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Biomedical subjects

K Y Kim

Publications and source records attributed to K Y Kim.

At least 145 records · Page 8Linked to original sources
PubMed1991

Differential regulation of the expression of transforming growth factor-beta s 1 and 2 by retinoic acid, epidermal growth factor, and dexamethasone in NRK-49F and A549 cells.

Although most biological activities of transforming growth factor-beta s 1 and 2 (TGF-beta 1 and TGF-beta 2) examined in vitro are similar or identical, recent studies suggest that each of these factors may be independently regulated in vivo. In this study we have used highly sensitive and specific sandwich enzyme-linked immunosorbent assays for TGF-beta 1 and TGF-beta 2 to examine the effects of a variety of treatments on expression of these two TGF-beta isoforms. We show that epidermal growth factor (EGF) induces secretion of TGF-beta 1 and not TGF-beta 2, whereas retinoic acid (RA) induces secretion of TGF-beta 2 and not TGF-beta 1 in NRK-49F normal rat kidney fibroblasts and A549 human lung carcinoma cells. Moreover, treatment with EGF diminishes the levels of TGF-beta 2, while RA decreases the levels of TGF-beta 1 in both cell lines. Dexamethasone (Dex), on the other hand, inhibits the secretion of both TGF-beta 1 and TGF-beta 2 in A549 cells, while selectively inhibiting TGF-beta 1 secretion in NRK-49F cells. The interactive effects of EGF, RA, and Dex on the production of TGF-beta 1 and TGF-beta 2, which were studied on NRK-49F cells, demonstrate that EGF blocks the induction of TGF-beta 2 mRNA and peptide by RA, while Dex inhibits the induction of TGF-beta 1 mRNA and peptide by EGF. These results demonstrate that RA, EGF and Dex are each unique, differential, and interactive regulators of the expression of TGF-beta s 1 and 2.

Animals↗
PubMed1991

Overexpression of transforming growth factor-beta in transgenic mice carrying the human T-cell lymphotropic virus type I tax gene.

Human T-cell lymphotropic virus type I (HTLV-I) has been associated with an adult form of T-cell leukemia as well as tropical spastic paraparesis, a neurodegenerative disease. Adult T-cell leukemia patients express high levels of the type 1 isoform of transforming growth factor-beta (TGF-beta 1), which is mediated by the effects of the HTLV-I Tax transactivator protein on the TGF-beta 1 promoter. To understand further the regulation of TGF-beta 1 expression by Tax, we examined its expression in transgenic mice carrying the HTLV-I tax gene. We show that tumors from these mice and other tissues, such as submaxillary glands and skeletal muscle, which express high levels of tax mRNA selectively express high levels of TGF-beta 1 mRNA and protein. Moreover, TGF-beta 1 significantly stimulated the incorporation of tritiated thymidine into one of three cell lines derived from neurofibromas of tax-transgenic mice, which suggests that the excessive production of TGF-beta 1 may play a role in tumorigenesis and that these mice may serve as a useful model for studying the biological effects of TGF-beta in vivo.

Animals↗
PubMed1991

Hodgkin's disease in a child with acute lymphoblastic leukemia.

Hodgkin's disease, manifested as a second malignant neoplasm in acute lymphoblastic leukemia, rarely occurs, with seventeen cases reported including this cases. We presented the clinical and pathological features of a nine-year-old male child with acute lymphoblastic leukemia in remission. He had cervical lymph node involvement 22 months after the diagnosis of leukemia as an initial presentation of Hodgkin's disease of mixed cellularity. A brief review of related literatures was also done.

Antineoplastic Agents↗
PubMed1990

Transactivation of the transforming growth factor beta 1 (TGF-beta 1) gene by human T lymphotropic virus type 1 tax: a potential mechanism for the increased production of TGF-beta 1 in adult T cell leukemia.

We examined the effect of the human T lymphotropic virus type 1 (HTLV-I) Tax gene product on the human transforming growth factor beta 1 (TGF-beta 1) promoter. Transfection of deleted constructs of the TGF-beta 1 promoter revealed regions homologous with AP-1 binding sites that were required for Tax-induced transactivation of the TGF-beta 1 promoter. In addition, we examined the expression and secretion of TGF-beta in fresh leukemic cells isolated from patients with adult T cell leukemia (ATL) and in HTLV-1-infected T cell lines. We report that fresh leukemic cells from ATL patients constitutively produce high levels of TGF-beta 1 mRNA and secrete TGF-beta 1 but not TGF-beta 2 into the culture medium. In addition, long-term ATL cell lines expressed significant amounts of TGF-beta 1 mRNA as well as detectable levels of TGF-beta 1 protein. These results suggest a role for Tax in the upregulation of TGF-beta 1 in HTLV-I-infected cells.

Cell Line↗
PubMed1990

Procollagen expression by nonparenchymal rat liver cells in experimental biliary fibrosis.

To localize the cellular sources of the collagens excessively deposited in the liver in the course of secondary biliary fibrosis, we have analyzed by in situ hybridization the distribution of alpha 2(I), alpha 1(III), and alpha 1(IV) procollagen and albumin RNA transcripts in rat livers up to 6 wk following common bile duct ligation and scission. In normal liver, moderate amounts of alpha 2(I) and alpha 1(III) procollagen RNA were found in nonparenchymal cells, while alpha 1(IV) procollagen gene expression was at the threshold of detection. Following bile duct obstruction, increasing amounts of alpha 2(I), alpha 1(III), and alpha 1(IV) procollagen gene transcripts were observed in cells of the expanding portal tracts and in perisinusoidal cells in areas of excessive collagen deposition. Procollagen gene expressing perisinusoidal cells were colocalized with desmin-immunoreactive cells, suggesting that Ito cells and transitional cells were among the collagen-expressing cell types. Only alpha 1(IV) procollagen transcripts were found in epithelial cells of newly formed bile ducts. Neither normal nor fibrotic liver showed any hybridization signal above background over hepatocytes, indicating that hepatocytes are unlikely to be a major source of hepatic collagen.

Animals↗
PubMed1990

Regulation of collagenase gene expression by okadaic acid, an inhibitor of protein phosphatases.

Human collagenase gene expression is regulated transcriptionally and is inducible by various mitogens in many cell types. To investigate the molecular mechanisms of this response, we examined the effects on collagenase gene expression of okadaic acid, a non-12-O-tetradecanoyl-phorbol-13-acetate (TPA)-type tumor promoter, which induces apparent "activation" of protein kinases by inhibition of protein phosphatases. Steady state levels of collagenase mRNA were markedly increased by okadaic acid treatment. We show that the AP-1 consensus sequence in the collagenase promoter is required for the induction of collagenase gene expression by okadaic acid, even though sequences upstream of the AP-1 consensus site have an additive effect. We also examined the regulation by okadaic acid of expression of the components of the AP-1 complex, c-fos and c-jun. c-fos expression is dramatically stimulated by okadaic acid, whereas c-jun expression is stimulated to a lesser extent. Induction of c-fos gene mRNA occurs through a region known to contain multiple regulatory elements. These results suggest that phosphorylation regulates collagenase gene expression mediated by an AP-1 binding site.

DNA-Binding Proteins↗
PubMed1990

Autoinduction of transforming growth factor beta 1 is mediated by the AP-1 complex.

The multifunctional actions of transforming growth factor beta 1 (TGF-beta 1) indicate that it has a pivotal control function in many physiological and pathological processes. An important property of TGF-beta 1 is its ability to activate its own mRNA expression and thereby increase its own secretion. Two distinct regions of the promoter of the TGF-beta 1 gene are responsive to autoregulation: one 5' to the upstream transcriptional start site and another located between the two major start sites. In both promoter regions, autoinduction is mediated by binding of the AP-1 (Jun-Fos) complex. An important contribution to this positive regulation is the autoactivation of c-jun transcription by AP-1. Cotransfection of antisense c-jun or antisense c-fos expression vectors prevents TGF-beta 1 autoinduction. These results demonstrate that both components of the AP-1 complex are required for TGF-beta 1 autoinduction. Induction of jun expression by TGF-beta 1, as well as jun autoinduction, may amplify the action of TGF-beta 1 during normal development and oncogenesis.

Adenocarcinoma↗
PubMed1990

Pulmonary diffuse alveolar septal amyloidosis--diagnosed by transbronchial lung biopsy.

Diffuse alveolar septal involvement is a rare form of pulmonary amyloidosis. Antemortem diagnosis is unusual, and most of the reported cases were diagnosed at autopsy. It has recently been reported that transbronchial lung biopsy via a flexible fiberoptic bronchoscope was a relatively safe method to confirm diffuse alveolar septal amyloidosis. We report a case of pulmonary diffuse alveolar septal amyloidosis confirmed by transbronchial lung biopsy. The patient's chief complaints were dyspnea on exertion and epigastric pain aggravated over a one-year period, while a chest roentgenogram showed bilateral diffuse interstitial infiltration. This case also showed nephrotic syndrome, cardiac arrhythmia, congestive heart failure, a tingling sensation in both hands and multiple nodules in the gastrointestinal tracts, suggesting involvement of the kidney, heart, peripheral nerves and gastrointestinal tracts. We propose that when diffuse interstitial lung disease is present with systemic signs such as nephrotic syndrome or cardiac arrhythmia, amyloidosis should be considered as a possible diagnosis. Also, transbronchial lung biopsy may be a useful confirmative diagnostic tool.

Amyloidosis↗
PubMed1989

Activation of the second promoter of the transforming growth factor-beta 1 gene by transforming growth factor-beta 1 and phorbol ester occurs through the same target sequences.

Two distinct regions of the transforming growth factor-beta 1 (TGF-beta 1) promoter are responsive to autoregulation and activation by phorbol ester (12-O-tetradecanoylphorbol-13-acetate): sequences located between nucleotides -454 to -323 (first promoter) and between the two transcriptional start sites. We have now characterized in detail the induction of the second promoter (sequences between nucleotides + 1 to +271) of the TGF-beta 1 gene by both TGF-beta 1 and phorbol ester. By assaying progressively deleted mutations in the second promoter, we have found two regions responsible for the induction; each contains a phorbol ester-responsive element. In vitro transcription of the second promoter-chloramphenicol acetyltransferase chimeric genes using nuclear extracts of A-549 cells showed that deletion of the putative phorbol ester-responsive elements results in a 70-80% decrease in activity. DNase I footprinting and gel mobility shift assays showed that binding to an Sp1 site and the putative TRE elements are required for maximal expression of the second promoter region of the TGF-beta 1 gene. These results suggest that AP-1, which is capable of conferring phorbol ester or TGF-beta 1 responsiveness, is the major transcription factor involved in the second promoter-derived transcription of the TGF-beta 1 gene.

Animals↗
PubMed1989

The integrated value of serum procollagen III peptide over time predicts hepatic hydroxyproline content and stainable collagen in a model of dietary cirrhosis in the rat.

To determine whether a serum parameter of collagen metabolism, serum procollagen type III peptide, correlated with hepatic collagen in a model of diet-induced fibrosis, rats were fed a control or cirrhogenic diet for 6 months and treated with either subcutaneous vehicle or the hepatoprotective prostaglandin 16,16-dimethyl prostaglandin E2 (100 micrograms per kg) twice daily. Pair-fed rats from each group were killed after 2, 4 or 6 months. The value of serum procollagen type III peptide to body weight integrated over time (Kt) correlated linearly with hepatic hydroxyproline content (r = 0.97) at killing time t. Good correlations were also seen between Kt and histopathological assessment of aniline blue-stainable collagen (r = 0.93) and between the histopathology and hydroxyproline content (r = 0.97). Rats receiving 16,16-dimethyl prostaglandin E2 had lower values of all three parameters compared to rats receiving vehicle, confirming the previously demonstrated hepatoprotective effect of 16,16-dimethyl prostaglandin E2. The excellent correlation between Kt and the two other traditional parameters of hepatic collagen suggest that sequential measurements of serum procollagen type III peptide can be used to predict alterations in liver collagen deposition in rats.

16,16-Dimethylprostaglandin E2↗
PubMed1989

Vimentin expression of newly formed rat bile duct epithelial cells in secondary biliary fibrosis.

The intermediate filament profile and the growth fraction of hepatocytes and bile duct epithelial cells were studied in a rat model of biliary fibrosis secondary to common bile duct ligation and scission. Strong vimentin expression was observed in epithelial cells of newly formed bile ductules, while normal liver contained only few weakly positive bile duct epithelial cells. All epithelial cells reacted with a pan-cytokeratin antibody. A monoclonal antibody specific for human cytokeratin 7 selectively reacted with both normal and newly formed bile duct epithelial cells. The intermediate filament profile of hepatocytes was constant, showing no changes during proliferation or in periportal areas adjacent to excessive bile duct formations. The proliferation-associated antigen detected by the antibody Ki-67 was present in many hepatocytes, homogeneously distributed in the lobules, but was seen only in a small proportion of the epithelial cells of the newly formed bile ducts. We conclude that vimentin may serve as an indicator for cellular reorganization in the bile duct system, and that the epithelial cells of newly formed bile ductules in this particular model of secondary biliary fibrosis were most likely to be derived from an outgrowth of the biliary duct system and recruitment of preductular epithelial cells. No morphological or immunohistological evidence suggesting a derivation from hepatocytes by ductular metaplasia or from oval cells was obtained.

Animals↗
PubMed1989

Sandwich enzyme-linked immunosorbent assays (SELISAs) quantitate and distinguish two forms of transforming growth factor-beta (TGF-beta 1 and TGF-beta 2) in complex biological fluids.

We have developed sandwich enzyme-linked immunosorbent assays (SELISAs) for TGF-beta 1 and TGF-beta 2 using both turkey and rabbit neutralizing polyclonal antibodies against native TGF-beta s. Each assay is based on the binding of two different antibodies to distinct epitopes of a single TGF-beta molecule. With these assays, TGF-beta types 1 and 2 can each be specifically quantitated in complex biological fluids, with detection limits of 2-5 pg. TGF-beta 3 and TGF-beta 5 either do not cross-react or cross-react very poorly in these assays. TGF-beta 1.2 heterodimer, although 50-80% neutralized by either TGF-beta 1 or TGF-beta 2 antibodies, shows only a 1.5 and 3.7% cross-reactivity in the TGF-beta 1 and TGF-beta 2 SELISAs, respectively. The SELISAs reported here represent the most specific, rapid, and precise assays for TGF-beta 1 and TGF-beta 2 reported thus far.

Animals↗
PubMed1989

[The prevalence of head louse infestation among urban and rural children in Korea].

The prevalence of head louse (Pediculus hamanus var. capitis) infestation in preschool and school children in 9 urban and 8 rural areas of Korea, was investigated. Of 11,865 children who were examined for head lice and nits, 2,900(24.4%) were found infested. The over-all infestation rate of rural children, 58.9%, was higher than that of urban children, 14.4%. There also existed significant differences in the infestation rate among various regions of urban as well as rural areas. Females were more infested than males. But there was no differences in infestation rate in either sex of preschool age. The infestation rate increased gradually from the age of 6, reached a plateau between 9-12 years of age and thereafter slowly decreased. The infestation rate of an orphanage children was higher than that of general childhood population. Health education and mass-delousing attempt are urgently required to lower such a high prevalence of head louse infestation in Korea.

Adolescent↗
PubMed1989

The effect of genetic counseling on performance of prenatal cytogenetic diagnosis.

Currently the number of pregnant women who have indications for, but do not receive, prenatal cytogenetic diagnosis is increasing. The purpose of this study was to review the prenatal cytogenetic services and to analyze the effect of genetic counseling on performance of the prenatal cytogenetic test. From January 1987 to July 1988, there were 2,796 deliveries at Severance Hospital, Yonsei Medical Center, of which 126 patients had indications for prenatal cytogenetic diagnosis. Chromosomal abnormalities were found in 5 patients (1, monosomy X; 1, trisomy 18; and 3, trisomy 21). Four patients were found in the group who had indications for prenatal cytogenetic diagnosis while only one was found in the group who did not (p less than 0.01). The most common indication for prenatal cytogenetic diagnosis was advanced maternal age (59%). The prenatal test rate was highest in patients whose indications were a previous child with chromosomal abnormality (100%) and parental translocation carrier (100%). Most (89%) of the patients were tested by amniocentesis between the 16th and 20th week of gestation. The two most common reasons for patients not receiving a prenatal cytogenetic diagnosis were late registration (41%) and absence of genetic counseling (34%).

Abnormalities, Multiple↗
PubMed1989

A comprehensive study of immunological abnormalities in Korean hemophiliacs.

To determine laboratory evidence suggesting immunological abnormalities in persons with hemophilia, we evaluated the immunological status of 75 Korean hemophiliacs, seronegative for human immunodeficiency virus (HIV) antibodies, who have been treated only with Korean factor VIII concentrates. From this study, it was shown that Korean hemophiliacs had decreased CD4 levels, increased CD8 levels, and decreased CD4:CD8 ratios. Diminished lymphocyte response to the mitogens, phytohemagglutinin and concanavalin A, and decreased natural killer cell activity were observed in the hemophiliacs. In addition, production of interleukin-II in the hemophiliacs was lower than in the healthy controls. The percentage of B lymphocytes was significantly reduced but the serum levels of immunoglobulin (Ig) G were elevated. However, the serum Ig A and Ig M levels were normal. This study demonstrated a high frequency of immunological abnormalities in HIV antibody negative Korean hemophiliacs treated only with domestic factor VIII concentrates.

Adolescent↗
PubMed1989

Transbronchial catheter drainage via fiberoptic bronchoscope in intractable lung abscess.

The use of the fiberoptic bronchoscope as a drainage procedure for lung abscess has become more and more widespread. We have recently adopted the technique of inserting a simple polyethylene catheter through the flexible fiberoptic bronchoscope into the abscess cavity of 11 patients with lung abscess. All cases had not responded to aggressive postural drainage and adequate antibiotic therapy for at least a week. The results were as follows: 1) Among 11 patients, the therapeutic response was dramatic in 6 patients. 2) In the successful group, the abscess sizes were greater than 8cm in diameter and the airfluid levels were higher than two-thirds of the cavity. 3) Additional diagnoses, other than bacterial lung abscess, could be made in 2 cases when otherwise the diagnosis would have remained in doubt. The authors suggest that catheter drainage via fiberoptic bronchoscope is an effective treatment modality in the large lung abscess with a high air-fluid level which is intractable to other medical approaches, and it is also a safe procedure.

Adult↗
PubMed1988

Collagen type IV and procollagen type III during granulation tissue formation: a serological, biochemical, immunohistochemical and morphometrical study on the viscose cellulose sponge rat model.

The serum concentrations of collagen type IV,7S, collagen type IV,nc1, and aminoterminal type III procollagen peptide immunoreactive components were measured by means of specific radioimmunoassays during development of granulation tissue in rats. The results were compared with tissue deposition of basement membranes and interstitial collagens in the granulation as measured morphometrically. A parallel sequential pattern in tissue deposition of collagen types III and IV, and serum increase of collagen types III- and IV-related fragments, was observed. Serum collagen type IV was less sensitive as a marker for development of granulation tissue than the serum procollagen type III N-peptide. This was in accordance with a low collagen type IV/interstitial collagen ratio in the granulation tissue. However, a cross-sectional study showed that serum collagens types IV,7S and IV,nc1 may be useful as early quantitative indicators of granulation tissue formation. Simultaneously, measurement of collagen type IV- and procollagen type III N-peptide-related antigens in serum provides a differentiated reflection of the dynamic matrix processes in developing granulation tissue.

Animals↗