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C Y Kim

Publications and source records attributed to C Y Kim.

At least 145 records · Page 8Linked to original sources
PubMed1994

Localization, synthesis, and processing of surfactant protein SP-C in rat lung analyzed by epitope-specific antipeptide antibodies.

Surfactant protein C (SP-C), a 3.7-kDa hydrophobic lung-specific protein, is synthesized and secreted by pulmonary type II cells through proteolytic processing of a 21-kDa propeptide (SP-C21) by currently undefined pathways. Previously, we reported the production of a polyclonal antibody against rat SP-C21 (anti-CPROSP-C) using a synthetic peptide as the immunizing antigen (Beers, M. F., Wali, A., Eckenhoff, M. E. F., Feinstein, S., Fisher, J. H., and Fisher, A. B. (1992) Am. J. Respir. Cell. Mol. Biol. 7, 368-378). In this study, two additional epitope-specific proSP-C antibodies produced using synthetic peptide sequences were utilized to examine synthetic processing of SP-C. Anti-NPROSP-C (Met10-Gln23) and anti-CTERMSP-C (Ser149-Ser166) recognized native proSP-C21 produced from in vitro translation of SP-C cDNA. Immunocytochemistry using anti-NPROSP-C confirmed the localization of proSP-C peptides exclusively in type II cells. Western analysis of subcellular fractions identified a single 21-kDa band in microsomes and a 16-kDa form in lamellar bodies each recognized by all three antisera, while anti-NPROSP-C also uniquely identified a prominent 5-6-kDa form in lamellar bodies. In a perfused rat lung model labeled with [35S]cysteine/methionine, immunoprecipitation of lung homogenate and lamellar body fractions identified early appearances of 35S-labeled 21-, 18-, and 16-kDa SP-C forms in homogenate and a 16-kDa intermediate form in lamellar bodies. Anti-NPROSP-C also exclusively detected time-dependent appearances of 5-10-kDa proSP-C forms in lamellar bodies and homogenates. Processing of proSP-C21 was completely blocked by inclusion of brefeldin A (15 micrograms/ml) in the perfusate. These results demonstrate that synthetic peptides can be used to produce epitope-specific antisera which recognize more hydrophilic domains of proSP-C and show that proSP-C processing occurs intracellularly in subcellular compartments of type II cells which are distal to the trans-Golgi network.

Amino Acid Sequence↗
PubMed1994

Activators of protein kinase C selectively mediate cellular cytotoxicity to hypoxic cells and not aerobic cells.

PURPOSE: By understanding the signal transduction pathways through which a cell responds to changes in environmental oxygen levels, we may be able to therapeutically exploit this response by manipulating these pathways. MATERIALS AND METHODS: The human adenocarcinoma cell line A549 was exposed to varying durations of hypoxia alone and then plated for survival, or treated with PKC activating agents for 1 h before plating for survival. Western blots were used to determine the kinetics of PKC epsilon and phospholipase C induction. RESULTS: The level of hypoxic killing was directly related to the time of exposure and inversely related to the level of oxygen in the environment. Exposure of the cells to protein kinase C (PKC) activators for 1 h after chronic hypoxic exposure increased cell killing by at least an additional three logs beyond that found for hypoxia alone. Treatment of cells with an inactive phorbol ester 4 alpha-phorbol-12,13-didecanoate (PDA) resulted in no increase in hypoxic cell killing, even at the highest concentrations of PDA which produced no detectable toxicity under normal aerobic conditions. Using inhibitors of phospholipases A2 and C, we were able to completely inhibit the additional hypoxic cell killing induced by TPA, but not the uninduced hypoxic cell killing. CONCLUSION: These studies suggest that accumulation of phospholipid breakdown products may be responsible for TPA induced cell killing, and that hypoxic cells differ from aerobic cells in their ability to tolerate these products.

Adenocarcinoma↗
PubMed1994

Osmotic regulation of myo-inositol uptake in primary astrocyte cultures.

Uptake of myo-inositol by astrocytes in hypertonic medium (440 mosm/kg H2O) was increased near 3-fold after incubation for 24 hours, which continued for 72 hours, as compared with the uptake by cells cultured in isotonic medium (38 nmoles/mg protein). myo-Inositol uptake by astrocytes cultured in hypotonic medium (180 mosm/kg H2O) for periods up to 72 hours was reduced by 74% to 8 to 10 nmoles/mg protein. Astrocytes incubated in either hypotonic or hypertonic medium for 24 hours and then placed in isotonic medium reversed the initial down- or up-regulation of uptake. Activation of chronic RVD and RVI correlates with regulation of myo-inositol uptake. A 30 to 40 mosm/kg H2O deviation from physiological osmolality can influence myo-inositol homeostasis. The intracellular content of myo-inositol in astrocytes in isotonic medium was 25.6 +/- 1.3 micrograms/mg protein (28 mM). This level of myo-inositol is sufficient for this compound to function as an osmoregulator in primary astrocytes and it is likely to contribute to the maintenance of brain volume.

Animals↗
PubMed1994

Intussusception: characteristic radiolucencies on the abdominal radiograph.

Six hundred and twenty-five sets of supine and erect abdominal radiographs of 288 patients with the confirmed diagnosis of intussusception (315 episodes) and 310 patients without intussusception were reviewed retrospectively to determine the characteristic radiographic features of intussusception. Among the patients with intussusception, 155 episodes (49%) showed a soft tissue mass and nearly half of these (71) showed characteristic radiolucencies (target, crescentic, or amorphous) in the soft tissue mass. Thirty-five episodes showed the radiolucencies on both the supine and erect radiographs; in 16 cases the type of radiolucency differed on the two films. In patients without intussusception, abnormal radiolucencies were seen in only seven cases (2.3%). Computed tomography performed prospectively in five patients showed the radiolucencies in the soft tissue mass to be intussuscepted mesenteric fat. We conclude that abnormal radiolucencies in the soft tissue mass on plain radiographs are characteristic of intussusception.

Adolescent↗
PubMed1994

Cloning, nucleotide sequence, and overexpression of the gene coding for delta 5-3-ketosteroid isomerase from Pseudomonas putida biotype B.

The structural gene coding for the delta 5-3-ketosteroid isomerase (KSI) of Pseudomonas putida biotype B has been cloned, and its entire nucleotide sequence has been determined by a dideoxynucleotide chain termination method. A 2.1-kb DNA fragment containing the ksi gene was cloned from a P. putida biotype B genomic library in lambda gt11. The open reading frame of ksi encodes 393 nucleotides, and the amino acid sequence deduced from the nucleotide sequence agrees with the directly determined amino acid sequence (K. Linden and W. F. Benisek, J. Biol. Chem. 261:6454-6460, 1986). A putative purine-rich ribosome binding site was found 8 bp upstream of the ATG start codon. Escherichia coli BL21(DE3) transformed with the pKK-KSI plasmid containing the ksi gene expressed a high level of isomerase activity when induced by isopropyl-beta-D-thiogalactopyranoside. KSI was purified to homogeneity by a simple and rapid procedure utilizing fractional precipitation and an affinity column of deoxycholate-ethylenediamine-agarose as a major chromatographic step. The molecular weight of KSI was 14,535 (calculated, 14,536) as determined by electrospray mass spectrometry. The purified KSI showed a specific activity (39,807 mumol min-1 mg-1) and a Km (60 microM) which are close to those of KSI originally obtained from P. putida biotype B.

Amino Acid Sequence↗
PubMed1994

Synthesis of type II cell lamellar body lysozyme-15 kD protein (lbl-15) by perfused rat lung.

Isolated alveolar type II pneumocytes of the rat have been shown to secrete a 14 to 15 kD protein that has some sequence homology and immunoreactivity with lysozyme. Using immunochemical analyses of rat lung subcellular fractions and 35S metabolic labeling of isolated perfused lung preparations, we studied the subcellular distribution and synthetic pathway for this protein. SDS-PAGE and Western blotting of lamellar bodies (LB) using a polyclonal anti-human lysozyme (anti-HLZ) demonstrated a single band at 15 kD that was significantly enriched over rat lung homogenates, isolated lysosomes, and type II cell lysates. This 15 kD protein isolated from LB by immunoprecipitation with anti-HLZ also demonstrated functional lysozyme activity and was termed lamellar body lysozyme (lbl-15). Analysis of LB and surfactant (SF) isolated from 12 separate perfused lung preparations labeled for 6 h with 35S-labeled amino acids demonstrated that lbl-15 represented a significant portion of the radiolabeled LB proteins (5.9% of total LB radioactivity). Lamellar bodies and an extracellular fraction (surfactant) obtained from rat lungs perfused with 35S-methionine-cysteine for varying times both showed time-dependent appearance of lbl-15. At all time points, the specific activity of lbl-15 was greater in LB than in SF. The kinetics for appearance of lbl-15 in LB and SF was similar to that for surfactant protein A. These results indicate that in the rat lung, type II cells synthesize a 15 kD protein (lbl-15) that is secreted into the alveolar space via an organellar pathway involving LB.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Time-dependent ovulation-blocking effect of ether anesthesia differs from pentobarbital in rats.

Time-dependent ovulation-blocking effect of ether anesthesia was investigated using female Wistar-Imamichi rats showing a 4-day cycling rhythm. A 6-hr (1400-2000) and 8-hr (1400-2200) anesthesia with ether vapor on proestrus caused ovulation blockade in 85% and 100% of the rats, respectively. On the other hand, pentobarbital injections at 1400 and 1500 completely blocked the spontaneous ovulation, while the injections at 1600 and 1700 did not. Ether (1400-2000) and pentobarbital anesthesia decreased the mean serum LH levels at 2000 on proestrus. The LH levels were 13.26 ng/ml for the control, 0.36 ng/ml for the ether group and 0.56 ng/ml for the pentobarbital group, respectively. These findings indicated that ether and pentobarbital similarly suppressed the LH surge, but difference between ovulation-blocking effects by ether and pentobarbital is possibly due to factor(s) other than suppression of the LH surge.

Anesthesia, Inhalation↗
PubMed1994

Universal emergence of precore mutant hepatitis B virus along with seroconversion to anti-HBe irrespective of subsequent activity of chronic hepatitis B.

OBJECTIVES: It has been controversial whether or not the emergence of precore mutant HBV is related to the severe form of chronic hepatitis B (CH-B). To further clarify the role of the precore mutant HBV in the natural course of CH-B, we conducted a longitudinal analysis of precore-region sequences according to the biochemical severity along with seroconversion to anti-HBe in patients with CH-B. METHODS: The precore sequences of the ten sets of serial serum samples, obtained from 6 chronic hepatitis B patients with (group I) and from 4 patients without subsequent biochemical remission after seroconversion to anti-HBe (group II), were analyzed by direct sequencing of DNA amplified by PCR. RESULTS: The precore mutant HBV having a G-A mutation at the nucleotide 1896 was most commonly found (9/10). Wild-type precore HBV was detected in 4 of 6 (66.7%) in group I and 3 of 4 (75.0%) in group II during HBeAg-positive period (p > 0.05), and during anti-HBe-positive period it was found in 2 of 6 (33.3%) in group I and 0 of 4 (0%) in group II (p > 0.05). In contrast, precore mutant HBV was detected in 5 of 6 (83.3%) in group I and 2 of 4 (50.0%) in group II during HBeAg-positive period (p > 0.05), and in all patients of both groups during anti-HBe-positive period. CONCLUSION: The most common type of precore mutant HBV in Korea was the mutant with a G-A mutation at nucleotide 1896. The emergence of precore mutant HBV was a universal phenomenon during the natural history of CH-B; therefore, the precore mutant does not appear to have an pathogenic role in determining the severity of the CH-B.

Adult↗
PubMed1994

Effects of long-term treatment of captopril and enalapril on rat intestinal angiotensin converting enzyme specific activities.

OBJECTIVES: Angiotensin converting enzyme (ACE) has been shown to be an important peptidasse that play a role in digestion and assimilation of protein rich in proline such as casein, gliadin and collagen. Despite that ACE inhibitors have been popular for various types of hypertension and congestive heart failure, the effects of their long-term treatment on intestinal ACE activities are not known. Therefore, we measured intestinal specific activities in rats after four weeks' treatment of ACE inhibitors. METHODS: Thirty Wistar rats weighing about 200g in average were divided into three groups, and supplied with tap water, captopril solution and enalapril solution respectively for four weeks. After sacrificing, intestinal ACE specific activities were measured in homogenate and brush border membrane fraction respectively, which was prepared from three equally divided segments of removed small intestine. RESULTS: ACE specific activities of proximal, middle and distal segments of control group were 178.6 +/- 64.2, 180.3 +/- 60.2 and 48.6 +/- 13.1 in brush border membrane (mean +/- SD, nmol/min/mg protein) respectively. Those of captopril group were 314.2 +/- 72.5, 281.0 +/- 69.8 and 67.7 +/- 21.8 respectively, showing tendency of increase in proximal and middle segments (p < 0.01 and 0.05 respectively). By contrast, those of enalapril group were 48.5 +/- 27.6, 70.7 +/- 15.6 and 11.6 +/- 4.4 respectively, which were significantly lower (p < 0.01) than those of control group. CONCLUSION: Rat intestinal ACE specific activities were not inhibited by captopril treatment, but inhibited by enalapril treatment. This finding may explain why there has not been any case report of malabsorption in patients taking captopril. But the malabsorption of prolyl peptide could be possible in cases with long-term administration of enalapril.

Animals↗
PubMed1993

Predominant etiologic association of hepatitis C virus with hepatocellular carcinoma compared with hepatitis B virus in elderly patients in a hepatitis B-endemic area.

BACKGROUND: It has been thought that the mean age of patients with hepatitis B surface antigen (HBsAg) positivity and hepatocellular carcinoma (HCC) is younger than that of patients who test positive for anti-hepatitis C virus. This study was to assess the relative etiologic association of hepatitis B virus (HBV) and hepatitis C virus (HCV) with HCC, according to age-specific groups. METHODS: A total of 336 Korean patients with HCC were enrolled in the study; the mean age was 53.7 +/- 9.1 years, and the male-to-female ratio was 5.9. HBV serologic markers and anti-HCV were tested using commercially available radioimmunoassay and enzyme immunoassay kits, respectively. RESULTS: Two hundred thirty-three (69.3%) patients tested positive for HBsAg; anti-HCV was positive in 42.7% of 103 patients with HBsAg-negative disease and in 17.0% of all patients with HCC. Coinfection rate of HBV and HCV in the total number of patients with HCC was 3.9%. The mean age was 51.6 years for patients with HBsAg-positive disease and 60.4 years for patients with anti-HCV-positive disease. The ratio of HBsAg positivity compared with anti-HCV positivity in patients with HCC was 29.7 for patients younger than 50 years; 0.9 for patients older than 61 years; and 5.2 for patients in their 50s. CONCLUSIONS: The authors conclude that although HBV infection plays a more important etiologic role in the development of HCC in Korea than does HCV, HCV is no less frequently involved than HBV in the etiology of HCC for patients older than 61 years. Thus, in surveillance programs for the early detection of HCC, closer attention should be directed to the patients with anti-HCV-positivity and chronic liver disease, especially patients older than 61 years, even in a hepatitis-B-endemic area.

Age Factors↗
PubMed1993

Endothelial potentiation of relaxation response to ascorbic acid in rat and guinea pig thoracic aorta.

The role of the endothelium was evaluated in the relaxation of rat and guinea pig aortic rings induced by ascorbic acid. Ascorbic acid relaxed rat and guinea pig aortic rings that were previously contracted with submaximal dose of phenylephrine (PE), in a concentration dependent manner. Removal of the endothelium significantly reduced the sensitivity but not the magnitude of the response to ascorbic acid. Methylene blue, but not propranolol, blocked the endothelial augmentation of vascular relaxation to ascorbic acid. Vessels precontracted with potassium chloride (high K+) were also relaxed by ascorbic acid. Methylene blue also inhibited the response to ascorbic acid in the intact vessels precontracted with high K+. A23187 and acetylcholine, but not ADP, variably caused endothelium dependent component relaxation in guinea pigs, whereas all of these three probes constantly caused it. In Ca(2+)-free medium, Ca(2+)-induced contraction of high K(+)-depolarized rat aorta was inhibited by the presence of ascorbate, which was more pronounced in endothelium intact rings than in endothelium denuded ones. PE-induced contraction in the presence of different concentrations of ascorbate reduced both the sensitivity and the maximal contractile force in rat aorta. Ascorbic acid (0.125-32 mM) did not change the pH in the medium. From these findings, it is speculated that 1) receptor- and potential-operated Ca2+ channels may be modulated by ascorbate, 2) endothelium has a significant role in promoting relaxation induced by ascorbic acid.

Animals↗
PubMed1993

Arterial thrombosis associated with nephrotic syndrome--a case report and review (adult cases in the English literature).

The thromboembolic complications of nephrotic syndrome are reasonably common, including spontaneous peripheral venous and/or arterial, pulmonary arterial, and renal venous occlusions. However, in comparison to the relatively high incidence of the venous thromboembolic complications with hypercoagulable status, arterial thromboses have been reported much less and it was only 20 cases in the English literature so far. Furthermore, the most cases were pediatric patients rather than adults. Therefore, this report describes an adult nephrotic cases complicated by superior mesenteric artery thrombosis leading to death via catastrophic hospital course. Also, we reviewed the literature in English regarding cases of arterial thromboses in adult nephrotic patients with special interest to locations of thrombosis, underlying histopathologic types of glomerulopathy, and use of steroids or diuretics before its development.

Humans↗
PubMed1993

[The transition of medical terms in Korea between 1935 and 1985].

Korean modern medicine was imported from American missionaries in the late 19th century. At the beginning of the 20th century, Japanese medicine, which was influenced by German medicine, was imported along with the Japanese invasion. After the liberation of Korea, however, American medicine influenced the Korean Medicine in a broad spectrum: for example, medical science, medical instruments, and health care system. Not only an unstable social environment but also the rapid development of medical science changed medical terms. In order to investigate the 50-year transition of medical terms in Korea, we compare the names of diseases in 'Cho-Sŏn-Eu-Bo' published in 1934, 1935 and 1936 with those in the 'Journal of the Korean Medical Association' published in 1985. The names of diseases were classified according to number 17 classification method of ICD-9 (International Classification of Disease). The proportionate ratio of the number of names of diseases between 1935 and 1985 was 3.2 in neoplasms, 3.1 in diseases of the circulatory system, and 2.7 in mental disorders. The causes of the transition of the names of diseases were three. The first was the simple change of the rules of spelling, the second was the change of the concept of disease, and the third was the subdivision of diseases. 26.1% (N=37) of the names of diseases in 1935 (N=142) were changed by 1985.

History, 20th Century↗
PubMed1993

Overproduction of indole acetic acid in Azospirillum lipoferum using the Escherichia coli trp operon.

A recombinant plasmid carrying the trp operon from Escherichia coli, which synthesizes tryptophan from chorismate, was constructed by using a broad host range plasmid vector pRK290; a mutant trp plasmid for tryptophan overproduction was then selected. The physiological, biochemical, and genetic properties of the Azospirillum lipoferum KY6, a potential nitrogen fixer of rice, harbouring the recombinant trp plasmid pMJC1 and its mutant pMJC101, were compared with those of the wild-type bacteria. Anthranilate synthetase is known to be the trpE gene product which plays a key role in the regulatory step in the feedback control of tryptophan biosynthesis. The enzyme activity of the Azospirillum lipoferum KY6 carrying pMJC1 or pMJC101 was respectively 7- and 30-fold higher than that of the wild type in the presence of 10(-4)M tryptophan. As expected, the amount of tryptophan biosynthesis in A. lipoferum KY6 (pMJC101) was increased approximately 100-fold as compared with the wild type, which led to overproduction of indole acetic acid even without addition of exogenous tryptophan. Moreover, the recombinant trp plasmid was fairly stable in A. lipoferum KY6 host, showing only 25% loss of the plasmid itself or the trp insert after 40 generations.

Azospirillum↗
PubMed1992

Compositional dependence of calcium phosphate layer formation in fluoride Bioglasses.

Bioglasses form a double layer composed of apatite and a silica-rich layer when placed in a simulated physiological solution as well as in living tissue [A.E. Clark, C.G. Pantano, and L. L. Hench, "Auger spectroscopic analysis of bioglass corrosion films," J. Am. Ceram. Soc., 59(1-2), 37-39 (1976).]. In the present work, the mechanisms of the calcium phosphate layer and the silica-rich layer formation of fluoride Bioglasses in Tris-buffer solution are studied as a function of the SiO2 content. Fourier Transform Infrared Reflection Spectroscopy (FTIRS) is used to investigate the mechanism of formation of calcium phosphate and silica-rich layers on the glass surface. Ion concentration in reacted solution and elemental depth profiles are obtained by Induced Coupled Plasma Atomic Emission Spectrometry (ICP) and Auger Electron Spectroscopy (AES), respectively. Si--O bonds with one nonbridging oxygen and Si--O--Si bonds form at the early stage of reaction. Strong phosphorus ion uptake occurs when an amorphous calcium phosphate layer crystallizes. Glasses with high silica content (conventional glass) form the silica-rich layer first followed by a calcium phosphate layer on top. However, glasses with low silica content (invert glass) form both layers simultaneously. The rate of apatite formation decreases with increasing SiO2 content, especially in the region of conventional glass compositions. Ion release rates decreases as SiO2 content increases, with a significant change occurring at the compositional boundary between invert and conventional glasses.

Biocompatible Materials↗
PubMed1992

Differential expression of protein kinase C epsilon protein in lung cancer cell lines by ionising radiation.

The effect of ionising radiation on the regulation of gene and protein expression is complex. This study focuses on the translational regulational of the epsilon isoform of protein kinase C by ionising radiation. We found that protein kinase C epsilon is rapidly increased in the human lung adenocarcinoma cell line A549 following irradiation. Western blots showed increased accumulation of this protein at doses as low as 75 cGy after 15 min post irradiation. Maximal induction (11-fold over unirradiated cells) of PKC epsilon occurred at 150 cGy within 1 h after treatment by X-rays in A549 cells. The increased levels of PKC epsilon protein after X-rays does not require de novo protein or RNA synthesis, suggesting that this increase is post-translationally controlled. In contrast to A549 cells PKC epsilon levels in the large cell lung carcinoma cell line NCI H661 were not induced by radiation. In the small cell lung carcinoma cell line NCI N417, PKC epsilon was also not induced but a higher molecular weight PKC epsilon protein, suggestive of phosphorylation, appeared at 2 h after irradiation. The variation in induction or phosphorylation of PKC epsilon by ionising radiation in the cell lines tested in this study suggested that no clear correlation existed between intrinsic radiation sensitivity and PKC epsilon induction. To determine whether PKC epsilon does play a role in cell survival to irradiation, we used the protein kinase inhibitor staurosporin to decrease PKC activity and found that staurosporin sensitised cells to killing by ionising radiation. Pulsed field gel electrophoresis, however, indicated that DNA double-strand break repair was not decreased, suggesting that PKC epsilon is modifying the fidelity of rejoining and not the overall magnitude of repair. The regulation of PKC by ionising radiation will be discussed with respect to the biological consequences of gene induction by DNA damage agents.

Adenocarcinoma↗
PubMed1992

Therapeutic effect of transcatheter oily chemoembolization therapy for encapsulated nodular hepatocellular carcinoma: CT and pathologic findings.

An emulsion of iodized oil and doxorubicin hydrochloride was intraarterially injected in 27 patients with encapsulated single nodular hepatocellular carcinoma (HCC). Computed tomography (CT) was performed 1-3 weeks after injection, and the lesions were resected 1-4 weeks thereafter. The percentages of tumor necrosis were evaluated in cut surfaces of resected specimens and were compared with the findings at iodized-oil CT. Six tumors with complete intratumor retention of iodized oil had 98% necrosis, and 21 tumors with incomplete retention had 64% necrosis. Two tumors with complete retention of iodized oil in the surrounding liver had 100% necrosis, while 16 tumors with partial retention and nine tumors without retention of iodized oil in surrounding liver had 74% and 62% necrosis, respectively. Complete retention of iodized oil in the tumor and surrounding liver demonstrated the best therapeutic effects. Evaluation of the pattern and distribution of iodized oil in the tumor and surrounding liver with iodized-oil CT is useful in the assessment of the therapeutic effects of transcatheter arterial embolization in encapsulated nodular HCCs.

Carcinoma, Hepatocellular↗