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Hwang IK, Namkung S, Yoo YS, Kim HK, Choi YH. Huge biliary cystadenoma mimicking cholecystic lymphangioma in subhepatic space. J Comput Assist Tomogr 2000; 24:652-4. [PMID: 10966204 DOI: 10.1097/00004728-200007000-00026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Biliary cystadenoma is a rare cystic neoplasm and constitutes only 5% of all intrahepatic cysts of biliary origin. We report a case of a 44-year-old woman with huge biliary cystadenoma in the subhepatic space, mimicking a cholecystic lymphangioma. Findings of various imaging modalities including reconstructed CT image are presented and correlated with surgical and pathologic findings.
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Heo HJ, Yang HC, Cho HY, Hong B, Lim ST, Park HJ, Kim KH, Kim HK, Shin DH. Inhibitory effect of Artemisia asiatica alkaloids on acetylcholinesterase activity from rat PC12 cells. Mol Cells 2000; 10:253-62. [PMID: 10901162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
We screened 42 Korean traditional tea plants to determine the inhibitory effect of acetylcholinesterase and attenuation of toxicity induced by amyloid-beta peptide, which were related to the treatment of Alzheimer's disease (AD). The methanolic extract from Artemisia asiatica among tested 42 tea plants, showed the highest inhibitory effect (48%) on acetylcholinesterase in vitro. The methanolic extract was further separated with n-hexane, chloroform, and ethyl acetate of water, in order. The chloroform solubles, which were high in inhibitory effect of acetylcholinesterase, were repeatedly subjected to open column chromatography on silica gel. From the highest inhibitory fraction (78%) on acetylcholinesterase, the single compound was obtained by the Sep-Pak Cartridge (C18: reverse phase column). This compound was found to react positively on Dragendorff's reagent (potassium bismuth iodide), which typically reacted with the alkaloid. This compound was purified by HPLC (mu-bondapack C18 reverse phase column: 3.9 x 150 mm). The IC50 (the concentration of 50% enzyme inhibition) value of this compound was 23 micrograms/ml and the inhibitory pattern on acetylcholinesterase was mixed with competitive/non-competitive type. We examined the effects of this compound on toxicity induced by A beta (25-35) in rat pheochromocytoma PC12 cells. Pretreatment of the PC12 cells for 2 h with an alkaloid of Artemisia asiatica (1200 microg/ml) reduced the toxicity induced by A beta. This study demonstrated that an alkaloid of Artemisia asiatica, which was metabolized to small molecule in digestive tract and then could pass through the blood-brain barrier, appeared to be an acetylcholinesterase inhibitor with a blocker of neurotoxicity induced by A beta in human brain causing Alzheimer's disease.
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Hong YK, Joe YA, Yang YJ, Lee KS, Son BC, Jeun SS, Chung DS, Cho KK, Park CK, Kim MC, Kim HK, Yung WK, Kang JK. Potentials and limitations of adenovirus-p53 gene therapy for brain tumors. J Korean Med Sci 2000; 15:315-22. [PMID: 10895975 PMCID: PMC3054646 DOI: 10.3346/jkms.2000.15.3.315] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We investigated the antineoplastic potentials of recombinant adenovirus containing wild-type p53 cDNA (Ad5CMV-p53) for malignant gliomas. In four human glioma cell lines (U-251 and LG expressing endogenous mutant p53, and U-87 and EFC-2 expressing wild-type p53) and two rat glioma cell lines (9L and C6, each expressing mutant and wild-type p53), gene transfer efficiency determined by X-gal staining and Western blotting was varied (10-99% at 10-500 multiplicity of infection, MOI). Growth inhibitory effect was drastic (>90% at 100 MOI) in U-251 cells and only moderate or minimal in other cell lines harboring wild-type p53 or low gene transfer efficiency. Ex vivo transduction of U-251 cells with Ad5CMV-p53 suppressed the in vivo tumorigenicity of the cells. Histopathologic examination for Ad5CMV-p53 toxicity to rat brains showed inflammatory reactions in half of the tested brains at 10(8) MOI. U-251 cells were inoculated intracerebrally in nude mice and injected Ad5CMV-p53 into the tumor, in which neither the tumor suppression nor the survival benefit was observed. In conclusion, heterogeneity of the cellular subpopulations of malignant glioma in p53 status, variable and insufficient gene delivery to tumor, and adenoviral toxicity to brain at higher doses may be limiting factors to be solved in developing adenovirus-p53 gene therapy for malignant gliomas.
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Jeong HJ, Chang LC, Kim HK, Kim IH, Kinghorn AD, Pezzuto JM. Aromatase inhibitors from Isodon excisus var. coreanus. Arch Pharm Res 2000; 23:243-5. [PMID: 10896056 DOI: 10.1007/bf02976453] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The diethyl ether extract of Isodon excisus var. coreanus exhibited significant inhibitory activity in aromatase assay. Bioactivity-guided fractionation of the extract led to the isolation of three active compounds: inflexin (ent-1alpha-hydroxy-3beta,6a-diacetoxykaur-16-en-11,15-dione ) (1), ursolic acid (2), and ursolic acid 3-O-acetate (3).
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Kim YS, Kim KH, Choi JA, Lee JH, Kim HK, Won NH, Kim I. Fas (APO-1/CD95) ligand and Fas expression in renal cell carcinomas: correlation with the prognostic factors. Arch Pathol Lab Med 2000; 124:687-93. [PMID: 10782148 DOI: 10.5858/2000-124-0687-faclaf] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND AND OBJECTIVE Fas ligand (FasL, CD95L) is a type II transmembrane protein of the tumor necrosis factor family that induces cells to send an apoptotic signal to cells expressing Fas (CD95, APO-1). It has been shown that cancers have a dysregulated expression of Fas and FasL system, conferring a survival advantage. It is important to understand FasL and Fas expression in tumors, because the growth of cancer might be controlled by Fas-mediated apoptosis. METHODS The expressions of FasL and Fas were studied by immunohistochemical analyses in 51 cases of renal cell carcinomas and the adjacent normal renal tissues, respectively. In addition, their expressions were compared with prognostic factors, such as tumor size, nuclear grade, TNM stage, and histologic types. RESULTS In nonneoplastic renal tissues, FasL was expressed in all nephron segments, whereas Fas also expressed in all tubules, except for glomeruli. In renal cell carcinomas, FasL protein was detected in 50 (98.0%) of 51 cases, whereas Fas expressed in 38 (74.5%) of 51 cases. In fact, the immunostaining of Fas was less intense than that in the adjacent normal segments of all cases. The staining pattern showing both high expression of FasL and low expression of Fas was found in 36 (70.6%) (P = .04) of 51 cases, most of which were Fuhrman grade 2 or 3 tumors. However, the expression pattern did not correlate statistically with the tumor size, histologic type, or clinical stage. On the other hand, most grade 4 tumors displayed high expression of both FasL and Fas (P<.001). CONCLUSION These data indicate that high expression of FasL and low expression of Fas protein in renal cell carcinomas may play a role in evading surveillance of the immune system. In addition, the FasL and Fas expressions appear to have a therapeutic implication for high-grade tumors rather than a prognostic one.
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Choi SK, Gal YS, Jin SH, Kim HK. Poly(1,6-heptadiyne)-Based Materials by Metathesis Polymerization. Chem Rev 2000; 100:1645-82. [PMID: 11749278 DOI: 10.1021/cr960080i] [Citation(s) in RCA: 341] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Cheon J, Kim HK, Moon DG, Yoon DK, Cho JH, Koh SK. Adenovirus-mediated suicide-gene therapy using the herpes simplex virus thymidine kinase gene in cell and animal models of human prostate cancer: changes in tumour cell proliferative activity. BJU Int 2000; 85:759-66. [PMID: 10759680 DOI: 10.1046/j.1464-410x.2000.00516.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVES To determine the feasibility and efficacy of suicide-gene therapy using adenovirus (Ad)-mediated herpes simplex virus thymidine kinase (HSV-TK) and the prodrug acyclovir, and to evaluate changes in the biological phenotype for tumour cell proliferative activity after suicide-gene therapy in animal models of human prostate cancer. MATERIALS AND METHODS Using a replication-defective adenoviral vector (cytomegalovirus, CMV) containing the beta-galactosidase gene (Ad-CMV-beta-gal) as a control and Ad-CMV-TK as the therapeutic vector under the transcriptional control of the CMV promoter, transduction efficiency was assessed in vitro by infecting LNCaP and PC-3 androgen-dependent and independent human prostate cancer cells with Ad-CMV-beta-gal, and using X-gal staining. The TK activity in prostate cancer cells infected with Ad-CMV-TK was determined by measuring TK-mediated [3H]-gancyclovir phosphorylation. The sensitivity of LNCaP and PC-3 cells to Ad-CMV-TK in vitro was determined after infection with the therapeutic vector with or without acyclovir. The inhibition of PC-3 tumour growth in vivo induced by the Ad-CMV-TK/acyclovir suicide-gene system was assessed in separate and controlled experiments using human prostate cancer mouse models. Ki-67 proliferative antigen and proliferating cell nuclear antigen (PCNA), both useful proliferative indices, were evaluated using immunohistochemical staining (MIB-1 monoclonal antibody and monoclonal anti-PCNA antibody) in formalin-fixed, paraffin-embedded tissues from gene therapy-treated and control animals. RESULTS The mean TK activity was significantly higher in LNCaP and PC-3 cells infected with Ad-CMV-TK than in cells infected with Ad-CMV-beta-gal, used as a control (P < 0.05). The growth of human prostate cancer cells with Ad-CMV-TK was significantly inhibited by adding acyclovir in vitro (P < 0.05). In the in vivo experiments using the PC-3 human prostate cancer mouse model, tumour volume and growth was lower in mice treated with Ad-CMV-TK/acyclovir than in those treated with Ad-CMV-TK only, acyclovir only or untreated (controls) (P < 0.05). Histochemical staining of tumour tissues showed that Ad-CMV-TK/acyclovir destroyed PC-3 tumours through tumour cell death and apoptosis, with local lymphatic infiltration. The mean PCNA labelling index in prostate cancer cells of mice treated with Ad-CMV-TK/acyclovir was significantly lower than that in untreated controls (P < 0.05, Mann-Whitney U-test). The Ki-67 labelling index in prostate cancer cells of mice treated with Ad-CMV-TK/acyclovir was also lower than that in untreated controls (P < 0.05, Student's t-test). Adenovirus-mediated suicide-gene therapy using the HSV-TK gene decreased the proliferative activity of PC-3 human prostatic cancer cells in vivo. CONCLUSIONS Adenovirus-mediated suicide-gene therapy using an HSV-TK/acyclovir system provided effective therapy in an experimental human prostate cancer mouse model, by significantly inhibiting tumour growth and decreasing the proliferative activity of human prostate cancer cells. Such therapy could be developed as a novel method for treating patients with androgen-independent prostate cancer.
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Kim SJ, Shin SJ, Kim HK, Jahng JS, Kim HS. Comparison of 1- and 2-incision posterior cruciate ligament reconstructions. Arthroscopy 2000; 16:268-78. [PMID: 10750007 DOI: 10.1016/s0749-8063(00)90051-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
This study compared the results of the 1-incision technique and the conventional 2- incision technique for the arthroscopic treatment of the posterior cruciate ligament (PCL) injury. The 2-incision technique was performed in 10 patients (group I) and the 1-incision technique in 45 patients (group II). The average duration of follow-up was 45 months in group I and 36 months in group II. Bone-patellar tendon-bone (BTB) autografts were used for all patients in group I. In group II, 34 BTB autografts and 11 BTB allografts were used. Postoperative Lysholm mean values were 90.0 in group I and 90.6 in group II. HSS mean values were 87.7 in group I and 92.6 in group II (P = .037). The Tegner activity level scales were 6.4 in group I and 6.5 in group II. The average side-to-side difference of the corrected posterior translation measured by the KT-2000 arthrometer were 2.10 mm in group I and 2.38 mm in group II. There were no statistically significant differences between the 2 groups in postoperative mean values except HSS scores. The arthroscopic PCL reconstruction using the 1-incision technique showed good results comparable with the conventional 2-incision technique. This technique needs no another incision or dissection over the medial femoral condyle.
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Keyzer H, Kim HK, Pan KC. Alternating current aspects of antimicrobial molecular complexes. Int J Antimicrob Agents 2000; 14:253-9. [PMID: 10773498 DOI: 10.1016/s0924-8579(99)00162-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A novel method was designed involving the titration of alternating current titration in a cell where one electrode was shielded by a capillary enclosure restricting access to it by charge carriers. With this cell, charge transfer complex titration of several thiazines all with some antimicrobial properties was effected in acetonitrile, against the electron accepting molecule iodine. The maxima of the Job plots generated by these titrations exhibited displacement of their positions for the forward and reverse titrations with respect to electron donor-acceptor complexation conductivity and apparent stoichiometry. A plot of inverse conductivity maxima differences against literature-cited dipole moments squared yielded a straight line passing through the origin. The titration plot profiles are discussed in terms of the type, number, and mobility of charge carriers produced in the complexation interaction. This novel method may be used to determine dipole moments of bioactive homologues empirically. There was correlation between thiazine drug dipole moments and minimal inhibitory concentrations of these drugs for some bacterial and yeast species. Several new avenues of investigation of possible relevance to microbiology are suggested.
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Dozal A, Keyzer H, Kim HK, Wang WW. Charge transfer complexes of K vitamins with several classes of antimicrobials. Int J Antimicrob Agents 2000; 14:261-5. [PMID: 10773499 DOI: 10.1016/s0924-8579(99)00163-6] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The charge transfer donor (D)-acceptor (A) complexes formed between three classes of vitamin K (all electron acceptors in this study) with several thiazine psychotropes, used also as antimicrobials, antimalarials, antibiotics, and anticoagulants, were studied by means of alternating current titrations. The monochloride thiazines formed 2:1 (D:A) complexes, interacting from 26 to 47.5%; the dihydrochloride formed a 3:1 (D:A) complex. The antimalarials quinine and its isomer quinidine yielded 2:1 (D:A) complexes, interacting 51 and 60%, respectively. Quinacrine did not complex with vitamin K. The antibiotics sulfisoxasole and sulfamethisole gave 1:1 complexes, respectively interacting 6.2 and 11.7%. The anticoagulants warfarin, coumarin and dicumarol, rather than forming complexes proceeded rapidly to chemical reaction. When the above thiazine antimicrobials, antimalarials and antibiotics are present in patients receiving vitamin K post-operatively the dosage of administered vitamin K should be increased to counteract the donor-acceptor interaction effect.
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Lee H, Kim HK, Lee JH, You WK, Chung SI, Chang SI, Park MH, Hong YK, Joe YA. Disruption of interkringle disulfide bond of plasminogen kringle 1-3 changes the lysine binding capability of kringle 2, but not its antiangiogenic activity. Arch Biochem Biophys 2000; 375:359-63. [PMID: 10700393 DOI: 10.1006/abbi.1999.1675] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Kringle 1-3 of human plasminogen is a potent inhibitor of endothelial cell proliferation. To understand a possible role for the unique cystine bridge between kringle 2 and kringle 3, we disrupted the interkringle disulfide bond by mutating Cys(169) and Cys(297) to serine residues. The yield of the mutant during the refolding process was decreased significantly. Anti-endothelial cell proliferative activity of the mutant was similar to that of the wild type. There was no significant difference in in vivo antiangiogenic activity between the wild type and the mutant in chorioallantoic membrane assay. However, in the mutant, the weak lysine binding capability of kringle 2 was not detected and its mobility in nonreducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis is different from that of the wild type. These results support the notion that the overall antiangiogenic function of angiostatin is mediated by individual kringles, and suggest that the lysine binding capability of kringle 2 is likely not important for the antiangiogenic activity of kringle 1-3.
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Kwon BM, Lee SH, Kim MJ, Kim HK, Kim HM. Isolation of farnesyltransferase inhibitors from herbal medicines. Ann N Y Acad Sci 2000; 886:261-4. [PMID: 10667234 DOI: 10.1111/j.1749-6632.1999.tb09431.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Lee JY, Chang C, Song HK, Moon J, Yang JK, Kim HK, Kwon ST, Suh SW. Crystal structure of NAD(+)-dependent DNA ligase: modular architecture and functional implications. EMBO J 2000; 19:1119-29. [PMID: 10698952 PMCID: PMC305650 DOI: 10.1093/emboj/19.5.1119] [Citation(s) in RCA: 138] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
DNA ligases catalyze the crucial step of joining the breaks in duplex DNA during DNA replication, repair and recombination, utilizing either ATP or NAD(+) as a cofactor. Despite the difference in cofactor specificity and limited overall sequence similarity, the two classes of DNA ligase share basically the same catalytic mechanism. In this study, the crystal structure of an NAD(+)-dependent DNA ligase from Thermus filiformis, a 667 residue multidomain protein, has been determined by the multiwavelength anomalous diffraction (MAD) method. It reveals highly modular architecture and a unique circular arrangement of its four distinct domains. It also provides clues for protein flexibility and DNA-binding sites. A model for the multidomain ligase action involving large conformational changes is proposed.
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Lee JY, Kim HK, Chang C, Eom SH, Hwang KY, Cho Y, Yu YG, Ryu SE, Kwon ST, Suh SW. Crystallization and preliminary x-ray crystallographic analysis of NAD+-dependent DNA ligase from Thermus filiformis. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2000; 56:357-8. [PMID: 10713526 DOI: 10.1107/s090744490000010x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A highly thermostable DNA ligase from Thermus filiformis has been crystallized at room temperature using methoxypolyethylene glycol 5000 as a precipitant. The crystal belongs to the monoclinic space group P2(1), with unit-cell parameters a = 90.63, b = 117.80, c = 98. 65 A, beta = 115.56 degrees. Two molecules of DNA ligase are present in the asymmetric unit, giving a crystal volume per protein mass (V(m)) of 3.1 A(3) Da(-1) and a solvent content of 61%. A native data set extending to 3.0 A resolution has been collected at 100 K using synchrotron X-rays.
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Song KS, Park YS, Kim HK. Prevalence of anti-protein S antibodies in patients with systemic lupus erythematosus. ARTHRITIS AND RHEUMATISM 2000; 43:557-60. [PMID: 10728748 DOI: 10.1002/1529-0131(200003)43:3<557::aid-anr11>3.0.co;2-o] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To determine the prevalence of circulating anti-protein S (anti-PS) antibodies in association with PS deficiency in patients with systemic lupus erythematosus (SLE). METHODS Plasma was obtained from blood samples collected from 27 patients with SLE (5 men, 22 women; mean +/- SD age 32 +/- 10 years). Anti-PS antibodies were detected by immunoblotting according to a previously described method. Levels of free and total PS antigen were measured by enzyme-linked immunosorbent assay. PS activity was assayed by a clotting method. Levels of C4b binding protein (C4bBP) were measured by latex immunoassay. RESULTS Among 27 patients with SLE, 19 (70.4%) had PS activity, and 12 (44.4%) had PS free antigen below the lower limit established for a normal population (mean -2SD). There was good correlation between PS activity and levels of PS free antigen (r = 0.851, P < 0.001), PS total antigen (r = 0.743, P < 0.001), and C4bBP (r = 0.597, P = 0.001). Circulating anti-PS antibodies and antiphospholipid antibodies (aPL) (IgG type) were detected in 7 (25.9%) and 14 (51.9%) of the 27 patients with SLE, respectively. Only 1 patient (3.7%) had both anti-PS antibodies and aPL. PS activities in patients who were positive for anti-PS antibodies (mean 38.7%) tended to be lower than those in patients who were negative for anti-PS antibodies (mean 54.9%), but the difference was not statistically significant. CONCLUSION Anti-PS antibodies, independently of aPL, may play a role in the occurrence of PS deficiency in some patients with SLE, with possible effects on the function of PS that do not change the levels of PS antigens.
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Chang DJ, Li XC, Lee YS, Kim HK, Kim US, Cho NJ, Lo X, Weiss KR, Kandel ER, Kaang BK. Activation of a heterologously expressed octopamine receptor coupled only to adenylyl cyclase produces all the features of presynaptic facilitation in aplysia sensory neurons. Proc Natl Acad Sci U S A 2000; 97:1829-34. [PMID: 10677541 PMCID: PMC26521 DOI: 10.1073/pnas.97.4.1829] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/02/1999] [Indexed: 11/18/2022] Open
Abstract
Short-term behavioral sensitization of the gill-withdrawal reflex after tail stimuli in Aplysia leads to an enhancement of the connections between sensory and motor neurons of this reflex. Both behavioral sensitization and enhancement of the connection between sensory and motor neurons are importantly mediated by serotonin. Serotonin activates two types of receptors in the sensory neurons, one of which is coupled to the cAMP/protein kinase A (PKA) pathway and the other to the inositol triphosphate/protein kinase C (PKC) pathway. Here we describe a genetic approach to assessing the isolated contribution of the PKA pathway to short-term facilitation. We have cloned from Aplysia an octopamine receptor gene, Ap oa(1), that couples selectively to the cAMP/PKA pathway. We have ectopically expressed this receptor in Aplysia sensory neurons of the pleural ganglia, where it is not normally expressed. Activation of this receptor by octopamine stimulates all four presynaptic events involved in short-term synaptic facilitation that are normally produced by serotonin: (i) membrane depolarization; (ii) increased membrane excitability; (iii) increased spike duration; and (iv) presynaptic facilitation. These results indicate that the cAMP/PKA pathway alone is sufficient to produce all the features of presynaptic facilitation.
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McBride AE, Weiss VH, Kim HK, Hogle JM, Silver PA. Analysis of the yeast arginine methyltransferase Hmt1p/Rmt1p and its in vivo function. Cofactor binding and substrate interactions. J Biol Chem 2000; 275:3128-36. [PMID: 10652296 DOI: 10.1074/jbc.275.5.3128] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Many eukaryotic RNA-binding proteins are modified by methylation of arginine residues. The yeast Saccharomyces cerevisiae contains one major arginine methyltransferase, Hmt1p/Rmt1p, which is not essential for normal cell growth. However, cells missing HMT1 and also bearing mutations in the mRNA-binding proteins Npl3p or Cbp80p can no longer survive, providing genetic backgrounds in which to study Hmt1p function. We now demonstrate that the catalytically active form of Hmt1p is required for its activity in vivo. Amino acid changes in the putative Hmt1p S-adenosyl-L-methionine-binding site were generated and shown to be unable to catalyze methylation of Npl3p in vitro and in vivo or to restore growth to strains that require HMT1. In addition these mutations affect nucleocytoplasmic transport of Npl3p. A cold-sensitive mutant of Hmt1p was generated and showed reduced methylation of Npl3p, but not of other substrates, at 14 degrees C. These results define new aspects of Hmt1 and reveal the importance of its activity in vivo.
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Kim MH, Kim HK, Lee JK, Park SY, Oh TK. Thermostable lipase of Bacillus Stearothermophilus: high-level production, purification, and calcium-dependent thermostability. Biosci Biotechnol Biochem 2000; 64:280-6. [PMID: 10737182 DOI: 10.1271/bbb.64.280] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
An efficient expression system was developed for the production of the thermostable lipase from Bacillus stearothermophilus L1 in an Escherichia coli system. A structural gene corresponding to mature lipase was subcloned in the pET-22b(+) expression vector and its expression was induced by IPTG at 30 degrees C in E. coli cells. The lipase activity in a cell-free extract was as high as 448,000 units/g protein, which corresponds to as much as 26% of the total cellular protein and is 77 times higher than that of E. coli RR1/pLIP1. Based on its pI (7.4) and pH stability data reported previously, the L1 lipase was efficiently purified to homogeneity with CM (at pH 6.0) and DEAE (at pH 8.8) column chromatographies with a recovery yield of 62%. The specific activity of the purified enzyme was 1700 units/mg protein when olive oil emulsion was used as a substrate. Its optimum temperature for the hydrolysis of olive oil was 68 degrees C and it was stable up to 55 degrees C for 30 min-incubation. The thermostability increased by about 8-10 degrees in the presence of calcium ions. This calcium-dependent thermostability was confirmed by the tryptophan fluorescence emission kinetics showing that the enzyme starts to unfold at 66 degrees C in the presence of calcium ions but at 58 degrees C in the absence of calcium ions, implying that the calcium ions bind to the thermostable enzyme and stabilize the protein tertiary structure even at such high temperatures.
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Wong BJ, Milner TE, Kim HK, Chao K, Sun CH, Sobol EN, Nelson JS. Proteoglycan synthesis in porcine nasal cartilage grafts following Nd:YAG (lambda = 1.32 microns) laser-mediated reshaping. Photochem Photobiol 2000; 71:218-24. [PMID: 10687397 DOI: 10.1562/0031-8655(2000)071<0218:psipnc>2.0.co;2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Mechanically deformed morphologic cartilage grafts undergo temperature-dependent stress relaxation during sustained laser irradiation resulting in stable shape changes. In this study, porcine nasal septal cartilage specimens were evaluated for viability by measuring the incorporation of Na2(35)SO4 into proteoglycan (PTG) macromolecules in whole tissue culture following laser-mediated reshaping. Synthesis rates of PTG were determined by scintillation counting lyophilized specimens and normalizing these values by total protein content. Positive controls were established by inducing chondrocyte apoptosis using prolonged exposure to nitric oxide (NO). In chondrocytes, apoptosis induced using NO resulted in significantly lower PTG synthesis rates compared to untreated native specimens. Cartilage specimens were irradiated with light emitted from a Nd:YAG laser (25 W/cm2, lambda = 1.32 microns) while recording simultaneously radiometric surface temperature, internal stress and back-scattered light intensity from a probe laser. Each specimen received one, two or three sequential laser exposures. The duration of each exposure was determined from real-time measurements of characteristic changes in back-scattered light intensity that correlate with accelerated stress relaxation. A 5 min time interval between each laser exposures allowed the cartilage specimen to return to thermal equilibrium. Average PTG synthesis rates decreased with successive laser exposures, though these were always higher than baseline rates established for NO-treated tissues, suggesting that laser-mediated cartilage reshaping acutely does not eliminate the entire population of viable chondrocytes. The reduction in PTG synthesis is correlated with the time-temperature-dependent heating profile created during laser irradiation, supporting our hypothesis that careful monitoring of laser dosimetry is required to ensure chondrocyte viability.
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Hong BK, Kwon HM, Lee BK, Kim D, Kim IJ, Kang SM, Jang Y, Cho SH, Kim HK, Jang BC, Cho SY, Kim HS, Kim MS, Kwon HC, Lee N. Coexpression of cyclooxygenase-2 and matrix metalloproteinases in human aortic atherosclerotic lesions. Yonsei Med J 2000; 41:82-8. [PMID: 10731924 DOI: 10.3349/ymj.2000.41.1.82] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Inflammation appears to have a major role in the development of atherosclerosis. Cyclooxygenase-2 (COX-2) is involved in the inflammatory response via the generation of prostanoids that, in turn, are involved in the production of matrix metalloproteinases (MMPs). This study aimed to investigate atherosclerosis in human aortas for in situ tissue distribution of COX-2, MMPs including MMP-9 and membrane type 1 MMP (MT1-MMP), and tissue inhibitor of metalloproteinase-2 (TIMP-2). Immunohistochemical studies were performed on atherosclerotic lesions of aortas from patients with aortic aneurysms (n = 4) and dissections (n = 3) by using antibodies to COX-2, MMP-9, MT1-MMP, and TIMP-2. Control tissues were obtained from traumatically dissected aortas (n = 2). All specimens from diseased aortas had atherosclerotic lesions ranging from fatty streak to atheromatous plaques. In control, there was no expression of COX-2, MMP-9, and MT1-MMP in all aortic layers. Immunoreactivity for COX-2 was predominantly noted in macrophages and smooth muscle cells (SMCs) of the intima including atherosclerotic plaque itself and the medial layer of the plaque base, as well as in SMCs and endothelial lining of the vasa vasorum in the adventitia. Immunoreactivity for MMP-9 and MT1-MMP was found in the same distribution as that of COX-2. Additionally, the expression of TIMP-2 increased in relation to MMP-9 expression. This study demonstrates that COX-2 is coexpressed with MMP-9 and MT1-MMP, not only by macrophages and SMCs in atherosclerotic lesions, but also in endothelial lining of the vasa vasorum of human aortas. Thus, vascular inflammatory reactions may influence extracellular matrix remodeling by coactivation of MMPs in the development of atherosclerosis and, in turn, the progression of disease.
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297
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Lee DY, Yoon YH, Shin HK, Kim HK, Hong YJ. Needle thoracic sympathectomy for essential hyperhidrosis: intermediate-term follow-up. Ann Thorac Surg 2000; 69:251-3. [PMID: 10654524 DOI: 10.1016/s0003-4975(99)01191-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
BACKGROUND Essential hyperhidrosis is a condition with excessive sweating localized to certain part of the body. A definitive cure can be obtained by upper thoracic sympathectomy. METHOD Between June and October 1997, 117 patients with essential hyperhidrosis underwent needle thoracoscopic sympathectomy. Of the 94 patients, 42 were men and 52 women. Their ages ranged from 14 to 63 years, with a mean age of 23 years. RESULTS There were no mortality or life-threatening complications. Symptomatic improvement was found in 95.7%. Compensatory hyperhidrosis was found in 71.2% of the patients, but in these compensatory hyperhidrosis were mostly tolerable. CONCLUSIONS This therapeutic procedure is minimally invasive and very effective. Further development of the new device and surgical technique are expected to follow.
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298
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Han SY, Kwon YJ, Jo SK, Shin JH, Cha DR, Cho WY, Pyo HJ, Kim HK. ACE gene polymorphism and renal responsiveness to ACE inhibitors in IgA nephropathy patients. Korean J Intern Med 2000; 15:13-8. [PMID: 10714086 PMCID: PMC4531733 DOI: 10.3904/kjim.2000.15.1.13] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
We examined the renal responsiveness to ACE inhibitor in IgA nephropathy (IgAN) patients according to the grouping of ACE gene polymorphism. Sixty one patients diagnosed as IgAN by renal biopsy and prescribed with ACE inhibitors were enrolled. Genomic DNA was extracted from whole blood and PCR was performed. The I/D polymorphism was determined by the presence of the 287 bp fragment in intron 16 of chromosome 17. During the follow-up period (mean; 44.6 months, median: 44.5 months, 5 to 113 months), the blood pressure of 61 patients was controlled below 130/80 mmHg. The renal responsiveness was determined by the degree of changes of proteinuria at 12 months after initiation of ACE inhibitors and by the slope of reciprocal variation of the serum creatinine against follow-up duration ¿(1/Cr2-1/Cr1)/durations¿. The distribution of the II, ID and DD genotype among 61 patients was 21, 16 and 24 patients, respectively. There were no differences among three genotypes in age, sex, the number of patients with initial blood pressure over 140/90 mmHg, initial serum creatinine level, the number of patients with initial azotemia (> 1.4 mg/dL) and with initial 24-hr proteinuria amount over 2.0 g. Significant anti-proteinuric effect of ACE inhibitor was found in IgAN (p = 0.001), but no significant difference was found among genotypes. Significant difference (p = 0.011) was noticed between II type and DD type in the slope of reciprocal variation of the serum creatinine against follow-up duration. In conclusion, efficacy of ACE inhibitors on renal function preservation in IgAN was more pronounced in DD genotype than II genotype.
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299
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Lee YH, Choi SJ, Ji JD, Shim JJ, Kang KH, Cho HD, Kim HK, Song GG. Dermatomyositis without elevation of creatine kinase presented as bronchiolitis obliterans organizing pneumonia. Korean J Intern Med 2000; 15:85-8. [PMID: 10714098 PMCID: PMC4531735 DOI: 10.3904/kjim.2000.15.1.85] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
A case of dermatomyositis presented as bronchiolitis obliterans organizing pneumonia has been rarely reported. We describe a 46-year-old female patient with dermatomyositis without elevation of creatine kinase presented as bronchiolitis obliterans organizing pneumonia. She was treated with prednisolone and azathioprine. Over a 2-year follow-up she has had no elevation of creatine kinase. The patient remains asymptomatic and has no medication for dermatomyositis and bronchiolitis obliterans organizing pneumonia two years after initial treatment. It has been suggested that the prognosis of dermatomyositis without creatine kinase elevation may be poor. Because the prognosis of bronchiolitis obliterans organizing pneumonia is generally believed to be good, we tentatively suggest that the normal value of creatine kinase in dermatomyositis does not always seem to herald a poor prognosis, an associated malignancy or severe interstitial lung disease.
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300
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Kim HK, Alman B, Cole WG. A shortened course of parenteral antibiotic therapy in the management of acute septic arthritis of the hip. J Pediatr Orthop 2000; 20:44-7. [PMID: 10641687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We reviewed 20 consecutive patients with a culture-proven acute septic arthritis of the hip who were treated with a shortened course of parenteral antibiotic therapy after a surgical drainage. Patients were switched over to an oral antibiotic when they showed clinical improvement. Sixteen of the 20 patients had parenteral antibiotic therapy of <10 days, whereas nine of these patients received <7 days of parenteral therapy (mean, 8.2 days). No recurrence of infection, readmission, or osteomyelitis was observed after the discharge. At the follow-up interview (mean, 32 months), 18 patients were completely asymptomatic, and two patients had occasional hip pain with activity but no physical limitations. All 20 patients had normal hip range of motion and gait. Their latest radiographs (mean, 26 months) revealed 11 patients with normal findings, six patients with mild coxa magna, and three patients with a smaller ossific nucleus compared with the unaffected side. We conclude that a community-acquired, acute gram-positive septic arthritis of the hip can be managed safely with a surgical drainage and a shortened course of parenteral antibiotic therapy, which can be switched over to an oral therapy based on the patient's response to the therapy.
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