626
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Fried MW, Fong TL, Swain MG, Park Y, Beames MP, Banks SM, Hoofnagle JH, Di Bisceglie AM. Therapy of chronic hepatitis B with a 6-month course of ribavirin. J Hepatol 1994; 21:145-50. [PMID: 7989704 DOI: 10.1016/s0168-8278(05)80387-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Ribavirin is a nucleoside analogue with broad spectrum antiviral activity that has been shown to inhibit viral replication in the woodchuck model of hepatitis B virus infection. We studied the effect of ribavirin on viral replication in 18 patients with chronic hepatitis B who were positive for hepatitis B e antigen. Patients were randomized to receive a 24-week course of oral ribavirin at a dose of either 800, 1000, or 1200 mg/kg per day. All patients completed 24 weeks of treatment and an additional 24 weeks of follow up without significant side effects except for mild, reversible hemolytic anemia. Response to ribavirin was similar among all three dosage groups (p > 0.5); hence the data were pooled and analyzed together. Mean hepatitis B virus DNA levels decreased from 162.7 (95% confidence interval, 106 to 219) pg/ml before treatment to its lowest level of 114.3 (95% confidence interval, 53 to 175) pg/ml at week 20 (p < 0.05). Two patients became negative for HBV DNA and lost hepatitis B e antigen. Mean serum alanine aminotransferase activity decreased markedly from 131.1 (95% confidence interval, 84 to 178) U/l before treatment to 62.4 (95% confidence interval, 48 to 77) U/l at the end of 24 weeks of ribavirin (p < 0.05) and became normal in four patients (22%). Aminotransferase levels returned to baseline within 4 weeks once ribavirin was discontinued, while HBV DNA concentrations remained below baseline even at the end of 24 weeks of follow up.(ABSTRACT TRUNCATED AT 250 WORDS)
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627
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Worley G, Erwin CW, Schuster JM, Park Y, Boyko OB, Griebel ML, Weidman ER, Radtke RA, Oakes WJ. BAEPs in infants with myelomeningocele and later development of Chiari II malformation-related brainstem dysfunction. Dev Med Child Neurol 1994; 36:707-15. [PMID: 8050624 DOI: 10.1111/j.1469-8749.1994.tb11913.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Thirty-seven infants with myelomeningocele received brainstem auditory evoked potentials (BAEPs) at a median age of eight days. No infant had brainstem dysfunction at the time of testing. Median follow-up was at 30 months. Of 12 infants who subsequently developed brainstem dysfunction at a median age of three months, 11 had had abnormal neonatal BAEPs. In contrast, only 10 of 25 infants who did not develop brainstem dysfunction had abnormal BAEPs. The mean average I-V interpeak latencies was greater among those who developed symptoms than among those who did not. Neonatal BAEPs can identify a group of asymptomatic infants with myelomeningocele who need close follow-up for the subsequent development of brainstem dysfunction.
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628
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Chen D, Park Y, Kemper B. Differential protein binding and transcriptional activities of HNF-4 elements in three closely related CYP2C genes. DNA Cell Biol 1994; 13:771-9. [PMID: 7772258 DOI: 10.1089/dna.1994.13.771] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
A functional binding site for a liver-enriched transcription factor, hepatocyte nuclear factor-4 (HNF-4), has previously been identified around -100 in the CYP2C2 promoter and proposed to be a common regulatory motif for the hepatic expression of many CYP2 genes. The transcriptional activity of the proximal promoters of three closely related cytochrome P450 genes (CYP2C1, CYP2C2, and CYP2C3) have been compared in HepG2 cells and correlated with the relative binding affinities of the HNF-4 motifs in the genes for proteins in liver, kidney, and HepG2 extracts that react with antisera to HNF-4. Gel-shift assays suggested that these highly similar motifs bound HNF-4 with significantly different affinities. The relative binding affinities to the protein in liver extracts were estimated by competitive gel-shift binding, and the binding affinity of CYP2C2 was two-fold and eight-fold greater than that of CYP2C1 and CYP2C3, respectively. These affinity differences correlated well with the transcriptional activities of either the minimal hepatic promoters (117 to 135 bp of 5'-flanking region) of the genes in HepG2 cells or minimal CYP2C2 promoters containing the HNF-4 motif from each gene. Identification of the CYP2C3 site was somewhat indirect; the HNF-4 element in the CYP2C3 promoter could be converted to a motif with binding affinity and hepatic cell-specific transcriptional activity similar to that of CYP2C2 by a single nucleotide substitution. The activities of the minimal promoters did not correlate well with hepatic expression of each gene in vivo, as estimated previously by the concentration of mRNA in livers of untreated animals.(ABSTRACT TRUNCATED AT 250 WORDS)
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629
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Han K, Hong J, Lim HC, Kim CH, Park Y, Cho JM. Tyrosinase production in recombinant E. coli containing trp promoter and ubiquitin sequence. Ann N Y Acad Sci 1994; 721:30-42. [PMID: 8010680 DOI: 10.1111/j.1749-6632.1994.tb47374.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We have successfully expressed the active tyrosinase of Streptomyces antibioticus in Escherichia coli under the control of the trp promoter by fusing the sequence to the ORF438 gene. Because our attempt to connect the polycistronic gene of ORF438 and tyrosinase directly to the trp promoter of E. coli resulted in the expression of functionally inactive tyrosinase, we decided to fuse the COOH-terminus of ubiquitin sequence to the NH2-terminus of ORF438. Ubiquitin fusion has been shown to augment the yield of cloned gene products in E. coli by increasing the stability or translational efficiency of the fusion proteins. As a result, E. coli transformants harboring a plasmid pTRUBF that contains the ubiquitin-fused ORF438 and the tyrosinase gene produced the strong black pigment of melanin. About 300 units of tyrosinase per liter of batch culture were detected when cultivated in M9 medium containing casamino acids, L-tyrosine, and copper supplements. The black pigment, however, was not seen when grown in LB medium, suggesting that the trp promoter is well regulated. When recombinant E. coli cells grown in LB medium were transferred to a tryptophan-deficient minimal medium with phenol, we observed that phenol was removed from the solution, and the color of the medium turned black. This is due to the fact that the tyrosinase has polyphenol oxidase properties. We expect to use this recombinant E. coli for the waste treatment of phenolic compounds.
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630
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Park Y, Devlin TM, Jones DP. Protection of hepatocytes against death due to mitochondrial failure: effect of di-Calciphor on antimycin A-induced toxicity. Toxicol Appl Pharmacol 1994; 126:33-8. [PMID: 8184430 DOI: 10.1006/taap.1994.1087] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Di-Calciphor is a synthetic derivative of prostaglandin B1 that protects against cerebral and cardiac ischemia apparently by preserving mitochondrial function. To determine whether di-Calciphor specifically protects against mitochondrial failure, we studied its effects on mitochondrial functions in hepatocytes treated with the specific mitochondrial poison, antimycin A. The results show that 1 microM di-Calciphor protects against cell death at concentrations of antimycin A that inhibited mitochondrial respiration and caused cellular ATP depletion. Di-Calciphor did not protect against loss of ATP but did protect against the loss of mitochondrial delta psi and delta pH. In addition, di-Calciphor protected against antimycin A-induced loading of phosphate into mitochondria and an associated mitochondrial swelling. Thus, these results show that di-Calciphor protects against a specific mitochondrial poison and support the interpretation that di-Calciphor is a mitochondrial protective agent. In addition, the results suggest that the protection of the mitochondria involves preservation of mitochondrial ionic and osmotic stability and does not involve improved ATP supply.
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631
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Miller CC, Park Y, Pariza MW, Cook ME. Feeding conjugated linoleic acid to animals partially overcomes catabolic responses due to endotoxin injection. Biochem Biophys Res Commun 1994; 198:1107-12. [PMID: 8117267 DOI: 10.1006/bbrc.1994.1157] [Citation(s) in RCA: 238] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The ability of conjugated linoleic acid to prevent endotoxin-induced growth suppression was examined. Mice fed a basal diet or diet with 0.5% fish oil lost twice as much body weight after endotoxin injection than mice fed conjugated linoleic acid. By 72 hours post injection, mice fed conjugated linoleic acid had body weights similar to vehicle injected controls; however, body weights of basal and fish oil fed mice injected with endotoxin were reduced. Conjugated linoleic acid prevented anorexia from endotoxin injection. Splenocyte blastogenesis was increased by conjugated linoleic acid.
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632
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Awad AB, Park Y, Fink CS, Horvath PJ. Influence of dietary fat and feeding period on phosphoinositide metabolism in rat colonocytes. Nutr Cancer 1994; 21:71-81. [PMID: 8183724 DOI: 10.1080/01635589409514305] [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: 01/29/2023]
Abstract
The objective of the present study was to examine the effect of dietary fat content on phosphoinositide (PI) metabolism, fatty acid composition in colonocytes, and colonic luminal content of bile acids (BA) and free fatty acids (FFA) in rats. Male Sprague-Dawley rats weighing approximately 166 g were fed to semipurified diet containing 3% or 21.5% beef fat and 2% corn oil. The nonfat ingredients were adjusted to correct for differences in food consumption of these diets. Animals were fed these diets ad libitum for one or four weeks. The isolated colonocytes had a viability of 88.9% in all groups. PI metabolism was examined in the absence (basal) or presence of agonists, 2 mM deoxycholic acid or 10 microM A23187. Dietary fat concentration had no effect on PI metabolism, but the length of feeding had a significant effect on basal and stimulated PI metabolism. Colonocytes of animals fed the diets for four weeks were less sensitive to stimulation of PI cycle by agonists than those of animals fed for one week. Colonocyte fatty acid composition was influenced by dietary fat and feeding period. Only the relative percentage of 20:3(n-6) was significantly lower in rats fed the high-fat diet for one week; 18:0 was lower and 18:3(n-6) was higher in colonocytes of animals fed the diets for one week than in those fed for four weeks. Several colonic fatty acids, namely, 16:0, 20:3(n-6), and 22:5(n-6), also exhibited diet-by-feeding period interaction. Intracolonic luminal contents from rats fed the high-fat diet contained elevated concentrations of BA and FFA (44% and 62%, respectively). It was concluded that despite the effects of dietary fat concentration on increased colonic BA and FFA and on altered membrane fatty acid composition, dietary fat had no effect on PI metabolism in colonocytes under the conditions in the present experiment. A difference in components between the purified diet and the commercial rat chow and/or an aging effect of the rats may alter the PI cycle of colonocytes.
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633
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Horsley WS, Whitlark JD, Hall JD, Gott JP, Huang AH, Park Y, Jones DP, Guyton RA. Revascularization for acute regional infarct: superior protection with warm blood cardioplegia. Ann Thorac Surg 1993; 56:1228-37; discussion 1237-8. [PMID: 8267418 DOI: 10.1016/0003-4975(93)90658-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Continuous retrograde warm blood cardioplegia was compared with two widely used hypothermic myocardial protection techniques in a canine model of acute regional myocardial ischemia with subsequent revascularization. Animals (n = 30) underwent 45 minutes of left anterior descending coronary artery occlusion then cardioplegic arrest (60 minutes), followed by separation from cardiopulmonary bypass and data collection. The cold oxygenated crystalloid cardioplegia group (CC; n = 8) and the cold blood cardioplegia group (CC; n = 10) had cardiopulmonary bypass at 28 degrees C, antegrade arrest, and intermittent retrograde delivery. The warm blood cardioplegia group (WB; n = 12) had normothermic cardiopulmonary bypass, antegrade arrest, and continuous retrograde delivery. Overall ventricular function (preload recruitable stroke work relationship; ergs x 10(3)/mL) was significantly (p < 0.001) better for WB (WB, 80 +/- 11; CB, 67 +/- 13; CC, 57 +/- 12). Systolic function (maximum elastance relationship; mm Hg/mL) was also significantly (p < 0.001) better for WB (WB, 11.6 +/- 3.6; CB, 8.6 +/- 2.7; CC, 6.2 +/- 1.3). Diastolic function (stress-strain relationship; dynes x 10(3)/cm2) revealed significantly (p < 0.001) decreased compliance for CC (WB, 20 +/- 6; CB, 19 +/- 7; CC, 27 +/- 11). Left anterior descending coronary artery regional adenosine triphosphate/adenosine diphosphate ratios were significantly (p = 0.02) worse for CC (WB, 10.2 +/- 2.3; CB, 9.4 +/- 2.6; CC, 5.6 +/- 1.5). Myocardial edema significantly (p = 0.03) increased over time only in the CC animals (WB, 0.4% +/- 2.3%; CB, -0.3% +/- 3.6%; CC, 5.5% +/- 2.3%). In this model of acute regional myocardial ischemia and revascularization, continuous retrograde warm aerobic blood cardioplegia provided superior myocardial protection compared with cold oxygenated crystalloid cardioplegia with intermediate results for cold blood cardioplegia.
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634
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Park Y, Gong G, Choe G, Yu E, Kim KS, Lee I. Jarcho-Levin syndrome--a report of an autopsy case with cytogenetic analysis. J Korean Med Sci 1993; 8:471-5. [PMID: 8179836 PMCID: PMC3053874 DOI: 10.3346/jkms.1993.8.6.471] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Jarcho-Levin syndrome (JLS) is a condition manifested by malformations of vertebral bodes and related ribs. There are two major subtypes spondylocostal dysostosis and spondylothoracic dysostosis, with different survival rates, associated malformations, and inheritance patterns. We have experienced an autopsy case of a premature female fetus with multiple congenital anomalies. She was 30 weeks of gestational age, born as the second baby of twins and expired shortly after birth. A post-mortem examination revealed multiple abnormalities including cervicothoracic hemivertebrae, a diminished number of right-sided ribs, and pulmonary hypoplasia with left diaphragmatic hernia. In addition, there were anomalous rotation of the foregut, unfused pancreas and anomalous drainage of the superior vena cava. Chromosomal analysis showed 46, XX, del(4)(q ter).
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635
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Hashimoto K, Kishima Y, Onishi N, Esa A, Sugiyama T, Park Y, Kohri K, Akiyama T, Kurita T. [Transurethral teflon paste injection for vesicoureteral reflux in neurogenic bladder dysfunction]. Nihon Hinyokika Gakkai Zasshi 1993; 84:2118-23. [PMID: 8309118 DOI: 10.5980/jpnjurol1989.84.2118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We experienced transurethral teflon paste injection for 12 refluxing ureters of 7 patients with neurogenic bladder dysfunction. Preoperative assessment of cystometry showed hypoactive bladder function with normal bladder compliance in 4 patients, and low compliance bladder (< 10 ml/cmH2O) in 1. Voiding cystography revealed grade 1 reflux in 2 ureters, grade 2 in 3, grade 3 in 2, grade 4 in 2, and grade 5 in 2. One ureter did not show reflux. Zero point two to 1.6 ml of teflon paste was injected on each ureter under cystoscopic observation. These patients were followed for a mean of 25.1 months. Reflux disappeared immediately after the first operations in all patients, however recurrence was observed in 2 ureters, in which improvement of reflux (grade 5 to 2) was achieved in 1 ureter but no improvement (grade 2 to 2) in another. Pyelonephritis was not encountered in any patients after injection. No complication was observed through the follow up period. In conclusion, we advocate that endoscopic teflon paste injection is a useful alternative to ureteroneocystostomy in the treatment of reflux in patients with neurogenic bladder dysfunction.
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636
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Kang K, Oh JH, Kwon C, Park Y. Generalization in a two-layer neural network. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1993; 48:4805-4809. [PMID: 9961164 DOI: 10.1103/physreve.48.4805] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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637
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Nelson WM, Park Y. N=2 supersymmetry in two-dimensional dilaton gravity. PHYSICAL REVIEW. D, PARTICLES AND FIELDS 1993; 48:4708-4712. [PMID: 10016124 DOI: 10.1103/physrevd.48.4708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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638
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Di Bisceglie AM, Fong TL, Fried MW, Swain MG, Baker B, Korenman J, Bergasa NV, Waggoner JG, Park Y, Hoofnagle JH. A randomized, controlled trial of recombinant alpha-interferon therapy for chronic hepatitis B. Am J Gastroenterol 1993; 88:1887-92. [PMID: 8237937] [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: 12/11/2022]
Abstract
OBJECTIVES To evaluate the effect of recombinant alpha-interferon in chronic hepatitis B. METHODS Patients were stratified at entry according to their serum aspartate aminotransferase (AST) values, randomized to receive alpha-interferon (alfa-2b, 10 million units three times weekly) or to be untreated controls for 16 wk. Effect of therapy on levels of hepatitis B viral (HBV) DNA and aminotransferase activities in serum and hepatitis B e antigen (HBeAg) status was monitored. RESULTS Forty-seven patients entered the trial; 11 of 25 (44%) patients receiving interferon responded by clearing HBeAg and HBV DNA within 6 months, compared to one of 22 (5%) controls (p < 0.05). Among those with serum AST values < 100 U/L, 33% responded and among those with AST values > 100 U/L, 60% responded. Within the 6-month study period, 36% of treated patients had normal serum alanine aminotransferase (ALT) values, and 16% had cleared hepatitis B surface antigen (HBsAg) from serum, whereas none of the controls had normal ALT values or had lost HBsAg. Interferon was stopped early in three patients (6.5%), and dosage was reduced in a further 16 patients (35%) because of adverse effects. Predictive factors for a response were the pretreatment serum ALT and AST activities. CONCLUSIONS alpha-Interferon therapy (three times weekly) is relatively well tolerated and is effective in clearing HBeAg and HBV DNA in approximately one-third of treated patients.
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639
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Park Y, McBride BC. Characterization of the tpr gene product and isolation of a specific protease-deficient mutant of Porphyromonas gingivalis W83. Infect Immun 1993; 61:4139-46. [PMID: 8406803 PMCID: PMC281136 DOI: 10.1128/iai.61.10.4139-4146.1993] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The previously described protease gene (tpr) of Porphyromonas gingivalis W83 was shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the recombinant protein and in vitro translation to encode a 50-kDa protein whose active form migrates with an apparent molecular mass of 90 kDa. The 50-kDa protein was expressed at high levels by using a T7 RNA polymerase/promoter system. The NH2-terminal sequence of the protein was identical to the amino acid sequence deduced from the DNA sequence of the protease gene. Affinity-purified antibody to the 90-kDa recombinant protease reacted with an 80-kDa P. gingivalis protein. A specific protease (Tpr)-deficient isogenic mutant of P. gingivalis was generated by homologous recombination between P. gingivalis chromosomal DNA and a suicide plasmid carrying the cloned gene disrupted by insertion of an erythromycin resistance gene. Gelatin substrate zymography showed that cell extracts of the mutant lacked a protease band that migrated with an apparent molecular mass of 80 kDa. Western immunoblots of the cell extracts indicated the loss of an antigen with a similar mass.
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640
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Cook ME, Miller CC, Park Y, Pariza M. Immune modulation by altered nutrient metabolism: nutritional control of immune-induced growth depression. Poult Sci 1993; 72:1301-5. [PMID: 8346156 DOI: 10.3382/ps.0721301] [Citation(s) in RCA: 323] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The ability of conjugated isomers of linoleic acid (CLA) to prevent reduced growth rate following endotoxin (lipopolysaccharide, LPS) injection was studied in two chick trials and one rat trial. Chicks (10 per treatment) were fed a corn and soybean meal-based diet with or without .5% CLA. At 21 days of age, chicks were weighed and injected i.p. with 1 mg/kg BW Escherichia coli LPS and sterile PBS. Body weights were again determined 24 h later. Antibody responses to SRBC were also determined. Rats fed .5% stearic acid or CLA for 4 wk (seven per treatment) were also injected with LPS, and BW change over a 24-h postinjection period was determined. Antibody responses to BSA, phytohemagglutinin foot pad swelling, and phagocytosis of elicited peritoneal macrophages were also determined. The CLA had no adverse effects on any immune variables measured in the chicks and rats. The CLA enhanced the phytohemagglutinin response and macrophage phagocytosis in rats. Chicks fed CLA and injected with LPS continued to grow, whereas those not fed CLA either failed to grow or lost weight following LPS injection. Both control and CLA-fed rats lost weight over the 24-h period after LPS injection; however, the loss of weight in rats fed CLA was only half of the weight loss of the control rats. Thus, CLA is effective in preventing the catabolic effects of immune stimulation.
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641
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Kwon C, Park Y, Oh J. Stability of the replica-symmetric solution for a perceptron learning from examples. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1993; 47:3707-3711. [PMID: 9960426 DOI: 10.1103/physreve.47.3707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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642
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Hoofnagle JH, Di Bisceglie AM, Waggoner JG, Park Y. Interferon alfa for patients with clinically apparent cirrhosis due to chronic hepatitis B. Gastroenterology 1993; 104:1116-21. [PMID: 8462800 DOI: 10.1016/0016-5085(93)90281-g] [Citation(s) in RCA: 143] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND The prognosis of advanced cirrhosis due to chronic hepatitis B is poor, and results of therapies, including liver transplantation, have been unsatisfactory. Little is known about the effectiveness of interferon alfa in patients with cirrhosis. METHODS Between 1984 and 1991, 18 patients with clinically-apparent cirrhosis due to hepatitis B were treated with interferon alfa at the Clinical Center of the National Institutes of Health. RESULTS Six treated patients (33%) had a sustained loss of hepatitis B virus DNA and hepatitis B e antigen (if present initially) and decrease of amino-transferase levels into the normal or near normal range. In follow-up, these 6 patients resolved all symptoms of cirrhosis and are alive and fully active. In contrast, the 12 patients who did not have a sustained loss of hepatitis B virus have had evidence of progressive liver disease, 6 have died and 4 underwent hepatic transplantation. Side effects of interferon were common and included bacterial infections (n = 5) and exacerbations of disease (n = 9). CONCLUSIONS These findings indicate that interferon alfa is effective in selected patients with mildly decompensated cirrhosis due to hepatitis B.
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643
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Park Y, Strominger A. Supersymmetry and positive energy in classical and quantum two-dimensional dilaton gravity. PHYSICAL REVIEW. D, PARTICLES AND FIELDS 1993; 47:1569-1575. [PMID: 10015734 DOI: 10.1103/physrevd.47.1569] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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644
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Fried MW, Korenman JC, Di Bisceglie AM, Park Y, Waggoner JG, Mitsuya H, Hartman NR, Yarchoan R, Broder S, Hoofnagle JH. A pilot study of 2',3'-dideoxyinosine for the treatment of chronic hepatitis B. Hepatology 1992; 16:861-4. [PMID: 1398494 DOI: 10.1002/hep.1840160402] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The nucleoside analog 2',3'-dideoxyinosine, currently being used to treat patients infected with the human immunodeficiency virus, has been shown to inhibit viral replication in certain cell culture systems of hepatitis B virus and the duck model of chronic hepatitis B infection. We studied the effect of dideoxyinosine on viral replication in patients with chronic hepatitis B. In the initial dose-finding phase, patients received sequential 2-wk courses of dideoxyinosine in escalating doses of 3, 6 and 9 mg/kg/day. In the second, long-term treatment phase, patients received dideoxyinosine at a dose of 9 mg/kg/day for 12 wk. Dideoxyinosine was given orally in three divided doses. The effects of dideoxyinosine on hepatitis B were assessed by serial measurements of ALT, hepatitis B virus DNA and DNA polymerase activity in serum. Six patients completed the dose-finding phase, and five patients continued into the long-term treatment phase. No significant differences were seen in serum aminotransferases, hepatitis B virus DNA levels or DNA polymerase activity at any time during treatment when compared with pretreatment levels. All patients remained positive for HBeAg during treatment and during 6 mo of follow-up. Thus at the doses tested, dideoxyinosine had no appreciable effect on viral replication in patients with chronic hepatitis B.
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645
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Di Bisceglie AM, Shindo M, Fong TL, Fried MW, Swain MG, Bergasa NV, Axiotis CA, Waggoner JG, Park Y, Hoofnagle JH. A pilot study of ribavirin therapy for chronic hepatitis C. Hepatology 1992; 16:649-54. [PMID: 1505907 DOI: 10.1002/hep.1840160307] [Citation(s) in RCA: 215] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Interferon-alpha therapy is of proven efficacy in chronic hepatitis C, but it is not universally effective and may be associated with intolerable side effects. Ribavirin is a nucleoside analog with a broad spectrum of antiviral action. We conducted an uncontrolled pilot study of ribavirin therapy in 13 patients with chronic hepatitis C. Ribavirin was given for 6 mo, in a dose that was increased, at 2-mo intervals, from 600 mg to 1,000 mg to 1,200 mg/day. Serum ALT levels gradually decreased in all 13 treated patients; the mean percentage of decrease was 67% (from 210 U/L [range = 109 to 593] to 63 U/L [range = 22 to 108 U/L]; p = 0.0006) after 6 mo of treatment. Serum aminotransferase levels fell to the normal range in four patients (31%). In the 3 to 6 mo after cessation of ribavirin therapy, serum aminotransferase activities gradually rose to near pretreatment levels in all but one patient. Therapy was associated with a significant decrease in the geometric mean titer of hepatitis C virus RNA in serum (1:1,981 vs. 1:199; p less than 0.02) although no patients lost hepatitis C virus RNA from serum during therapy. No significant improvement was seen in liver histological appearance. Ribavirin therapy resulted in mild, reversible hemolysis; no patient exhibited symptomatic anemia. These findings suggest that ribavirin has a beneficial effect in patients with chronic hepatitis C, although further studies are needed to determine how ribavirin is best used.
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646
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Park Y, Devlin TM, Jones DP. Protective effect of the dimer of 16,16-diMePGB1 against KCN-induced mitochondrial failure in hepatocytes. THE AMERICAN JOURNAL OF PHYSIOLOGY 1992; 263:C405-11. [PMID: 1514587 DOI: 10.1152/ajpcell.1992.263.2.c405] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The dimer and trimer of 16,16-dimethyl-15-dehydroprostaglandin B1 (16,16-diMePGB1) previously have been shown to have protective effects on mitochondrial function. To examine the potential mechanisms involved in protection against mitochondrial failure, we have studied the effects of the dimer of 16,16-diMe-PGB1 (dicalciphor) on mitochondrial function in hepatocytes exposed to KCN. Addition of micromolar concentrations of dicalciphor provided substantial protection against KCN-induced toxicity in a concentration- and time-dependent manner. Dicalciphor, however, had no effect on total or mitochondrial ATP losses in KCN-treated cells. The dimer prevented the marked loss of mitochondrial membrane potential (delta psi) and delta pH that occurs as a result of KCN treatment and prevented KCN-induced loading of phosphate in mitochondria. Furthermore, the dimer of 16,16-diMePGB1 also prevented KCN-induced mitochondrial and cellular swelling. These results demonstrate that dicalciphor protects against KCN-induced damage and that this protection is associated with regulation of specific mitochondrial ion transport functions.
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D'Agostino HB, Park Y, Moyers JP, vanSonnenberg E, Sanchez RB, Goodacre BW, Kim YH, Vieira MV. Influence of the stopcock on the efficiency of percutaneous drainage catheters: laboratory evaluation. AJR Am J Roentgenol 1992; 159:407-9. [PMID: 1632367 DOI: 10.2214/ajr.159.2.1632367] [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: 12/28/2022]
Abstract
The effects of stopcocks on percutaneous fluid drainage were tested in a laboratory model by using a standard stopcock (6-French inner diameter) and a prototype stopcock (9-French inner diameter) connected to 8-, 10-, 12-, 14-, and 16-French catheters. Catheters were immersed in water alone or in viscous fluid with particulate matter, and the system was connected to low wall suction or gravity drainage. The average volume of fluid aspirated in a given period with and without a stopcock was compared for each catheter. The standard stopcock decreased drainage efficiency for these catheters by 13-42%. This decreased drainage efficiency was worse with the larger catheters. Particulate fluid blocked the stopcock connection for all catheters. With the prototype stopcock, drainage of water alone was reduced by 0-9% for the catheters of different sizes. Particulate fluid did not obstruct the prototype stopcock with any size catheter. With gravity drainage, the volume of water aspirated was reduced by 12-42% with the standard stopcock and by 3-6% with the prototype stopcock. These data suggest that stopcock connections greatly influence the efficiency of the percutaneous drainage systems. Stopcocks with larger inner diameters may improve drainage over that achievable with the stopcocks that are currently available.
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Park Y, McBride BC. Cloning of a Porphyromonas (Bacteroides) gingivalis protease gene and characterization of its product. FEMS Microbiol Lett 1992; 71:273-8. [PMID: 1320588 DOI: 10.1016/0378-1097(92)90721-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
A clone expressing a Porphyromonas gingivalis protease from the recombinant plasmid (pYS307) has been identified in a genomic library of P. gingivalis W83. The cloned gene was localized to a 2.4-kb DNA fragment between BamHI and HindIII sites. When a 3.2-kb HindIII fragment of pYS307 was used as a probe in Southern hybridization, HindIII-digested chromosomal DNA of P. gingivalis W83, as well as those of W50 and W12, showed a single 3.2-kb hybridizing band, while that of P. gingivalis 33277 showed a 5.0-kb band. Colonies of E. coli containing pYS307 showed pronounced proteolytic zones on skim milk agar plates only when incubated in an oxygen-free environment. BSA substrate zymography of whole cell extract of E. coli containing pYS307 revealed a protease of approx. 80 kDa which was active under reducing conditions. These results suggest that the cloned protease is thiol-dependent. Antiserum to P. gingivalis W50 reacted with a single band of 80 kDa when a cell lysate sample of an E. coli JM83 containing pYS307 was prepared for electrophoresis in the absence of beta-mercaptoethanol. When samples were solubilized in the presence of beta-mercaptoethanol prior to electrophoresis, the antiserum reacted with the bands of 50 and 38 kDa, but there was no reaction observed at 80 kDa. The activity of the cloned protease was inhibited by TLCK, TPCK, EDTA, PMSF, iodoacetic acid and ZnCl2.
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Bergasa NV, Talbot TL, Alling DW, Schmitt JM, Walker EC, Baker BL, Korenman JC, Park Y, Hoofnagle JH, Jones EA. A controlled trial of naloxone infusions for the pruritus of chronic cholestasis. Gastroenterology 1992; 102:544-9. [PMID: 1732125 DOI: 10.1016/0016-5085(92)90102-5] [Citation(s) in RCA: 182] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
To test the hypothesis that opioid agonist activity contributes to the pruritus of cholestasis, a placebo-controlled single-blinded trial of naloxone, an opioid antagonist, was conducted in eight patients with primary biliary cirrhosis. After discontinuation of all conventional antipruritic medications, one or two continuous (24-hour) IV infusions of naloxone (0.2 micrograms.kg-1.min-1) and placebo solution were administered consecutively in an order that was not predetermined. Pruritus was assessed subjectively by means of four hourly recordings of a visual analogue score. In addition, objective measurements of scratching activity that were independent of gross body movements were continuously recorded using an apparatus specifically designed to measure the frequencies associated with this activity. No side effects associated with naloxone infusions were observed. Only scratching activity data obtained for the same periods of day and night during both naloxone and placebo infusions were compared. Naloxone infusions were consistently associated with a decrease in values of the scratching activity index. In addition, in 50% of the patients the infusions were associated with a decrease in visual analogue score. The mean decrease in scratching activity ranged from 29% to 96% (mean, 50%; P less than 0.001). These findings imply that increased opioid agonist activity contributes to scratching activity in cholestatic patients.
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