• The Plant Pathology Journal
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• v.21 no.4
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• pp.395-401
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• 2005

The dlm (disease lesion mimic) mutant of soybean (Glycine max L. Merr) shows the similar lesion of a soybean disease caused by a fungus, Corynespora cassilcola. The lesion was examined at cellular and molecular level. Trypan blue staining result indicated that cell death was detectable in the entire region of leaves excluding veins when the lesions had already been developed. We found that the mesophyll cells of palisade layer in the dim mutant appeared to be wider apart from each other. The chloroplasts of the dim mutant cells contained bigger starch granules than those in normal plants. We also found that the lesion development of dlm plant was light-dependent and the starch degradation during the dark period of diurnal cycle was impaired in the mutant. Three soybean pathogenesis-related genes, PR-1a, PR-4, and PR-10, were examined for their expression patterns during the development of disease lesion mimic. The expression of all three genes was up-regulated to some extent upon the appearance of the disease lesion mimic. Although the exact function of DLM protein remains elusive, our data would provide some insight into mechanism underling the cell death associated with the dim mutation.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.68.1-68
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• 2003

When plants are infected by plant pathogens, typical disease symptom termed lesion, appears in compatible interaction. Whereas, in incompatible interactions, only small speck of lesions are visible on the leaf surfaces. Hypersensitive response (HR) of plant which is the result of infection by incompatible pathogens, is a well known defense response inducing rapid cell death resulting in complete resistance. However, some rice mutants show spontaneous disease symptoms during the growth stages without interaction with pathogens. We investigated the spontaneous cell death mutant called Blast Lesion Mimic(BLM) generated by EMS mutation, on the relationship with the hypersensitive response as well as resistant characteristics. Accumulation of phenolic compounds were detected around the lesions as lesions develop on leaf surface. Activation of PR gene was detected before the lesion appeared, and that result indicates the defense-related response are started earlier than lesion formation. The BLM mutant showed resistant response to inoculation of Magnaporthe grisea KJ201 with which the wild type Hwacheong is totally susceptible. Informations on the formation of spontaneous lesions and detail analysis of lesion mimic mutants and related genes are very limited to date. It is really important to understand the phenomenon of the defense-related lesion formation for developing resistant cultivar for rice blast pathogens

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2004.10a
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• pp.48-52
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• 2004

We have found the role of rice mitogen-activated protein kinase kinase kinase (MAPKKK), OsEDR1, as controling hypersensitive response (HR) and increased disease resistance to rice blast fungus Magnaporthe grisea. Generation of transgenic rice plants through introduction of the over-expression construct of OsEDR1 using Agrobacterium-mediated transformation results in lesion mimic phenotype. Up-regulation of defense mechanism was detected through detection of increased transcription level of rice PBZ1 and PR1a. Inoculation of rice blast fungus on the lesion mimic transgenic lines displayed significantly increased resistance. The disease symptoms were arrested like HR responses which are commonly detected in the incompatible interactions. High accumulation of phenolic compounds around developing lesions was detected under UV light. There was variation among transgenic lines on the timing of lesion progression as well as the lesion numbers on the rice leaves. Transgenic lines with few lesions also show increased resistance as well as equal amount of grain yields compared to that of wild type rice cultivar Nipponbare. This is the first report of the MAPKKK as a positive regulator molecule on defense mechanism through inducing HR-like cell death lesion mimic phenotype. The application of OsEDR1 is highly expected for the development of resistant cultivars against rice pathogens.

• The Plant Pathology Journal
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• v.26 no.2
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• pp.159-169
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• 2010

Lesion mimic mutant (LMM) plants display spontaneous necrotic lesions on their leaves without any pathogenic infection. Specific rice LMMs designated as spotted leaf (spl) including spl1, spl3, spl4, spl5 and spl6 are genetically known as lesion resembling disease (lrd) mutant. The inheritance patterns in the $F_1$ and $F_2$ progenies of these mutants are controlled by recessive genetic factors. Lesion development in the rice LMMs were controlled by both development stages and environmental factors. The rice LMMs exhibited higher numbers of spots under $45^{\circ}C$ temperature than those under $30^{\circ}C$. Contents of chlorophyll were drastically reduced at 60 days old LMM leaves when the spot formation was severe. The levels of endogenous hydrogen peroxide were highest at 45 days old mutants but reduced at 60 days old. Transcription levels of stress related genes including thioredoxin peroxidase and protein disulfide isomerase were reduced in spotted leaves than those of non spotted leaves. It could be suggested that scavenging system against reactive oxygen species induced by either stresses or innate metabolisms may not work properly in the rice LMMs. As these rice LMMs autonomously expressed clear lesions of lrd phenotype without pathogen infection, it could be useful to understand stresses responses in plants.

• Investigative Magnetic Resonance Imaging
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• v.24 no.1
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• pp.61-65
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• 2020

Langerhans cell histiocytosis (LCH) is generally considered a childhood disease that exhibits various nonspecific clinical and radiological manifestations that mimic infection or malignancy. Here, we present a case of LCH involving the rib in an adult patient. CT and MRI revealed an expansile lytic lesion with periosteal reaction on the left 8th rib, suggesting a malignant bone tumor. Surgical resection was performed and histopathological examination was consistent with LCH. Owing to its rare occurrence in adults and nonspecific aggressive features, LCH should be included in the differential diagnosis of an aggressive-appearing rib lesion in both adults and children.

• Investigative Magnetic Resonance Imaging
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• v.23 no.2
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• pp.136-141
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• 2019

Pelvic actinomycosis is an uncommon infectious disease. It induces a chronic, suppurative illness characterized by an infiltrative and granulomatous response and, thus, the clinical and radiologic findings may mimic other inflammatory and neoplastic conditions. A 56-year-old female with a long-standing intrauterine device was diagnosed with pelvic actinomycosis manifesting as a large uterine mass with locally infiltrative spread into surrounding tissue that mimicked uterine malignancy. Actinomyces israelii infection was confirmed with a surgical specimen, and the patient was treated with antibiotic medication. Pelvic actinomycosis must be included in the differential diagnoses of patients with an infiltrative pelvic mass extending across tissue planes or in patients with findings of multiple microabscesses, particularly in a patient with an intrauterine device, even the lesion primarily involves the uterus.

• Restorative Dentistry and Endodontics
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• v.26 no.4
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• pp.341-349
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• 2001

Dental caries is the most common oral disease. There are many factors contributing to its development, but complete understanding and prevention are not fully known. However, it is possible to remineralize the early enamel curious lesion by fluoride containing remineralization solution. Recently the pH-cycling model has been used to examine the effect of fluoride solution on remineralization of artificial caries in vitro as it can closely simulate the conditions encountered in vivo within a carefully controlled environment. The aim of this study was to evaluate the remineralizing effects of supersaturated buffer solutions under pH-cycling model. The specimen with 3mm-diameter was made using mature bovine incisors which has no caries and has sound enamel surface. Early curious lesions were produced by suspending each specimens into demineralization solution at pH 5.0 for 33 hours and the specimen whose surface hardness value ranged from 25 to 45 VHN were used. The pH cycling treatment regimen consisted of 5 min soaks of three treatment solutions four times per days for 15 days and the continuous cycling of demineralization and remineralization were carried out for 15 days. Following the pH-cycling treatment regimen, the specimens' surface microhardness were measured by the Vickers hardness test (VHN) and analyzed by ANOVA and Duncan's multiple-range test. 1. The surface microhardness value of supersaturated solution, Senstime, and Gagline groups were increased after pH cycling, and that of supersaturated solution was significantly Increased compared to saline group(P<0.05). 2. The surface remineralization effect of fluoride containing solutions was accelerated by saliva under pH-cycling mode 3. The pH cycling model was considered appropriate to mimic the intra-oral pH changes when evaluating demineralization and remineralization in vitro. Under the results of above study, salivary remineralization effect can be improved by fluoride containing remineralization solution. The pH-cycling model was considered appropriate to mimic the intra-oral pH changes when evaluating demineralization and remineralization in vitro.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.5
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• pp.473-477
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• 2010

Organized hematoma of the maxillary sinus is a rare, nonneoplastic benign lesion with locally destructive behavior that may mimic a malignancy. Clinically, symptoms do not usually occur while the lesion remains localized to the maxillary sinus. Because there is gradual enlargement of the lesion causing erosion and displacement of the adjacent bony structures, symptoms such as epistaxis, cheek swelling, nasal obstruc-tion, headache, and exophthalmos become manifest. Radiologically, unilateral cases are much more fre-quent than bilateral, and Waters' view shows complete opacity of the expanded maxillary sinus and some masses. CT scan shows a large heterogeneous enhancing mass causing considerable expansion of the max-illary sinus with bony erosion. On MR imaging, the mass usually has a variable signal intensity on T1- and T2- weighted images, ranging from low to high. After contrast administration, discrete areas of enhance-ment are present within the mass. Although the disease is essentially benign and nonneoplastic, differen-tial diagnosis from neoplastic disease including malignancy both clinically and radiologically has been always problematic. Accurate preoperative diagnosis of organized hematoma of the maxillary sinus is important to avoid unnecessary extensive surgery, because this condition is curative with a simple, conservative surgical approach and rarely recur. Organized hematoma of the maxillary sinus should be included in the differential diagnosis when patients have recurrent epistaxis, slow-growing mass of the cheek, nasal obstruction, and expansile mass in the maxillary sinus. A 33-year-old man was referred to the department of oral and maxillofacial surgery with a three-month history of slowly growing painful swelling of the left cheek. The mass of the maxillary sinus was resected by a Caldwell-Luc approach. Histopahtoly showed only a fibous encapsulated organized hematoma. To our knowledge, organized hematoma of the maxillary sinus has not been previously described in the Korean literature of the oral and maxillofacial surgery. We report a case of organized hematoma of the maxillary sinus presenting with an enlarging maxillary sinus mass.

• Journal of Chest Surgery
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• v.15 no.2
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• pp.155-161
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• 1982

The term hamartoma was first used by Albrecht to describe what he considered to be localized errors of development involving one or more tissue native to the organ of origin. The definition was meant to encompass not only abnormal local growth rate, but also the spatial arrangement, relative proportions and degree of the component tissue. But lately the major conclusions are that this group of lesion is neoplastic than developmental in origin. The Importance of pulmonary hamartoma is that they are relatively common among the benign tumor of the lung, but they usually present as asymptomatic coin lesion on chest x-ray film and were find out In routine check up and frequently mimic clinically the more common lung tumor such as cancer. Recently, we have experienced three cases of pulmonary hamartoma which were all discovered during routine chest film check up for certificate of health and evaluation of other disease. All of these were surgically resected with good result. Among the operations, one of these was mass enucleation and the others were lobectomy of lung involved by the mass.

• Journal of Korean Neurosurgical Society
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• v.39 no.6
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• pp.451-454
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• 2006

We present a case of a 68-year-old female with an atypical form of spinal tuberculosis, which involved posterior elements with multiple foci in two noncontiguous vertebral levels. The lesions caused spastic paraparesis and urinary hesitation. There was no evidence of pulmonary or other extrapulmonary tuberculous disease. Based on clinical and radiographic findings, this atypical spinal tuberculosis was preoperatively misdiagnosed as metastatic spine tumor. The histopathologic finding confirmed tuberculosis and the patient was treated successfully with surgery and antituberculous therapy. In case of a spinal lesion of unknown origin, it is important to be aware that atypical spinal tuberculosis can mimic metastatic spine tumor and tuberculosis should always be considered.