401
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Lee YH, Sinko PJ. Preface. Adv Drug Deliv Rev 1999; 39:1-3. [PMID: 10837764 DOI: 10.1016/s0169-409x(99)00016-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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402
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Lee YH, Chen CY. Lumbar vertebral angles and back muscle loading with belts. INDUSTRIAL HEALTH 1999; 37:390-397. [PMID: 10547954 DOI: 10.2486/indhealth.37.390] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The study examined belt effects on the change of lumbosacral angle (LSA) and back muscle activity in postures of standing, erect sitting, and slump sitting. We thought that the resulting changes of LSA and back muscle activity when wearing belts with different mechanical characteristics should be different. Eighteen healthy male subjects participated in this study. Though we failed to identify a significant belt effect on the back muscle EMG, the radiographic data revealed an interactive effect of postures and belts on the change of LSA. In standing, the belts increased LSA by increasing almost every lumbar vertebral angle. In erect sitting, the lumbar belt had no effect but the pelvic belt decreased LSA through a decrease in the L1/L3. While sitting slump with a trunk flexion of 15 degrees, both belts increased LSA by restricting the movement of the pelvis. Belt effect on LSA was accompanied with a change of pelvic angle. Significant correlation was found between the backward rotation angles of the pelvis and the angles of LSA (r = 0.692, p < 0.0001), also between the decrease of pelvic angles and the increase of back muscle EMG (r = -0.4, p = 0.017). A change in LSA and pelvic angle after wearing a belt along with posture change seems lead to an increase of the myoelectric activities on the back.
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403
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Lee YH, Ku YS. Effects of cyclosporin on the pharmacokinetics of propranolol after intravenous and oral administration to control rats and to rats with uranyl nitrate-induced acute renal failure. J Pharm Pharmacol 1999; 51:1149-54. [PMID: 10579686 DOI: 10.1211/0022357991776840] [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: 10/31/2022]
Abstract
The effects of cyclosporin on the pharmacokinetics of propranolol have been investigated after intravenous and oral administration of the drugs to control rats and to rats with uranyl nitrate-induced acute renal failure. The effects of intravenous cyclosporin, 30 mg kg(-1), on the pharmacokinetics of intravenous propranolol, 3 mg kg(-1), were significant both in control rats and in rats with uranyl nitrate-induced acute renal failure; after intravenous administration of cyclosporin plasma concentrations of propranolol were significantly lower, the area under the plasma concentration-time curve (AUC) for propranolol from time zero to time infinity was significantly smaller, and the time-averaged total body clearance of propranolol was significantly faster. The effects of oral cyclosporin, 100 mg kg(-1), on the pharmacokinetics of oral propranolol, 10 mg kg(-1), were also significant, both in control rats and in rats with uranyl nitrate-induced acute renal failure; after administration of oral cyclosporin plasma concentrations of propranolol were significantly higher and the AUC of propranolol was significantly greater. These data suggest that cyclosporin increases the elimination of propranolol, and that the first-pass effects of propranolol are reduced, or gastrointestinal absorption of propranolol is increased, or both, by cyclosporin.
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404
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Kim YS, Jin SH, Lee YH, Kim SI, Park JD. Ginsenoside Rh2 induces apoptosis independently of Bcl-2, Bcl-xL, or Bax in C6Bu-1 cells. Arch Pharm Res 1999; 22:448-53. [PMID: 10549570 DOI: 10.1007/bf02979151] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In ginsenoside Rh2-treated rat glioma C6Bu-1 cells, apoptotic morphological changes, such as cell shrinkage, chromatin condensation and pyknosis were confirmed by means of electron microscopy. To evaluate whether induction of apoptosis by ginsenoside Rh2 is mediated by the members of Bcl-2 family, we first established C6Bu-1 cells overexpressing Bcl-2. It was demonstrated that the expression of Bcl-2, Bcl-xL and Bax was not altered in ginsenoside Rh2-treated C6Bu-1 cells. Bcl-2 overexpressing C6Bu-1 cells failed to prevent from ginsenoside Rh2-induced cell death. These results suggest the existence of other apoptotic pathway that requires induction of apoptosis by ginsenoside Rh2 rather than the pathway through Bcl-2, Bcl-xL or Bax in C6Bu-1 cells.
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405
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Lee I, Lee YH. The effect of various therapeutic solutions including colloidal chromic 32P via an intratumoral injection on the tumor physiological parameters of AsPC-1 human pancreatic tumor xenografts in nude mice. Clin Cancer Res 1999; 5:3139s-3142s. [PMID: 10541354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
To overcome the physiological barrier in solid tumors (i.e., tumor hypertension), a large volume of material is required via an intratumoral injection. Alternatively, a method of reduction in tumor hypertension is also feasible. In this study, we focused on the physiological response after an intratumoral infusion of various therapeutic agents. Tumor interstitial fluid pressure (TIFP) was intermittently monitored for up to 7 days after treatment using AsPC-1 human pancreatic tumors in nude mice. Macroaggregated albumin (MAA), colloidal chromic 32P (32P-CP), albumin, dexamethasone, 5-fluoro-2'deoxyuridine, dextrose, saline, and trypan blue increased TIFP within approximately 5 min, and TIFP returned to the original level within 1 h, except in the case of MAA and 32P-CP. We also found that the maximal uptake for AsPC-1 tumors in both the exponential and plateau growth phases occurred at approximately 100 min postincubation; the maximum value in the exponential growth phase was approximately 2 times less than that of plateau growth phase (P < 0.01). Therefore, this study supports intralesional 32P-CP brachytherapy for nonresectional pancreatic cancer patients. This may offer a promising treatment modality for delivering high doses of tumor-selective radiation, mainly due to two physiological mechanisms: (a) the high adherence of 32P-CP to the infused regions; and (b) reduction in either tumor blood flow or TIFP by this therapeutic colloid.
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406
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Chae JH, Lee YH, Kim CG. Transcription factor CP2 is crucial in hemoglobin synthesis during erythroid terminal differentiation in vitro. Biochem Biophys Res Commun 1999; 263:580-3. [PMID: 10491335 DOI: 10.1006/bbrc.1999.1408] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The transcription factor CP2 was initially identified to bind to the promoter region of the murine alpha-globin gene and known to stimulate the expression of alpha-globin by increasing CP2 transcripts 3- to 5-fold during induced differentiation of mouse erythroleukemic (MEL) cells in vitro. Here, we report that this increment of CP2 expression is crucial in erythroid-specific globin gene expression and hemoglobin synthesis. When antisense CP2 was overexpressed in MEL cells, production of endogenous CP2 protein was reduced 70-80%, and significant loss of its promoter binding activity was observed. During HMBA-induced terminal differentiation of antisense CP2 expressing MEL cells, the transcription of endogenous alpha-globin gene was suppressed as expected. Moreover, both beta-globin gene expression and hemoglobin synthesis were also severely impaired, without affecting the expression of key heme enzyme genes or HMBA-induced proliferation and viability.
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407
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Lee YH, Kim S, Kim J, Young Kim K, Kim MJ, Ryu SH, Suh P. Overexpression of phospholipase C-gamma1 suppresses UVC-induced apoptosis through inhibition of c-fos accumulation and c-Jun N-terminal kinase activation in PC12 cells. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1440:235-43. [PMID: 10521707 DOI: 10.1016/s1388-1981(99)00128-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Ultraviolet-C (UVC) irradiation induces DNA damage and UVC-irradiated cells undergo cell growth arrest to repair the damaged DNA or the induction of apoptosis to prevent the risk of neoplastic transformation. Phospholipase C-gamma1 (PLC-gamma1) is a mediator of growth factor induced-signal cascade, catalyzing the hydrolysis of phosphatidyl 4,5-bisphosphate to generate second messengers, diacylglycerol and inositol 1,4,5-trisphosphate (IP(3)). PLC-gamma1 is activated by phosphorylation of tyrosine residues upon occupation of cell surface receptors by growth factors and plays an important role in controlling cellular proliferation and differentiation. In this study, we found that PLC-gamma1 was tyrosine phosphorylated within 2.5 min after UVC irradiation. To investigate the role of UVC-induced tyrosine phosphorylation of PLC-gamma1, we compared the effect of UVC between PLC-gamma1 overexpressing cells and empty vector transfected cells. Overexpression of PLC-gamma1 inhibited UVC-induced sub-diploid peak and DNA fragmentation. Northern blot analysis revealed that UVC-induced c-fos mRNA accumulation was inhibited in PLC-gamma1 overexpressing cells, while c-jun expression was not affected. In addition, UVC-induced activation of c-Jun N-terminal kinase (JNK) was significantly suppressed in PLC-gamma1 overexpressing cells. These results suggest that PLC-gamma1 may associate with the protective function against the UVC-induced cell death progression via the inhibition of accumulation of c-fos mRNA and the inhibition of JNK kinase activity.
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408
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Kim YH, Park TJ, Lee YH, Baek KJ, Suh PG, Ryu SH, Kim KT. Phospholipase C-delta1 is activated by capacitative calcium entry that follows phospholipase C-beta activation upon bradykinin stimulation. J Biol Chem 1999; 274:26127-34. [PMID: 10473563 DOI: 10.1074/jbc.274.37.26127] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To characterize the regulatory mechanism of phospholipase C-delta1 (PLC-delta1) in the bradykinin (BK) receptor-mediated signaling pathway, we used a clone of PC12 cells, which stably overexpress PLC-delta1 (PC12-D1). Stimulation with BK induced a significantly higher Ca(2+) elevation and inositol 1,4,5-trisphosphate (IP(3)) production with a much lower half-maximal effective concentration (EC(50)) of BK in PC12-D1 cells than in wild type (PC12-W) or vector-transfected (PC12-V) cells. However, BK-induced intracellular Ca(2+) release and IP(3) generation was similar between PC12-V and PC12-D1 cells in the absence of extracellular Ca(2+), suggesting that the availability of extracellular Ca(2+) is essential to the activation of PLC-delta1. When PC12-D1 cells were treated with agents that induce Ca(2+) influx, more IP(3) was produced, suggesting that the Ca(2+) entry induces IP(3) production in PC12-D1 cells. Furthermore, the additional IP(3) production after BK-induced capacitative calcium entry was detected in PC12-D1 cells, suggesting that PLC-delta1 is mainly activated by capacitative calcium entry. When cells were stimulated with BK in the presence of extracellular Ca(2+), [(3)H]norepinephrine secretion was much greater from PC12-D1 cells than from PC12-V cells. Our results suggest that PLC-delta1 is activated by capacitative calcium entry following the activation of PLC-beta, additively inducing IP(3) production and Ca(2+) rise in BK-stimulated PC12 cells.
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409
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Lee SH, Shin M, Lee KJ, Lee SY, Lee JT, Lee YH. Frequency of sister chromatid exchange in chrysotile-exposed workers. Toxicol Lett 1999; 108:315-9. [PMID: 10511277 DOI: 10.1016/s0378-4274(99)00104-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Chrysotile, which is an industrial carcinogen, has been shown to induce a dose-dependent increase in the frequency of sister chromatid exchange (SCE) in vitro. Authors designed this study to examine the increase of SCEs frequency in the workers occupationally exposed to chrysotile. Heparinized whole blood samples from 45 chrysotile-exposed and 45 control volunteers were cultured for 72 h. The significant difference of SCE frequency was found between chrysotile-exposed workers and control group. The highest SCEs frequency was found in chrysotile-exposed smokers, and the lowest in control non-smokers. The effect of chrysotile exposure on SCEs was marginally significant after controlling the effects of age and smoking by multiple regression analysis.
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410
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Karaki S, Mochida J, Lee YH, Nishimura K, Tsutsumi Y. Low-grade malignant perineurioma of the paravertebral column, transforming into a high-grade malignancy. Pathol Int 1999; 49:820-5. [PMID: 10504555 DOI: 10.1046/j.1440-1827.1999.00948.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A demarcated 6 x 5 cm right paravertebral tumor at the level of T6 in a 39-year-old male was removed surgically. Histologically, the tumor consisted of monomorphous benign-looking, low-cellular spindle cells embedded in desmoplastic stroma. Ten years later, the tumor recurred locally with metastasis to systemic organs, including the occipital skin. Malignancy was histologically evident by the increased cellularity, cellular atypia and mitotic activity. The patient died of respiratory failure at the age of 49. Retrospectively reviewed, the primary lesion was low-grade fibrosarcoma-like spindle cell tumor, with secondary transformation into a highly malignant form. The differential diagnoses included sclerosing epithelioid fibrosarcoma, low-grade fibromyxoid sarcoma and malignant peripheral nerve sheath tumor. Immunohistochemically, the spindle cells in the primary and recurrent tumors consistently expressed epithelial membrane antigen, vimentin, type 4 collagen and laminin. The tumor cells in the present case showed a differentiation toward perineurial cells, which are normally positive for these immunohistochemical markers. Hence, the appropriate diagnostic term should be 'malignant perineurioma', a subtype of malignant peripheral nerve sheath tumor.
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411
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Ito A, Lee YH, Chai HB, Gupta MP, Farnsworth NR, Cordell GA, Pezzuto JM, Kinghorn AD. 1',2',3',4'-tetradehydrotubulosine, a cytotoxic alkaloid from Pogonopus speciosus. JOURNAL OF NATURAL PRODUCTS 1999; 62:1346-1348. [PMID: 10514334 DOI: 10.1021/np990255u] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Bioassay-guided phytochemical investigation of the stems of Pogonopus speciosus, using human oral epidermoid carcinoma (KB) cells as a monitor, led to the isolation of a novel alkaloid, 1',2', 3',4'-tetradehydrotubulosine (1), along with tubulosine (2) and psychotrine (3) as bioactive constituents. The structure of the novel compound was elucidated through 1D- and 2D-NMR spectroscopic methods. Alkaloids 1 and 3 showed weak cytotoxic activity against a panel of human cancer cell lines, with the potency of these compounds being markedly less than that of tubulosine (2).
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412
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Lee YH, Huang GM, Cameron RA, Graham G, Davidson EH, Hood L, Britten RJ. EST analysis of gene expression in early cleavage-stage sea urchin embryos. Development 1999; 126:3857-67. [PMID: 10433914 DOI: 10.1242/dev.126.17.3857] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A set of 956 expressed sequence tags derived from 7-hour (mid-cleavage) sea urchin embryos was analyzed to assess biosynthetic functions and to illuminate the structure of the message population at this stage. About a quarter of the expressed sequence tags represented repetitive sequence transcripts typical of early embryos, or ribosomal and mitochondrial RNAs, while a majority of the remainder contained significant open reading frames. A total of 232 sequences, including 153 different proteins, produced significant matches when compared against GenBank. The majority of these identified sequences represented ‘housekeeping’ proteins, i.e., cytoskeletal proteins, metabolic enzymes, transporters and proteins involved in cell division. The most interesting finds were components of signaling systems and transcription factors not previously reported in early sea urchin embryos, including components of Notch and TGF signal transduction pathways. As expected from earlier kinetic analyses of the embryo mRNA populations, no very prevalent protein-coding species were encountered; the most highly represented such sequences were cDNAs encoding cyclins A and B. The frequency of occurrence of all sequences within the database was used to construct a sequence prevalence distribution. The result, confirming earlier mRNA population analyses, indicated that the poly(A) RNA of the early embryo consists mainly of a very complex set of low-copy-number transcripts.
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413
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Lee KM, Kim DH, Lee YH, Choi BS, Chung JH, Lee BL. Antifungal activities of recombinant antifungal protein by conjugation with polyethylene glycol. Mol Cells 1999; 9:410-6. [PMID: 10515605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
Tenecin 3, an antifungal protein isolated from coleopteran insect Tenebrio molitor larvae, inhibited growth of the fungus Candida albicans. We have previously reported that tenecin 3 has a propensity of random structure with very loose turn-like elements by circular dichroism (CD) analysis and 2D nuclear overhauser effect spectroscopy [Lee et al. (1999)]. However, the antifungal mechanism of tenecin-3 has not yet been studied due to its very low availability from natural sources. As an initial step to study the antifungal mechanism of tenecin 3, recombinant tenecin 3 (RT-3) obtained from an expression system in Escherichia coli showed antifungal activity against C. albicans as did natural tenecin 3. To elucidate the antifungal mechanism of RT-3 and to explore the possibility of preparing polyethylene glycol (PEG) conjugated derivative, we synthesized PEG conjugated RT-3 (RT-3-PEG) and examined its antifungal activity against C. albicans in vitro. RT-3-PEG showed greater antifungal activity against C. albicans than RT-3 alone at the same dose. When C. albicans was treated with RT-3-PEG in vitro, K+ in the C. albicans cell was leaked out rapidly compared to the C. albicans treated with RT-3 alone. When the morphological change of RT-3-PEG treated C. albicans was examined by scanning electron microscopy, string-like substances, which may have been derived from the fungus, were stacked around the cell whose wall was damaged. Also, no appreciable hemolysis of mouse erythrocytes was detected under conditions in which 1% melittin caused 100% hemolysis. These results suggested that the RT-3-PEG derivative probably does not interact with mammalian cell appreciably, although it has antifungal activity.
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414
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Taggart MJ, Lee YH, Morgan KG. Cellular redistribution of PKCalpha, rhoA, and ROKalpha following smooth muscle agonist stimulation. Exp Cell Res 1999; 251:92-101. [PMID: 10438574 DOI: 10.1006/excr.1999.4565] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Efficient receptor-coupled activation of smooth muscle requires discrete coordination of many signal transducing events from the plasma membrane to the myofilaments. Recruitment of key factors to the plasma membrane is thought to be crucial for transduction of extracellular signals leading to contractility. We investigated, therefore, for the first time in intact differentiated smooth muscle cells, the distributions of three molecules important for receptor-coupled excitation: protein kinase Calpha (PKCalpha), rhoA, and rho kinase (ROK). We also directly confirmed, by single cell force measurements, carbachol-induced [Ca(2+)](i) sensitization of contractility. Laser scanning confocal immunofluorescent microscopy of central smooth muscle cell sections determined that, at rest, PKCalpha, rhoA, and ROKalpha were distributed predominantly throughout the cytosol. Muscarinic stimulation resulted in significant redistribution of each protein to the cell membrane. By digital image analysis, peripheral:cytosolic distributions of PKCalpha, rhoA, and ROKalpha were calculated as, respectively, 1.05 +/- 0.03 (8), 1.09 +/- 0.03 (5), and 1.26 +/- 0.04 (12) at rest, increasing significantly following stimulation to 2.09 +/- 0.22 (6), 2.02 +/- 0.12 (8), and 1.93 +/- 0.05 (10). It is proposed that this receptor-coupled recruitment to the cell periphery of the downstream signaling molecules PKCalpha, rhoA, and ROKalpha contributes to the efficacy of agonist-induced contractile activation of smooth muscle.
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415
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Miyata M, Kudo G, Lee YH, Yang TJ, Gelboin HV, Fernandez-Salguero P, Kimura S, Gonzalez FJ. Targeted disruption of the microsomal epoxide hydrolase gene. Microsomal epoxide hydrolase is required for the carcinogenic activity of 7,12-dimethylbenz[a]anthracene. J Biol Chem 1999; 274:23963-8. [PMID: 10446164 DOI: 10.1074/jbc.274.34.23963] [Citation(s) in RCA: 151] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Microsomal epoxide hydrolase (mEH) is a conserved enzyme that is known to hydrolyze many drugs and carcinogens, and a few endogenous steroids and bile acids. mEH-null mice were produced and found to be fertile and have no phenotypic abnormalities thus indicating that mEH is not critical for reproduction and physiological homeostasis. mEH has also been implicated in participating in the metabolic activation of polycyclic aromatic hydrocarbon carcinogens. Embryonic fibroblast derived from the mEH-null mice were unable to produce the proximate carcinogenic metabolite of 7,12-dimethylbenz[a]anthracene (DMBA), a widely studied experimental prototype for the polycylic aromatic hydrocarbon class of chemical carcinogens. They were also resistant to DMBA-mediated toxicity. Using the two-stage initiation-promotion skin cancer bioassay, the mEH-null mice were found to be highly resistant to DMBA-induced carcinogenesis. In a complete carcinogenesis bioassay, the mEH mice were totally resistant to tumorigenesis. These data establish in an intact animal model that mEH is a key genetic determinant in DMBA carcinogenesis through its role in production of the ultimate carcinogenic metabolite of DMBA, the 3,4-diol-1,2-epoxide.
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416
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Tsuda T, Nakamura T, Yamamoto Y, Teramachi M, Kiyotani T, Lee YH, Shimizu Y. Prevention of postoperative air leakage from lungs using a purified human collagen membrane-polyglycolic acid sheet. Ann Thorac Surg 1999; 68:339-42. [PMID: 10475392 DOI: 10.1016/s0003-4975(99)00567-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Human amnion has useful biomedical applications because it contains a large amount of human collagen fibers. We prepared purified human collagen membrane (HCM) from human amnion and used it to develop a new sheet by combining it with synthetic bioabsorbable polyglycolic acid (PGA) mesh. We evaluated its efficacy in preventing air leakage from the lungs of dogs. METHODS In 20 dogs, HCM-PGA sheet (n = 5), sheets using fibrin glue with a separate application method (n = 5), a mixed application method (n = 5), and fibrin glue alone (n = 5), were used as dressing materials after partial lung resection. RESULTS The HCM-PGA sheet using fibrin glue with a separate application method was shown to be significantly more effective by an air leakage pressure test than the other three methods. These results indicate that the HCM-PGA sheet is useful for preventing air leakage from the lung. CONCLUSIONS The HCM-PGA sheet is more effective than conventional fibrin glue for controlling postoperative air leakage.
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417
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Lee YH, Perry BA, Labruno S, Lee HS, Stern W, Falzone LM, Sinko PJ. Impact of regional intestinal pH modulation on absorption of peptide drugs: oral absorption studies of salmon calcitonin in beagle dogs. Pharm Res 1999; 16:1233-9. [PMID: 10468025 DOI: 10.1023/a:1014849630520] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE To investigate the relationship between the modulation of intestinal pH and the oral absorption properties of a model peptide drug, salmon calcitonin (sCT), in conscious beagle dogs. METHODS Studies were performed to characterize the disintegration of the formulation, intestinal pH changes, and the appearance of the peptide in the blood. Enteric-coated formulations containing sCT and various amounts of citric acid (CA) were tethered to a Heidelberg capsule (HC) and given orally to normal beagle dogs. Blood samples were collected and analyzed by radioimmunoassay (RIA). Intestinal pH was continuously monitored using the Heidelberg pH capsule (HC) system. The integrity of the HC-delivery system tether was verified by fluoroscopy. RESULTS The intra-individual variation in gastric emptying (GE) of the delivery system was large. There were also large inter-individual differences in the disintegration and absorption properties of the various formulations. However, the peak plasma concentrations of sCT were always observed when the intestinal pH declined. The average baseline intestinal pH was 6.1 +/- 0.2 (mean +/- SEM, n = 12). The intestinal pH reduction was 2.6 +/- 0.4 (mean +/- SEM, n = 12, ranged from 0.5 to 4.0 units from baseline). There was a good correlation between the time to reach the trough intestinal pH (t(pH,min)) and time to reach the peak plasma concentration (tconc,max)) of sCT (t(conc,max) = 0.95 x t(pH,min) + 14.1, n = 11, r2 = 0.91). Plasma Cmax and area under the curve (AUC) increased with increasing amounts of CA in the formulations. CONCLUSIONS The results of these studies demonstrate that the oral absorption properties of a model peptide drug, sCT, can be modulated by changing intestinal pH. sCT is a substrate for the pancreatic serine protease trypsin which has maximal activity at pH 5 to 6. Reducing intestinal pH presumably stabilizes sCT in the GI tract enabling greater absorption of the intact peptide.
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418
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Wu TT, Lu CM, Lee YH, Hwang JK. Management of stage pTxN+ adenocarcinoma of the prostate: influence of radical prostatectomy on progression-free interval. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 1999; 62:514-20. [PMID: 10462828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
BACKGROUND Whether stage pN+ prostate cancer patients will benefit from radical prostatectomy remains a controversial issue. We assess the impact of radical prostatectomy on a progression-free interval for patients with stage pN+ prostate cancer. METHODS From October 1990 to June 1997, 25 patients were diagnosed with stage pTxN+ adenocarcinoma of the prostate in our institute. Ten of these patients were treated with radical retropubic prostatectomy (RRP) due to false-negative frozen sections at staging pelvic lymphadenectomy. In 15 patients, radical surgery was discontinued because of grossly enlarged lymph nodes and/or positive frozen section results during staging pelvic lymph node dissection (PLND). All patients received immediate androgen ablation therapy with or without radiotherapy. Serum prostate-specific antigen (PSA) was regularly monitored in all patients. RESULTS During a median follow-up period of 33 months (range, 15-89 months), eight patients (53%) in the PLND group and two (20%) in the RRP group experienced disease progression as defined by significant elevation of serum PSA concentrations. The median progression-free intervals were 46 and 51 months, respectively. Both univariate and multivariate analyses failed to show statistically significant differences in the progression-free survival between the RRP and PLND groups. CONCLUSIONS Based on our limited experience, surgical removal of the primary tumor may have only a marginal effect in terms of the progression-free interval for prostatic cancer patients with metastasized pelvic lymph nodes (p = 0.124, log-rank test). The follow-up period was not long enough to evaluate the difference in cancer-specific survival.
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419
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Lee YH, Tokunaga T, Oshika Y, Suto R, Yanagisawa K, Tomisawa M, Fukuda H, Nakano H, Abe S, Tateishi A, Kijima H, Yamazaki H, Tamaoki N, Ueyama Y, Nakamura M. Cell-retained isoforms of vascular endothelial growth factor (VEGF) are correlated with poor prognosis in osteosarcoma. Eur J Cancer 1999; 35:1089-93. [PMID: 10533453 DOI: 10.1016/s0959-8049(99)00073-8] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Vascular endothelial growth factor (VEGF) is a major angiogenic factor. Osteosarcoma is characterised by hypervascularity and metastatic potential. We examined VEGF mRNA expression, VEGF isoform pattern and VEGF receptor (flt-1 and KDR) by RT-PCR analysis in 30 osteosarcomas. All 30 osteosarcomas expressed VEGF mRNA. 17 osteosarcomas (57%) expressed flt-1 mRNA, whilst 20 (67%) expressed KDR mRNA. 6/30 (20%) osteosarcomas were positive for VEGF121 only, 8 (27%) for VEGF121 + VEGF165, and 16 (53%) for VEGF121 + VEGF165 + VEGF189. Patients with osteosarcomas with VEGF165 (n = 24) had significantly poorer prognosis in comparison with those without VEGF165 (P = 0.022, Wilcoxon's test). The osteosarcomas with VEGF165 had significantly increased vascularity assessed on sections immunostained for CD34 (P < 0.001, Mann-Whitney U test). Although VEGF165 is a soluble isoform, it is also retained on the cellular surface. These results suggest that cell-retained VEGF isoforms (VEGF165, VEGF189) might be essential for neovascularisation in osteosarcoma, whilst the soluble VEGF121 isoform is not sufficient to stimulate neovascularisation in this type of neoplasm.
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420
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Abstract
The sequential segmental approach is now universally used in the diagnosis of congenital heart disease. Its utilization during fetal sonography has not been well described. In this review, we show how the fetal heart can be approached in a sequential segmental manner by using six basic sonographic views. The transverse view of the fetal upper abdomen is obtained to determine the arrangement of the abdominal organs, which, in most cases, provides the important clues to the determination of the atrial arrangement. The four-chamber view is obtained to evaluate the atrioventricular junctions. The views of the left and right ventricular outflow tracts are obtained to evaluate the ventriculoarterial junctions. The three-vessel view and the aortic arch view are obtained for the evaluation of the arrangement and size of the great arteries, which provides the additional clues to the diagnosis of the abnormalities involving the ventriculoarterial junctions and the great arteries. The standard protocol to acquire these six basic views is also introduced.
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421
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Yoo SJ, Lee YH, Kim ES, Ryu HM, Kim MY, Yang JH, Chun YK, Hong SR. Tetralogy of Fallot in the fetus: findings at targeted sonography. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 1999; 14:29-37. [PMID: 10461335 DOI: 10.1046/j.1469-0705.1999.14010029.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
OBJECTIVES To evaluate the findings of tetralogy of Fallot in various fetal sonographic views. METHODS We reviewed the fetal sonograms and medical records of 20 fetuses with prenatal diagnosis of tetralogy of Fallot. We analyzed the indications for targeted sonography, the abnormalities seen in various sonographic views, the postnatal echocardiographic and angiographic findings and autopsy findings. RESULTS The most common indication for targeted sonography was an abnormal (n = 12) or inadequate (n = 3) finding on sonographic screening in which the abnormality was most frequently found on the three-vessel view (n = 9). The key pathological features of tetralogy of Fallot were uniformly demonstrated in the ventricular outflow tract, three-vessel and short-axis views. The ductus arteriosus was small in 70% of cases and not identifiable in the remaining fetuses. In three of six fetuses with no identifiable ductus, the ductus was shown to be absent at autopsy. The direction of ductal flow was variable. CONCLUSION The key features of tetralogy of Fallot were always demonstrable in the ventricular outflow tract, three-vessel and short-axis views. The most common reason for referral was the abnormal three-vessel view.
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422
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Park KJ, Kim HJ, Hwang SC, Lee SM, Lee YH, Hahn MH, Kim SK, Lee WY. The imbalance between coagulation and fibrinolysis is related to the severity of the illness and the prognosis in sepsis. Korean J Intern Med 1999; 14:72-7. [PMID: 10461428 PMCID: PMC4531923 DOI: 10.3904/kjim.1999.14.2.72] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [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
OBJECTIVES The coagulation and fibrinolytic system appears to be activated by the septic process independently, leading to the syndrome of disseminated intravascular coagulation (DIC). In this study, we investigated the changes within the hemostatic system related to the severity of the illness and the prognosis in patients with sepsis. METHODS Plasma thrombin-antithrombin III (TAT) and plasmin-alpha 2-antiplasmin (PAP) complexes were measured using ELISA methods in 32 patients with sepsis and 20 controls and were analyzed according to the APACHE III scores and survival of the patients. RESULTS Plasma TAT and PAP in patients with sepsis were significantly higher than controls. Nonsurvivors showed greater levels of TAT (21.7 +/- 22.3 ng/mL) and lower levels of PAP (628.4 +/- 378.1 ng/mL) than survivors (TAT: 11.1 +/- 11.2 ng/mL; PAP: 857.1 +/- 364.1 ng/mL). The imbalance between coagulation and fibrinolysis described as TAT/PAP ratio was closely related with APACHE III scores in patients with sepsis (r = 0.47) and the TAT/PAP ratio in nonsurvivors was significantly higher compared with survivors (34.4 +/- 21.4 vs. 14.4 +/- 13.8). CONCLUSION In sepsis, both coagulation and the fibrinolysis system are activated and the imbalance between coagulation and fibrinolysis predisposes to the hypercoagulation state and is closely related to the severity of the disease and the prognosis.
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423
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Deka RK, Lee YH, Hagman KE, Shevchenko D, Lingwood CA, Hasemann CA, Norgard MV, Radolf JD. Physicochemical evidence that Treponema pallidum TroA is a zinc-containing metalloprotein that lacks porin-like structure. J Bacteriol 1999; 181:4420-3. [PMID: 10400603 PMCID: PMC93947 DOI: 10.1128/jb.181.14.4420-4423.1999] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although TroA (Tromp1) was initially reported to be a Treponema pallidum outer membrane protein with porin-like properties, subsequent studies have suggested that it actually is a periplasmic substrate-binding protein involved in the transport of metals across the treponemal cytoplasmic membrane. Here we conducted additional physicochemical studies to address the divergent viewpoints concerning this protein. Triton X-114 phase partitioning of recombinant TroA constructs with or without a signal sequence corroborated our prior contention that the native protein's amphiphilic behavior is due to its uncleaved leader peptide. Whereas typical porins are trimers with extensive beta-barrel structure, size exclusion chromatography and circular dichroism spectroscopy revealed that TroA was a monomer and predominantly alpha-helical. Neutron activation, atomic absorption spectroscopy, and anomalous X-ray scattering all demonstrated that TroA binds zinc in a 1:1 molar stoichiometric ratio. TroA does not appear to possess structural features consistent with those of bacterial porins.
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424
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Lee YH, Deka RK, Norgard MV, Radolf JD, Hasemann CA. Treponema pallidum TroA is a periplasmic zinc-binding protein with a helical backbone. NATURE STRUCTURAL BIOLOGY 1999; 6:628-33. [PMID: 10404217 DOI: 10.1038/10677] [Citation(s) in RCA: 142] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The crystal structure of recombinant TroA, a zinc-binding protein component of an ATP-binding cassette transport system in Treponema pallidum, was determined at a resolution of 1.8 A. The organization of the protein is largely similar to other periplasmic ligand-binding proteins (PLBP), in that two independent globular domains interact with each other to create a zinc-binding cleft between them. The structure has one bound zinc pentavalently coordinated to residues from both domains. Unlike previous PLBP structures that have an interdomain hinge composed of beta-strands, the N- and C-domains of TroA are linked by a single long backbone helix. This unique backbone helical conformation was possibly adopted to limit the hinge motion associated with ligand exchange.
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425
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Lee HB, Lew DH, Oh SH, Tark KC, Kim SW, Chung YK, Lee YH. Simultaneous reconstruction of the Achilles tendon and soft-tissue defect using only a latissimus dorsi muscle free flap. Plast Reconstr Surg 1999; 104:111-9. [PMID: 10597683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
The combined loss of the Achilles tendon and the overlying soft tissue in the young ambulant patient with expectations of a normal life is a challenging problem. These patients need not only soft tissue but also dynamic and functional reconstruction. Four cases of major defects of the Achilles tendon and overlying soft tissue after trauma are presented. In each case, the tendon and the overlying soft tissues were reconstructed using only a latissimus dorsi muscle free flap and overlying split-thickness skin graft. In conventional methods, evolved in the reconstruction of the Achilles tendon and soft tissue, the size of the defect was a limit. However, this technique can be used to reconstruct an extensive defect, including distal calf muscle to the plantar metatarsal area. In one case, the flap was harvested in a myocutaneous unit, and the skin portion was deepithelialized for the coverage and enough padding on the bony exposure area in reverse position. The purpose of the present study was to reevaluate the potential of denervated muscle flap for a force-bearing conduit as an alternative reconstructive method of the Achilles tendon. The denervated latissimus dorsi muscle in this study eventually experienced the process of atrophy and fibrosis but maintained its original length. Although there remained some atrophic muscle fibers, a fibrosis of the muscle fibers formed a tendon-like fibrous band, and so the action of the posterior calf muscle could be transmitted through the tendon-like fibrotic change of the denervated latissimus dorsi muscle. The advantages of this technique are that (1) it is a single procedure, (2) it is adaptable to a wide range of defect sizes, (3) it allows faster wound healing supported by well-vascularized tissues, (4) it produces satisfactory function of the ankle joint and a padding effect, and (5) it produces good contour of the posterior calf to the sole and an acceptable donor-site morbidity.
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