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Min WK, Chun S, Hwang SH, Park H. No relationship between serum lipoprotein(a) and albumin concentrations in patients with acute phase response. Ann Clin Biochem 1999; 36 ( Pt 5):617-21. [PMID: 10505212 DOI: 10.1177/000456329903600509] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The aim of this study was to investigate the relationship between lipoprotein(a) [Lp(a)] and albumin concentrations in the serum of patients with acute phase response (APR). We have compared the Lp(a) concentrations and apolipoprotein [apo(a)] phenotypes of 40 controls with those of 40 APR patients with normoalbuminaemia and 40 APR patients with hypoalbuminaemia. We have also compared concentrations of haptoglobin (Hp) and alpha 1-antitrypsin (AAT) containing a high sialic acid content, similar to Lp(a). The mean serum Lp(a) concentration (SD) of the 40 controls was 0.190 (0.142) g/L. The mean serum Lp(a) concentration was 0.358 (0.257) g/L (P < 0.001) in 80 APR patients. However, there was no difference in serum Lp(a) concentrations between the APR patients with hypoalbuminaemia [0.353 (0.268) g/L] and the APR patients with normoalbuminaemia [0.362 (0.249) g/L]. No significant difference was found in the distributions of apo(a) phenotypes between the controls, the APR patients with hypoalbuminaemia, and the APR patients with normoalbuminaemia (P = 0.183). In the APR patients, the serum concentrations of AAT and Hp were respectively 2.709 (0.822) g/L and 2.631 (1.340) g/L, whereas those of normal controls were respectively 1.422 (0.219) g/L (P < 0.001) and 0.956 (0.442) g/L (P < 0.001). In conclusion, the Lp(a) is one of the acute phase reactants whose synthesis concurrently increases with other APRs, especially those with a high sialic acid content. The increase of the serum Lp(a) concentrations in the APR patients is not related to serum albumin concentration.
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Hwang SH, Maitani Y, Qi XR, Takayama K, Nagai T. Remote loading of diclofenac, insulin and fluorescein isothiocyanate labeled insulin into liposomes by pH and acetate gradient methods. Int J Pharm 1999; 179:85-95. [PMID: 10053205 DOI: 10.1016/s0378-5173(98)00392-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Remote loading of the model drugs diclofenac, insulin and fluorescein isothiocyanate labeled insulin (FITC-insulin) into liposomes by formation of transmembrane gradients were examined. A trapping efficiency of almost 100% was obtained for liposomal diclofenac, by the calcium acetate gradient method, whereas liposomes prepared by the conventional reverse-phase evaporation vesicle method had 1-8% trapping efficiencies. Soybean-derived sterol was a better stabilizer of the dipalmitoylphosphatidylcholine bilayer membrane than cholesterol, as shown from trapping efficiencies and drug release. The pH gradient method resulted in a 5-50% of FITC-insulin liposomal trapping efficiency, while insulin could not be loaded by this method. Liposomes released calcein in response to insulin, showing insulin interacts with the liposomal membrane in the presence of a transmembrane gradient. The present work has demonstrated a remote loading method for weak acids such as diclofenac into liposomes by the acetate gradient method. From the result of remote loading of FITC-insulin into liposomes by the pH gradient method, this method may be available for the preparation of liposomal peptides.
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153
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Cho SW, Cho EH, Hwang SH, Choi SY. Reactive cysteine residue of bovine brain glutamate dehydrogenase isoproteins. Mol Cells 1999; 9:91-8. [PMID: 10102578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
Protein chemical studies of glutamate dehydrogenase isoproteins (GDH I and GDH II) from bovine brain reveal that one cystein residue is accessible for reaction with thiol-modifying reagent. Reaction of the two types of GDH isoproteins with p-chloromercuribenzoic acid resulted in a time-dependent loss of enzyme activity. The inactivation followed pseudo first-order kinetics with the second-order rate constant of 83 M(-1) s(-1) and 75 M(-1) s(-1) for GDH I and GDH II, respectively. The inactivation was partially prevented by preincubation of the glutamate dehydrogenase isoproteins with NADH. A combination of 10 mM 2-oxoglutarate with 2 mM NADH gave complete protection against the inactivation. There were no significant differences between the two glutamate dehydrogenase isoproteins in their sensitivities to inactivation by p-chloromercuribenzoic indicating that the microenvironmental structures of the GDH isoproteins are very similar to each other. Allosteric effectors such as ADP and GTP had no effects on the inactivation of glutamate dehydrogenase isoproteins by thiol-modifying reagents. By a combination of peptide mapping analysis and labeling with [14C] p-chloromercuribenzoic acid, a reactive cystein residue was identified as Cys323 in the overall sequence. The cysteine residue was clearly identical to sequences of other GDH species known.
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154
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Lee BC, Hwang SH, Chang GY. Hemiballismus-hemichorea in older diabetic women: a clinical syndrome with MRI correlation. Neurology 1999; 52:646-8. [PMID: 10025807 DOI: 10.1212/wnl.52.3.646] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Eight older women from two different continents, all with nonketotic hyperglycemia, presented with hemiballismus-hemichorea (HB-HC) and high signal intensity in the contralateral striatum on T1-weighted MRI scans. Correction of underlying hyperglycemia and supportive care resulted in resolution within days to weeks. This characteristic clinicoradiologic picture suggests a clinical syndrome with benign outcome.
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155
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Lee BC, Hwang SH, Chang GY. Isolated dysphagia due to a medullary infarction: a new lacunar syndrome. Eur Neurol 1999; 41:53-4. [PMID: 9885331 DOI: 10.1159/000008000] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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156
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Hwang SH, Saitoh H, Mizuki E, Higuchi K, Ohba M. A novel class of mosquitocidal delta-endotoxin, Cry19B, encoded by a Bacillus thuringiensis serovar higo gene. Syst Appl Microbiol 1998; 21:179-84. [PMID: 9704107 DOI: 10.1016/s0723-2020(98)80022-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Partially digested HincII fragments of DNA from a mosquitocidal strain of Bacillus thuringiensis serovar higo were cloned into pBluescript II SK(+) and propagated in Escherichia coli. Recombinant cells were screened immunologically for the production of parasporal inclusion antigens. One E. coli clone harboring a recombinant plasmid exhibited larvicidal activity to Culex pipiens molestus, but not to Anopheles stephensi. Hybridization experiments revealed that the gene of the toxin protein is located on a 110 kb plasmid of B. thuringiensis serovar higo. Sequence analysis detected an open reading frame of 2046 nucleotides encoding a polypeptide of 682 amino acid residues with a predicted molecular weight of 78,467. The gene encoded five block regions commonly conserved in the insecticidal protein genes of B. thuringiensis. Amino acid sequence of the 78 kDa protein shared 49% identity and 56% similarity with that of the Cry19A protein from B. thuringiensis serovar jegathesan. A new class of delta-endotoxin protein, designated Cry19B, was established on the basis of this protein.
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157
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Saitoh H, Higuchi K, Mizuki E, Hwang SH, Ohba M. Characterization of mosquito larvicidal parasporal inclusions of a Bacillus thuringiensis serovar higo strain. J Appl Microbiol 1998; 84:883-8. [PMID: 9674143 DOI: 10.1046/j.1365-2672.1998.00426.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The parasporal inclusion proteins of the type strain of Bacillus thuringiensis serovar higo (H44), that have moderate mosquitocidal activity, were characterized. The purified parasporal inclusions, spherical in shape, were examined for activity against the two mosquito species, Culex pipiens molestus and Anopheles stephensi and the moth-fly, Telmatoscopus albipunctatus. The LC50 values of the inclusion for the two mosquitoes were 3.41 and 0.15 microgram.ml-1, respectively. No mortality was shown for T. albipunctatus larvae by the inclusions at concentrations up to 1 mg ml-1. Solubilized parasporal inclusions exhibited no haemolytic activity against sheep erythrocytes. Parasporal inclusions consisted of eight proteins with molecular masses of 98, 91, 71, 63, 59, 50, 44 and 27 kDa. Of these, the 50 and 44 kDa proteins were the major components. Analysis with immunoblotting revealed that, among several inclusion proteins of B. thuringiensis serovar israelensis, only two proteins of 130 kDa and 110 kDa reacted weakly with antibodies against higo proteins. N-terminal amino acid sequences of the 98, 91, and 71 kDa proteins showed 85-100% identity to those of the two established Cry protein classes, Cry4A and Cry10A.
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158
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Hwang SH, Shin KJ, Kang YK, Kim DJ, Kim DC, Yoo KH, Park SW, Lee KJ. Synthesis and antibacterial activities of new carbapenems having a proline reverse amide moiety at the C-2 position. Arch Pharm (Weinheim) 1998; 331:139-42. [PMID: 9648522 DOI: 10.1002/(sici)1521-4184(199804)331:4<139::aid-ardp139>3.0.co;2-u] [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: 11/06/2022]
Abstract
The synthesis of new 1 beta-methylcarbapenems (1a-l) having a proline reverse amide moiety at the C-2 position and their in vitro antibacterial activities are described. The compounds were evaluated by the Mueller-Hinton agar dilution method and compared with meropenem as control. Aliphatic amides (1a-h) are found to show greater antibacterial activity than aromatic amides (1i-l). Moreover, C-2 free amino compound (1m) reveals greater activity than any other amide compounds (1a-l).
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159
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Higuchi K, Saitoh H, Mizuki E, Hwang SH, Ohba M. A novel isolate of Bacillus thuringiensis serovar leesis that specifically exhibits larvicidal activity against the moth-fly, Telmatoscopus albipunctatus. Syst Appl Microbiol 1998; 21:144-50. [PMID: 9741119 DOI: 10.1016/s0723-2020(98)80018-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A soil isolate designated 88-KO-14-45, belonging to Bacillus thuringiensis serovar leesis (H33), exhibited larvicidal activity against the moth-fly, Telmatoscopus albipunctatus (Diptera: Psychodidae), but not for larvae of the culicine and aedine mosquitoes and Lepidoptera. Purified parasporal inclusions had an LC50 value of 5.78 micrograms/ml for the larval moth-fly, but gave no mortality against larvae of Culex pipiens molestus (Diptera: Culicidae) at protein concentrations up to 10 mg/ml. Electron microscopic observations revealed that the parasporal inclusions are homogeneous round-shaped bodies enclosed with thick, electron dense envelopes. Haemolytic activity against sheep erythrocytes was not detected in the solubilized inclusions. SDS-PAGE showed that the inclusions are composed of 72, 68, 56 and 30 kDa proteins. Immunologically, these proteins were unrelated to the inclusion proteins of B. thuringiensis serovar israelensis, while a 70 kDa protein of the strain 73-E-10-2 (B. thuringiensis serovar darmstadiensis) was seroactive to antibodies against proteins of 88-KO-14-45.
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160
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Jeong SC, Bae JC, Hwang SH, Kim HC, Lee BC. Cerebral sparganosis with intracerebral hemorrhage: a case report. Neurology 1998; 50:503-6. [PMID: 9484381 DOI: 10.1212/wnl.50.2.503] [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: 02/06/2023] Open
Abstract
We describe the clinical case and radiologic findings in a woman with cerebral sparganosis in which intracerebral hemorrhage was the presenting feature with hemiparesis and dysarthria. CT demonstrated high-density lesions in the right frontoparietal area, suggesting a hematoma. With conservative management, hemiparesis improved and follow-up CT revealed what looked like a resolving hematoma. Two weeks later, she complained once again of aggravated left hemiparesis and facial weakness. Diagnosis of sparganosis was made on the basis of brain MRI and ELISA. Stereotactic surgery was performed, and a live larva of sparganum was successfully removed.
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161
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Hwang SH, Bobrinev VI, Son JY, Shestak SA, Jeon HW. Achromatized transmission-type holographic screen for a multiview stereoscopic image system. APPLIED OPTICS 1997; 36:6605-6610. [PMID: 18259521 DOI: 10.1364/ao.36.006605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The main drawback of the use of transmission-type holographic screens is poor color reproduction caused by their high spectral dispersion. For overcoming this drawback, a long, narrow diffusing slit is used as an object when recording the screen. The necessary size and position of the slit relative to the photoplate and to the recording and reconstruction beams are determined by the phase relations of the beams. By use of the slit, holographic screens of 30 cm x 40 cm are recorded with a diverging reference beam and are used to display a multiview full-color stereoscopic image. The images displayed on the screen show no sign of color separation except near the edges of the screen. The image brightness on the screen is high enough that it can be watched in a normally illuminated room.
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162
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Lee BC, Hwang SH, Kim HC, Song HK. 3-07-22 Clinical features and etiology of striatocapsular infarction. J Neurol Sci 1997. [DOI: 10.1016/s0022-510x(97)85564-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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163
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Chen LM, Chao TY, Chiang JH, Nieh S, Chang JY, Hwang SH, Hseuh EJ, Wang CC. Examination of pericardial effusions by cytology and immunocytochemistry. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 1996; 58:248-53. [PMID: 8994328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Cytologic examination of pericardial effusions (PE) has been uncommonly reported in the literature. Fewer reports have studied the role of immunocytochemistry in diagnosis of PE. We described our experience, according to cytologic examination and immunocyto-chemical staining of PE. METHODS Over a four-year period, 50 PE specimens from 36 patients were examined cytologically by Wright-Giemsa stain and/or Papanicolaou stain, at Tri-Service General Hospital. Immunocytochemical stainings were further performed to ensure the cell nature. RESULTS Eighteen of these patients had benign etiologies; the others suffered from malignant diseases. Sixteen cases, including eight benign and eight malignant, received pericardial biopsy for comparison. Commonly encountered cells in PE with any kind of etiology included neutrophils, lymphocytes macrophages and mesothelial cells. Cancer cells were additionally seen in malignant PE, but not in all cases with cancers. Furthermore, reactive mesothelial cells and macrophages were sometimes not easily distinguished from cancer cells, and reactive lymphocytes frequently mimicked hematopoietic malignancies. Further, the nature of small round tumor cells can hardly be ensured by morphologic examination only. Immunocytochemical studies were successfully used to solve these dilemmas in some suspicious cases. CONCLUSIONS This study showed that cytology together with clinical information and immunocytochemistry can achieve excellent sensitivity and specificity in identification of malignant PE. The use of immunocytochemistry can even ensure the nature of certain cancers such as small cell carcinoma and B cell lymphoma.
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164
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Choy JH, Kim DK, Hwang SH, Demazeau G. Cu K-edge x-ray-absorption spectroscopic study on the octahedrally coordinated trivalent copper in the perovskite-related compounds La2Li0.5Cu0.5O4 and LaCuO3. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 50:16631-16639. [PMID: 9976051 DOI: 10.1103/physrevb.50.16631] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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165
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Lawrence GN, Hwang SH. Beam propagation in gradient refractive-index media. APPLIED OPTICS 1992; 31:5201-5210. [PMID: 20733694 DOI: 10.1364/ao.31.005201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A generalized beam propagation method is described that uses the ABCD matrices to treat optical systems that have modest amounts of aberrations including gradient refractive-index elements. We can make calculations from any point in the near or far field to any other point by using appropriate numerical algorithms. The variation of the reduced length is discussed as a limitation to accuracy. The diffraction properties of a complex stigmatic system may be represented by those of an equivalent elementary system. This facilitates calculations using the standard diffraction operations for homogeneous media. The modified propagation technique replaces the large number of diffraction steps commonly used for the split-step solution of inhomogeneous media with one step for stigmatic media and in general no more than a few steps for aberrated media. Maxwell's fisheye lens is discussed in detail to show application of the method.
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166
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Ko WS, Chen LM, Hwang SH, Hwang WS. [Evaluation of marrow neutrophilic reserve in normal subjects and aplastic anemia patients]. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 1992; 49:189-93. [PMID: 1316211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The widespread use of potent marrow suppressing drugs in malignant diseases has gained increasing importance in the functional assessment of neutrophil system. A peripheral neutrophil count of 500 cells/cumm is considered to be a good indicator of risk of bacterial infection. However, despite extreme neutropenia, infection is rare in chronic benign neutropenia patients. It may be presumed that adequate marrow reserve delivers mature neutrophil during bacterial infection in these patients. Currently available methods such as determination of blood neutrophil concentration, differential counts, estimation of bone marrow cellularity provide a relatively crude estimates of the functional capacity of the neutrophil system. The use of endotoxin, etiocholanolone and steroids have been introduced to determine the marrow neutrophil reserve with greater accuracy. In this study, intravenous hydrocortisone 100 mg was used to evaluate marrow neutrophilic reserve in normal and aplastic anemia subjects. The results showed significant statistical differences (P less than 0.001) between controls and aplastic subjects in 2, 3, 4 and 5th hour groups after steroid injection. The sensitivity and specificity occurring 3 and 4 hours after steroid injection were 78.6% and 100%, respectively. The normal marrow neutrophilic reserve showed more than 1198/cumm of increment neutrophilic counts 4 hours after steroid injection. No complication was found. The present finding suggests that steroid may be useful as an accurate evaluator of marrow neutrophilic reserve.
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167
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Lee KS, Im JG, Kim YH, Hwang SH, Bae WK, Lee BH. Treatment of thoracic multiloculated empyemas with intracavitary urokinase: a prospective study. Radiology 1991; 179:771-5. [PMID: 2027990 DOI: 10.1148/radiology.179.3.2027990] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The authors prospectively treated 10 consecutive patients with multiloculated empyemas with intracavitary instillation of urokinase via a percutaneous drainage catheter. Urokinase (100,000 IU) in 100 mL of 5% dextrose in water was instilled into the pleural cavity via a percutaneous drainage catheter. After overnight clamping, the catheter was opened and the empyema drained with use of negative suction (20 cm H2O). Intermittent irrigation of the catheter with normal saline was performed to prevent clogging of the catheter. Complete drainage of multiloculated empyemas was accomplished in nine patients by means of intracavitary instillation of urokinase via a single 8-F catheter. One patient showed complete drainage of multiloculated empyema, but recurrent empyema appeared in the site of a previous tube thoracostomy. A total of 100,000-700,000 IU (mean, 400,000 IU) of urokinase were needed for complete drainage in all patients. Plasminogen and fibrin degradation product levels in empyema fluid were determined before instillation of urokinase to demonstrate any fibrinolytic action. No complications occurred.
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Abstract
We analyzed the CT features of 22 patients with endobronchial tuberculosis (EBTB) showing segmental collapse and/or mas-like infiltrates. The CT findings of involved bronchi were bronchial stenosis with wall thickening or peribronchial cuff of soft tissue (n = 9), bronchial obstruction with peribronchial cuff or soft tissue (n = 7), bronchial involvement with tuberculous lymphadenitis (n = 5), or intraluminal lower density polypoid mass with narrowing (n = 1). Enhancement of the peribronchial cuff following intravenous contrast medium administration was noted in four of seven patients in the bronchial obstruction group. The parenchymal lesions distal to the bronchial lesion were segmental collapse, collapse with multiple low density areas (presumed caseous pneumonia), cavities, and round low density lesion (presumed mucoid impaction distal to an endobronchial obstruction). Ill-defined small nodular densities and larger confluent densities suggesting endobronchially disseminated pulmonary tuberculosis were found in the adjacent lung in 10 patients.
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169
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Chung CW, Hwang SH, Choi YC, Sohn YH, Kim JS, Lee BC, Chi JG. A case of Leigh's disease with initial manifestation of dystonia. Yonsei Med J 1990; 31:274-9. [PMID: 2281687 DOI: 10.3349/ymj.1990.31.3.274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
A case of Leigh's disease (subacute necrotizing encephalomyelopathy) is reported with such noteworthy features as early onset, dystonia, paraparesis the presence of low attenuation areas in both basal ganglias on computerized tomography of the brain and the presence of a high signal intensity in both basal ganglias in T2 weighted image by MR. The electron microscopic findings of muscle biopsy are suggestive of pleoconial mitochondrial myopathy.
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Abstract
Occlusion of the anterior choroidal artery (AChA) can cause infarction in the posterior limb of the internal capsule. Infarction is less frequently observed in the thalamus, midbrain, temporal lobe, and lateral geniculate body (LGB) territories of the AChA. The most common clinical finding is hemiparesis. Hemianesthesia may be severe at onset but is usually transient. Homonymous hemianopia, upper-quadrant anopia, or upper- and lower-quadrant sector anopia can be present. Occasionally these patients are reported to have transient abnormalities of higher cortical function. The most common stroke mechanism is known to be small-vessel occlusive disease, predominantly found in hypertensive and diabetic patients. Vasospasm due to ruptured aneurysm or intraoperative mechanical manipulation, and cardiac origin the AChA territory. The infarct lesion is usually recognized and diagnosed by computed tomography. The best treatment is still unknown.
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171
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Hwang SH, Nowak T. Stereoselective ligand interactions of chicken liver phosphoenolpyruvate carboxykinase with fluorophosphoenolpyruvate. Arch Biochem Biophys 1989; 269:646-63. [PMID: 2919888 DOI: 10.1016/0003-9861(89)90150-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The stereospecific interactions of chicken liver phosphoenolpyruvate carboxykinase (P-enolpyruvate carboxykinase) with the two geometric isomers of 3-fluorophosphoenolpyruvate (F-P-enolpyruvate) were examined. Previous studies have shown that the Z isomer of F-P-enolpyruvate is a substrate for P-enolpyruvate carboxykinase but the E isomer is a competitive inhibitor [T. H. Duffy and T. Nowak (1984) Biochemistry 23, 661-670]. The reasons for this substrate selectivity were investigated. Studies of the 1H, 19F, and 31P relaxation rates of the ligands in the binary Mn-ligand complexes indicate the formation of direct coordination complexes. The temperature and frequency dependence of the proton relaxation rates (PRR) of the respective enzyme-Mn-ligand complexes demonstrates that the perturbation of the electronic environment at the Mn(II) site on the enzyme is different upon binding of the inhibitor (E-F-P-enolpyruvate) in contrast to the binding of substrates (P-enolpyruvate or Z-F-P-enolpyruvate). Structural studies demonstrate that Z-F-P-enolpyruvate forms a second sphere coordination complex with enzyme-bound Mn(II). E-F-P-enolpyruvate exchanges slowly from the ternary complex and binds less than or equal to 10 A from the bound Mn(II). CD studies in the far-uv region demonstrate that the alpha-helical content of P-enolpyruvate carboxykinase is increased at the expense of antiparallel and parallel beta-sheet structure upon binding of Mn(II) and substrate (P-enolpyruvate or Z-F-P-enolpyruvate) to the apoenzyme, but show no such structural change upon binding of Mn(II) and E-F-P-enolpyruvate. Analogous results are observed from CD studies at the aromatic amino acid region (250-350 nm). The stereoselective catalytic activities of P-enolpyruvate carboxykinase with F-P-enolpyruvate analogs can be explained by different interactions of these ligands within the catalytic site of the enzyme.
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Hwang SH, Nowak T. Stereochemistry of phosphoenolpyruvate carboxylation catalyzed by phosphoenolpyruvate carboxykinase. Biochemistry 1986; 25:5590-5. [PMID: 3778875 DOI: 10.1021/bi00367a037] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The stereochemistry of the carboxylation of phosphoenolpyruvate to yield oxalacetate, catalyzed by chicken liver phosphoenolpyruvate carboxykinase and by Ascaris muscle phosphoenolpyruvate carboxykinase, was determined. The substrate (Z)-3-fluorophosphoenolpyruvate was used for the stereochemical analysis. The carboxylation reaction was coupled to malate dehydrogenase to yield 3-fluoromalate, and the stereochemistry of the products was identified by 19F NMR. In separate experiments, the enantiomeric tautomers of 3-fluorooxalacetate were shown to be utilized by malate dehydrogenase to yield (2R,3R)- and (2R,3S)-3-fluoromalate in nearly identical amounts. The products were identified by 19F NMR. When (Z)-3-fluorophosphoenolpyruvate was used as a substrate for phosphoenolpyruvate carboxykinase from avian liver and from Ascaris, and malate dehydrogenase was used to trap the product, only a single diastereomer was observed. This product was shown to be (2R,3R)-3-fluoromalate in each case. The assignments were based on coupling constants taken from Keck et al. [Keck, R., Hess, H., & Rétey, J. (1980) FEBS Lett. 114, 287]. These results indicate that the stereochemistry of carboxylation, catalyzed by chicken phosphoenolpyruvate carboxykinase and by Ascaris phosphoenolpyruvate carboxykinase, is identical and takes place from the si side of the enzyme-bound phosphoenolpyruvate. The carboxylation reaction was run both in H2O and in D2O. No deuterium incorporation into fluoromalate was shown to occur. The product 3-fluorooxalacetate is thus released from phosphoenolpyruvate carboxykinase as the keto form and is reduced more rapidly by reduced nicotinamide adenine dinucleotide with malate dehydrogenase than by the occurrence of tautomerization.
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Denton R, Forsman W, Hwang SH, Litt M, Miller CE. Viscoelasticity of mucus. Its role in ciliary transport of pulmonary secretions. THE AMERICAN REVIEW OF RESPIRATORY DISEASE 1968; 98:380-91. [PMID: 5673097 DOI: 10.1164/arrd.1968.98.3.380] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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