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J G Chi

Publications and source records attributed to J G Chi.

At least 73 records · Page 4Linked to original sources
PubMed1998

Engagement of CD99 induces apoptosis through a calcineurin-independent pathway in Ewing's sarcoma cells.

Programmed cell death (PCD) is a prominent feature of the development of the immune and nervous systems. In both systems, widespread PCD occurs in primitive progenitor cells during development. In this study, we demonstrated that Ewing's sarcoma (ES) cells, undifferentiated neural precursors, underwent apoptosis upon engagement of CD99 with anti-CD99 monoclonal antibody. Apoptosis via CD99 occurred only in the undifferentiated state of ES cells, but not in differentiated ES cells. CD99-induced apoptosis in ES cells appeared to require de novo synthesis of RNA and protein as well as caspase activation. Cyclosporin A, known to be a potent inhibitor of both calcineurin activation and mitochondrial permeability transition pore opening, inhibited CD99-mediated apoptosis, whereas FK-506, a specific calcineurin inhibitor, did not, indicating the induction of CD99-mediated apoptosis through a calcineurin-independent pathway. Furthermore, the dying cells displayed the reduction of mitochondrial transmembrane potential (delta psi m). These results suggest that CD99 engagement induce CsA-inhibitable mitochondrial permeability transition pore opening, followed by a reduction of delta psi m and caspase activation, thereby leading to apoptosis. Based on these results, we suggest the possible involvement of CD99 in the apoptotic processes that occur during nervous system development and also its application in immunotherapeutic trials for ES cases.

12E7 Antigen↗
PubMed1998

Microsatellite instability in young patients with colorectal cancer.

Genetic instability is closely correlated to the pathogenesis of hereditary non-polyposis colon cancer (HNPCC), which is clinically characterized by a family history and early onset. To investigate the role of genetic instability in young patients with colorectal cancer (CRC), 22 CRC patients, who were aged younger than 30 at the time of diagnosis, were studied. Patients with familial adenomatous polyposis were excluded. Among the 22 cases, seven were identified as microsatellite instability positive (MI+), and more than five microsatellite markers among the 15 tested markers showed an additional band pattern in the tumor tissue. None of the remaining 15 cases showed instability in any microsatellite marker. Two of seven MI+ cases were classic HNPCC. While all MI+ cases had one or no metastatic lymph node, 53.3% of MI- cases showed metastasis in two or more regional lymph nodes. Allelic deletion of the 17p12-13 chromosome around the p53 locus occurred in 16.7% of MI+ cases, and 80.0% of MI- cases showed loss of heterozygosity at that locus. hMSH2 Protein expression, assessed by immunohistochemistry, was absent in two cases, both of which were MI+. When we tested two to four sites of MI+ tumors, transforming growth factor beta receptor type II was mutated in a homogeneous pattern in five MI+ cases. In addition, frame-shift mutations of BAX, insulin-like growth factor II receptor, hMSH3 and hMSH6 were found in three cases, five cases, five cases and one case, respectively. In contrast to the consistent mutation of the transforming growth factor-beta receptor type II gene, mutations of other genes varied in different portions of the tumors.

Adenocarcinoma, Mucinous↗
PubMed1998

Hemophagocytic syndrome associated with occult B-cell lymphoma: an autopsy case.

Hemophagocytic syndrome has been observed in various disorders, including malignant histiocytosis, peripheral T-cell lymphoma, and viral or bacterial infections. However, B-cell lymphoma has seldom been associated with hemophagocytic syndrome. We report a case of B-cell lymphoma that was associated with hemophagocytic syndrome. The diagnosis was not made until the time of autopsy.

Aged↗
PubMed1998

Short-rib polydactyly syndrome, Beemer-Langer type, with bilateral huge polycystic renal dysplasia: an autopsy case.

Short rib-polydactyly syndrome (SRPS) is a group of lethal skeletal dysplasia of an autosomal recessive inheritance characterized by markedly narrow ribs, micromelia, and multiple anomalies of major organs. We report a case of type IV SRPS with uncommon associations of polydactyly and bilateral polycystic kidneys, in a 28 week old female fetus. She was born dead to a 28 year old mother, showing a hydropic change, narrow thorax, and shortened limbs with postaxial heptasyndactyly of both hands and feet. Radiologic examination revealed short horizontal ribs, curved short tubular limb bones, small ilia and scapula, and a mild vertebral abnormality. Postmortem examination disclosed pulmonary hypoplasia, pancreatic cysts, hepatic fibrosis, and left persistent superior vena cava. In addition this case had bilateral huge polycystic renal dysplasia that was seldom described in any type of SRPS. Histologic sections of the vertebrae disclosed abnormal enchondral ossification with irregular and retarded hypertrophic zone.

Female↗
PubMed1998

Cytokinetic pattern in the thoracic spinal cord of chick embryos (incubation day 5-13) using PCNA staining and TUNEL method.

For the cytokinetic studies using spinal cords of chick embryos, chronological patterns of cell proliferation and programmed cell death (apoptosis) should be known. Information in the early stages of chick embryos is available while data on later stages are seldom available. To investigate the chronological patterns of cell proliferation and apoptosis in the thoracic spinal cord of normal chick embryos on incubation day 5, 6, 8, 10 and 13 (Hamburger and Hamilton stage 26-40), proliferating cell nuclear antigen (PCNA) staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method were used. Cell proliferation was active at the germinal layer on days 5 and 6. It markedly declined on day 8 and became negligible on day 13. TUNEL-positive cells were mainly found in the germinal layer, the ventrolateral part of the mantle layer and the dorsal root ganglion. Compared to PCNA-positive cells, TUNEL-positive cells were sparse, especially after day 10, when only a few positive cells were scattered. These results will be used as a control data for the studies such as an experimental research for neural tube defects.

Animals↗
PubMed1998

Temporal lobe epilepsy caused by intrahippocampal calcified cysticercus: a case report.

The major differential diagnoses of epilepsy associated with small solitary lesion are tuberculous or cysticercus granuloma which are enhanced in CT and/or MRI study. We report of a 47-year-old man with intractable temporal lobe epilepsy as the presenting feature of a solitary intrahippocampal calcified mass without enhancement, which turned out to be a Taenia solium cysticercus. There was no apparent evidence of systemic cysticercosis. Imaging studies revealed a small solitary intrahippocampal calcification without perilesional enhancement, and atrophy of the hippocampal head portion. Cysticercosis should be considered as an etiology in the differential diagnosis in lesional medial temporal lobe epilepsy even without perilesional enhancement.

Animals↗
PubMed1998

Histotopographic distribution of placental inflammation: analysis of 22 cases.

Twenty-two placentas were investigated for the presence and patterns of inflammation by extensive examination, and divided into four groups: 1) term vaginal delivery [group I; n=6]; 2) term cesarean section delivery [group II; n=5]; 3) preterm vaginal delivery [group III; n=4], and 4) preterm cesarean section delivery [group IV; n=7]. In group I, all had deciduitis, and choriodeciduitis/ chorionitis was present in two cases (33.3%). In group II, four cases (80%) showed deciduitis and/or choriodeciduitis/chorionitis; three of these had intact membranes. In group III, three cases (75%) showed deciduitis, and two had chorionitis. In group IV, three cases (42.9%) showed no evidence of inflammation, three had deciduitis and one had deciduitis/chorioamnionitis. In all groups, membranitis was more severe, confined to the inner and mid segments in general, and deciduitis, choriodeciduitis/chorionitis and chorioamnionitis tended to overlap. The study newly demonstrates major characteristics of placental inflammation: higher prevalence and severity of inflammation in the inner segments of membrane and at the periphery of the placenta. Taking this histotopography into account, it is desirable to take sections from the placental margin, and the current concept of placental inflammation as a surrogate marker of intrauterine infection should be reevaluated.

Female↗
PubMed1997

Characterization of a mitochondrial DNA deletion in patients with mitochondrial myopathy.

Kearns-Sayre syndrome (KSS) is the most commonly diagnosed mitochondrial myopathy and it produces severe neuromuscular symptoms. The most frequent cause is a mitochondrial DNA (mtDNA) deletion (common deletion) that removes a 4,977-bp segment of DNA that includes several genes encoding respiratory chain subunits. In this disorder, the population of deleted mtDNA molecules coexists with a population of normal, wild-type, full-length mtDNAs. We have performed a morphological study and a 3-primer polymerase chain reaction (PCR) on paraffin-embedded muscle tissues from two Korean KSS patients. Our results show that these patients have the essential clinical manifestations of KSS, as well as morphological evidence of mitochondrial myopathy. PCR analysis revealed the existence of two co-amplified fragments, the wild-type fragment having 152 bp and the deleted fragment having the 123 bp characteristic of common deletion. This study may provide valuable information for the molecular diagnosis of KSS in Koreans.

Adult↗
PubMed1997

Quantitative analysis of mitochondrial DNA deletion in paraffin embedded muscle tissues from patients with KSS and CPEO.

The percentage of common deletion of mitochondrial DNA (mtDNA) was determined quantitatively by a PCR-based, non-radioactive method in DNA extracted from formalin-fixed, paraffin-embedded skeletal muscle tissues from two patients with Kearns Sayre syndrome (KSS) and one with chronic progressive external ophthalmoplegia (CPEO). The method involved PCR cycle titration of wild-type and deleted mtDNA in parallel, staining of gel bands with the sensitive fluorescence dye SYBR Green I, and quantitation of intensity on a computer screen by the NIH image program. We determined 75% and 71% common deletion of mtDNA in the KSS patients and 35% in the CPEO patient.

Adult↗
PubMed1997

Central neurocytoma: the role of radiation therapy and long term outcome.

BACKGROUND: It has been suggested that the biologic behavior of central neurocytoma is indolent, although little is known regarding the role of radiation therapy and long term outcome. To clarify the role of radiation therapy and long term outcome, the authors retrospectively analyzed 15 cases of central neurocytoma. METHODS: Clinical records and radiologic findings of 15 cases of central neurocytoma diagnosed at Seoul National University Hospital between January 1982 and February 1995 were carefully reviewed. The duration of follow-up was from 18-168 months (mean, 52 months); follow-up images were reviewed and the patient's Karnofsky performance scale (KPS) was assessed up to the time of last follow-up. RESULTS: The age of the patients ranged from 15 to 60 years (mean, 25 years) and the male to female ratio was 11:4. Macroscopic total resection of the tumor was performed in seven patients, two of whom received fractionated radiation therapy. Subtotal removal of the tumor was performed in eight patients, five of whom received this same therapy. In 2 of the 5 patients who did not receive radiation therapy after macroscopic total resection, the tumors recurred 8 and 21 months after surgery, respectively; in contrast, recurrence was not detected in the 2 patients who received fractionated radiation therapy after macroscopic total resection. In all five patients who received fractionated radiation therapy after subtotal resection, the tumor shrank (n = 3) or disappeared (n = 2) during the postsurgical follow-up period ranging from 27-113 months; the tumor began to shrink from 6 months to 2 years after radiation. No change was found in the three patients who did not receive radiation therapy after subtotal resection. At the time of last follow-up, the KPS was greater than 90 in all patients except one who required assistance in his daily activities because of complications from radiation therapy. CONCLUSIONS: It is suggested that even if the biologic behavior of a central neurocytoma is benign, radiation therapy appears to have an effect on tumor control. However, it should be carefully decided whether to use radiation therapy for a residual tumor because radiation can cause delayed complications and the clinical course of subtotally resected patients who do not receive radiation therapy is extremely benign.

Activities of Daily Living↗
PubMed1997

Abnormal expression of four novel molecular markers represents a highly aggressive phenotype in breast cancer. Immunohistochemical assay of p53, nm23, erbB-2, and cathepsin D protein.

BACKGROUND: In view of the cumulative results to date, p53, nm23, erbB-2, and cathepsin D are the most promising investigational prognostic factors in breast cancer. OBJECTIVES: The clinical utility of these molecular markers to predict recurrence was evaluated. METHODS: Archival pathology tissues of 100 breast cancer patients were analyzed by immunohistochemical assay. Molecular biologic data were merged with clinicopathologic variables. RESULTS: Thirty-two patients (32%) had recurrence of disease at a median follow-up of 48 months (range 26-72 months). Investigational factor expression had statistical correlation for recurrence with increasing coexpression: one variable 20.6%, two variables 34.2%, three variables 47.1%, four variables 80.0% (P = 0.003). In univariate analysis, lymph node metastasis, tumor size, erbB-2 protein overexpression, and loss of nm23 protein expression were significant variables to determine recurrence; in multivariate analysis, node status and tumor size emerged as the most significant variables for recurrence. CONCLUSIONS: Coexpression of the studied investigational variables functioned as significant prognostic correlates for recurrence. These findings suggest that the studied investigational prognostic factors possess the ability to discriminate a highly aggressive phenotype in breast cancer.

Biomarkers, Tumor↗
PubMed1997

Mixed tumour of schwannoma and meningioma components in a patient with NF-2.

The authors present the case of an intracranial tumour consisting of both schwannoma and meningioma within the same tumour, in a patient with neurofibromatosis-2 (NF-2). A pre-operative diagnosis of this mixed tumour was not made. However, retrospectively, a meningiomatous area was found inside the acoustic neurinoma on magnetic resonance (MR) images. Predominant schwannoma with a minor component of meningioma was confirmed by histopathological and immunohistochemical examinations. The transitional zones of these two different tumours were macroscopically sharp but microscopically interdigitated. The patient had another meningioma and schwannoma in a separate section of the cranial cavity. Based on this patient, it is suggested that the collision of two kinds of tumours is the most likely hypothesis to explain the development of mixed components of schwannoma and meningioma within the same tumour.

Adolescent↗
PubMed1997

High expression of tumor necrosis factor-alpha and interleukin-6 in periventricular leukomalacia.

OBJECTIVE: Periventricular leukomalacia, a common neonatal brain white matter lesion, is a major risk factor for cerebral palsy. Subclinical chorioamnionitis is a risk factor for the development of periventricular leukomalacia, and inflammatory cytokines have been implicated as central mediators of brain injury in this disorder. To elucidate the relationship between the local expression of cytokines and periventricular leukomalacia, we studied neonatal brains to determine whether high expression of tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6 was observed in these lesions. STUDY DESIGN: Immunohistochemical staining for cytokines (tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6) was performed in 10% formalin-fixed, paraffin-embedded brain sections of 17 cases with periventricular leukomalacia. Specimens were obtained from autopsies performed between 1987 and 1994. Brain sections from 17 cases of neonatal deaths without periventricular leukomalacia lesions matched for gestational age at birth, duration of postnatal survival, and presence or absence of infection-related morbidity were used as controls. RESULTS: The expression of tumor necrosis factor-alpha, interleukin-1 beta, or interleukin-6 was demonstrated in 88% (15/17) of cases with and in 18% (3/17) of cases without periventricular leukomalacia (p < 0.001). Cytokines were expressed mainly in hypertrophic astrocytes and microglial cells. The expression of tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6 was identified in 82% (14/17), 29% (5/17), and 71% (12/17) of cases of periventricular leukomalacia, respectively. However, a significantly lower proportion of cases without periventricular leukomalacia expressed tumor necrosis factor-alpha (18%, 3/17) and interleukin-6 (6%, 1/17) than those with the disorder (p < 0.005 for each). CONCLUSIONS: Expression of tumor necrosis factor-alpha and interleukin-6 was observed more frequently in brain lesions with periventricular leukomalacia than in those without periventricular leukomalacia. These findings provide strong support for the hypothesis that proinflammatory cytokines play a role in the genesis of periventricular leukomalacia.

Brain Chemistry↗
PubMed1997

Experimentally induced intrauterine infection causes fetal brain white matter lesions in rabbits.

OBJECTIVE: Periventricular leukomalacia, a common brain white matter lesion in preterm neonates, is a major risk factor for cerebral palsy. Epidemiologic studies have demonstrated an association between infection and periventricular leukomalacia. The purpose of this study was to determine whether ascending intrauterine infection could cause brain white matter lesions in the fetal rabbit. STUDY DESIGN: Rabbits with timed pregnancies underwent hysteroscopy at 20 to 21 days of gestation (70%). Animals were allocated in a ratio of 2:1 for inoculation with either Escherichia coli (0.2 ml containing 10(3) to 10(4) colony-forming units) or sterile saline solution. Both groups were treated with ampicillin-sulbactam (Unasyn, 100 mg/kg per day; Pfizer, Seoul) every 8 hours until they were killed 5 to 6 days after hysteroscopy. Histologic examination of the placentas and fetal brains was conducted. RESULTS: Forty-five animals underwent hysteroscopy; 31 were inoculated with E. coli and 14 with sterile saline solution. At the time the animals were killed, the rate of intrauterine infection was higher and there were fewer live fetuses in the E. coli-inoculated animals than in the saline solution group. Histologic evidence of brain white matter damage was identified in 12 fetuses born to 10 E. coli-inoculated rabbits but none in the saline solution group (p < 0.05). All rabbits with brain white matter lesions had evidence of intrauterine infection. Evidence of white matter damage included increased karyorrhexis, rarefaction, and disorganization of white matter. Apoptosis was demonstrated in areas of white matter damage by immunohistochemical studies. CONCLUSION: Experimental ascending intrauterine infection can cause fetal brain white matter lesions.

Animals↗
PubMed1997

Congenital cystic adenomatoid malformation of the lung: CT-pathologic correlation.

OBJECTIVE: The purpose of this study was to correlate CT findings of congenital cystic adenomatoid malformation (CCAM) of the lung with pathologic findings. MATERIALS AND METHODS: CT scans of CCAM from 21 consecutive patients were analyzed retrospectively by two chest radiologists who achieved consensus. Pathologic findings were assessed by an experienced pulmonary pathologist. Preoperative CT findings were correlated with pathologic findings. RESULTS: Areas with small cysts (< 2 cm in diameter) were seen on CT scans in 19 (90%) of 21 patients, whereas areas with a large cyst (> 2 cm in diameter) were observed in 18 patients (86%). Areas of consolidation (n = 9; 43%) with heterogeneous attenuation on enhanced scans and areas of low attenuation (lower than normal lung) around cystic lesions (n = 6; 29%) were also seen on CT scans. The diameter of the largest cyst seen on CT scans in each patient ranged from 1.0 to 8.0 cm (median, 4.5 cm). Cysts that CT showed to be filled with air, fluid, or both correlated completely with the pathologic findings. Areas of consolidation corresponded histologically to areas of glandular or bronchiolar structures with or without areas of endogenous lipoid or organizing pneumonia or mucus plugs. Areas of low attenuation corresponded to areas of microcysts blended with normal lung parenchyma. CONCLUSION: CT scans show the variable internal characteristics of CCAM and can suggest the underlying pathology of such lesions.

Adolescent↗
PubMed1997

In-vivo study on the harmful effect of the extremely low frequency unipolar pulsating magnetic field in mice.

We studied the biological effect of a magnetic field on murine brain and kidney. Magnetic field we used was generated by Magno-DR apparatus (Hanil Co., Korea) which produced a high density unipolar square pulsating magnetic field, about 0.3 approximately 0.5 Tesla at 7 Hertz. Animals were placed in the chamber of the machine for various times from 4 hours to 24 hours. Histological sections of brain and kidney were made after perfusion fixation with paraformaldehyde. The light microscopic examination showed eosinophilic change of cytoplasm and positive immunohistochemical reaction to amyloid precursor protein in the neurons of the cerebral cortex. However, the thalamus and brain stem were less affected. The changes in the brain was seen in the mouse exposed more than 12 hours. The renal tubular epithelium showed degenerated tubules scattered in cortical area but little change was noted in glomeruli in the cortex and collecting tubules in the medulla. Immunohistochemistry of the kidney showed weakly positive reaction for the amyloid precursor protein in the distal tubular epithelium after 4 hours of exposure. These data suggest that strong pulsating magnetic fields could induce deleterious effect on the murine brain tissue and renal cortical tubules.

Amyloid beta-Protein Precursor↗
PubMed1997

Neonatal adenoviral pneumonia--report of three autopsy cases.

Adenovirus pneumonia, while common in infancy and childhood, is rarely documented but may be fatal in the neonatal period. In regard to the serious outcome and no responsiveness to common anti-viral agents, adenovirus infection should be considered in the differential diagnosis of pneumonia in neonates. We report three cases of fatal neonatal adenovirus pneumonia, all of which were diagnosed by postmortem examination. Two patients were born by cesarean section at 35 or 36 weeks of gestation, and the other was a 5100 gm postmature baby born by vaginal delivery at 43 weeks of gestation. Respiratory insufficiency was detected just after birth or in the immediate postnatal period, and was associated with lethargy and chest X-ray findings of pneumonic infiltration. The postmortem findings of these patients were remarkably consistent and characterized by predominant lung involvement. The lungs showed diffuse massive consolidation with scattered patchy hemorrhage, and histologically revealed multifocal necrotizing alveolitis and/or bronchiolitis, often with hemorrhage. Alveolar lining cells and desquamated cells contained numerous smudge ells and many cells with characteristic inclusion bodies. Electron microscopy revealed that these inclusion bodies consisted of arrays of icosahedral particles of adenovirus. It is unusual that one of the patients, who was born by cesarean section without any evidence of prenatal infection, developed adenoviral pneumonia; this indicates that infection may occur in the immediate postnatal period as well as during passage of the birth canal.

Adenoviridae Infections↗