6901
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Zhang J, Zhang L, He A, Liu L. Applications of optical logic-operated moiré in moiré topography and deflectometry. APPLIED OPTICS 1992; 31:7355-7360. [PMID: 20802606 DOI: 10.1364/ao.31.007355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The optical logic-operated moiré is a new method to extract a specific moiré pattern. It has the capabilities of eliminating original carrier frequencies, increasing the contrast, and narrowing the fringes. We introduce its applications in moiré topography and deflectometry and also present the experimental results.
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6902
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Zhang L. [An investigation of sequelae of paralytic poliomyelitis in some districts of inner Mongolia autonomous region]. ZHONGHUA LIU XING BING XUE ZA ZHI = ZHONGHUA LIUXINGBINGXUE ZAZHI 1992; 13:366-7. [PMID: 1303320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Three hundreds and twelve sequelae of paralytic poliomyelitis were diagnosed among 163,013 lame children under 12 years of age. The prevalence of paralytic poliomyelitis was 1.91%. The result showed that although the morbidity of poliomyelitis has greatly decreased since the programme on immunization against polio were introduced, there were still a number of unreported cases. Of the cases diagnosed, ninety-three per cent were those who were unvaccinated and were mostly infected in the first four years of life.
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6903
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Zhang L, Mohan PM, Padmanabhan R. Processing and localization of Dengue virus type 2 polyprotein precursor NS3-NS4A-NS4B-NS5. J Virol 1992; 66:7549-54. [PMID: 1433530 PMCID: PMC240467 DOI: 10.1128/jvi.66.12.7549-7554.1992] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Processing of dengue virus type 2 polyprotein precursor NS3-NS4A-NS4B-NS5 could be mediated by the catalytically active NS3 protease domain and NS2B in trans at the dibasic sites NS3-NS4A and NS4B-NS5. Subcellular localization of the unprocessed precursor NS3-NS4A-NS4B-NS5 showed that it was confined to a distinct subcellular organelle in the cytoplasm, which was distinct from the distribution of the mature NS5.
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6904
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Zhang L, Rau AR. Electron-pair analysis for doubly excited ridge states. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1992; 46:6933-6941. [PMID: 9908026 DOI: 10.1103/physreva.46.6933] [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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6905
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Zhang L, Waters C, Nichols J, Crumpacker C. Inhibition of HIV-1 RNA production by the diphtheria toxin-related IL-2 fusion proteins DAB486IL-2 and DAB389IL-2. JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES 1992; 5:1181-7. [PMID: 1453329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Productive infection of cells by human immunodeficiency virus type 1 (HIV-1) is associated with the activation state of the cell and its obligatory expression of the interleukin-2 receptor (IL-2R), the latter providing a new target for antiviral therapy. A quantitative RNA-RNA hybridization assay is employed to detect production of HIV-1 RNA and to show that two IL-2 diphtheria toxin-related fusion proteins (DAB486IL-2 and its more potent, truncated form DAB389IL-2) inhibit HIV-1 RNA production in infected cells. A mutant form of DAB486IL-2 containing a single point mutation that inactivates the adenosine diphosphate ribosyltransferase activity of the toxin does not inhibit HIV RNA production, even though the molecule binds to the IL-2R. The active fusion proteins inhibit viral RNA replication in cells infected with HIV-1 clinical isolates as well as with a ZDV-resistant strain of HIV-1. These results indicate that IL-2 receptor-targeted fusion proteins can be utilized to inhibit HIV-1 replication effectively in infected human lymphocytes.
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6906
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Abstract
The frequencies of chromosomal aberrations (CA), sister-chromatid exchanges (SCE), and micronuclei (MN) in human blood lymphocytes exposed to sodium bisulfite (sulfur dioxide) at various concentrations ranging from 5 x 10(-5) M to 2 x 10(-3) M in vitro were studied. It was shown that sodium bisulfite (NaHSO3 and Na2SO3, 1:3 M/M) caused an increase in SCE and MN in human blood lymphocytes in a dose-dependent manner, and also induced mitotic delays and decreased mitotic index. For CA, our results indicated that sodium bisulfite induced an increase of chromatid-type aberrations in lymphocytes from three of four donors in a dose-dependent manner. The chemical at low concentrations induced chromatid-type aberrations, but not chromosome-type aberrations; high concentrations induced both chromatid- and chromosome-type aberrations. No cytogenetic damage in human lymphocytes was induced by sodium sulfate. The results have confirmed that sulfur dioxide is a clastogenic and genotoxic agent.
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6907
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Ozaki H, Zhang L, Buxton IL, Sanders KM, Publicover NG. Negative-feedback regulation of excitation-contraction coupling in gastric smooth muscle. THE AMERICAN JOURNAL OF PHYSIOLOGY 1992; 263:C1160-71. [PMID: 1476162 DOI: 10.1152/ajpcell.1992.263.6.c1160] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The role of phosphatidylinositol (PI) turnover in excitation-contraction coupling was investigated in canine antral smooth muscle. Acetylcholine (ACh; 0.1-1 microM) transiently increased tissue levels of inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] and increased the amplitudes of the plateau phase of slow waves and associated Ca2+ transients and phasic contractions. ACh also increased basal concentrations of cytosolic Ca2+ ([Ca2+]c), but these changes were not associated with an increase in resting tension. ATP (0.3 mM) had similar effects on Ins(1,4,5)P3 levels, basal [Ca2+]c, and resting tension. However, in contrast to the effects of ACh, ATP transiently reduced the amplitude of the plateau phase of slow waves and reduced the amplitudes of associated Ca2+ transients and phasic contractions. We investigated the possibility that two products of PI turnover, diacylglycerol (DAG) and Ins(1,4,5)P3, might provide negative feedback to regulate Ca2+ entry during slow waves. 1) DAG is known to activate protein kinase C (PKC). Activation of PKC by phorbol 12,13-dibutyrate (PDBu, 0.5 microM) reduced the amplitude of the plateau phase of slow waves and corresponding Ca2+ transients and phasic contractions. Assay of PKC showed that ACh, ATP, and PDBu stimulated enzyme activity. 2) Ins(1,4,5)P3 is known to increase [Ca2+]c by release of Ca2+ from internal stores. Basal [Ca2+]c was also increased by elevated external K+, ionomycin, thapsigargin, or caffeine. Each of these compounds reduced the amplitude and duration of slow waves. Results suggest that products of PI turnover may provide negative-feedback control of Ca2+ influx during slow waves, tending to reduce the amplitude of phasic contractile activity in gastric muscles. Differences in responses to ACh and ATP can be explained by a G protein-dependent mechanism in which ACh suppresses the voltage dependence of Ca(2+)-activated K+ channels.
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6908
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Chen SR, Zhang L, MacLennan DH. Characterization of a Ca2+ binding and regulatory site in the Ca2+ release channel (ryanodine receptor) of rabbit skeletal muscle sarcoplasmic reticulum. J Biol Chem 1992; 267:23318-26. [PMID: 1385418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
A region in the skeletal muscle ryanodine receptor between amino acids 4014 and 4765 was expressed as a trpE fusion protein. Overlay studies revealed that this region bound Ca2+ and ruthenium red, an indicator of Ca(2+)-binding sites. Ca2+ binding was mapped to subregion 13b between amino acids 4246 and 4377, encompassing a predicted high affinity Ca(2+)-binding site, and to subregion 13c between amino acids 4364 and 4529, encompassing two predicted high affinity Ca(2+)-binding sites. Ca2+ binding was then mapped to three shorter sequences, 22(13b1), 36(13c1), and 35(13c2), amino acids long, each encompassing one of the three predicted Ca(2+)-binding sites. Site-directed polyclonal antibodies were raised against these three short sequences and purified on antigen affinity columns. The antibody against sequence 13c2, lying between residues 4478 and 4512, specifically recognized both denatured and native forms of the ryanodine receptor, suggesting that at least part of the 35 amino acid sequence containing the Ca(2+)-binding site is surface-exposed. The affinity purified antibody increased the Ca2+ sensitivity of ryanodine receptor channels incorporated into planar lipid bilayers, resulting in increased open probability and opening time without altering channel conductance. The antibody-activated channel was still modulated by Ca2+, Mg2+, ATP, ryanodine, and ruthenium red. These observations suggest that sequence 13c2 may be involved in Ca(2+)-induced Ca2+ release.
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6909
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Youden KE, James SW, Eason RW, Chandler PJ, Zhang L, Townsend PD. Photorefractive planar waveguides in BaTiO3 fabricated by ion-beam implantation. OPTICS LETTERS 1992; 17:1509. [PMID: 19798230 DOI: 10.1364/ol.17.001509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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6910
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You WC, Blot WJ, Chang YS, Li JY, Jin M, Zhao YX, Kneller RW, Xie YQ, Zhang L, Xu GW. Comparison of the anatomic distribution of stomach cancer and precancerous gastric lesions. Jpn J Cancer Res 1992; 83:1150-3. [PMID: 1483930 PMCID: PMC5918719 DOI: 10.1111/j.1349-7006.1992.tb02738.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The anatomic distribution of precancerous gastric lesions among 3,400 residents in Linqu, Shandong Province of China, was compared with the anatomic distribution of stomach cancer (SC) among 959 patients in Tokyo, Japan. The incidence of SC is high in both areas, and locations within the stomach of the precancerous and malignant lesions were classified using similar criteria. Chronic atrophic gastritis (CAG) affected 98% of the population in Linqu, with intestinal metaplasia (IM) the most severe diagnosis in 33% and dysplasia (DYS) in 20%. Neither the SC nor precancerous lesions were uniformly distributed in the stomach. Among the DYS 3% were along the greater curvature of the body, 15% along the lesser curvature of the body, 25% in the angulus, 22% along the lesser curvature of the antrum, and 34% elsewhere in the antrum. Among the SC the corresponding percentages were 2, 16, 28, 25 and 29. The similarity to the SC distribution increased gradually from CAG to IM to DYS, providing further evidence for the multistage progression of precancerous gastric lesions.
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6911
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Zhang L, Weiner JL, Carlen PL. Muscarinic potentiation of IK in hippocampal neurons: electrophysiological characterization of the signal transduction pathway. J Neurosci 1992; 12:4510-20. [PMID: 1432107 PMCID: PMC6575990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Central cholinergic (muscarinic) systems play an important role in learning and memory. In mammalian central neurons, muscarinic stimulation depresses several voltage-activated K+ currents and modulates synaptic transmission. Using whole-cell voltage-clamp recordings in hippocampal CA1 neurons of rat brain slices, we report that activation of muscarinic receptors potentiates a voltage-activated, sustained K+ current (IK-type). This potentiation of IK is mediated by activation of protein kinase C and involves a G-protein-linked, intracellular Ca(2+)-dependent process. This underlying second messenger pathway may prove to be important in the mediation of other previously reported muscarinic neuronal actions.
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6912
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Chen S, Zhang L, MacLennan D. Characterization of a Ca2+ binding and regulatory site in the Ca2+ release channel (ryanodine receptor) of rabbit skeletal muscle sarcoplasmic reticulum. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)50093-4] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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6913
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Hubert R, Weber JL, Schmitt K, Zhang L, Arnheim N. A new source of polymorphic DNA markers for sperm typing: analysis of microsatellite repeats in single cells. Am J Hum Genet 1992; 51:985-91. [PMID: 1415267 PMCID: PMC1682826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
We show that dinucleotide and tetranucleotide repeat polymorphisms can be analyzed in single cells without using radioactivity or denaturing gels. This provides a rich new source of DNA polymorphisms for genetic mapping by sperm typing. The recombination fraction between two CA repeat polymorphisms was determined after whole genome amplification of single sperm, followed by typing of two different aliquots, one aliquot for each polymorphic locus. Single-cell analysis of microsatellites may also be valuable both for preimplantation genetic disease diagnosis based on single-blastomere or polar-body analysis and for the typing of forensic or ancient DNA samples containing very small amounts of nucleic acid.
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6914
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Zhang L, Olsen E, Kisil FT, Hill RD, Sehon AH, Mohapatra SS. Mapping of antibody binding epitopes of a recombinant Poa p IX allergen. Mol Immunol 1992; 29:1383-9. [PMID: 1383697 DOI: 10.1016/0161-5890(92)90175-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Antibody binding epitopes of a recombinant Poa p IX allergen were delineated using recombinant DNA and solid-phase peptide synthesis procedures. The full-length cDNA clone KBG60 and its four overlapping recombinant fragments, KBG60.1, KBG60.2, KBG8.3 and KBG10 which spanned the entire molecule were synthesized in E. coli with aid of the plasmid expression vector, pWR590.1. The antigenic and allergenic sites of these recombinant proteins were analyzed by ELISA using human IgE and murine IgG antibodies. It was thus demonstrated that although the epitopes were found on all the fragments tested, the majority of these were located on a C-terminal fragment, rKBG8.3. Furthermore, synthetic peptides were also employed to identify the epitopes of rKBG60 protein. The use of antisera raised against native KBG pollen extract and the recombinant KBG8.3 protein to scan a total of 56 overlapping deca-penta peptides, covering the entire rKBG60 protein, revealed that 10 positive peptides involved in the antibody-binding site(s). Taken together, the results of these studies indicate that rKBG60 protein possesses at least 10 antibody binding epitopes.
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6915
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Amenomori M, Cao Z, Ding LK, Feng ZY, Hibino K, Hotta N, Huang Q, Huo AX, Jia HY, Jiang GZ, Jiao SQ, Kajino F, Kasahara K, Mei DM, Meng L, Meng XR, Mizutani K, Mu J, Nanjo H, Nishizawa M, Oguro A, Ohnishi M, Ohta I, Ren JR, Saito T, Sakata M, Shi ZZ, Shibata M, Shirai T, Sugimoto H, Sun XX, Tai A, Taira K, Tan YH, Tateyama N, Torii S, Wang H, Wen CZ, Yamamoto Y, Yao XY, Yu GC, Yuan P, Yuda T, Zeng JG, Zhang CS, Zhang HM, Zhang L, Zhou WD. Search for steady emission of 10-TeV gamma rays from the Crab Nebula, Cygnus X-3, and Hercules X-1 using the Tibet air shower array. PHYSICAL REVIEW LETTERS 1992; 69:2468-2471. [PMID: 10046502 DOI: 10.1103/physrevlett.69.2468] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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6916
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Liu JZ, Zhang L, Lan MD, Shelton RN, Fluss MJ. Observation of power-law time relaxation of the magnetization of a LuBa2Cu3O7 single crystal. PHYSICAL REVIEW. B, CONDENSED MATTER 1992; 46:9123-9127. [PMID: 10002698 DOI: 10.1103/physrevb.46.9123] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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6917
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Zhang L, McSpadden B, Pakrasi HB, Whitmarsh J. Copper-mediated regulation of cytochrome c553 and plastocyanin in the cyanobacterium Synechocystis 6803. J Biol Chem 1992; 267:19054-9. [PMID: 1326543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In certain cyanobacteria and algae, cytochrome c553 or plastocyanin can serve to carry electrons from the cytochrome bf complex to photosystem I. The availability of copper in the growth medium regulates which protein is present. To investigate copper induced control of gene expression we isolated these proteins from the cyanobacterium Synechocystis 6803. Using immunodetection and optical spectroscopy, the steady state levels of cytochrome c553 and plastocyanin were measured in cells grown at different copper concentrations. The results show that in cells grown in 20-30 nM copper, cytochrome c553 was present, whereas plastocyanin was not detected. The opposite behavior was observed in cells grown in the presence of 1 microM copper; plastocyanin was present, whereas cytochrome c553 could not be detected. Both proteins were present in cells grown in 0.3 microM copper. Northern analysis of total RNA, probed with a gene fragment for cytochrome c553 or the plastocyanin gene, showed that cells grown in the presence of 20-30 nM copper have message for cytochrome c553, but not for plastocyanin, whereas cells grown in 1 microM copper have message for plastocyanin, but not for cytochrome c553. These results demonstrate that copper regulates expression of both of the genes encoding cytochrome c553 and plastocyanin prior to translation in Synechocystis 6803.
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6918
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Zhang L, Jain JK, Emery VJ. Phase transition as a function of orbital degeneracy in a generalized Hubbard model. PHYSICAL REVIEW. B, CONDENSED MATTER 1992; 46:5599-5605. [PMID: 10004348 DOI: 10.1103/physrevb.46.5599] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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6919
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Gu YD, Zhang LY, Zhang L, Sung QL, Sun LX. Vessel pathology and its clinical significance in toe transfer. J Reconstr Microsurg 1992; 8:363-70. [PMID: 1404065 DOI: 10.1055/s-2007-1006719] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
One hundred cases of toe transfer were subjected to histopathologic vessel examination. Results indicated that vascular injuries are crucially responsible for perioperative and postoperative crisis. A thorough resection of the abnormal vessel segment can prevent circulatory crisis and elevate the survival rate.
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6920
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Zhang L, Liu B. [Apolipoprotein C III binding sites (receptor) on non-parenchymal cells from rat liver]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1992; 23:233-6. [PMID: 1338544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Binding sites of apolipoprotein (apo) C III on non-parenchymal cells (NPC) isolated from rat liver were found. Apo C III was purified from delipided human plasma very low density lipoproteins. 125I-labeled-apo C III was prepared by chloramine-T method. Non-parenchymal cells were isolated from rat liver by collagenase method. Freshly isolated rat liver NPC bound 125I-labeled apo C III in a saturable way with Kd 0.1-0.55 mumol/L and Bmax 18.1-42.0 ng/ml cell protein. There were about 1.0-4.5 x 10(5) specific binding sites of apo C III on each NPC. Unlabeled apo C III, but not apo AI and B100, could inhibit these binding activities. The results demonstrate the presence of saturable and specific apo C III receptors (binding sites) on rat liver NPC, but their nature and biologic properties remain to be investigated.
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6921
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Zhang L, Fan Y, Ma M. Finite-size scaling analysis of the random-Tc model with anisotropy. PHYSICAL REVIEW. B, CONDENSED MATTER 1992; 46:6099-6104. [PMID: 10002293 DOI: 10.1103/physrevb.46.6099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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6922
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Zhang L, Yang LW, Yang LJ. [Relation between Helicobacter pylori and pathogenesis of chronic atrophic gastritis and the research of its prevention and treatment]. ZHONGGUO ZHONG XI YI JIE HE ZA ZHI ZHONGGUO ZHONGXIYI JIEHE ZAZHI = CHINESE JOURNAL OF INTEGRATED TRADITIONAL AND WESTERN MEDICINE 1992; 12:521-3, 515-6. [PMID: 1298465] [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 total detectable rate of Helicobacter pylori (HP) of 485 patients suffering from gastric diseases was 59.6%. The HP in gastric mucosa of chronic atrophic gastritis (CAG) patients was separated from the cell culture in vitro and transferred successively. The mice were perfused with exciccate alum, and the rabbits with aspirin to injure their gastric mucosa, then HP was perfused. Result showed that the change of experimental animals was identical with that of CAG patients by means of bacteriological and pathological examination. It revealed that HP was in agreement with Robert Koch's three principles about pathogenic bacteria. According to the bacterial infectious hypothesis of CAG, 53 Chinese medicinal herbs and prescriptions were investigated with bacteriostatic test. Panax notogenseng and Magnolia officinalis were discovered to be sensitive, Prunus mume and Corydalis yanhusuo were moderate sensitive, and Coptis chinensis and Rheum palmatum highly sensitive to HP. Decoction of Clearing up the Heat and Relieving the Blood Stasis and No.2 recipe of Huowei were used to treat 70 CAG patients with Stomach Heat Syndrome. The effective rate of gastroscopic examination was 85.7%, that of pathological study was 80%. In comparing with the group of Shanjiu Weitai, there was significant difference between the traditional Chinese medicine treated group and Shanjiu Weitai control group, the former being markedly better.
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6923
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Zhang L, McSpadden B, Pakrasi H, Whitmarsh J. Copper-mediated regulation of cytochrome c553 and plastocyanin in the cyanobacterium Synechocystis 6803. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)41739-5] [Citation(s) in RCA: 115] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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6924
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Chen JW, Zhang L, Lian X, Hwang F. Effect of hydroxyl radical on Na(+)-K(+)-ATPase activity of the brain microsomal membranes. CELL BIOLOGY INTERNATIONAL REPORTS 1992; 16:927-36. [PMID: 1330332 DOI: 10.1016/s0309-1651(06)80172-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Sphingomyelin liposomes and brain microsomes were oxidized by exposure to hydrogen peroxide and ferrous ion. Lipid peroxidation were measured by the formation of thiobarbituric acid- reactive substances (TBAR). Hydroxyl radical was detected using the spin- trapping technique. Incubation of sphingomyelin liposomes with H2O2-Fe2+ resulted in an increase in the formation of TBAR. Na(+)-K(+)-ATPase activity was markedly inhibited and the SH group content decreased during incubation of microsomes in the presence of H2O2-Fe2+. Sodium ferulate effectively inhibited TBAR formation, protected Na(+)-K(+)-ATPase activity and prevented the oxidative modification of SH groups. Spin-trapping experiments showed that sodium ferulate effectively scavenged the hydroxyl radicals.
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6925
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Zhang L, Li S, Liu Q, Luo H, Xiao J, Xue Z. [Relation between the occurrence of malignant arrhythmia during acute myocardial ischemia and the weight of ischemic myocardium in goats]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1992; 23:297-300. [PMID: 1298721] [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 coronary collateral circulation of goat is very spare, so myocardiac ischemia model of goat can simulate the patient previously with normal coronary circulation and suddenly developing complete occlusion of coronary arteries. In this study 80 Chengdu goats were used, and the branches of their left coronary artery were ligated. Ventricular tachycardia (VT) developed in 23 goats and ventricular fibrillation (VF) in 39 goats. VT and VF both occurred in the early phase of acute myocardial ischemia, and both had 6 min as the median time of onset. In 71 cases data on the weight of myocardiac ischemic area were collected, in which the weight percentage of ischemic area relating to the ventricles of 34 goats with VF was significantly higher than that of 37 goats without VF (35.4 +/- 2.4% vs 19.5 +/- 1.9%). After coronary ligation, 9 cases directly precipitated into VF which could not be defibrillated. In the remaining 62 cases, the weight percentage of ischemic area of 21 cases with VT was higher than that of 41 cases without VT (32.9 +/- 2.8% vs 20.9 +/- 2.1%). The relationships between the incidence of VT or VF and the weight percentage of ischemic area were fitted with logistic curve. The likelihood of occurrence of VT or VF is increased as the weight percentage of ischemia area goes up.
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6926
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Zhang L, Nakaya K, Yoshida T, Kuroiwa Y. Induction by bufalin of differentiation of human leukemia cells HL60, U937, and ML1 toward macrophage/monocyte-like cells and its potent synergistic effect on the differentiation of human leukemia cells in combination with other inducers. Cancer Res 1992; 52:4634-41. [PMID: 1324788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We have recently demonstrated that bufalin is a new potent inducer of the differentiation of human myeloid leukemia cells. The present work was carried out to examine further the effect of bufalin on the growth and characteristics of human leukemia-derived cell lines U937, ML1, and HL60. At concentrations of 5-10 nM, bufalin decreased the growth of ML1 cells preferentially at the G2 phase and U937 cells at the S and G2 phases of the cell cycle. Bufalin, under these conditions, induced the differentiation of U937, ML1, and HL60 cells to monocyte/macrophage-like cells by measuring the expression of various differentiation markers, as assessed by morphology and histochemistry, and ability to phagocytose latex particles, to reduce nitroblue tetrazolium, and to develop Fc receptors. U937 and ML1 cells started to differentiate at 4 and 6 h, respectively, after treatment with 10 nM bufalin and showed maximum differentiation 72 h later. At present, a mechanism for the bufalin-mediated induction of the differentiation of these human leukemia cells remains to be determined. The combination of bufalin with all-trans retinoic acid, 1 alpha,25-dihydroxyvitamin D3, 4'-demethylepipodophyllotoxin ethylidene-beta-D-glucoside (VP16), or human gamma-interferon synergistically induced the differentiation of HL60 and U937 cells. A similar effect on ML1 cells was observed with the combination of bufalin with VP16 or human rTNF-alpha. These results suggest that bufalin in combination with VP16, all-trans retinoic acid, 1 alpha,25-dihydroxyvitamin D3, rTNF-alpha, or gamma-interferon may be very useful in the differentiation of human leukemia.
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6927
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Snider WD, Zhang L, Yusoof S, Gorukanti N, Tsering C. Interactions between dorsal root axons and their target motor neurons in developing mammalian spinal cord. J Neurosci 1992; 12:3494-508. [PMID: 1326607 PMCID: PMC6575749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
We have utilized the lipid-soluble tracers Dil and DiA to investigate interactions between group la dorsal root afferent axons and their target motor neurons in developing rat spinal cord. We show here that la axons project toward motor pools in fascicles that exhibit a considerable degree of spatial order. A rough topography is present in that axons that innervate medially located axial motor neurons cross over others in the intermediate zone and follow a separate path along the midline toward their appropriate targets. Surprisingly, we have also found that motor neuron dendritic projections are well established in the transverse plane prior to the arrival of la afferents. Although dendrites from motor pools innervating limb muscles project directly in the path of incoming la afferents, they do not guide afferents to appropriate motor pools. The la afferents pass over the distal dendrites and grow all the way to the border between gray and developing white matter. A significant amount of terminal branching and bouton formation is in the vicinity of motor neuron somata and proximal regions of the dendritic arbors. Few boutons are found near dendrites that project dorsal to the motor pools, and virtually no boutons are found on dendrites in white matter. Our results show that la afferent axons are not guided to appropriate motor pools by random encounters with motor dendrites, and raise the possibility that mechanisms exist that promote an orderly projection of la afferents to particular regions of the ventral horn. The striking lack of innervation of white matter and dorsally directed dendrites by la afferents raises the question of whether descending and intersegmental systems have their initial interactions with these regions of the motor neuron dendritic arbor.
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6928
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Kneller RW, You WC, Chang YS, Liu WD, Zhang L, Zhao L, Xu GW, Fraumeni JF, Blot WJ. Cigarette smoking and other risk factors for progression of precancerous stomach lesions. J Natl Cancer Inst 1992; 84:1261-6. [PMID: 1640486 DOI: 10.1093/jnci/84.16.1261] [Citation(s) in RCA: 110] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Stomach cancer is generally thought to evolve through a series of gastric mucosal changes, but the determinants of the precancerous lesions are not well understood. PURPOSE Our purpose was to assess risk factors for intestinal metaplasia and gastric dysplasia arising from chronic atrophic gastritis in a general population at high risk for stomach cancer. METHODS A population-based gastroscopic screening of more than 3000 residents was conducted in a county in China with one of the world's highest rates of stomach cancer. Information on the lifestyle and other characteristics of the participants was obtained by interview, and responses were compared between those in whom the most advanced gastric lesion was dysplasia or intestinal metaplasia versus those with chronic atrophic gastritis. RESULTS Cigarette smoking was found to nearly double the risk of transition to dysplasia and to be a mild risk factor for intestinal metaplasia. Smoking accounted almost entirely for the 55% higher prevalence of dysplasia among men than among women. Risk of transition to dysplasia had a weak association with several dietary factors and was increased among those participants with a family history of stomach cancer and with blood type A. CONCLUSIONS The findings provide strong evidence for a role of tobacco consumption and offer clues to other environmental and genetic factors involved in the process of gastric carcinogenesis.
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6929
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Zhang L, Jhingan A, Castellino FJ. Role of individual gamma-carboxyglutamic acid residues of activated human protein C in defining its in vitro anticoagulant activity. Blood 1992; 80:942-52. [PMID: 1498334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
To evaluate the contributions of individual gamma-carboxyglutamic acid (gla) residues to the overall Ca(2+)-dependent anticoagulant activity of activated human protein C (APC), we used recombinant (r) DNA technology to generate protein C (PC) variants in which each of the gla precursor glutamic acid (E) residues (positions 6, 7, 14, 16, 19, 20, 25, 26, and 29) was separately altered to aspartic acid (D). In one case, a gla26V mutation ([gla26V]r-PC) was constructed because a patient with this particular substitution in coagulation factor IX had been previously identified. Two additional r-PC mutants were generated, viz, an r-PC variant containing a substitution at arginine (R) 15 ([R15]r-PC), because this particular R residue is conserved in all gla-containing blood coagulation proteins, as well as a variant r-PC with substitution of an E at position 32 ([F31L, Q32E]r-PC), because gla residues are found in other proteins at this sequence location. This latter protein did undergo gamma-carboxylation at the newly inserted E32 position. For each of the 11 recombinant variants, a subpopulation of PC molecules that were gamma-carboxylated at all nonmutated gla-precursor E residues has been purified by anion exchange chromatography and, where necessary, affinity chromatography on an antihuman PC column. The r-PC muteins were converted to their respective r-APC forms and assayed for their amidolytic activities and Ca(2+)-dependent anticoagulant properties. While no significant differences were found between wild-type (wt) r-APC and r-APC mutants in the amidolytic assays, lack of a single gla residue at any of the following locations, viz, 7, 16, 20, or 26, led to virtual complete disappearance of the Ca(2+)-dependent anticoagulant activity of the relevant r-APC mutant, as compared with its wt counterpart. On the other hand, single eliminations of any of the gla residues located at positions 6, 14, or 19 of r-APC resulted in variant recombinant molecules with substantial anticoagulant activity (80% to 92%), relative to wtr-APC. Mutation of gla residues at positions 25 and 29 resulted in r-APC variants with significant but low (24% and 9% of wtr-APC, respectively) levels of anticoagulant activity. The variant, [R15L]r-APC, possessed only 19% of the anticoagulant activity of wrt-APC, while inclusion of gla at position 32 in the variant, [F31L, Q32gla]r-APC, resulted in a recombinant enzyme with an anticoagulant activity equivalent to that of wtr-APC.
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6930
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Chen JW, Shi K, Zhang L, Huang F. Effect of glycolipids on the phase behavior and dynamic properties of phospholipid liposomes. Biochem Biophys Res Commun 1992; 186:1294-8. [PMID: 1510663 DOI: 10.1016/s0006-291x(05)81546-3] [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: 12/27/2022]
Abstract
The glycolipids of Acholeplasma laidlawii AIH089 membranes were identified and purified. The effect of monoglucosyldiacylglycerol (MGDG) and diglucosyldiacylglycerol (DGDG) on the thermotropic behavior of multilamellar vesicles of dipalmitoylphosphatidylcholine (DPPC), dipalmitoylphosphatidylglycerol (DPPG) has been investigated by high sensitivity differential scanning calorimetry. The main transition peaks were broadened, the enthalpies were decreased. DGDG caused the decrease in the transition temperatures of DPPC, DPPG liposomes by 3.08 degrees C, 4.18 degrees C, respectively. MGDG did not cause the alteration of the transition temperature of DPPC liposomes but caused the decrease of the transition temperatures of DPPG liposomes by 2.20 degrees C. ESR experiments indicate that MGDG decreased the rotational correlation time of DPPC and DPPG liposomes.
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6931
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Liu R, Zhang L. [The incidence of low birth weight infant in north China]. ZHONGHUA YI XUE ZA ZHI 1992; 72:456-8, 508. [PMID: 1337717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
From September 1989 to August 1990, the incidence of low birth weight (LBW) infant was studied collaboratively in 8 areas in north China. 29,941 infants (14,003 males and 12,938 females) were investigated, 1,348 LBW infants included those of preterm and small for gestational age (SGA) term. The incidence of LBW infant was 5.00%. The incidence of male preterm (3.15%) was higher than that of female preterm (2.39%). The incidence of female SGA term (2.46%) was higher than that of male SGA term (1.82%). 52.09% of the infants with birth weight (BW) < 2,500g was of SGA term. 35-36 weeks premature infants accounted for 61.78% and 1,500-2,499g LBW infants for 93.28%. The incidence of SGA preterm (GA < 37 weeks) was 17.8%. In this study, the incidence of LBW infant was higher in Changchun and Huhehot than in other areas.
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6932
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Yu X, Dluz S, Graves DT, Zhang L, Antoniades HN, Hollander W, Prusty S, Valente AJ, Schwartz CJ, Sonenshein GE. Elevated expression of monocyte chemoattractant protein 1 by vascular smooth muscle cells in hypercholesterolemic primates. Proc Natl Acad Sci U S A 1992; 89:6953-7. [PMID: 1379728 PMCID: PMC49623 DOI: 10.1073/pnas.89.15.6953] [Citation(s) in RCA: 161] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Atherosclerosis is marked by an overt inflammatory infiltrate, with enhanced recruitment of monocytes/macrophages observed in both human and experimental atherosclerosis. We previously determined that monocyte chemoattractant protein 1 (MCP-1) accounts for virtually all of the chemotactic activity produced by vascular (aortic) smooth muscle cells in culture. We now report that arteries from a primate model of atherosclerosis with dietary-induced hypercholesterolemia exhibit increased levels of MCP-1 mRNA expression in vivo, whereas their normal counterparts demonstrate minimal MCP-1 expression. Furthermore, immunohistochemistry and in situ hybridization clearly indicate that the expression of MCP-1 protein and mRNA is in the smooth muscle cells of the medial layer of the artery and in monocyte-like and smooth muscle-like cells found in the overlying intimal lesion. These studies indicate that one of the responses to dietary hypercholesterolemia is the expression of MCP-1 by vascular smooth muscle cells. This expression, when augmented with other cellular and molecular factors, could significantly contribute to the recruitment of monocytes/macrophages to the vessel wall.
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MESH Headings
- Animals
- Blotting, Northern
- Carotid Arteries/pathology
- Carotid Arteries/physiology
- Carotid Arteries/physiopathology
- Chemokine CCL2
- Chemotactic Factors/biosynthesis
- Chemotactic Factors/genetics
- Cholesterol/blood
- Cholesterol, Dietary
- Diet, Atherogenic
- Hypercholesterolemia/genetics
- Hypercholesterolemia/metabolism
- Hypercholesterolemia/pathology
- Macaca fascicularis
- Muscle, Smooth, Vascular/pathology
- Muscle, Smooth, Vascular/physiology
- Muscle, Smooth, Vascular/physiopathology
- Nucleic Acid Hybridization
- RNA/genetics
- RNA/isolation & purification
- RNA, Messenger/analysis
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Reference Values
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6933
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Zhang L, Jiang ZD. Development of the brainstem auditory pathway in low birthweight and perinatally asphyxiated children with neurological sequelae. Early Hum Dev 1992; 30:61-73. [PMID: 1396291 DOI: 10.1016/0378-3782(92)90087-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Low birthweight (LBW) and perinatal asphyxia are known to be high-risk factors for a number of neurodevelopmental deficits. In this study, we analyzed brainstem auditory evoked response (BAER) in 18 LBW and 36 perinatally asphyxiated children with non-progressive neurological sequelae after the age of 6 months to inspect and compare the long-term influence of LBW and perinatal asphyxia on the brainstem auditory pathway. The typical changes in the BAER of children born with LBW were slightly shorter III-V interpeak interval and smaller III-V/I-III interval ratio than normal controls. On the contrary, the abnormalities in the BAER of 36 children surviving perinatal asphyxia were characterized by a reduction of the amplitude of wave V with normal intervals. This discrepancy in the BAER between the children born with LBW and those with perinatal asphyxia implies that the two high-risk factors exert different long-term influences on the development of the brainstem auditory pathway. It is hypothesized that these characteristic changes may be indicative of a major influence of LBW on the generators contributing to wave III and that of asphyxia on the generators contributing to wave V. An increase in response threshold with abnormal latency-intensity function was found in 11% of the LBW children and 19% of the asphyxiated children, suggesting that sensorineural hearing impairment occurred more frequently in children surviving perinatal asphyxia than in those born with LBW. Follow-up study demonstrates that the abnormalities in the brainstem auditory pathway of LBW and asphyxiated children after the age of 6 months is likely to be persistent.
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6934
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Zhang L, Mock D, Cameron R. Development of glutathione S-transferase placental form (GST-P) stained foci during hamster buccal pouch mucosa carcinogenesis. Cancer Lett 1992; 64:241-7. [PMID: 1379118 DOI: 10.1016/0304-3835(92)90049-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The expression of the placental form of glutathione S-transferase (GST-P) using anti-rat liver GST-P antibody was investigated in hamster buccal pouch mucosa (HBPM) treated with 0.5% dimethylbenz[a]anthracene (DMBA) biweekly for 12 weeks. This preliminary study showed that the anti-rat liver GST-P antibody is applicable to the HBPM model and that DMBA treatment induced GST-P positive foci. These foci are randomly distributed and frequently involved the hyperplastic and dysplastic segments of the epithelium, as well as squamous cell carcinoma. Further study is needed to explore the kinetics of these GST-P positive foci.
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6935
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Spigelman I, Zhang L, Carlen PL. Patch-clamp study of postnatal development of CA1 neurons in rat hippocampal slices: membrane excitability and K+ currents. J Neurophysiol 1992; 68:55-69. [PMID: 1517828 DOI: 10.1152/jn.1992.68.1.55] [Citation(s) in RCA: 162] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
1. The postnatal development of membrane properties and outward K+ currents in CA1 neurons in rat hippocampal slices was studied with the use of whole-cell patch-clamp techniques. 2. Neurons at all postnatal ages (2-30 days; P2-30) were capable of generating tetrodotoxin (TTX)-sensitive action potentials in response to intracellular injection of depolarizing current pulses. There was a gradual increase in the amplitude and a decrease in the duration of these action potentials with age. Stable values for spike duration were reached by P15, whereas spike amplitude increased until P20-25. In P2-5 neurons, the duration of action potentials was greatly prolonged by depolarization from the resting membrane potential, indicating a weak spike repolarizing mechanism at depolarized potentials. In contrast, the duration of spikes evoked in P20-30 neurons was not affected by similar changes in the membrane potential. 3. Application of tetraethylammonium (TEA, 10 mM) had no effect on the duration of spikes in P3-5 neurons, whereas application of 4-aminopyridine (4-AP, 2 mM) produced large increases in spike duration. In contrast, the duration of spikes in P26 neurons was greatly increased after TEA application, whereas 4-AP had smaller effects on spike duration in these neurons. 4. The input resistance and membrane time constant decreased with age from P2 to P15. The values for both parameters were considerably greater than those reported with conventional intracellular recording electrodes in the immature hippocampus. The resting membrane potential became more hyperpolarized with age. When the recording pipettes contained KCl (140 mM), the resting potential of P3-4 neurons was 34 mV depolarized compared with resting potentials observed with potassium gluconate-filled pipettes. Only a 13-mV change in resting potential was observed during similar comparisons in P27-28 neurons. 5. Outward currents activated by depolarization were examined with the use of voltage-clamp techniques in P2-30 neurons. In P2-5 cells, a small, slowly inactivating outward current was evoked with depolarizing commands from holding potentials near -50 mV. By preceding the depolarizing commands with a hyperpolarizing prepulse, an additional early transient outward current was evoked. The sustained and transient outward currents were separated by their kinetic properties and their sensitivity to cobalt (Co2+), TEA, and 4-AP.(ABSTRACT TRUNCATED AT 400 WORDS)
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6936
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Zhang L, Mock D. Effect of benzoyl peroxide on two-stage oral carcinogenesis and gamma-glutamyl transpeptidase in hamsters. J Oral Pathol Med 1992; 21:270-4. [PMID: 1354260 DOI: 10.1111/j.1600-0714.1992.tb01009.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Hamster buccal pouches were treated with 7,12-dimethylbenz(a)anthracene (DMBA) triweekly for 3 wk and subsequently with 40% benzoyl peroxide (BP) in acetone for up to 27 wk. BP treatment resulted in a marked hyperplasiogenic effect and a weak tumor promoting effect. Whereas most carcinogens and tumor promoters induce gamma-glutamyl transpeptidase (GGT) activity, BP diminished its activity as compared to controls. Comparable results have also been noted in the liver, where a group of newly isolated hepatocarcinogens, peroxisome proliferators (PP), also characteristically deplete the GGT activity and placental glutathione S-transferase (GST-P), another tumor marker.
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6937
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Dong LP, Wang TY, Zhang L. [Effect of mexiletine on energy metabolism of ischemic brain in mice]. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1992; 13:354-6. [PMID: 1456059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
After 30 s ischemia induced by decapitation, the contents of ATP and phosphocreatine (PC) in mouse brain reduced, while that of lactic acid (LA) increased. When mexiletine (3.1-50 mg.kg-1) was injected ip 30 min before decapitation, the brain ATP and PC reduction, and LA accumulation were both alleviated in a dose-dependent manner. These findings suggested that mexiletine was effective in ameliorating the energy exhaustion in the ischemic brain.
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6938
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Gregoire CD, Zhang L, Daniels CK. Expression of the polymeric immunoglobulin receptor by cultured aged rat hepatocytes. Gastroenterology 1992; 103:296-301. [PMID: 1612337 DOI: 10.1016/0016-5085(92)91126-o] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The Fischer rat shows an age-related loss of both hepatic blood to bile transport and secretory component-specific binding sites for polymeric immunoglobulin (Ig) A. This age-related loss of hepatic IgA receptor function is also shown by cultured hepatocytes. It is reported here that compared with young cells, binding and uptake of 125I-polymeric IgA by cultured hepatocytes was markedly reduced in cells from senescent animals. In addition, cells from old animals showed markedly diminished secretion of secretory component determined by enzyme-linked immunosorbent assay and expression of polymeric immunoglobulin receptor determined by incorporation of 35S-labeled amino acid and fluorography. It is suggested that the age-related decrease in IgA receptor-mediated transport from serum to bile results, at least in part, from decreased expression and secretion of total hepatic secretory component.
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6939
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Wang Z, Wang L, Zhang L, Liu Q, Xue Z, Cornélissen G, Halberg F. Circadian relations among cardiovascular variables of young adults. CHRONOBIOLOGIA 1992; 19:111-20. [PMID: 1478112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Every 4 hours for 24 hours, 14 clinically healthy young individuals (6 women and 8 men), 26 +/- 4 years of age, measured systolic (S) and diastolic (D) blood pressure (BP) by sphygmomanometer and heart rate by ECG and did impedance cardiography under usual living conditions. Stroke volume (SV), cardiac output (CO) and total peripheral resistance (TPR) were calculated. Time series of SBP, DBP, HR, SV, CO and TPR were analyzed by single and population-mean cosinor. A circadian cardiovascular rhythm is demonstrated by rejection of the zero amplitude assumption in the population-mean cosinor test for SBP, DBP, HR, SV, CO and TPR (P < 0.01). TPR peaks around 0400 (-61 degrees from local midnight), in antiphase with all other variables, their acrophase occurring around 1600 (-240 degrees). A circadian rhythm of statistical significance or of borderline statistical significance is found for all variables except TPR in women. Circadian rhythm characteristics were otherwise mostly similar in men and women with a statistically significant gender difference found by parameter tests only for the MESOR and amplitude of SBP.
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6940
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Zhang L, Cui X, Schmitt K, Hubert R, Navidi W, Arnheim N. Whole genome amplification from a single cell: implications for genetic analysis. Proc Natl Acad Sci U S A 1992; 89:5847-51. [PMID: 1631067 PMCID: PMC49394 DOI: 10.1073/pnas.89.13.5847] [Citation(s) in RCA: 614] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We have developed an in vitro method for amplifying a large fraction of the DNA sequences present in a single haploid cell by repeated primer extensions using a mixture of 15-base random oligonucleotides. We studied 12 genetic loci and estimate that the probability of amplifying any sequence in the genome to a minimum of 30 copies is not less than 0.78 (95% confidence). Whole genome amplification beginning with a single cell, or other samples with very small amounts of DNA, has significant implications for multipoint mapping by sperm or oocyte typing and possibly for genetic disease diagnosis, forensics, and the analysis of ancient DNA samples.
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6941
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Stein SB, Zhang L, Roos RP. Influence of Theiler's murine encephalomyelitis virus 5' untranslated region on translation and neurovirulence. J Virol 1992; 66:4508-17. [PMID: 1602556 PMCID: PMC241260 DOI: 10.1128/jvi.66.7.4508-4517.1992] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The DA strain of Theiler's murine encephalomyelitis virus (TMEV), a picornavirus, causes a persistent, restricted infection and demyelinating disease in mice. In contrast, the GDVII strain causes an acute, fatal, neuronal disease and is highly neurovirulent. To investigate the role of the TMEV 5' untranslated region (UTR) in translational efficiency and the TMEV subgroup differences, we tested the translational efficiency of transcripts in vitro derived from plasmids containing DA, GDVII, or DA/GDVII chimeric 5' UTRs preceding a reporter gene or the rest of the TMEV genome. We demonstrated that GDVII RNA translates more efficiently in rabbit reticulocyte lysate than DA RNA and that this enhanced translation is mediated by multiple domains in the GDVII 5' UTR as well as a region of the genome outside of the 5' UTR. We also identified a region within DA nucleotides 14 to 395 which inhibits translation of DA RNA and could contribute to the persistent, restricted DA central nervous system infection; the predicted secondary structure of the 5' UTR demonstrates a remarkable stem-loop structure within this region that is relatively unique among picornaviruses. Data from experiments involving DA/GDVII chimeric 5' UTR full-length infectious cDNA clones suggested that sequences in the 5' UTR can affect the neurovirulence phenotype but that translational efficiency is necessary but not sufficient for neurovirulence. These studies emphasize the multigenic nature of neurovirulence and the importance of translation in the regulation of picornaviral gene expression.
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6942
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Shintaku MH, Zhang L, Palukaitis P. A single amino acid substitution in the coat protein of cucumber mosaic virus induces chlorosis in tobacco. THE PLANT CELL 1992; 4:751-7. [PMID: 1392593 PMCID: PMC160171 DOI: 10.1105/tpc.4.7.751] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Some strains of cucumber mosaic virus (CMV) induce a bright yellow/white chlorosis in tobacco instead of the light green/dark green mosaic induced by most CMV strains. This property is controlled by RNA 3 of this tripartite virus. Recombination between cDNA clones of RNA 3 from a green mosaic strain, Fny-CMV, and a chlorotic strain, M-CMV, and inoculation of infectious transcripts of the chimeric RNAs 3, together with RNAs 1 and 2 of Fny-CMV, localized the chlorosis induction domain to a region of the coat protein gene containing two nucleotide differences. Site-directed mutagenesis of one nucleotide to change the codon for Leu129 in the M-CMV coat protein to Pro129 of Fny-CMV changed the phenotype from chlorotic to green mosaic, whereas the opposite change in phenotype was observed when the Pro129 in the Fny-CMV coat protein was altered to Ser129. Thus, the local secondary structure surrounding amino acid 129 rather than a particular amino acid per se is involved in chlorosis induction.
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6943
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Küster H, Zhang L, Brini AT, MacGlashan DW, Kinet JP. The gene and cDNA for the human high affinity immunoglobulin E receptor beta chain and expression of the complete human receptor. J Biol Chem 1992; 267:12782-7. [PMID: 1535625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The high affinity IgE receptor (Fc epsilon RI) is a tetrameric hetero-oligomer composed of an alpha chain, a beta chain, and two disulfide-linked gamma chains. The beta chain contains four transmembrane (TM) segments and long cytoplasmic domains that are thought to play an important role in intracellular signaling. We now report the structural characterization and the sequence of the complete human beta gene and cDNA. The gene spans approximately 10 kilobases and contains seven exons. There is a single transcription initiation site preceded by a TATA box. The first exon codes for the 5'-untranslated region and a portion of the N-terminal cytoplasmic tail. TM-1 is encoded in exons 2 and 3, TM-2 in exons 3 and 4, TM-3 in exon 5, and TM-4 in exon 6. The seventh and final exon encodes the end of the C-terminal cytoplasmic tail and the 3'-untranslated sequence. The human beta gene appears to be a single copy gene. Two corresponding transcripts, detected as a doublet around 3.9 kilobases, are present in cells of mast cell and basophil lineage from different individuals, but not in the other hematopoietic cells tested here. The human beta protein is homologous to rodent beta. The consensus amino acid sequences of human, mouse, and rat beta show 69% identical residues. Analysis of the surface expression of transfected receptors indicates that human alpha gamma and alpha beta gamma complexes are expressed with comparable efficiency. Human beta interacts with human alpha more efficiently than does rat beta, and both rat and mouse beta interact with their corresponding alpha more efficiently than does human beta, demonstrating a species specificity of the alpha/beta interaction.
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6944
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Küster H, Zhang L, Brini A, MacGlashan D, Kinet J. The gene and cDNA for the human high affinity immunoglobulin E receptor beta chain and expression of the complete human receptor. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)42344-7] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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6945
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Zhang L, Liu B. [Composition and distribution of lipid and apolipoprotein in plasma lipoproteins of endogenous hypertriglyceridemia]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1992; 23:117-21. [PMID: 1452137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Lipids and apolipoproteins in plasma VLDL, IDL, LDL, HDL2 and HDL3 isolated by one-step density gradient ultracentrifugation from 7 subjects with endogenous hypertriglyceridemia (HTG) and 4 normalipemics were determined. HTG VLDL was enriched with cholesterol, and its triglyceride (TG), phospholipid (PL) and apo CII, CIII contents (mg/100 mg protein) were significantly higher than those in normal VLDL. ApoE content in HTG VLDL was prone to increasing, and apoB100 content had no apparent difference from that in normal VLDL. Compared with normal HDL2 and HDL3, the contents of total cholesterol (TC), apoAI, CII, and CIII in HTG HDL2, and apoCII, CIII in HTG HDL3 decreased. HTG HDL2 and HDL3 were rich in TG. By analysis of distribution of these lipids and apolipoproteins in various plasma lipoproteins, it was found that the abnormal composition of VLDL and HDL in HTG seemed to be a result of transport of TC, PL, and apoCII, CIII from HDL to VLDL. There was a significantly positive correlation between TC and apoAI, CII, CIII in HDL respectively, which indicated that apoCII and CIII were also associated with the alteration of HDL cholesterol. It is suggested that the elevated plasma VLDL-TG concentration in endogenous hypertriglyceridemia may induce abnormal redistribution of lipid and apolipoprotein among apoCII plasma lipoproteins, and and CIII may play an important role in these changes.
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6946
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Zhang L, Huang X, Li J. Xanthogranuloma of the stomach: a case report. EUROPEAN JOURNAL OF SURGICAL ONCOLOGY 1992; 18:293-5. [PMID: 1607043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A case of xanthogranuloma of the stomach causing clinical signs and symptoms suggestive of gastric cancer is reported. The pathological findings and the malignant potential of this lesion are discussed.
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6947
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Chen GH, Zhang L. Vulval stone. Chin Med J (Engl) 1992; 105:438. [PMID: 1499378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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6948
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Engelbrecht JR, Randeria M, Zhang L. Landau f function for the dilute Fermi gas in two dimensions. PHYSICAL REVIEW. B, CONDENSED MATTER 1992; 45:10135-10138. [PMID: 10000911 DOI: 10.1103/physrevb.45.10135] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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6949
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Roelen D, Datema G, van Bree S, Zhang L, van Rood J, Claas F. Evidence that antibody formation against a certain HLA alloantigen is associated not with a quantitative but with a qualitative change in the cytotoxic T cells recognizing the same antigen. Transplantation 1992; 53:899-903. [PMID: 1566356 DOI: 10.1097/00007890-199204000-00035] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Previous studies in highly sensitized patients waiting for a renal transplant, showed a lack of correlation between the B cell and T cell allorepertoire. The cytotoxic T cell precursor (CTLp) frequencies against HLA-antigens, toward which patients had formed antibodies (not-acceptable mismatches, NAM) were similar to those against HLA antigens, toward which no antibodies were present (acceptable mismatches, AM). In the present study we have tested whether the immunological triggering leading to antibody formation might have resulted in a different population of cytotoxic T cells. Limiting dilution assays performed in the absence or presence of antibodies against CD8 showed that CTL directed against NAM were significantly less inhibited by anti-CD8 compared to AM. A possible clinical relevance of these findings is suggested by experiments showing that the CTL against NAM were also more resistant to cyclosporine than CTL against AM.
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6950
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Zhang L, Weetman AP, Jayne DR, Turner I, Yeaman SJ, Bassendine MF, Oliveira DB. Anti-mitochondrial antibody IgG subclass distribution and affinity in primary biliary cirrhosis. Clin Exp Immunol 1992; 88:56-61. [PMID: 1563107 PMCID: PMC1554353 DOI: 10.1111/j.1365-2249.1992.tb03039.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
We have studied the total IgG subclass and anti-mitochondrial antibody (AMA) specific IgG subclass distribution in primary biliary cirrhosis (PBC) sera. In order to solve the problems caused by the differing affinities of subclass specific monoclonals and the competitive inhibition of antibodies in a whole serum assay, six sera were separated into subclass-specific fractions by affinity-depletion chromatography. AMA subclass distribution of 20 further sera from patients with PBC was assessed using conventional methods and the results were calibrated against one of the fractionated sera. Light chain distribution and AMA functional affinity were also assessed for the fractionated subclasses. Total amounts of IgG3 were significantly increased compared with normal controls. AMA were found in all IgG subclasses and not restricted predominantly to IgG3 as previously described. The functional affinity of IgG3 AMA is generally lower as compared with that of other subclasses. No light chain restriction was found.
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