Biomedical subjects

Je Geun Chi

Publications and source records attributed to Je Geun Chi.

At least 19 recordsLinked to original sources

PubMed2006

Paediatric brain-stem gliomas: MRI, FDG-PET and histological grading correlation.

BACKGROUND: MRI and FDG-PET may predict the histological grading of paediatric brain-stem gliomas. OBJECTIVE: To assess MRI findings and metabolic imaging using FDG-PET of brain-stem gliomas based on histological grading. MATERIALS AND METHODS: Included in the study were 20 paediatric patients (age 3-14 years, mean 8.2 years) with brain-stem glioma (five glioblastomas, ten anaplastic astrocytomas and five low-grade astrocytomas). MR images were assessed for the anatomical site of tumour origin, focality, pattern of tumour growth, and enhancement. RESULTS: All glioblastomas were located in the pons and showed diffuse pontine enlargement with focally exophytic features. Eight anaplastic astrocytomas were located in the pons and demonstrated diffuse pontine enlargement without exophytic features. Low-grade astrocytomas were located in the pons, midbrain or medulla and showed focally exophytic growth features and peripheral enhancement. In 12 patients in whom FDG-PET was undertaken, glioblastomas showed hypermetabolic or hypometabolic lesions, anaplastic astrocytomas showed no metabolic change or hypometabolic lesions and low-grade astrocytomas showed hypometabolism compared with the cerebellum. CONCLUSION: MRI findings correlated well with histological grading of brain-stem gliomas and MRI may therefore predict the histological grading. FDG-PET may be helpful in differentiating between anaplastic astrocytoma and glioblastomas among high-grade tumours.

Adolescent↗

PubMed2006

Radiological trace of mandibular primary growth center in postnatal human mandibles.

The mandibular primary growth center (MdPGC) of human fetus was conspicuously defined in the soft X-ray view of fetal mandibles. As the peripheral adaptive growth of mandible advances during the postnatal period, the MdPGC image became overshadowed by condensed cortical bones in soft X-ray view. In this study, we traced a sclerotic sequela of MdPGC during the postnatal period. Panoramic radiograms of 200 adults and soft X-ray views of 30 dried adult mandibles were analyzed by statistical methods. The former clearly showed an MdPGC below the middle portion of apices of canine and first premolar, which was distinguishable from mental foramen, and the latter also showed the MdPGC at the same area as a radiating and condensed radiopaque image, measuring 0.5-1.0 cm in diameter. This MdPGC position was seldom changed in the elderly people, even in the edentulous mandibles. Additionally, in the radiological examination, the benign tumors including odontogenic cysts hardly involved the MdPGC, while the malignant tumors of both primary and metastatic cancer frequently destroyed the MdPGC.

Adolescent↗

PubMed2005

Antisense inhibition of transglutaminase 2 affects development of mouse embryo submandibular gland in organ culture.

Tissue transglutaminase (TGase 2) has been implicated in numerous cellular functions, i.e., apoptosis, differentiation, extracellular matrix protein cross-linking and organogenesis. Earlier report of the strong transient expression of TGase 2 localized at the anchoring sites of muscle bundles of human embryo and recent findings of a similar transient expression of the TGase 2 in the salivary myoepithelial cells of mouse embryo indicated a definitive role of TGase 2 in the cytodifferentiation of myoepithelial cells. To understand functional role(s) of TGase 2 in the organogenesis of salivary gland, antisense inhibition of TGase 2 expression was performed in the organ culture of mouse embryo submandibular gland. The antisense of TGase 2 transfection tested using oral keratinocyte cell line, KB cells, elicited significant inhibition of cellular transglutaminase expression. The same antisense treatment of submandibular glands in organ culture also resulted in the suppression of cellular TGase 2 expression as indicated by weak immunoreaction against anti-TGase 2 in the myoepithelial cells of submandibular glands in contrast to strong reaction in those of the normal and sense-treated glands. Antisense to TGase 2 treatment induced retarded growth of salivary epithelium in 1 week and severe aberrant growth of salivary ducts and acini in 2 weeks and also expression of apoptotic inducer, Bax specifically localized in the myoepithelial cells, suggesting apoptotic state of myoepithelial cells. These data suggest that the antisense inhibition of TGase 2 expression affects the cytodifferentiation of ductal cells and myoepithelial cells, and resulted in severe retardation of tubuloalveolar structure formation of salivary gland.

Animals↗

PubMed2005

HUlip, a human homologue of unc-33-like phosphoprotein of Caenorhabditis elegans; Immunohistochemical localization in the developing human brain and patterns of expression in nervous system tumors.

HUlip is a human homologue of a C. elegans gene, unc-33, that is developmentally regulated during maturation of the nervous system. HUlip is highly expressed only in the fetal brain and spinal cord, and is undetected in the adult brain. The purpose of this study was to investigate the pattern of hUlip expression in the developing human brain and nervous system tumors. Ten human brains at different developmental stages and 118 cases of nervous system tumor tissues were examined by immunohistochemistry. Twelve related tumor cell lines were also analyzed by northern blotting and immunoblotting. HUlip was expressed in late fetal and early postnatal brains; strongly in the neurons of the brain stem, basal ganglia/thalamus, and dentate gyrus of the hippocampus, and relatively weakly in the cerebral and cerebellar cortex. Among tumors, hUlip expression was easily detected in tumor cells undergoing neuronal differentiation such as ganglioneuroblastomas and ganglioneuromas. Furthermore, hUlip immunoreactivity was also found in various brain tumors showing neuronal differentiation: central neurocytomas (6 of 6 cases were positive), medulloblastomas (5/11), atypical teratoid rhabdoid tumor (1/1) and gangliogliomas (4/7). Some astrocytic tumors also showed weak positivity: astrocytomas (1 of 5 cases), anaplastic astrocytomas (2/5), and glioblastomas (3/11). Subependymal giant cell astrocytomas and subependymomas, which are of controversial histogenetic origin, showed strong hUlip immunoreactivity. The results of this study indicate that the expression of hUlip protein is distinctly restricted to the late fetal and early postnatal periods of human nervous system development and to certain subsets of nervous system tumors. The exact function of hUlip needs to be further clarified; yet the results of our study strongly imply that hUlip function is important in human nervous system development and its aberrant expression in various types of nervous system tumors suggests a role of hUlip as an oncofetal neural antigen.

Astrocytes↗

PubMed2005

Transglutaminase 2 expression in the salivary myoepithelial cells of mouse embryo.

Earlier a strong transient expression of transglutaminase 2 (TGase 2) localized at the anchoring sites of muscle bundles in human embryo was observed. In this study, we report a similar transient expression of the TGase 2 in the salivary myoepithelial cells of mouse embryo by immunohistochemistry, RNA in situ hybridisation, and RT-PCR. From 35 submandibular glands of mouse embryos and postnatal mice, a consistent expression of TGase 2 in the myoepithelial cells via a stage-specific manner was identified by mono-clonal antibody to TGase 2 immunostaining. A similar expression pattern of TGase 2 in the myoepithelial cells was also observed by RNA in situ hybridisation analysis. The expression of TGase 2 in the salivary epithelium and mesenchyme during the prenatal 14.5-15.5 days was found minimally diffusely spread and became intensely focalised in the myoepithelial cells of salivary acini and ducts during the prenatal 16.5-18.5 days but thereafter gradually decreased until postnatal 7 days and remained weak in postnatal 3 weeks. Such transient rise and fall expressions of TGase 2 were also found with the sequential amount of RT-PCR products during the same period. The alpha-smooth muscle actin (alpha-SMA) as a positive control in the myoepithelial cells of mouse submandibular glands was consistently expressed during the prenatal and postnatal period. These results of transient expression of TGase 2 in the myoepithelial cells coincided with the formation of the dendritic basket structure in the periphery of acini and ducts, suggest a possible catalytic role of transglutaminase in a newly formed cellular matrixes during the cytodifferentiating stage of mouse prenatal and neonatal submandibular glands.

Animals↗

PubMed2005

Diagnostic challenge of fetal ontogeny and its application on the ovarian teratomas.

Although neuroepithelial tubules (NET) often are a component of immature teratoma (IT), they are not always required for diagnosis. Other somatic elements are sufficient and often verified with immunohistochemical stain. This study was designed to determine the definition of immaturity versus fetal ontogeny, using several molecular markers in IT. It is our contention that IT is equivalent to an embryonic stage less than a fertilization age (FA) of 8 weeks, and a mature teratoma (MT) to a fetal stage later than a FA of 8 weeks, whereas an embryonal carcinoma (Eca) matches a pre-embryonic stage earlier than a FA of 2 weeks. The teratomatous components used as a roadmap to evaluate maturity included: a lobular structure of primitive endodermal tubules (FA 4 to 6 weeks), a ventricle-lined cortical plate (FA 9 weeks), a complex papillary choroid plexus (FA 10 weeks), melanin deposition in hair follicles (FA 15 weeks), and the bell stage of odontogenesis (FA 19 weeks). The teratomatous components of 25 resected ovarian solid teratoma samples were compared with fetal ontogeny. For an immunohistochemical analysis, the CD30, CD34, CD99, bcl-2, alpha-fetoprotein (AFP), and placenta-like alkaline phosphatase (PLAP) were assessed. The AFP and Ki-1 were positive in the embryoid body, which was identified at a FA less than 4 weeks in Eca. The AFP was positive in the primitive endodermal components and some of the squamous epithelium in IT. The CD99 and bcl-2 were selectively stained in the primitive NET, which was detected no later than a FA of 6 weeks. The CD34 and bcl-2 were positive in the immature-looking precartilage blastomatous components, which proved useful for detecting immature cartilage, corresponding to a FA of 5 to 6 weeks. The ontogeny of IT was found to correspond to the embryonic stage at a FA of 2 to 8 weeks, and CD99, CD34, bcl-2, AFP, CD30, and PLAP could be used as supportive tools to define IT. This new grading system could be more scientific and more reproducible in any spectra of teratoma.

Female↗

PubMed2003

Aggressive angiomyxoma of childhood: two unusual cases developed in the scrotum.

Aggressive angiomyxoma (AAM) is a locally invasive soft tissue tumor and is predominantly found in the female pelvis and perineum. The incidence of AAM in adult and adolescent males is low, and is very rare in male children. However, two cases of AAM occurred in the scrotum of 8-year-old and 1-year-old boys. Grossly, both tumors were ill-delineated nodules showing myxoid homogenous and lobulated cut surface. The scrotum of case 2 was replaced by the exuberant mass, making a polypoid appearance. On microscopic examination, both had hypocellular myxoid stroma, spindle and stellate stromal cells, and blood vessels of various calibers. Both lesions typically showed infiltrating borders and penetrated into skin adnexa and Dartos' muscle fibers. AAM should be considered in the differential diagnosis of a scrotal mass found in childhood.

Child↗

PubMed2002

Elafin expression in human fetal and adult submandibular glands.

Elafin, a bifunctional protein, has the NH(2)-terminal domain functions as a transglutaminase substrate for crosslinking to lysine-containing proteins and the COOH-terminal whey acidic protein domain as a potent anti-elastase. Human fetal submandibular glands (n=100) and adult submandibular glands (n=10) were used to elucidate the expression pattern of elafin in the developmental processes of human submandibular gland by immunohistochemistry, in situ hybridization, and western blot analysis. Elafin mRNA was expressed both in the gland epithelium and intralobular mesenchymal tissue of fetal submandibular gland in an early developmental stage (10-18 weeks) and an early intermediate developmental stage (EIDS; 19-24 weeks). The elafin antigen was also found in the intralobular mesenchyme of submandibular gland in the same stages. Thereafter, elafin was transitionally expressed in the ducts and acini of submandibular glands. In the late intermediate developmental stage (LIDS; 25-32 weeks) and the late developmental stage (LDS; 33-40 weeks), elafin became markedly positive in the excretory and striated ducts but weakly positive in the intralobular mesenchymal tissue. The elafin was heavily present in the excretory and striated ducts of adult submandibular gland, while it was sparse in the intralobular mesenchymal tissues. Western blot analysis showed the protein extracts from submandibular glands of EIDS, LIDS, and LDS, adult submandibular gland, fetal tissues (8 weeks), and adult parotid saliva migrated into multiple bands, about 25, 50, 65, and 140 kDa, which were higher than the putative size of elafin protein, 12 kDa. These data suggest that elafin, anti-elastase, is an essential component highly utilized during the morphogenetic processes of fetal salivary gland development and continuously plays a role for the protection of the tubuloalveolar structures of adult salivary gland.

Blotting, Western↗

PubMed1986

A human case of gallbladder fascioliasis in Korea.

The authors would record the fifth case of human fascioliasis in Korea, occurring in a 48 year old Korean man who lived in Munkyong, Kyongsangbuk-do. The diagnosis was based on the morphology and measurements of the eggs which were collected in necrotic debris from the tunnel-like ulcerations of the gallbladder wall which was surgically removed for a gall stone. Although we failed to find out the fluke in the specimen, there found an evidence of once presence of Fasciola in the inflamed wall of the gallbladder in this patient.

Journal Article↗

PubMed1985

A histopathological study on the intestine of mice and rats experimentally infected by Fibricola Seoulensis.

A histopathological study was carried out on the duodenum of mice and rats experimentally infected by F. seoulensis. Each mouse was infected wit 500 metacercariae and killed after 1, 2, 3 days, 1 and 2 weeks from infection. Each rat was given 1,000 metacercariae and was examined after 1, 2, and 4 weeks from infection. The duodenal tissue sections of mice and rats were stained with hematoxylin and eosin, and PAS stained for the rats of 1 week group. The pathological findings are summarized as below. There were no differences in mucosal findings between the mice and the rats, adn between the location of duodenum, 1 and 5 cm distal to the pylorus. Each worm embraced a villus exclusively with its foliate forebody which was inserted into the intervillous spaces. The fluke pinched villous epithelia using its oral and ventral suckers. The tribocytic organ destroyed the villous epithelia deeply up to the stroma after 3 days from infection. Apparent villous changes were observed in the mice after 3 days from infection. Villous changes were shortening, widening, blunting or fusion. The villous stroma showed edema, microscopic hemorrhage, capillary congestion, dilatation of lymphatics and inflammatory cell infiltration. The cells were lymphocytes, plasma cells, eosinophils and giant cells. Rarely submucosal and transmural inflammation was encountered.

Journal Article↗

PubMed1985

Two cases of imported cutaneous leishmaniasis in Korea.

Two Korean men who had worked in Saudi Arabia complained of skin ulcers in the right wrist for 5 months or in the face and left forearm for 4 months each. Ulcers accompanying crust was observed in both cases. The characteristic cellular destruction and amastigote in the cytoplasm of histiocyte supported the diagnosis of cutaneous leishmaniasis. Those are 17th and 18th imported cases of cutaneous leishmaniasis in Korea(summarized from text).

Journal Article↗

PubMed1983

An Imported Case Of Kala-Azar In Korea.

An imported case of Kala-azar in a 26-year-old Korean man is reported. The diagnosis was made by liver needle biopsy. Amastigotes were seen in Kupffer cells under light microscope, and their characteristic ultrastructural features were recognized under the electron microscope. This case represents an imported disease from Saudi Arabia where the patient spent one year as a construction worker, 8 months before the onset of the disease. This report also signifies the second description of Kala-azar in Korea, and the first case of Kala-azar imported from Saudi Arabia. This patient was successfully treated with sodium antimony gluconate (Pentostam(R)), and follow up liver biopsy showed focal fibrous scar and otherwise normal liver without demonstrable organism.

Journal Article↗

PubMed1982

A Case Of Systemic Paragonimiasis With Ovarian Involvement.

The authors reported a case of ectopic paragonimiasis in a 40 year old Korean housewife who came to the hospital because of abdominal mass and pain. She was proved to have multiple parasitic granulomas involving lung, uterus, uterine tube and subcutaneous tissue. The ovary was also the site of parasitism. The past history revealed an episode of ingestion of fresh water crabs soaked in soybean sauce which were obtained in a market of Seoul City 2 years prior to the present illness. The patient was treated for tuberculosis for a year without confirmation of etiologic agent. After surgical removal of all abdominal and most of pelvic granulomas, the patient was treated with praziquantel 25 mg/kg t.i.d. for 3 days, and was judged to be cured after 4 months.

Journal Article↗

PubMed1982

Studies On Intestinal Trematodes In Korea: VI. On The Metacercaria And The Second Intermediate Host Of Fibricola Seoulensis.

This study was carried out to confirm the infection source of the human case of Fibricola seoulensis, and to reveal out a part of its life cycle in Korea. Also the morphological characteristics of the metacercaria were described. The results were summarized as follows: 1. Rana nigromaculata and Natrix tigrina lateralis were found to be infected naturally by the metacercariae(diplostomula) of F. seoulensis. The metacercarial capsule was round to elliptical in tissue of the intermediate hosts with a long diameter 0.232~0.385 mm. Liberated metacercariae were ovoid with small conical posterior body. Body length measured 0.199~0.312 mm and width 0.153~0.252 mm. 2. The infection rate of R. nigromaculata by the metacercariae ranged from 87% to 100% by area, and the number of the larvae ranged from 3 to 390 by frog. The metacercariae were found in skeletal muscle of frogs, from head to hindlegs. 3. All examined N. t. lateralis were found to be infected by the metacercariae with the range of numbers frome 3 to 35,918. The larvae were collected from all viscera and body segments except for the head of the snakes. However, a great majority of the metacercariae were collected from the stomach. 4. Hematoxylin-eosin stained preparations of frog skeletal muscle and snakes stomach revealed that the metacercariae had no cyst wall of worm origin, but encapsulated by the host tissue. Some of them were found in dilated lymphatic vessels. The larval infection was associated with slight or severe inflammatory reaction even with granuloma formation. By above results, it was concluded that the frog, Rana nigromaculata, was the second intermediate host, and the snake Natrix tigrina lateralis was a paratenic host of F. seoulensis in nature in Korea.

Journal Article↗

PubMed1982

[Changes Of Liver And Diaphragm In Experimental Paragonimiasis]

Changes of abdominal organs in early paragonimiasis are described in dogs and cats. Experimental infection was induced by feeding 40~50 and 20~30 metacercariae of Paragonimus westermani to 15 dogs and 15 cats respectively. These animals were killed sequentially starting from 8 days to 120 days after infection. Complete autopsies were carried out in all animals and the tissues were examined microscopically with the main emphasis on changes of the liver and the diaphragm. A definite bout of acute diffuse fibrinoexudative peritonitis with ascites ranging from 5 to 20 ml was present in both dogs and cats at the time of 20 days after infection. This was also the period of the maximum liver damage and diaphragmatic injuries. The peritonitic changes became minimized after 45 days of infection. The liver changes were of two folds. The first one was characterized by numerous pin-point or linear tissue defects on the surface of the lobes, which were often covered with fibrin clots. Some of these defects were impacted by the larvae. These "scratch" marks appeared to be of mechanical effect, and the margins were often banal without a significant inflammatory reaction. The scratch marks were no longer observed in animals examined after 45 days. The second was noted in the Kupffer cells of the liver. A large amount of hemosiderin pigment was noted in the Kupffer cells and became prominent by 20 days through 45 days. Hemosiderin-laden macrophages were found also in the spleens of these animals. Some animals in 30 days group showed the most Kupffer cells heavily loaded with hemosiderin. However, no associated degenerative changes were noted in these cells. The diaphragm was quite unique in early phase of infection in all animals examined. Numerous pinpoint perforative lesions could definitely be seen grossly, and some of these lesions included migrating larval worms inside the tunnels. These lesions were microscopically characterized by tract or tunnel formation with accompanying tissue reaction. The diaphragmatic changes were manifest by 20 days after infection. The tracts of tunnels appeared to have been made by pressure necrosis and surrounding edema, and subsequently were associated with a massive eosinophilic influx and myocytolysis. The eosinophilic abscess and multinucleated giant cells were often observed in the animals of the 30 days group. The diaphragmatic changes seemed to be repaired with or without fibrous scar formation which was occasionally seen in 45 days and later.

Journal Article↗

PubMed1982

A Human Case Of Ectopic Fascioliasis In Korea.

A case of ectopic fascioliasis involving cecum and ascending colon was reported. This case was a 19-year old Korean female who had a history of postprandial aggravation of intermittent abdominal pain of 3 weeks duration. She was presented with an abdominal mass in the right upper quadrant, for which an operation(right hemicolectomy) was performed. Whole cecum and ascending colon showed multifocal tunnel-like necrotizing granulmas with central cavitations. Numerous Charcot-Leyden crystals were seen along tracts of the worm. The lesion was distributed throughout the entire thickness of the wall. Parasitological examination confirmed the worm found in the intestinal wall to be juvenile form of Fasciola species. Possibilities were discussed on the localization of the fluke and the mode of infection of present case.

Journal Article↗

PubMed1981

Splenic Paragonimiasis: A Case In A Dog.

A case of Paragonimus westermani cysts found deep inside the spleen is described. This spleen was from a dog that was experimentally infected via oral route with a hundred metacercariae and was killed 3 months after. At autopsy, beside the usual lesions due to Paragonimus in the lungs, the spleen was the site of multiple parasitic cysts. The involved spleen was slightly enlarged and showed an area of hemorrhagic dome on the capsular surface. There found a total of 8 adult worms in four well demarcated parasitic cysts containing a pair of worms each. All of them were found deep into the splenic parenchyme and were surrounded by a well formed connective tissue wall, thus resembling the features of the pulmonary paragonimiasis. The route of infection was assumed to be a direct transcapsular invasion during the phase of larval migration.

Journal Article↗

PubMed1981

Study On The Pathology Of Metagonimiasis In Experimentally Infected Cat Intestine.

To study the basic pathological changes of small intestine in metagonimiasis, light- and electron microscopic studies were made, using a total of 21 cats which were experimentally infected with metacercariae of Metagonimus yokogawai. The metacercariae were obtained from naturally infected sweetfish (Plecoglossus altivelis) by digestion technique. The cats were divided in control, light-infection(10,000 metacercariae infected) and heavy-infection(50,000 metacercariae infected) groups. Cats were killed at the 5th, 10th, 15th day, and 4th, 8th and 10th week after the infection. And the small intestine was prepared for the study. Pathological studies comprised gross examination, worm distribution pattern, light microscopic examination and both transmission and scanning electron microscopic examinations. The results obtained were summarized as follows. 1. Gross morphologic changes were the most marked during the first 2 weeks after infection. The gross abnormalities were severer in the heavily infected animals. The changes were dryness and listlessness of serosal surface due to dehydration, mushy and/or watery intestinal content, effacement of transverse nodes and enlargement of mesenteric lymph folds and Peyer's patches. After 4 weeks of infection, these changes became less marked showing a tendency to return to normal. 2. The sectioned flukes were distributed from duodenum to proximal ileum. However, individual variation was marked in distribution. In the heavy-infection group, the locality of parasitism tended to extend more distally. 3. The locality of M. yokogawai in the intervillous space was mostly in the lower-most portion of intervillous space, where they compressed and eroded epithelial cells probably due to mechanical damage to the structure. Very rarely the worms were found in lumen of Lierberkuehn's crypt, and reaching, in two occasions, into proprial lymphoid tissue. 4. Light-microscopically the lesion was restricted in mucosa: Early mucosal changes were shortening, blunting, fusion, and thickening of the villi, crypt hypertrophy with consequent decrease of villus/crypt ratio, as well as stromal changes of edema, capilliary ectasia and marked inflammatory cell infiltration of lymphocytes and plasma cells. Goblet cells were markedly reduced in number as with depletion of its cytoplasmic content. In the later stages of infection, mucosa restored its normal configuration in spite of persistent parasitism of the worms. 5. At the infection stage of 5-15 days, there was significant shortening of the microvillous height with varible destruction of glycocalyx in electron microscopic examination. With lapse of infection time, microvilli became to restore the normal pattern. With these morphological changes, it appears that diarrhea in experimental metagonimiasis would be related to the decrease of absorptive surface of the small intestine particularly in the early phase of infection. The significant changes seen in villi and microvilli might be due to massive intrusion or invasion of Metagonimus worms into the crypts, causing direct mechanical and possible host-immune response to the small bowel mucosa.

Journal Article↗