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J G Chi

Publications and source records attributed to J G Chi.

At least 55 records · Page 3Linked to original sources
PubMed1999

Reduced expression of CD99 and functional disturbance in anencephalic cortical thymocytes.

In a significant proportion of cases, anencephaly is associated with thymic enlargement, suggesting a possibility that anencephalic fetuses have a functional disturbance in thymocyte differentiation and development. In this report, we demonstrated that CD99 expression was consistently reduced in cortical thymocytes of all anencephalic fetuses. In addition, the CD99-dependent aggregation of immature cortical thymocytes was almost completely impaired and apoptosis of thymocytes was markedly reduced in several cases. These results are in agreement with previous findings that CD99 regulates the aggregation and apoptosis of various types of cells. These data strongly suggest that functional disturbance of thymocytes and thymic hyperplasia are related to the reduced expression of CD99 molecule in anencephalic fetuses.

12E7 Antigen↗
PubMed1999

Nitrofen-induced congenital malformations of the heart and great vessels in rats: an animal model.

BACKGROUND: Nitrofen (2,4-dichloro-4'-nitrodiphenyl ether), a diapheny ether herbicide, is known to induce in rat fetuses a variety of congenital cardiovascular anomalies, together with diaphragmatic hernia and hydronephrosis. The purpose of the current study was to produce congenital cardiovascular anomalies in rat fetuses by oral nitrofen administration at the indicated doses and days of gestation, and to determine the characteristics of resulting nitrofen-induced cardiovascular anomalies. METHODS: All the observed fetuses were removed from pregnant Sprague-Dawley rats killed on the 21st day of gestation. They were preserved in 10% formalin, and dissection for examination was carried out under a dissecting microscope. RESULTS: The following results were based on dissecting microscopic findings of 482 offspring: (1) The 11th day of gestation was the most sensitive for nitrofen induction of congenital cardiovascular anomalies. The incidence of these was dose related. (2) Ventricular septal defect was the most common single cardiovascular anomaly, representing more than half of all such irregularities. The next most common were aortic arch anomalies and tetralogy of Fallot. (3) Cardiac anomalies derived from infundibular maldevelopment such as tetralogy of Fallot and pulmonary atresia with ventricular septal defect were observed only in the group treated with nitrofen on the 11th gestational day. (4) Aortic arch anomalies were very frequent; the great majority were anomalous right subclavian artery with left aortic arch. CONCLUSION: This animal model is suitable for further embryological investigation of the development of congenital cardiovascular anomalies.

Animals↗
PubMed1999

The histological spectrum of subperiosteal fibrocartilaginous pseudotumor of long bone (focal fibrocartilaginous dysplasia).

Clinicopathological features in six cases of focal fibrocartilaginous dysplasia (FFCD) which involved either the tibia (n = 4) or the femur (n = 2) were reviewed. All cases presented clinical and radiological characteristic features, and histopathological findings were analyzed in five of the six cases. The subject group comprised three boys and three girls, ages ranged from 12 to 18 months. Histologically, the individual lesions showed regional variation in cellularity, amount of fibrous and cartilaginous components. Paucicellular areas were mainly composed of dense fibrous tissue while more cellular areas contained foci of fibrocartilaginous element. The chondrocytes and stellate cells around cartilaginous area were positive for S-100 protein. One case contained both hyaline and fibrocartilage, and architecturally mimicked normal tendinous insertion. One case, which involved proximal tibia, was purely composed of fibrous tissue without fibrocartilage. All cases formed undulating and irregular borders against underlying cortical bone. Histopathologically variable spectrum suggests a strong possibility of undergoing transition from initial cellular and cartilagnous to late paucicellular, fibrous phase. Although any evidence that can explain basic pathogenesis or prognostic histological parameter is lacking, we believe that the term FFCD is not relevant because the presence of fibrocartilage is not an essential feature, and it can cause confusion with other pathological processes. We propose the term 'subperiosteal fibrocartilaginous pseudotumor of long bone' for this unique clinicopathological entity with which heterologous cartilaginous element can be associated.

Female↗
PubMed1999

Sequential change of MR signal intensity of the brain after manganese administration in rabbits. Correlation with manganese concentration and histopathologic findings.

RATIONALE AND OBJECTIVES: High signal intensity in the basal ganglia on T1-weighted MR imaging has been reported in chronic manganese (Mn) poisoning. However, the exact meaning of the high signal intensity remains unclear: does it result from Mn itself, secondary pathologic changes of the brain tissue, or both? The goal of this study was to evaluate the sequential change of MR signal intensity and to correlate the MR intensity of the globus pallidus and the hypothalamus with the Mn concentration in the blood and the brain tissue, and with the histopathologic findings. METHODS: Ten milligrams per kilogram of Mn was administered once a week for 4 weeks to 14 rabbits. The rabbits in the control group (n = 2) were killed without Mn administration; those in group I (n = 4) were killed 1 day after the completion of Mn administration, those in group II (n = 4) were killed at 4 weeks, and those in group III (n = 6) were killed at 8 weeks. Sequential MR imaging, blood and tissue concentration measurement, and pathologic examination were performed. Sequential changes of the percent contrasts, contrast-to-noise ratios, and T1 relaxation times were analyzed with blood and tissue concentrations and histopathologic findings. RESULTS: The signal intensity of the basal ganglia on T1-weighted imaging was highest 1 day after cessation of Mn administration and sequentially washed out. The contrast, contrast-to-noise ratio, and T1 relaxation time showed significant correlations with blood concentration. Only the T1 relaxation time of the globus pallidus showed a significant correlation with tissue concentration. Histopathologic examination disclosed mild abnormalities in the globus pallidus, thalamus, and hypothalamus. CONCLUSIONS: The high signal intensity on T1-weighted MR imaging presumably indicates mainly the exposure marker of Mn, although mild pathologic findings were observed.

Animals↗
PubMed1999

Congenital intraorbital optic nerve cyst. Case report.

Congenital cystic lesions of the optic nerve are exceedingly rare; only one case is reported in the world literature. The authors describe a case of congenital simple glial cyst in the intraorbital portion of the optic nerve with a brief review of the literature and comment on its histogenesis. A 45-day-old male infant was admitted to the hospital because of progressive proptosis and hypotropia in the left eye, which had been present since birth. Magnetic resonance imaging of the left orbit revealed an ovoid, well-demarcated, homogeneous cystic mass in the intraconal retrobulbar area. The mass compressed the left eyeball with downward and lateral displacement. The wall of the cystic mass was very thin, and a needle puncture of the cyst released clear, colorless, watery fluid. The cystic wall was lined by loose astroglial nerve fibers with some scattered glial cells.

Astrocytes↗
PubMed1999

Cardiac laterality and ventricular looping in retinoic acid-treated rat embryos.

To determine the ventricular looping pattern in relation to cardiac laterality, we studied rat embryos treated with retinoic acid (RA). A total of 243 Wistar rat embryos from an in vivo treated group (a single dose of 20-40 mg/kg all-trans RA administered to pregnant rats on day 6.5 to 9.5) and 29 control embryos were examined on day 13 of gestation. Twenty-nine embryos from the in-vitro treated group (treated by all-trans RA at 2 x 10(-7) M for 6 hr on day 9.0 or 9.5 during the entire embryo culture for 72 hr) and seven control embryos were examined on day 12 of gestation. Abnormalities in cardiac laterality and ventricular looping were found in the in-vivo groups treated on day 8.5 and 8.75 and in the in-vitro group on day 9.0. Among 25 animals with abnormal laterality, right isomerism was the most common feature (22 cases), while the type of ventricular looping varied. Cases with normal laterality had a low incidence of abnormal looping (1.4%). In rat embryos treated with all-trans RA, normal cardiac looping was expected when cardiac laterality was normal. But in cases with abnormal laterality, the type of abnormal ventricular looping was unexpected.

Animals↗
PubMed1999

A pathologic study of abdominal lymphangiomas.

Abdominal lymphangiomas are uncommon angiomatous tumor occurring mainly in childhood. This is a retrospective clinicopathologic study of 17 cases of abdominal lymphangioma. The patients included are five children and 12 adults, with a mean age at initial presentation of 30.7 years (age ranges 3-63). The locations of the tumors were mesentery (5), retroperitoneum (4), colon (3), omentum (3), mesocolon (1) and gallbladder (1). Infiltrative growth was more common pattern than entirely circumscribed pattern. Masses were mostly multilocular cysts and contained chyle or serous fluid. On immunohistochemical staining, 16 cases were reactive for either CD31 or factor VIII-related antigen. These fact would suggest that intra-abdominal lymphangiomas simulate the immunohistochemical features of collecting lymphatics. Follow up was possible in 12 cases for 3-50 months (mean 19 months) and only one patient showed local recurrence. Although abdominal lymphangiomas are rare in adulthood and correct preoperative diagnosis is difficult, awareness of such a possibility in adulthood will contribute to make a correct preoperative diagnosis.

Abdominal Neoplasms↗
PubMed1999

Solid mesenchymal hamartoma of the liver in adult.

This paper presents an unusual solid mesenchymal hamartoma of the liver (MHL) in adult. A well defined solid mass in the left lobe of the liver was found in a 57-year-old female. Preoperative radiologic examinations demonstrated solid mass with multifocal calcifications abutting the gallbladder. By light microscopy, the lesion was composed of dense fibrous stroma with hyalinization, bile ducts and thick-walled vessels without hepatocytes. The solid and hyalinized mesenchymal component would suggest an unusual degenerative change representing a burnt-out MHL.

Female↗
PubMed1999

Gliosarcoma: a case with unusual epithelial feature.

Astrocytic tumors, particularly gliosarcoma, may contain epithelial features in the form of trabecular, adenoid, papillary arrangement, and squamous metaplasia. A case of gliosarcoma with unusual epithelial feature is described. The patient was a 60-year-old male with frequent seizures. The mass was 4 cm and in the left frontal lobe. Trabecular or rarely adenoid arrangement of neoplastic astrocytes was present in the mucinous stroma, and there was a distinctive transition between the trabecular area and typical anaplastic astrocytoma. The tumor cells in the trabecular area showed positive immunostain for glial fibrillary acidic protein, but did not react with various kinds of cytokeratin. The sarcomatous area was undifferentiated and was not labeled by factor-VIII, desmin, and anti-smooth muscle actin. Occurrence and histogenesis of epithelial features in gliosarcoma are reviewed. The importance to recognize the existence of epithelial feature in malignant astrocytic tumor is emphasized.

Brain Neoplasms↗
PubMed1999

Insulin-like growth factor-II expression is down-regulated in TrkA-transfected SK-N-AS neuroblastoma cells.

Expression level of trkA tyrosine kinase receptor for nerve growth factor is a major prognostic determinant of neuroblastoma, suggesting that defective trkA-mediated signaling is responsible for the tumorigenesis of this childhood malignancy. We investigated the biologic effect of trkA, with special reference to its effect on insulin-like growth factor-II (IGF-II) expression, in SK-N-AS human neuroblastoma cells transfected with human trkA cDNA. Nerve growth factor treatment of trkA-transfected cells promoted growth and changed the morphologic phenotype into a substrate-adherent, flatter phenotype (S-type), and down-regulated the mRNA expression of IGF-II. The effects on both growth and the morphologic differentiation of SK-N-AS cells differed significantly from those of previous studies, and implied that trkA effects can be diverse, depending on the phenotype of the individual neuroblastoma cells. Immunohistochemical screening of trkA and IGF-II expression in adrenal neuroblastomas (n = 25) also favored the nonoverlapping pattern of trkA and IGF-II expression (p < 0.05). Because IGF-II is believed to play a significant role in the tumorigenesis of neuroblastoma, the inverse relationship between trkA and IGF-II strongly suggests that a low level of trkA can be a feature of the pathogenetic mechanism of IGF-II expressing adrenal neuroblastomas.

Adrenal Gland Neoplasms↗
PubMed1999

Introduction and development of pathology.

If one defines pathology as gross and microscopic examination of abnormal tissue there was no comparable discipline in traditional medicine of Korea until the introduction of Western medicine in Korea. However, when one widens the scope of pathology to include pathogenesis and etiology, there were some pathology-related descriptions in Oriental medicine long before this period. The pathology based on Virchow's cellular pathology was introduced to Korea through two tracks independently in 1910s. One was academic pathology, through Japanese pathologists, namely Dr. Inamoto and Dr. Tokumitzu, and the other track was hospital pathology through Western missionaries who introduced the American system of laboratory medicine (clinical pathology). It was Japanese who dominated the introduction and development in Korea. The Koreans played a minor role in the development of pathology from the introduction period until 1945, when the Korea was liberated from Japan. Pathology teaching, research and hospital service had been consistently carried out through three medical schools, namely Severance Medical School and two government medical schools until 1945. After independence, the Korean Society of Pathologists was quickly organized and made a rapid promotion. The Korean war provided opportunities to experience and adopt the American pathology system in Korea. The hospital pathology system has been established, together with the pathology specialty system in Korea. Balanced promotion of research pathology and service pathology is expected in Korea.

History, 19th Century↗
PubMed1998

Overexpression of cyclin D1 and cdk4 in tumorigenesis of sporadic hepatoblastomas.

Abnormality of the cyclin D1/cdk4/p16INK4a/pRb pathway during tumorigenesis has recently been reported. Hepatoblastoma is a rare malignant liver tumor of childhood, but underlying abnormalities of cell-cycle regulating protein remain to be elucidated. The expression of cyclin D1, cdk4, p16 and retinoblastoma gene product (pRb) was studied by immunohistochemistry in 17 paraffin-embedded tissues consisting of both tumor and corresponding non-neoplastic tissues. Tumor tissues showed overexpression of cyclin D1 (13/17, 76%) and cdk4 (15/17, 88%). Eleven cases showed co-overexpression of both cyclin D1 and cdk4. No abnormal p16 or pRb expression was noted. In the group with a high score (+4) for cyclin D1 expression, a positive correlation with tumor recurrence was noted (P = 0.043). These data suggest that overexpressed cyclin D1 and cdk4 protein might play an important role in the tumorigenesis of hepatoblastoma and that in the group with high cyclin D1 expression, tumor recurrence may be more frequent.

Adolescent↗
PubMed1998

Cell kinetics of surgically induced spinal open neural tube defect in chick embryos.

In an attempt to understand cell kinetics of open neural tube defects (ONTDs) in the embryonic stages, chronological changes of cell proliferation and cell death patterns in the surgically induced spinal ONTDs of chick embryos were investigated using proliferating cell nuclear antigen (PCNA) staining and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL) method. ONTDs were induced at Hamburger and Hamilton stages 17-19. Compared with the control group, the surgery group showed a lower PCNA labeling index for 5 days after surgery and demonstrated more TUNEL-positive cells at 6 h, 3 and 5 days after surgery. Decreased cell proliferation and enhanced apoptosis were seen in the ventral as well as in the dorsal spinal cord. These results partly explain the functional deficits of ONTDs.

Animals↗
PubMed1998

Loss of heterozygosity and somatic mutations of the VHL tumor suppressor gene in sporadic cerebellar hemangioblastomas.

Cerebellar hemangioblastoma is a benign central nervous system neoplasm with characteristic proliferation of vascular and stromal cells. There is increasing evidence that the stromal cell population may represent the neoplastic component of hemangioblastoma, whereas the vascular component may be composed of reactive, nonneoplastic cells. Therefore, successful genetic testing for loss of heterozygosity requires selective analysis of target cell populations. Here, tissue microdissection was used to selectively analyze the stromal cell component of 20 archival sporadic cerebellar hemangioblastomas for loss of heterozygosity at the Von-Hippel Lindau (VHL) gene and somatic VHL gene mutations. Allelic deletions at the VHL gene locus were detected in the stromal cell component with one or more markers (D3S1038, D3S1110, and/or 104/105) in 10 of 19 (52.6%) informative cases. In all cases, heterozygosity at the VHL gene locus was retained in the vascular component. In two cases, aberrant bands in exon 2 of the VHL gene were demonstrated in the stromal cells by PCR-based single-strand conformation polymorphism analysis, and somatic missense mutations were successfully characterized in two of the sporadic hemangioblastomas by direct sequencing. The results suggest that allelic losses and mutations of the VHL tumor suppressor gene play a role in sporadic cerebellar hemangioblastoma tumorigenesis. Furthermore, because the genetic changes were detected in selectively procured stromal cell areas, the data provide strong evidence that the stromal cell represents a neoplastic component of hemangioblastoma.

Adolescent↗
PubMed1998

Intramedullary anaplastic oligodendroglioma in a child.

Primary intramedullary anaplastic oligodendroglioma is a rare tumor, only four cases of which have been reported. The authors present the case of a 38-month-old boy with primary intramedullary anaplastic oligodendroglioma. He underwent partial removal of the tumor and spinal radiation therapy. The residual tumor disappeared 12 months after radiation, and 48 months after treatment there was no evidence of recurrence. This case shows that in primary intramedullary anaplastic oligodendroglioma, postoperative radiation therapy confined to the spinal cord can yield an optimal result.

Child, Preschool↗
PubMed1998

Thymic epithelial tumor progression in an SV40T transgenic mouse model. Cortical thymoma-thymic carcinoma sequence.

There have been several reports that thymoma in human is a progressive disease, and that thymoma and thymic carcinoma form a continuum. We established a stable line of SV40T transgenic mice, which consistently produced thymic epithelial tumours progressing to thymic carcinoma within a predictable time span. Using this animal model and a morphological approach, thymic epithelial tumour progression was studied with reference to sequential changes at different time points in animals aged from 3 to 32 weeks. At all ages, SV40T was expressed in the nuclei of thymic epithelial cells; in these transgenic mice we observed the entire spectrum from cortical type thymoma to thymic carcinoma. Thymic size tended to increase with ageing in SV40T TG mice. While younger mice had predominantly cortical (organoid) or cortical thymoma, older mice had well-differentiated thymic carcinoma (WDTC) or poorly differentiated thymic carcinoma. When SV40T TG mice (248 line) reached a certain age, carcinoma of the thymus was present in all of them. Cortical-type thymoma became malignant within a predictable time span, suggesting a cortical thymoma-carcinoma sequence. When the mice were 9 weeks of age, the thymuses formed gross masses compatible with cortical thymoma. At 14 weeks of age, WDTC appeared against the background of cortical thymoma. Poorly differentiated thymic carcinoma was found after 15 weeks and affected all animals over 23 weeks of age. Most thymic carcinomas coexisted in varying proportions with cortical-type thymoma. Medullary thymomas did not develop in the mice, and no transition from medullary-type thymomas to thymic carcinomas was observed. In this SV40T transgenic mouse model, thymic carcinoma is clearly preceded by cortical-type thymoma. These transgenic mice may provide an interesting model for the progression from cortical thymoma to WDTC and/or high-grade carcinoma.

Aging↗
PubMed1998

Gliomatosis cerebri: clinical features, treatment, and prognosis.

To clarify clinical features and to elucidate prognostic factors and prognosis, the authors retrospectively analyzed 16 cases of gliomatosis cerebri treated at Seoul National University Hospital between January 1988 and December 1995. Age at diagnosis ranged from 19 to 62 (median 34) years and male to female ratio was 10:6. Most presented with headache or seizure, and the mean duration of symptoms was 12.8 months. A poorly defined diffuse high signal intensity lesion, extending in T2-weighted images for two lobes or more, was the characteristic magnetic resonance (MR) image finding. On postcontrast T1-weighted MR imaging, focal enhancement of the lesion was detected in five cases. All patients underwent histological confirmation by craniotomy (9 cases) or stereotactic biopsy (7 cases). Histologically, all patients had compatible findings of gliomatosis cerebri which are the widespread infiltration of neoplastic glial cells with minimal destruction of pre-existing structures. After histological diagnosis, external radiation therapy was begun except in one case, who declined this treatment. Fourteen patients completed the whole procedure and received the planned dose (mean 5780 cGy). Median survival time after diagnosis was 38.4 months. In univariate analysis, the Ki-67 labelling index (> 1) showed significant correlation with the length of survival (p = 0.006). It is suggested that 1) gliomatosis cerebri can be diagnosed by a combination of MR imaging findings and histological examination; 2) histological diagnosis and external radiation therapy might be a good treatment modality; 3) the Ki-67 labelling index correlates significantly with survival time.

Adult↗