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Tsai SL, Chen YM, Chen MH, Huang CY, Sheen IS, Yeh CT, Huang JH, Kuo GC, Liaw YF. Hepatitis C virus variants circumventing cytotoxic T lymphocyte activity as a mechanism of chronicity. Gastroenterology 1998; 115:954-65. [PMID: 9753499 DOI: 10.1016/s0016-5085(98)70268-9] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS High rate of chronicity after acute hepatitis C virus (HCV) infection cannot be explained in the presence of a multispecific cytotoxic T lymphocyte (CTL) response. The aim of this study was to investigate the effect of virus variants on CTL activity in patients in whom chronicity developed. METHODS CTL clones specific to a decapeptide epitope derived from hypervariable region 1 were generated from 5 HLA-A2-positive patients with acute hepatitis C by in vitro stimulation with synthetic peptides. The sequential change of this CTL epitope and its influence on the CTL recognition were examined. RESULTS Virus variants did not appear in 3 patients with recovery, whereas variants with altered peptide ligands capable of antagonizing CTL activity emerged rapidly in the remaining 2 patients in whom chronicity developed. Importantly, these HLA-A2-restricted, hypervariable region 1-specific CTL clones shared the use of T-cell receptor (TCR) genes AV6 and BV17. CONCLUSIONS These data suggest that there is only a narrow T-cell repertoire responding to a single viral peptide/HLA ligand. The emergence of HCV variants with altered peptide ligands as TCR antagonists accompanied by a limited TCR repertoire may provide a mechanism for HCV chronicity.
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Huang CY, Kasai M, Buetow DE. Extremely-rapid RNA detection in dot blots with digoxigenin-labeled RNA probes. GENETIC ANALYSIS : BIOMOLECULAR ENGINEERING 1998; 14:109-12. [PMID: 9834850 DOI: 10.1016/s1050-3862(98)00003-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
An RNA dot blot technique is described which uses digoxigenin-labeled antisense RNA probes and a highly-sensitive chemiluminescent substrate. Detection is extremely rapid: 10 s for even low abundance mRNA.
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Wang F, Huang CY, Kanagawa O. Rapid deletion of rearranged T cell antigen receptor (TCR) Valpha-Jalpha segment by secondary rearrangement in the thymus: role of continuous rearrangement of TCR alpha chain gene and positive selection in the T cell repertoire formation. Proc Natl Acad Sci U S A 1998; 95:11834-9. [PMID: 9751751 PMCID: PMC21726 DOI: 10.1073/pnas.95.20.11834] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A rearranged T cell receptor (TCR) Valpha and Jalpha gene from a cytochrome c-specific T cell hybridoma was introduced into the genomic Jalpha region. The introduced TCR alpha chain gene is expressed in a majority of CD3 positive and CD4 CD8 double-negative immature thymocytes. However, only a few percent of the double-positive and single-positive thymocytes express this TCR alpha chain. This decrease is caused by a rearrangement of TCR alpha chain locus, which deletes the introduced TCR gene. Analysis of the mice carrying the introduced TCR alpha chain and the transgenic TCR beta chain from the original cytochrome c-specific T cell hybridoma revealed that positive selection efficiently rescues double-positive thymocytes from the loss of the introduced TCR alpha chain gene. In the mice with negatively selecting conditions, T cells expressing the introduced TCR alphabeta chains were deleted at the double-positive stage. However, a large number of thymocytes escape negative selection by using an endogenous TCR alpha chain created by secondary rearrangement maintaining normal thymocyte development. These results suggest that secondary rearrangements of the TCR alpha chain gene play an important role in the formation of the T cell repertoire.
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Huang CY, Wang RS, Gu HQ, Chen H, Yuan JH. A survey of social nutrition status of the elderly in the urban area of Chengdu, Sichuan Province. BIOMEDICAL AND ENVIRONMENTAL SCIENCES : BES 1998; 11:277-285. [PMID: 9861487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The social nutrition status was investigated among 246 subjects aged 60-90 living at three urban communities in Chengdu of Sichuan Province. The questionnaire was designed to evaluate socio-demographic background, the subjects' nutrition knowledge, and the support systems for geriatric nutrition. Fasting venous blood was collected for the analysis of biochemical parameters. Blood pressure, bone mineral contents (BMC), body weight (BW) and body height (BH) were measured at the same time. Only 49.7% of the subjects correctly answered four basic questions on nutrition. Food patterns for the elderly were simple and modest. Several nutrition-related disorders for the elderly were including high systolic blood pressure (44.6%), hypertriglyceridemia (25.9%), high diastolic blood pressure (25.1%), obesity (24.5%), high PBG (20.6%), emaciation (19.9%), high FBG (17.9%) and osteoporosis (16.8%). These data indicate that the support systems for the geriatric nutrition will have to be improved.
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Abstract
This study assesses how social desirability affects responses in clinical self-report inventories. Six hundred items gathered from four normal personality questionnaires were adapted to devise a pre-experimental personality questionnaire (pre-EMHQ). Results obtained from administering Ko's Mental Health Questionnaire (KMHQ) and the pre-EMHQ to separate samples were the proportion of individuals answering "true" to each item (i.e., P(t)) and the social desirability scale value (i.e., SDSV) of each item. The Experimental Mental Health Questionnaire (EMHQ) was established from the pre-EMHQ by closely matching the P(t)s and the SDSVs of the two questionnaires. Administering the KMHQ and the EMHQ concurrently to another sample provided results for factor analysis and other statistical analyses. The SDSVs and the P(t)s for each of the KMHQ items certainly displayed a linearly increasing relation. The two sets of corresponding subscales also correlated significantly. By applying the polynomial regression analysis, the tendency to score might be expressed as a quadratic function of SDSVs. Two iterative principal-factor analyses of the two sets of subscales each resulted in two factors, and Factor 1 is similar in both the KMHQ and the EMHQ. In brief, social desirability plays a critical role in affecting responses in a clinical self-report inventory. The factors involved and suggestions proposed will be of value for further research.
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Huang CY, Uno T, Murphy JE, Lee S, Hamer JD, Escobedo JA, Cohen FE, Radhakrishnan R, Dwarki V, Zuckermann RN. Lipitoids--novel cationic lipids for cellular delivery of plasmid DNA in vitro. CHEMISTRY & BIOLOGY 1998; 5:345-54. [PMID: 9653553 DOI: 10.1016/s1074-5521(98)90173-9] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND Although synthetic nonviral vectors hold promise for the delivery of plasmid DNA, their gene-transfer efficiencies are far from matching those of viruses. To systematically investigate the structure-activity relationship of cationic lipids, a small library of cationic lipid-peptoid conjugates (lipitoids) was synthesized. The compounds were evaluated for their ability to form complexes with plasmid DNA and to mediate DNA transfer in vitro. RESULTS Lipid-peptoid conjugates were conveniently prepared in high yield using solid-phase synthesis. Several lipitoids condensed plasmid DNA into 100 nm spherical particles and protected the DNA and DNase digestion. A subset of lipitoids with a repeated (aminoethyl, neutral, neutral) sidechain trimer motif conjugated with dimyristoyl phosphatidyl-ethanolamine (DMPE) mediated DNA transfer with high efficiency. CONCLUSIONS Automated solid-phase synthesis of cationic lipids allowed the rapid synthesis of a diverse set of transfection reagents. The most active compound DMPE-(Nae-Nmpe-Nmpe)3 (Nae, N-aminoethyl glycine; Nmpe, N-p-methoxyphenethyl-glycine) is more efficient than lipofectin or DMRIE-C (two commercial cationic lipid transfection reagents) and is active in the presence and absence of serum. The activity in the presence of serum suggests potential for applications in vivo.
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Huang CY, Wang WJ, Wong CK. Skin biopsy gives the potential benefit in the diagnosis of systemic amyloidosis associated with cardiovascular involvement. ARCHIVES OF DERMATOLOGY 1998; 134:643-5. [PMID: 9606347 DOI: 10.1001/archderm.134.5.643] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Newton DL, Boque L, Wlodawer A, Huang CY, Rybak SM. Single amino acid substitutions at the N-terminus of a recombinant cytotoxic ribonuclease markedly influence biochemical and biological properties. Biochemistry 1998; 37:5173-83. [PMID: 9548748 DOI: 10.1021/bi972147h] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Onconase is a cytotoxic ribonuclease with antitumor properties. A semisynthetic gene encoding the entire protein sequence was constructed by fusing oligonucleotides coding for the first 15 and the last 6 of the 104 amino acids to a genomic clone that encoded the remaining amino acid residues [Newton, D. L., et al. (1997) Protein Eng. 10, 463-470]. The resulting protein product expressed in Escherichia coli exhibited little enzymatic or cytotoxic activity due to the unprocessed N-terminal Met amino acid residue. In this study, we demonstrate that modification of the 5'-region of the gene to encode [Met-(-1)]Ser or [Met-(-1)]Tyr instead of the native pyroglutamate results in recombinant onconase derivatives with restored activities. [Met-(-1)]rOnc(E1S) was more active than [Met-(-1)]rOnc(E1Y) in all assays tested. Consistent with the action of native onconase, [Met-(-1)]rOnc(E1S) was a potent inhibitor of protein synthesis in the cell-free rabbit reticulocyte lysate assay, degrading tRNA at concentrations that correlated with inhibition of protein synthesis. An interesting difference between the recombinant onconase derivatives and the native protein was their susceptibility to inhibition by the major intracellular RNase inhibitor, PRI (onconase is refractory to PRI inhibition). [Met-(-1)]rOnc(E1S) and [Met-(-1)]rOnc(E1Y) inhibited protein synthesis in intact SF539 neuroblastoma cells with IC50's very similar to that of onconase (IC50 3.5, 10, and 10 microg/mL after 1 day and 0.16, 0.35, and 2.5 microg/mL after 5 days for onconase, [Met-(-1)]rOnc(E1S), and [Met-(-1)]rOnc(E1Y), respectively). Similar to that of onconase, cytotoxic activity of the recombinant derivatives was potentiated by monensin, NH4Cl, and retinoic acid. Brefeldin A completely blocked the enhancement of cytotoxicity caused by retinoic acid with all three proteins. Thus, drug-induced alterations of the intracellular trafficking of the recombinant derivatives also resembles that of onconase. Stability studies as assessed in serum-containing medium in the presence or absence of cells at 37 degreesC showed that the recombinant proteins were as stable to temperature and cell culture conditions as the native protein. Therefore, exchanging the Glu amino acid residue at the amino terminus of onconase with an amino acid residue containing a hydroxyl group produces recombinant proteins with ribonuclease and cytotoxic properties similar to native onconase.
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Huang CY, Patel BK, Mah RA, Baresi L. Caldicellulosiruptor owensensis sp. nov., an anaerobic, extremely thermophilic, xylanolytic bacterium. INTERNATIONAL JOURNAL OF SYSTEMATIC BACTERIOLOGY 1998; 48 Pt 1:91-7. [PMID: 9542080 DOI: 10.1099/00207713-48-1-91] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
An anaerobic, extremely thermophilic, xylanolytic, non-spore-forming bacterium was isolated from a sediment sample taken from Owens Lake, California, and designated strain OLT (T = type strain). Strain OLT had a Gramnegative reaction and occurred as short rods which sometimes formed long chains containing a few coccoid cells. It grew at 50-80 degrees C, with an optimum at 75 degrees C. The pH range for growth was 5.5-9.0 with an optimum at about pH 7.5. When grown on glucose at optimal conditions, its doubling time was 7.3 h. In addition to glucose, the isolate utilized sucrose, xylose, fructose, ribose, xylan, starch, pectin and cellulose. Yeast extract stimulated growth on carbohydrates but was not obligately required. The end products from glucose fermentation were lactate, acetate, ethanol, H2 and CO2. The G + C content of strain OLT was 36.6 mol%. The 16S rDNA sequence analysis indicated that strain OLT was a member of the subdivision containing Gram-positive bacteria with DNA G + C content of less than 55 mol% and clustered with members of the genus Caldicellulosiruptor. Because strain OLT is phylogenetically and phenotypically different from other members of this genus, it is proposed to designate this isolate Caldicellulosiruptor owensensis sp. nov. Strain OLT is the type strain (= ATCC 700167T).
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Huang CY, Chang TC, Tsai WY, Hsiao YL. Clinical significance of thyrotropin-binding inhibitor immunoglobulin levels in newborns and their mothers. J Formos Med Assoc 1997; 96:943-7. [PMID: 9444912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We investigated whether determination of thyrotropin-binding inhibitor immunoglobulin (TBII) indices in newborns with hyperthyrotropinemia on neonatal screening, or those born to mothers with autoimmune thyroid diseases, and their mothers could predict the newborns' thyroid status. We selected 195 babies born between 1988 and 1996. TBII indices in the sera of these newborns and their mothers were tested at some time from Day 1 to Day 30 after birth, and followed up after that. The subjects were divided into four groups according to the TBII index. Group 1 consisted of 17 pairs of mothers and newborns who both had serum TBII indices greater than or equal to 15%, including four transiently hyperthyroid and 13 transiently hypothyroid newborns. Group 2 comprised 166 pairs who both had a TBII index less than 15%, including one euthyroid and 165 hypothyroid newborns. Eight of the 165 warranted permanent thyroxine therapy due to athyreosis or ectopic thyroid gland. Group 3 consisted of one pair in which the newborn's serum TBII index was 15% or higher but the mother's was less than 15%: the newborn was transiently hypothyroid. Group 4 comprised 11 pairs in which the newborns' serum TBII indices were greater than or equal to 15% but the mothers' were less than 15%. These 11 newborns were all transiently hypothyroid and nine of them warranted transient thyroxine replacement therapy. The results suggest that the long-term outcome of newborns is good when TBII indices are at least 15% in the mother and child because their thyroid dysfunction seems to be related to the transient presence of the transplacental TBII from the mother. When TBII indices in both mother and child are less than 15%, the newborns warrant further investigation due to the likelihood of permanent hypothyroidism.
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Tsai SL, Liaw YF, Chen MH, Huang CY, Kuo GC. Detection of type 2-like T-helper cells in hepatitis C virus infection: implications for hepatitis C virus chronicity. Hepatology 1997; 25:449-58. [PMID: 9021963 DOI: 10.1002/hep.510250233] [Citation(s) in RCA: 271] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
One striking clinical feature of hepatitis C virus (HCV) infection is that more than 50% of patients with acute hepatitis C will develop chronic infection. To investigate its possible mechanisms, we examined the activation of type 2-like T-helper (Th2-like) cells relating to the development of chronicity. Peripheral blood CD4+ T-cell proliferation and cytokine secretion in response to a panel of recombinant HCV antigens including core (C22), envelope 1 (E1), E2, nonstructural (NS) protein 4 (C100), fusion protein of NS3 and NS4 (C200), and NS5 were assayed in 17 patients with acute hepatitis C. All six patients with self-limited disease had a significant CD4+ T-cell proliferation to C22, E1, C100, C200, and NS5, running parallel with the antigen-stimulated secretion of interleukin (IL)-2 and interferon gamma (IFN-gamma), but not with interleukin (IL)-4 and IL-10, indicating predominant Th1 responses. Among the remaining 11 patients who developed chronicity, 6, 2, and 9 cases showed a specific CD4+ T-cell response to C22, C100, and C200, respectively, and the responses were significantly lower than those of cases with recovery in terms of stimulation index (SI) (P < .05) and of antigen-stimulated IL-2 and IFN-gamma production. Importantly, IL-4 and IL-10 (Th2 responses) were detectable, and C22-specific Th2-like T-cell clones could be generated from patients with chronicity. The data suggested that activation of Th2 responses in acute hepatitis C patients may play a role in the development of chronicity.
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Huang CY, Huang KL, Cheng TJ, Wang JD, Hsieh LL. The GST T1 and CYP2E1 genotypes are possible factors causing vinyl chloride induced abnormal liver function. Arch Toxicol 1997; 71:482-8. [PMID: 9248625 DOI: 10.1007/s002040050416] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Vinyl chloride monomer (VCM) is hepatotoxic as well as carcinogenic in humans. There are reports that exposure to VCM seems to induce abnormal liver function, liver fibrosis, cirrhosis, portal hypertension, and angiosarcoma of the liver. In vivo, VCM is metabolized by cytochrome P450 2E1 (CYP2E1) to form the electrophilic metabolites, chloroethylene oxide (CEO) and chloroacetaldehyde (CAA), which may either cause cell damage or be further metabolized and detoxified by glutathione S-transferases (GSTs). This study investigated whether or not the genotypes CYP2E1, glutathione S-transferase theta (GST T1) and mu (GST M1) correlated with abnormal liver function found in vinyl chloride exposed workers. For this study, 251 workers from five polyvinyl chloride plants were enrolled. The workers were classified into two exposure groups (high and low) and the degree of exposure was determined based on their job titles and airborne VCM concentration. The activity of serum alanine aminotransferase (ALT) was used as the parameter of liver function. The genotypes CYP2E1, GST T1 and GST M1 were determined by polymerase chain reaction and restriction fragment length polymorphism on peripheral white blood cell DNA. Other potential risk factors were also ascertained and the confounding effect was adjusted accordingly. Stratified analyses were used to explore the correlation between the alteration of liver function and the genotypes CYP2E1, GST T1 and GST M1 among the workers exposed to different levels of VCM. The following results were obtained (1) at low VCM exposure, the odds ratio (OR) of positive GST T1 on abnormal ALT was 3.8 (95% CI 1.2-14.5) but the CYP2E1 genotype was not associated with abnormal ALT. (2) At high VCM exposure, a c2c2 CYP2E1 genotype was associated with increased OR on abnormal ALT (OR 5.4, 95% CI 0.7-35.1) and positive GST T1 was significantly associated with decreased OR on abnormal ALT (OR 0.3, 95% CI 0.1-0.9). (3) Multiple linear and logistic regression also showed strong interactions of the VCM exposure to CYP2E1 as well as to the GST T1 genotype. These observations suggest that the two genotypes, CYP2E1 and GST T1, may play important roles in the biotransformation of VCM, the effect of which leads to liver damage.
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Liu BD, Huang CY. Design and implementation of the tree-based fuzzy logic controller. IEEE TRANSACTIONS ON SYSTEMS, MAN, AND CYBERNETICS. PART B, CYBERNETICS : A PUBLICATION OF THE IEEE SYSTEMS, MAN, AND CYBERNETICS SOCIETY 1997; 27:475-87. [PMID: 18255886 DOI: 10.1109/3477.584954] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In this paper, a tree-based approach is proposed to design the fuzzy logic controller. Based on the proposed methodology, the fuzzy logic controller has the following merits: the fuzzy control rule can be extracted automatically from the input-output data of the system and the extraction process can be done in one-pass; owing to the fuzzy tree inference structure, the search spaces of the fuzzy inference process are largely reduced; the operation of the inference process can be simplified as a one-dimensional matrix operation because of the fuzzy tree approach; and the controller has regular and modular properties, so it is easy to be implemented by hardware. Furthermore, the proposed fuzzy tree approach has been applied to design the color reproduction system for verifying the proposed methodology. The color reproduction system is mainly used to obtain a color image through the printer that is identical to the original one. In addition to the software simulation, an FPGA is used to implement the prototype hardware system for real-time application. Experimental results show that the effect of color correction is quite good and that the prototype hardware system can operate correctly under the condition of 30 MHz clock rate.
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Huang CY, Chen TC. Bullous pemphigoid associated with systemic lupus erythematosus: the discrimination of antibasement membrane zone antibody. Int J Dermatol 1997; 36:40-2. [PMID: 9071614 DOI: 10.1111/j.1365-4362.1997.tb03301.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Yang Y, Huang CY, Peng SS, Li J. Carotenoid analysis of several dark-green leafy vegetables associated with a lower risk of cancers. BIOMEDICAL AND ENVIRONMENTAL SCIENCES : BES 1996; 9:386-392. [PMID: 8988807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We have examined the carotenoid contents of several dark green vegetables found to be associated with a lower risk of various epithelial cancers in our epidemiological study and animal study. Samples of these vegetables were quantitatively examined by high-performance liquid chromatography (HPLC) on a C-18 reversed-phase column for individual carotenoid content. Pure reference compounds (alpha-carotene, beta-carotent, lycopene, canthaxanthin, and lutein) and internal standard (beta-Apo-8'-carotenal) were employed to quantify xanthophylls and carotenes in these vegetables. The results indicated that fresh, dark-green, leafy vegetables were high in beta-carotene (0.94-9.36 mg/100 g) and oxygenated carotenoids or xanthophylls, primarily lutein (0.94-7.39 mg/100 g), whereas lycopene and alpha-carotene were not prominent and canthaxanthin was non existent in these vegetables. These analyses suggest that consumption of carotenoids such as lutein in addition to beta-carotene may be associated with a lower risk of cancers.
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Huang CY, Ferrell JE. Ultrasensitivity in the mitogen-activated protein kinase cascade. Proc Natl Acad Sci U S A 1996; 93:10078-83. [PMID: 8816754 PMCID: PMC38339 DOI: 10.1073/pnas.93.19.10078] [Citation(s) in RCA: 731] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The mitogen-activated protein kinase (MAPK) cascade is a highly conserved series of three protein kinases implicated in diverse biological processes. Here we demonstrate that the cascade arrangement has unexpected consequences for the dynamics of MAPK signaling. We solved the rate equations for the cascade numerically and found that MAPK is predicted to behave like a highly cooperative enzyme, even though it was not assumed that any of the enzymes in the cascade were regulated cooperatively. Measurements of MAPK activation in Xenopus oocyte extracts confirmed this prediction. The stimulus/response curve of the MAPK was found to be as steep as that of a cooperative enzyme with a Hill coefficient of 4-5, well in excess of that of the classical allosteric protein hemoglobin. The shape of the MAPK stimulus/ response curve may make the cascade particularly appropriate for mediating processes like mitogenesis, cell fate induction, and oocyte maturation, where a cell switches from one discrete state to another.
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Huang CY, Wen SH, Yu MD. [Enteral nutrition in the severely head injured patients]. ZHONGHUA HU LI ZA ZHI = CHINESE JOURNAL OF NURSING 1996; 31:435-8. [PMID: 9295496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This study evaluated the effect of modified element diet as early nutritional support in 20 severe head-injured patients. The study group (20 cases) was fed gastrically with the element diet of dextrin as glycogen by a nasal feeding tube, and the control group (20 cases) was nutritional supported with common method. The enteral nutrition (EN) was started within 5.0 +/- 2. 1 days post injury for study group versus 9.1 #+/- 4.6 days for control group (P < 0.05). The serum albumin levels of the study group rose in the third week post injury, the data of the forth week was slightly higher than that of the first week. In control group, the serum albumin levels reduced continuously within four weeks post injury. The serum glucose levels of the study group was significantly lower than that of the control group on the fifth day post injury (P < 0.05). 45% patients in the study group had diarrhea. This study showed that the modified element diet can be helpful for the early enteral nutrition and beneficial to improve the nutritional condition of the severe head-injured patients.
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Chueh SC, Yu HJ, Chiu TY, Huang CY, Lai MK. Treating benign prostatic hyperplasia with finasteride in Chinese men: one-year experience. J Formos Med Assoc 1996; 95:650-2. [PMID: 8870441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
To evaluate the long-term efficacy and safety of finasteride in the treatment of symptomatic benign prostatic hyperplasia (BPH), 50 patients with symptomatic BPH were initially evaluated in a double blind, placebo-controlled study for 6 months. The patients were then treated with finasteride in an open extension study in which all received the same dose of finasteride (5 mg/day) for another 6 months. Among the patients (n = 23) who completed the extension study, prostate volume was significantly reduced from baseline by 15%, maximum urine flow rate improved by 1.9 mL/second, symptom scores improved by 37% and serum prostatic specific antigen (PSA) level decreased by 1.34 ng/mL. Other than serum PSA level, these data differed insignificantly from data at the end of the first 6 months. The adverse events observed at the end of the first 6 months (two patients with decreased sexual libido and two with impotency) persisted throughout the study extension period. At the end of the 12 months study, one more patient reported decreased libido. The sustained clinical efficacy and low incidence of side-effects of daily treatment with finasteride 5 mg for 1 year indicate that finasteride is safe and effective for managing symptomatic BPH in Chinese men.
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Huang CY, Bi G, Miller PS. Triplex formation by oligonucleotides containing novel deoxycytidine derivatives. Nucleic Acids Res 1996; 24:2606-13. [PMID: 8692703 PMCID: PMC145961 DOI: 10.1093/nar/24.13.2606] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Homopurine sequences of duplex DNA are binding sites for triplex-forming oligodeoxyribopyrimidines. The interactions of synthetic duplex DNA targets with an oligodeoxyribopyrimidine containing N4-(6-amino-2-pyridinyl)deoxycytidine (1), a nucleoside designed to interact with a single C-G base pair interruption of the purine target tract, was studied by UV melting, circular dichroism spectroscopy and dimethylsulfate alkylation experiments. Nucleoside 1 supports stable triplex formation at pH 7.0 with formation of a 1-Y-Z triad, where Y-Z is a base pair in the homopurine tract of the target. Selective interaction was observed when Y-Z was C-G, although A-T and, to a lesser extent, T-A and G-C base pairs were also recognized. The circular dichroism spectra of the triplex having a 1-C-G triad were similar to those of a triplex having a C(+)-G-C triad, suggesting that the overall structures of the two triplexes are quite similar. Removal of the 6-amino group from 1 essentially eliminated triplex formation. Reaction of a triplex having the 1-C-G triad with dimethylsulfate resulted in a 50% reduction of methylation of the G residue of this triad. In contrast, the G of a similar triplex containing a U-C-G triad was not protected from methylation by dimethylsulfate. These results are consistent with a binding mode in which the 6-amino-2-pyridinyl group of 1 spans the major groove of the target duplex at the 1-C-G binding site and forms a hydrogen bond with the O6 of G. An additional stabilizing hydrogen bond could form between the N4 of the imino tautomer of 1 and the N4 amino group of C.
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Zhu DM, Tekle E, Chock PB, Huang CY. Reversible phosphorylation as a controlling factor for sustaining calcium oscillations in HeLa cells: Involvement of calmodulin-dependent kinase II and a calyculin A-inhibitable phosphatase. Biochemistry 1996; 35:7214-23. [PMID: 8679550 DOI: 10.1021/bi952471h] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The role of reversible phosphorylation in histamine-induced Ca2+ oscillations in HeLa cells has been investigated by using various activators and inhibitors of protein kinases and phosphatases. Electroporation was employed to introduce impermeable materials into single cells, which proved to be a useful and convenient tool. Of the kinases examined, cAMP-dependent kinase, protein kinase C, and calmodulin-dependent kinase II (CaMK II), only CaMK II was essential. When added during oscillations, both W-7, a calmodulin antagonist, and KN-62, a specific CaMK II inhibitor, caused one large Ca2+ spike before halting the process. Introduction of the Ca2+/calmodulin-independent catalytic domain of CaMK II into the cells forestalled their response to histamine. These results show that intracellular Ca2+ cannot oscillate when CaMK II is locked in either the inactive or the stimulated state. External Ca2+ electroporated into cells preloaded with the catalytic domains was quickly removed (but not when the cells were pretreated with the endoplasmic reticulum Ca(2+)-ATPase inhibitor, tapsigargin), indicating that the ATP-driven Ca2+ pump was somehow activated by CaMK II. Protein phosphatase inhibitors calyculin A and okadaic acid abolished ongoing oscillations and, when added at low concentrations, prolonged the interspike interval. Immunoprecipitation experiments with 32P(i)-labeled cells provided the first evidence that inositol 1,4,5-trisphosphate receptor (IP3R) was phosphorylated by CaMK II in vivo. The extent of phosphorylation was increased in the presence of histamine, significantly enhanced by calyculin A, and greatly reduced by W-7. Our observations are consistent with the concept that repetitive phosphorylation-dephosphorylation cycles regulating IP3R and Ca2+ pumps are a controlling factor for sustained Ca2+ oscillations in HeLa, and possibly other, cells.
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Huang CY, Ferrell JE. Dependence of Mos-induced Cdc2 activation on MAP kinase function in a cell-free system. EMBO J 1996; 15:2169-73. [PMID: 8641282 PMCID: PMC450139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The progression of G2-arrested Xenopus laevis oocytes into meiotic M-phase is accompanied by the nearly simultaneous activation of p42 MAP kinase and Cdc2/cyclin B. This timing raises the possibility that the activation of one kinase might depend upon the other. Here we have examined whether Cdc2 activation requires p42 MAP kinase function. We have reconstituted Mos-induced Cdc2 activation in cell-free Xenopus oocyte extracts, and have found that Mos-induced Cdc2 activation requires active p42 MAP kinase, is inhibited by a MAP kinase phosphatase and is independent of protein synthesis. These findings indicate that p42 MAP kinase is an essential component of the M phase trigger in this system.
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147
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Pirrung MC, Huang CY. A general method for the spatially defined immobilization of biomolecules on glass surfaces using "caged" biotin. Bioconjug Chem 1996; 7:317-21. [PMID: 8816954 DOI: 10.1021/bc960013v] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A method has been developed to spatially define the immobilization of proteins on surfaces using the classic avidin-biotin link, for which a wide variety of biochemical reagents are commercially available. A derivative of biotin bearing a photoremovable nitrobenzyl group (MeNPOC-biotin) has been prepared in a form suitable for simple linkage to biomolecules and surfaces. It has been used to functionalize bovine serum albumin (BSA) to form MeNPOC-biotin-BSA, which can then be coated onto glass. On photolithographic patterning of the surface, biotins are freed in the irradiated areas, permitting avidin to be localized at the irradiated sites. Subsequent addition of a biotinylated molecule permits its site-specific localization. Patterning of a biotinylated antibody and dye-labeled avidins or streptavidin using this reagent has been demonstrated by fluorescence microscopy.
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Lin JG, Huang CY, Xue YY, Chu CW, Cheng XL, Ho JC. Pressure effect on Tc for (Yb1-xPrx)Ba2Cu3O7. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:11855-11859. [PMID: 9982815 DOI: 10.1103/physrevb.53.11855] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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149
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Lee DD, Huang CY, Wong CK, Kao KP. Systemic amyloidosis with initial polyneuropathy. J Dermatol 1996; 23:296-8. [PMID: 8935350 DOI: 10.1111/j.1346-8138.1996.tb04018.x] [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: 02/03/2023]
Abstract
We report a case of systemic amyloidosis with the initial sign of polyneuropathy. The patient eventually developed heart failure, macroglossia, and ecchymoses 6 years later. Biopsies from the sural nerve and normal-looking skin both proved the existence of amyloid.
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150
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Huang CY, Dong P, Lu ZY. [Analysis of early nutritional status of 63 cases following severe head injury]. ZHONGHUA HU LI ZA ZHI = CHINESE JOURNAL OF NURSING 1996; 31:187-9. [PMID: 8826203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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