

Biomechanical Phenomena↗

PubMed2005

Use of an immediate provisional implant to support a full-arch interim restoration: a clinical report.

The use of provisional implants as the sole or adjunct mean of stabilization for interim fixed partial dentures has gained popularity in implant prosthodontic treatment. These implants can be used between submerged implants during the healing phase to provide support for interim fixed or removable partial dentures. In this clinical report, a provisional implant used to provide support for a full-arch fixed interim restoration is described. Positioned between adjacent conventional implants, the provisional implant was placed during the same surgical procedure. As a result, an immediate acrylic fixed partial denture supported by natural teeth and the provisional implant provided a comfortable and esthetic interim restoration during the osseointegration period.

Dental Implantation, Endosseous↗

PubMed2004

The suggestive association of eotaxin-2 and eotaxin-3 gene polymorphisms in Korean population with allergic rhinitis.

The eotaxin gene family (eotaxin, eotaxin-2 and eotaxin-3) has been implicated in the recruitment of eosinophils, basophiles and Th2 lymphocytes that are central aspects of allergic diseases. To determine whether single-nucleotide polymorphisms (SNPs) of the eotaxin-2 and eotaxin-3 genes are associated with susceptibility to allergic rhinitis, we scanned 178 allergic rhinitis patients and 281 controls without allergic rhinitis using the direct sequencing and single-base extension (SBE) methods. We also calculated the haplotype frequencies between +179T>C and +275C>T of eotaxin-2 and +2497T>G of eotaxin-3 in both controls and allergic rhinitis patients. The haplotype frequency between controls and allergic rhinitis patients was suggestively associated (P=0.0001). The genotype frequencies of eotaxin-3 +2497T>G in allergic rhinitis patients were suggestively different from those in non-allergic rhinitis controls (P=<0.0007). Our results strongly suggest that the SNP of eotaxin-3 might be associated with susceptibility to allergic rhinitis.

Chemokine CCL24↗

PubMed2004

Phytosphingosine in combination with ionizing radiation enhances apoptotic cell death in radiation-resistant cancer cells through ROS-dependent and -independent AIF release.

The use of chemical modifiers as radiosensitizers in combination with low-dose irradiation may increase the therapeutic effect on cancer by overcoming a high apoptotic threshold. Here, we showed that phytosphingosine treatment in combination with gamma-radiation enhanced apoptotic cell death of radiation-resistant human T-cell lymphoma in a caspase-independent manner. Combination treatment induced an increase in intracellular reactive oxygen species (ROS) level, mitochondrial relocalization of B-cell lymphoma-2(Bcl-2)-associated X protein (Bax), poly-adenosine diphosphate (ADP)-ribose polymerase 1 (PARP-1) activation, and nuclear translocation of apoptosis-inducing factor (AIF). siRNA targeting of AIF effectively protected cells from the combination treatment-induced cell death. An antioxidant, N-acetyl-L-cysteine (NAC), inhibited Bax relocalization and AIF translocation but not PARP-1 activation. Moreover, transfection of Bax-siRNA significantly inhibited AIF translocation. Pretreatment of PARP-1 inhibitor, DPQ (3,4-dihydro-5-[4-(1-piperidinyl)-butoxy]-1(2H)-isoquinolinone), or PARP-1-siRNA also partially attenuated AIF translocation, whereas the same treatment did not affect intracellular ROS level and Bax redistribution. Taken together, these results demonstrate that enhancement of cell death of radiation-resistant cancer cells by phytosphingosine treatment in combination with gamma-radiation is mediated by nuclear translocation of AIF, which is in turn mediated both by ROS-dependent Bax relocalization and ROS-independent PARP-1 activation. The molecular signaling pathways that we elucidated in this study may provide potential drug targets for radiation sensitization of cancers refractive to radiation therapy.

Active Transport, Cell Nucleus↗

PubMed2004

The CaPRP1 gene encoding a putative proline-rich glycoprotein is highly expressed in rapidly elongating early roots and leaves in hot pepper (Capsicum annuum L. cv. Pukang).

Most of the proline-rich cell wall glycoprotein genes isolated from higher plants are preferentially expressed in the transmitting tissues of the flower organ. In conducting expressed sequence tag (EST) analysis, which was prepared from 5-day-old early roots of hot pepper (Capsicum annuum L. cv. Pukang), we identified a cDNA clone, pCaPRP1, encoding a putative cell wall proline-rich glycoprotein. CaPRP1 (Mr=28 kDa, pI=9.98) was most closely related to Nicotiana alata NaPRP4 (71%), while most distantly related to soybean PvPRP (37%). The predicted primary structure of CaPRP1 contains a putative N-terminal signal peptide, six repeats of the Lys-Pro-Pro tripeptide, four repeats of a five-amino acid sequence [Pro-(Ser/The)-Pro-Pro-Pro] and one potential N-glycosylation site (Asn-Asn-Ser). In contrast to most proline-rich cell wall glycoprotein genes, CaPRP1 was highly expressed in rapidly elongating very early roots and young leaves as well as developing flower tissues. Although the physiological function of CaPRP1 is not yet clear, there are several possibilities for its role in cell expansion and elongation during early development of hot pepper plants.

Amino Acid Sequence↗

PubMed2004

Molecular variations in Th1-specific cell surface gene Tim-3.

The family of T-cell immunoglobulin domain and mucin domain (TIM) proteins is identified to be expressed on T cells. A member of Tim family, Tim-3 (T cell immunoglobulin mucin 3) is selectively expressed on the surface of differentiated Th1 cells. Tim-3 might have an important role in the induction of autoimmune diseases by regulating macrophage activation and interacts with Tim-3 ligand to regulate Th1 responses. To determine the variation sites in the coding and promoter region of human Tim-3 gene, we performed variation scanning by direct sequencing using the genomic DNA isolated from the patients with asthma or allergic rhinitis and healthy controls without asthma and allergic rhinitis. We identified four single nucleotide polymorphisms (SNPs) including one novel SNPs (-1541C>T) and two variation sites (-1292_-1289delTAAA and -1282_-1278dupTAAAA) in the coding and promoter region of human Tim-3 gene in both the patients and healthy groups.

Asthma↗

PubMed2004

The Vr-PLC3 gene encodes a putative plasma membrane-localized phosphoinositide-specific phospholipase C whose expression is induced by abiotic stress in mung bean (Vigna radiata L.).

Phosphoinositide-specific phospholipase C (PI-PLC) catalyzes the hydrolysis of phosphatidylinositol 4,5-bisphosphate to generate inositol 1,4,5-trisphosphate and diacylglycerol, both of which act as secondary messengers in animal cells. In this report, we identified in Vigna radiata L. (mung bean) three distinct partial cDNAs (pVr-PLC1, pVr-PLC2, and pVr-PLC3), which encode forms of putative PI-PLC. All three Vr-PLC genes were transcriptionally active and displayed unique patterns of expression. The Vr-PLC1 and Vr-PLC2 transcripts were constitutively expressed to varying degrees in every tissue of mung bean plants examined. In contrast, the Vr-PLC3 mRNA level was very low under normal growth conditions and was rapidly induced in an abscisic acid-independent manner under environmental stress conditions (drought and high salinity). An isolated genomic clone, about 8.2 kb in length, showed that Vr-PLC1 and Vr-PLC3 are in tandem array in the mung bean genome. The predicted primary sequence of Vr-PLC3 (M(r)=67.4 kDa) is reminiscent of the delta-isoform of animal enzymes which contain core sequences found in typical PI-PLCs, such as the catalytic domain comprising X and Y motifs, a lipid-binding C2 domain, and the less conserved EF-hand domain. Results of in vivo targeting experiment using a green fluorescent protein (GFP) showed that the GFP-Vr-PLC3 fusion protein was localized primarily to the plasma membrane of the Arabidopsis protoplast. The C2 domain was essential for Vr-PLC3 to be targeted to the plasma membrane. The possible biological functions of stress-responsive Vr-PLC3 in mung bean plants are discussed.

Amino Acid Sequence↗

PubMed2004

The ethylene-responsive factor like protein 1 (CaERFLP1) of hot pepper (Capsicum annuum L.) interacts in vitro with both GCC and DRE/CRT sequences with different binding affinities: possible biological roles of CaERFLP1 in response to pathogen infection and high salinity conditions in transgenic tobacco plants.

From a pathogen-inoculated hot pepper (Capsicum annuum L. cv. Pukang) leaf EST, we identified a cDNA clone, pCaERFLP1, encoding a putative transcription factor that contains a single ERF/AP2 DNA binding domain. CaERFLP1 was most closely related to tomato LeERF2 (73%), both of which belong to the novel ERF class IV typified by the N-terminal MCGGAIL signature sequence, while it had a limited sequence identity (25-30%) with Arabidopsis AtERFs and tobacco NtERFs. Quantitative gel retardation assays revealed that bacterially expressed full-length CaERFLP1 was able to form a specific complex with both the GCC box and DRE/CRT motif, with its binding affinity for GCC being stronger than for DRE/CRT. When fused to the GAL4 DNA binding domain, the N-terminal CaERFLP1(1-37) and C-terminal CaERFLP1(198-264) mutant polypeptides could function individually as transactivators in yeast. This suggests that two separate domains of CaERFLP1 may play distinct roles in transcription activation. In particle co-bombardment experiments, CaERFLP1 activated the transcription of reporter genes containing the 4X[GCC] element in tobacco cells. In hot pepper plants, the steady-state level of CaERFLP1 mRNA was markedly induced by multiple environmental factors, such as pathogen infection, ethylene, mechanical wounding and high salinity. Furthermore, ectopic expression of CaERFLP1 in transgenic tobacco plants resulted in partially improved tolerance against the bacterial pathogen Pseudomonas syringae and salt stress (100 mM NaCl). Consistently, various defense-related genes, including GCC box-containing PR genes and the DRE/CRT-containing LTI45 (ERD10) gene, were constitutively expressed in 35S::CaERFLP1 tobacco plants. Thus, it appears that CaERFLP1 is functional in tobacco cells, where it induces the transactivation of some GCC- and DRE/CRT-genes to trigger a subset of stress response. Here, the possible biological role(s) of CaERFLP1 is discussed, especially with regard to the possibility that CaERFLP1 has multiple functions in the regulation of GCC- and DRE/CRT-mediated gene expression in hot pepper plants.

Amino Acid Sequence↗

PubMed2004

The association of TIM-3 gene polymorphism with atopic disease in Korean population.

The family of T-cell immunoglobulin domain and mucin domain (TIM) proteins is identified to be expressed on T cells. A member of the TIM family, TIM-3 is selectively expressed on the surface of differentiated T helper 1 (Th1) cells. TIM-3 might have an important role in the induction of autoimmune diseases by regulating macrophage activation and interacts with the TIM-3 ligand to regulate Th1 responses. In the present study, we analyzed the association of the genotype and allele frequencies between asthma or allergic rhinitis patients and nonatopic controls using large samples size at -1516G > T, -574T > G, and 4259G > T polymorphic sites of the Tim-3 gene. The genotype and allele frequencies of -574T > G polymorphism in asthma patients (p = 0.042 and p = 0.017, respectively) as well as allergic rhinitis patients (p = 0.008 and p = 0.003, respectively) were significantly different from those of nonatopic controls. Furthermore, the allele frequency of 4259G > T polymorphism in allergic rhinitis patients (p = 0.029) was also significantly different. Our results strongly suggest that the -574T > G polymorphism of Tim-3 might be associated with the susceptibility of atopic diseases such as asthma and allergic rhinitis.

Adult↗

PubMed2003

Molecular and biochemical characterization of VR-EILs encoding mung bean ETHYLENE INSENSITIVE3-LIKE proteins.

ETHYLENE INSENSITIVE3 (EIN3) is a transcription factor involved in the ethylene signal transduction pathway in Arabidopsis. Two full-length cDNA clones, pVR-EIL1 and pVR-EIL2, encoding EIN3-LIKE proteins were isolated by reverse transcriptase-polymerase chain reaction and by screening the cDNA library of mung bean (Vigna radiata) hypocotyls. VR-EIL1 and VR-EIL2 share 70% identity and display varying degrees of sequence conservation (39%-65%) with previously isolated EIN3 homologs from Arabidopsis, tobacco (Nicotiana tabacum) and tomato (Lycopersicon esculentum) plants. Gel retardation assay revealed that both VR-EILs were able to interact specifically with optimal binding sequence-1, the recently identified optimal binding sequence for tobacco TEIL, with the binding of VR-EIL2 being more efficient than that of VR-EIL1. Transient expression analysis using a VR-EIL::smGFP fusion gene in onion (Allium cepa) epidermal cells indicated that the VR-EIL proteins were effectively targeted to the nucleus. The fusion protein of VR-EIL2 with GAL4 DNA-binding domain strongly activated transcription of a reporter gene in yeast cells, and an essential domain for transcription-stimulating activity was localized to the amino-terminal acidic region that consists of 50 amino acid residues. In contrast with what has been previously found in EIN3- and TEIL-overexpressing Arabidopsis plants, transgenic tobacco seedlings expressing the VR-EIL genes under the control of cauliflower mosaic virus 35S promoter did not exhibit a constitutive triple response. Instead, they displayed a markedly enhanced proliferation of root hairs, one of the typical ethylene response phenotypes, and increased sensitivity to exogenous ethylene. In addition, the pathogenesis-related (PR) genes encoding beta-1,3-glucanase, osmotin, and PR1 were constitutively expressed in 35S::VR-EIL lines without added ethylene, and were hyperinduced in response to ethylene treatment. These results indicate that VR-EILs are functional in tobacco cells, thereby effectively transactivating the GCC-box-containing PR genes and enhancing sensitivity to ethylene. The possible physiological role of VR-EILs is discussed in the light of the suggestion that they are active components of the ethylene-signaling pathway and their heterologous expressions constitutively turn on a subset of ethylene responses in tobacco plants.

Active Transport, Cell Nucleus↗

PubMed2002

Clinical evaluation of compression ratios using JPEG2000 on computed radiography chest images.

The efficient compression of radiographic images is of importance for improved storage and network utilization in support of picture archiving and communication systems (PACS) applications. The DICOM Working Group 4 adopted JPEG2000 as an additional compression standard in Supplement 61 over the existing JPEG. The wavelet-based JPEG2000 can achieve higher compression ratios with less distortion than the Discrete Cosine Transform (DCT)-based JPEG algorithm. However, the degradation of JPEG2000-compressed computed radiography (CR) chest images has not been tested comprehensively clinically. The authors evaluated the diagnostic quality of JPEG2000-compressed CR chest images with compression ratios from 5:1 to 200:1. An ROC (receiver operating characteristic analysis) and t test were performed to ascertain clinical performance using the JPEG2000-compressed images. The authors found that compression ratios as high as 20:1 can be utilized without affecting lesion detectability. Significant differences between the original and the compressed CR images were not recognized up to compression ratio of 50:1 within a confidence level of 99%.

Algorithms↗