Biomedical subjects

J Y Han

Publications and source records attributed to J Y Han.

At least 19 recordsLinked to original sources

PubMed2002

Prenatal diagnosis of a familial complex chromosomal rearrangement involving chromosomes 5, 10, 16 and 18.

We report one case of a familial complex chromosomal rearrangement (CCR) involving four different chromosomes 5, 10, 16 and 18. The CCR was detected prenatally at 20 weeks' gestation because of advanced maternal age and history of recurrent miscarriages. Cytogenetic analysis of cultured amniotic fluid cells with GTG banding showed a 46,XX,t(5;16;10;18)(q13;q22;q11.2;q21) karyotype. Parental cytogenetic study revealed that the mother has the same CCR. RBG banding, high resolution banding and fluorescence in situ hybridization (FISH) were used to characterize further and confirm the conventional banding data. No physical abnormalities were shown in the targeted fetal ultrasonography examination. The parents decided to continue the pregnancy. The child is now 2 years old and has neither congenital anomalies nor evidence of delayed psychomotor development. The fetal targeted ultrasound and FISH analysis helped us reassure fetal status.

Abortion, Habitual↗

PubMed2001

Mutations of tumor necrosis factor-related apoptosis-inducing ligand receptor 1 (TRAIL-R1) and receptor 2 (TRAIL-R2) genes in metastatic breast cancers.

Several lines of evidence suggest that apoptosis dysregulation plays an important role in cancer metastasis. In this study, to explore the possibility that the mutations of death receptors are involved in the metastasis mechanism, we analyzed the death domains of Fas and tumor necrosis factor-related apoptosis-inducing ligand-receptor 1 and -2 (TRAIL-R1 and -R2) genes for the detection of somatic mutations in 57 breast cancers with (n = 34) or without (n = 23) metastasis to the regional lymph nodes. We found seven mutations (three TRAIL-R1 and four TRAIL-R2 mutations), and these mutations were detected only in the breast cancers with metastasis. Furthermore, we also analyzed the allelic losses of chromosome 8p21-22, where TRAIL-R1 and R2 reside in the same series of breast cancers, and found that the allelic losses were significantly higher in metastatic breast cancers. We expressed the tumor-derived TRAIL-R1 and TRAIL-R2 mutants in 293 cells and found that apoptosis was suppressed. These data suggest that TRAIL-R1 and R2 genes are relevant to the frequent loss of chromosome 8p21-22 in breast cancer and that the inactivating mutations of TRAIL-R1 and -R2 genes play a role in the metastasis of breast cancer.

Apoptosis↗

PubMed2001

Noninvasive detection of hydroxyl radical generation in lung by diesel exhaust particles.

Diesel exhaust particles (DEP) induce pulmonary tumors, asthma-like symptoms, and the like in experimental animals. The involvement of reactive oxygen species (ROS) is suggested in the injuries induced by DEP, though the generation of ROS has not been proven. The present study provided the first direct evidence of *OH generation in the lungs of living mice after intratracheal instillation of DEP, using noninvasive L-band ESR spectroscopy and a membrane-impermeable nitroxyl probe. *OH generation is confirmed with the enhancement of in vivo ESR signal decay rate of the probe. The decay rate at mid-thorax was significantly enhanced in DEP-treated mice compared to that in vehicle-treated mice. The enhancement was completely suppressed by the administration of either *OH scavengers, catalase, or desferrioxamine, while the administration of SOD further increased the rate. The administration of Fenton's reagents into the lung also enhanced the decay rate of the probe at mid-thorax of mice. These results clearly provided evidence that the intratracheal exposure to DEP in mice produced *OH in the lung through an iron-catalyzed reaction of superoxide/H(2)O(2). This first direct evidence of *OH generation in DEP-treated mice lung may be utilized to determine treatments for DEP-induced lung injury.

Animals↗

PubMed2001

Generation and characterization of recombinant ScFv antibodies detecting Eimeria acervulina surface antigens.

In our previous attempt to generate monoclonal antibodies (MAbs) against coccidia parasites that more accurately reflect the natural avian humoral immune response, we produced two chicken B-cell hybridomas, 5D11 and 2-1. While both cell lines secreted antibodies reactive with sporozoites of Eimeria acervulina, they were produced in yields too low to conduct meaningful in vivo studies. To circumvent this problem, we produced four single chain variable fragment (scFv) antibodies from the V(H) and V(L) genes of hybridomas 5D11 and 2-1. The concentration of these recombinant antibodies expressed in E. coli and purified to homogeneity was 5-6 mg/L. Three of the antibodies exhibited antigen binding specificity to Eimeria surface antigens equivalent to that of the native MAbs. Nucleotide sequence analysis of the V(L) genes from hybridomas 5D11 and 2-1 and genomic DNA revealed vestiges of gene conversion with V(lambda) pseudogenes. These recombinant scFv antibodies will prove useful for further characterization of natural Eimeria surface antigens as potential vaccine candidates.

Animals↗

PubMed2001

Chronic ethanol consumption exacerbates microcirculatory damage in rat mesentery after reperfusion.

Although the negative effect of excessive alcohol consumption on later stressful events has long been recognized, pathophysiological mechanisms are incompletely understood. We examined possible roles of oxygen radicals and glutathione content in mesenteric venules of chronically ethanol-fed rats exposed to ischemia-reperfusion. Changes in microvascular hemodynamics, such as red blood cell (RBC) velocity, leukocyte adherence, and albumin extravasation, were monitored in postcapillary venules by intravital fluorescence microscopy. Chronic ethanol feeding significantly exaggerated the magnitude of the decrease in RBC velocity, the increased number of adherent leukocytes, and increased albumin leakage elicited by 10 min of ischemia followed by 30 min of reperfusion. Oxidative stress in the endothelium of venules monitored by dihydrorhodamine 123 (DHR) fluorescence was more severe in rats fed ethanol chronically. Both superoxide dismutase and N-acetyl-L-cysteine, which is known to increase glutathione content, reduced the ischemia-reperfusion-induced decrease in RBC velocity, the number of adherent leukocytes, and the increase in albumin leakage, as well as oxidative activation of DHR. This suggests that the increased reperfusion-induced microvascular disturbances in the mesenteric venules of rats fed ethanol chronically are significantly correlated with excessive production of oxygen-derived free radicals and decreased glutathione synthesis.

Alcoholism↗

PubMed2001

The findings of ruptured hepatocellular carcinoma on helical CT.

To evaluate the helical CT findings of ruptured hepatocellular carcinoma (HCC), 12 patients with ruptured HCC were reviewed with regard to the tumour's location, size and contour protrusion, the appearance of the mass, the enhancement pattern, multiplicity and secondary changes. All ruptured tumours were located at the periphery of the liver and had a protruding contour. The maximum diameter of tumours ranged from 2 cm to 16 cm. Discontinuity of the hepatic surface was seen in 11 cases. In eight cases, CT images during the arterial phase showed a non-enhancing low attenuating lesion with focal discontinuity and peripheral rim enhancement. Seven cases showed separation of tumour content from the peripheral enhancing rim and intraperitoneal rupture of tumour content into the perihepatic space. Because of the similar appearance to an enucleated orbital globe with remaining sclera, this was termed the "enucleation sign". As well as ruptured masses, 10 cases with non-ruptured masses also showed a non-enhancing low attenuating pattern. Seven cases showed a haematoma with high attenuation around the ruptured mass. The peripheral location, protruding contour, discontinuity of the hepatic surface and surrounding haematoma are helpful signs in the diagnosis of ruptured HCC. The "enucleation sign" may be a characteristic finding in ruptured HCC.

Adult↗

PubMed2001

Vinorelbine-associated myelopathy in a patient who previously received paclitaxel: a case report.

Vinorelbine seems to cause less neurotoxicity than other vinca alkaloids because of its selective activity on mitotic cells over axonal microtubules. Clinical trials report very mild peripheral neurotoxicity with distal paresthesiae and there are no reports of myelopathy in these series of patients. The authors describe a patient who developed a rare event of myelopathy while on vinorelbine for non-small-cell lung cancer.

Antineoplastic Agents, Phytogenic↗

PubMed2001

Detection of fetal erythroid cells from maternal blood using fluorescence in situ hybridization and liquid culture.

Fetal nucleated erythrocytes circulating in maternal blood are a potential source of fetal DNA for noninvasive prenatal genetic diagnosis. However, the estimated ratio of fetal to maternal cells is extremely small. In order to enrich these cells, we performed direct culture using a two-phase liquid system. Mononuclear cells were obtained from maternal blood samples at 8-10(+3) weeks of gestation and cultured in the first phase. After 4-5 days, the nonadherent cells were harvested and recultured with erythropoietin in the second phase for another 3-5 days. We examined cellular morphology, and counted the number of benzidine- positive cells and the percentage of glycophorin A/CD71 positive erythroid cells. We also did Kleihauer-Betke stain for Hb F, polymerase chain reaction (PCR) for SRY/DYZ1, chromosome analysis, and fluorescence in situ hybridization (FISH). The number of total erythroid cells reached about 0.1 x 10(6)-1.0 x 10(6)/mL with a purity of 84.0-97.3%. Hb F stain showed total erythroid cells of approximately 0.4 x 10(4)-9.8 x 10(4)/mL. Male DNA was detected in one case by PCR. In this case, the XY karyotype was confirmed by FISH and amniocentesis. This approach provides enriched source of fetal cells for further prenatal genetic analysis without complicated separation or sorting procedures.

Cell Culture Techniques↗

PubMed2001

Frequencies of fetal chromosomal abnormalities at prenatal diagnosis: 10 years experiences in a single institution.

We present frequencies of fetal chromosomal abnormalities in 4,907 prenatal cytogenetic examinations at Samsung Cheil Hospital from 1988 to 1997 for 10 yr duration. Prenatal karyotypes were undertaken in 3,913 amniotic fluid samples, 800 chorionic villi samples, and 194 percutaneous umbilical blood samples. The frequency of fetal abnormal karyotypes was 3.1% (150 cases). Numerical chromosome abnormalities were 87 cases (1.8%) and structural aberrations of chromosomes were 63 cases (1.3%). In the numerical chromosomal abnormalities, the frequency of trisomy 21 was by far the highest (36 cases), followed by trisomy 18 in 22 cases and sex chromosome aneuploidies in 19 cases. In the structural chromosomal aberrations, 5 cases had the inversions in chromosome 2, 7, 17, and Y. Chromosomal deletions in 6 cases and additions in 4 cases were analysed. Of the remaining 47 translocation in abnormal fetuses, reciprocal translocation was in 26 cases and Robertsonian translocation in 21 cases. Among them, 41 cases were balanced translocation and 6 were unbalanced. Thirty five cases of translocation were inherited from one of the parents. Four had de novo chromosome rearrangements, and 8 cases were unknown.

Chromosome Aberrations↗

PubMed2001

The relationship of histologic activity to serum ALT, HCV genotype and HCV RNA titers in chronic hepatitis C.

It is unclear whether serum ALT levels or virological characteristics of hepatitis C virus(HCV) including HCV genotypes and HCV RNA titers, can reflect the degree of histological injury in chronic hepatitis C. The aim of this study was to investigate the relationships between the levels of histological damage and serum ALT levels, HCV genotypes or circulating HCV RNA titers in chronic hepatitis C. A total of 56 patients underwent liver biopsy and the histological activity index (HAI) was evaluated by Knodell's scoring system. HCV genotype by RT-nested PCR and HCV RNA quantitation by competitive RT-PCR were performed. Thirty-four patients were infected with HCV genotype 1b, 20 patients with genotype 2a, and 2 patients with undetermined type. Serum ALT levels were not positively correlated with total HAI score or HCV RNA titers, but showed a linear correlation with scores of piecemeal necrosis (r=0.32, p<0.05) and portal inflammation (r=0.27, p<0.05). HCV genotype had no significant correlation with RNA titers, HAI score or with serum ALT levels. Also, no statistical relationship was seen between HCV RNA titer and HAI score. These results suggest that liver histology is essential to evaluate the severity of chronic hepatitis C precisely.

Adolescent↗

PubMed2001

A case of hemorrhagic gallbladder paraganglioma causing acute cholecystitis.

Gallbladder paraganglioma is a very rare tumor and so far only a few cases have been reported. Most of these were asymptomatic and were found incidentally during operation. Recently, we experienced a gallbladder paraganglioma that gave rise to hemorrhage, which in turn caused acute cholecystitis. Our case involved a 45 year-old female patient complaining of an intermittent right upper abdominal pain. After a preoperative evaluation, cholecystectomy and lymphadenectomy were performed under the impression of gallbladder cancer with acute cholecystitis. Postoperative pathologic examination revealed a hemorrhagic gallbladder paraganglioma accompanied by acute cholecystitis. Immunohistochemical staining of the chief cells for neuron specific enolase, chromogranin and synaptophysin were positive. Sustentacular cells also stained positively for S100 protein.

Acute Disease↗

PubMed2001

Fatal pulmonary-renal syndrome manifested with immune complex crescentic glomerulonephritis in a patient with MPO-ANCA seropositivity.

Recent reports have indicated that a significant number of immune complex glomerulonephritis (GN) cases are associated with antineutrophilic cytoplasmic antibody (ANCA). However, most of the reported cases were associated with underlying primary glomerular diseases. When primary glomerular diseases were not found, immune deposits tended to be non-specific and the level of ANCA is usually borderline. We report here upon a case of life-threatening pulmonary-renal syndrome manifested simultaneously with immune complex GN and myeloperoxidase (MPO)-ANCA seropositivity. A 29- year-old man was admitted with pulmonary hemorrhage and rapidly progressing renal dysfunction. On admission, ANCA revealed perinuclear staining with a titer of 1:160. The MPO-ANCA level was 59 IU by ELISA. Other serologic markers including ANA, anti-DS-DNA and anti-GBM Ab were negative. Renal biopsy showed cellular crescents in eight of 18 glomeruli. Immunofluorescence staining showed strong granular deposits of C3, C1q, IgG and IgM in the capillary loop and the mesangium. Electron microscopy showed multifocal electron dense deposits scattered in the mesangium, paramesangium, and the subendothelial and subepithelial areas. The patient initially responded to steroid and cyclophosphamide. MPO-ANCA decreased to less than 10 IU. Twenty three days after hospital discharge, the patient was re-admitted urgently with fever, generalized papulonodular skin lesions, and a recurrence of massive pulmonary hemorrhage and renal dysfunction. He died from uncontrolled pulmonary hemorrhage and respiratory insufficiency. P-ANCA titer and MPO-ANCA level at the second admission were 1:320 and 82 U/ml respectively. Interestingly, relapse was shown to be triggered by varicella zoster infection.

Adult↗

PubMed2001

Enrichment and detection of fetal erythroid cells from maternal peripheral blood using liquid culture.

Isolating fetal cells from maternal blood for prenatal genetic analysis is the least invasive method currently being investigated. In order to enrich these fetal erythroid cells we employed a two-phase liquid culture system that supports the growth and differentiation of erythroid progenitor cells. Mononuclear cells were separated from ten maternal blood samples at 8-14(+3) weeks of gestation and cultured in the first phase. After 4-5 days, the non-adherent cells were harvested and recultured with erythropoietin for another 3-4 days. The mean number of total erythroid cells reached approximately 0.77x10(6)/ml with an average purity of 90.5%. Hb F stain disclosed fetal erythroid cells averaging approximately 5.7%, therefore the mean number of fetal erythroid cells isolated was 0.49x10(5)/ml. Female karyotypes were only observed while counting 5-66 metaphases. However, male DNA (SRY or DYZ1) was detected by PCR in 7/10 cases; in four of these cases and in one SRY-negative pregnancy the 46,XY karyotype was found by amniocentesis performed during the second trimester. This liquid culture system provided an enriched source of fetal cells without the need for more complicated separation or sorting procedures.

Blood Cells↗

PubMed2001

Involvement of p38 kinase in hydroxyurea-induced differentiation of K562 cells.

Hydroxyurea is a differentiation-inducing agent of human erythroleukemia K562 cells. However, the cellular mechanisms by which hydroxyurea exerts its effects on tumor cells, leading to the inhibition of cell growth and the induction of differentiation markers, are largely unknown. This study examined the role of different mitogen-activated protein kinase signal transduction pathways in hydroxyurea-induced erythroid differentiation of K562 cells. Using a panel of anti-extracellular signal-related kinase (ERK), c-Jun NH2-terminal kinase (JNK), and p38 phosphospecific antibodies, we demonstrated that phosphorylation of ERK and JNK is decreased after the treatment of cells with hydroxyurea, whereas phosphorylation of p38 is increased. Moreover, inhibition of ERK activity by PD98059 induced erythroid differentiation, and it acted synergistically with hydroxyurea on hemoglobin synthesis, whereas inhibition of p38 activity by SB203580 inhibited induction of hemoglobin production by hydroxyurea. These findings suggest that the activation of p38 kinase may play important roles in the signal transduction mechanisms of hydroxyurea leading to erythroid differentiation.

Cell Differentiation↗

PubMed2000

A DNA vaccine encoding a conserved Eimeria protein induces protective immunity against live Eimeria acervulina challenge.

Coccidiosis is caused by several distinct intestinal protozoa of Eimeria sp., and is responsible for intestinal lesions and severe body weight loss in chickens. To develop a DNA vaccination strategy for coccidiosis, an expression vector pMP13 encoding a conserved antigen of Eimeria was constructed by subcloning 3-1E cDNA into pBK-CMV and used to elicit protective immunity against E. acervulina. One-day-old chickens were immunized intramuscularly (IM) or subcutaneously (SC) with various doses of pMP13 expression vector ranging from 5 to 100 ug two weeks apart and were challenged with 5x10(3) E. acervulina. Chickens immunized with 5, 10, 50 or 100 ug of pMP13 plasmid, but not control plasmid, pBK-CMV, showed significantly reduced oocysts following challenge infection with E. acervulina. Two injections were in general more effective than one injection with higher dose of DNA eliciting better protection. At 10 days post challenge infection, maximum levels of circulating antibodies were detected regardless of the routes of injection, although IM injection provided higher levels of serum antibodies compared to SC injection. Serum antibody levels demonstrated a dose-dependent response showing higher antibody production at higher DNA dose. DNA immunization with pMP13 also induced significant changes in T-cell subpopulations in the spleen and duodenum intraepithelial lymphocytes. At 4 days post DNA immunization, pMP13-immunized chickens showed lower CD8, and higher CD4(+) and gammadelta T(+) cells in the duodenum compared to the pBK-CMV-immunized chickens. Following challenge infection with E. acervulina, pMP13-immunized chickens showed lower CD8(+) and alphabeta T(+) cells, and higher CD4(+) cells than pBK-CMV-immunized chickens in the duodenum. These findings demonstrate that DNA immunization with pMP13 induce local and systemic host immune responses against Eimeria.

Animals↗

PubMed2000

Detection of cryptic Y chromosome mosaicism by coamplification PCR with archived cytogenetic slides of suspected Turner syndrome.

Turner syndrome is one of the most common cytogenetic abnormalities. It is known that the Y chromosome or Y derived material is present in 6-9% of TS patient and it may develop a high risk of gonadoblastoma in 15-25%. So it is crucial to carry out cyto genetic analysis and Y-specific probe studies for all persons with gonadal dysgenesis to rule out mosaicism with Y-bearing cell line; eg 45,X/46,XY. In this study, 26 archival slides previously analyzed cytogenetically as 45,X, 45,X/46,X,i(X), 45,X/46,X,r(X), and 45,X/46,XX were examined. Coamplification PCR, having the advantage of providing rapid result and confirming PCR failure, was performed with the slide samples in the regions of dystrophin gene in Xp21and DYZ3 in the Y centromeric region. All of archived slides were positive for X-specific gene and one slide of 45,X was found to have the cryptic Y chromosome material. Our result suggests that the archived cytogenetic slides could be applied for the detection of Y chromosome rapidly and efficiently in TS patients.

Biopsy↗

PubMed2000

Derivation and characterization of pluripotent embryonic germ cells in chicken.

Embryonic germ (EG) cell lines established from primordial germ cells (PGCs) are undifferentiated and pluripotent stem cells. To date, EG cells with proven germ-line transmission have been completely established only in the mouse with embryonic stem (ES) cells. We isolated PGCs from 5.5-day-old (stage 28) chicken embryonic gonads and established a putative chicken EG cell line with EG culture medium supplemented with stem cell factor (SCF), leukemia inhibitory factor (LIF), basic fibroblast growth factor (bFGF), interleukin-11 (IL-11), and insulin-like growth factor-I (IGF-I). These cells grew continuously for ten passages (4 months) on a feeder layer of mitotically active chicken embryonic fibroblasts. After several passages, these cells were characterized by screening with the periodic acid-Schiff reaction, anti-SSEA-1 antibody, and a proliferation assay. The chicken EG cells maintained characteristics of gonadal PGCs and undifferentiated stem cells. When cultured in suspension, the chicken EG cells successfully formed an embryoid body and differentiated into a variety of cell types. The chicken EG cells were injected into stage X blastodermal layer and produced chimeric chickens with various differentiated tissues derived from the EG cells. Chicken EG cells will be useful for the production of transgenic chickens and for studies of germ cell differentiation and genomic imprinting.

Alkaline Phosphatase↗

PubMed2000

Myositis ossificans of the chest wall simulating malignant neoplasm.

Myositis ossificans originating from the chest wall is extremely rare. We report a case of myositis ossificans occurring in a young woman with progressive painful swelling in the chest wall. Preoperative examination suggested a malignant neoplasm originating from soft tissue. Although rare, myositis ossificans is one of the potential causes of painful swelling in the chest wall, and can be mistaken for a malignant neoplasm.

Adolescent↗