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Liu PP, Le J, Nian M. Nuclear factor-kappaB decoy: infiltrating the heart of the matter in inflammatory heart disease. Circ Res 2001; 89:850-2. [PMID: 11701609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
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27
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Zhang H, Le J, Huang X. [The clinical value of the TSGF pre and post-therapy in patients with nasopharyngeal carcinoma(NPC)]. LIN CHUANG ER BI YAN HOU KE ZA ZHI = JOURNAL OF CLINICAL OTORHINOLARYNGOLOGY 2001; 15:356-7. [PMID: 12541902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To investigate the role of TSGF (tumor supplied group of factor) in early diagnosing and predicting in patients with NPC. METHOD EBV-IgA and level of TSGF were measured before therapy and 1 month, 1 year after therapy in 35 patients with NPC, and the relationship between them was researched. RESULT The diagnostic sensitivity of TSGF and EBV-IgA was 91%, 97% respectively, there is no significant relation between them. After treatment, the level of TSGF in PD (progression disease) patient remained higher, but had a significantly drop in RR(including the CR, PR and SI)) patient. CONCLUSION Results suggested that TSGF may be useful in diagnosing and prediction of NPC.
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Abraham MH, Le J, Acree WE, Carr PW, Dallas AJ. The solubility of gases and vapours in dry octan-1-ol at 298 K. CHEMOSPHERE 2001; 44:855-863. [PMID: 11482678 DOI: 10.1016/s0045-6535(00)00288-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Ostwald solubility coefficients of 74 compounds in dry octan-1-ol at 298 K have been determined, and have been combined with literature values and additional values we have calculated from solubilities in dry octan-1-ol and vapour pressures to yield a total of 161 log L(OctOH) values at 298 K. These L(OctOH) values are identical to gas-to-dry octan-1-ol partition coefficients, often denoted as K(OA). Application of the solvation equation of Abraham to 124 values as a training set yielded a correlation equation with n = 124, S.D. = 0.125, r2 = 0.9970 and F = 7731. This equation was then used to predict 32 values of log L(OctOH) as a test set, giving a standard deviation, S.D. of 0.131, an average absolute deviation of 0.085 and an average deviation of -0.009 log units. The solvation equation for the combined 156 log L(OctOH) values was log L(OctOH) = -0.120 - 0.203R2 + 0.560pi2(H) + 3.560 sum(alpha2(H)) + 0.702 sum(beta2(H)) + 0.939 logL16, n =156, r2 = 0.9972, S.D. = 0.125, F = 10573, where, n is the number of data points (solutes), r the correlation coefficient, S.D. the standard deviation and F is the F-statistic. The independent variables are solute descriptors as follows: R2 is an excess molar refraction, pi2(H) the dipolarity/polarisability, sum(alpha2(H)) the overall or summation hydrogen-bond acidity, sum(beta2(H)) the overall or summation hydrogen-bond basicity and L16 is the Ostwald solubility coefficient on hexadecane at 298 K. The equation is consistent with similar equations for the solubility of gases and vapours into methanol, ethanol and propan-1-ol. It is suggested that the equation can be used to predict further values of log L(OctOH), for which the solute descriptors are known, to within 0.13 log units.
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Van Gestel K, Le J, Verbelen JP. A comparison of F-actin labeling methods for light microscopy in different plant specimens: multiple techniques supplement each other. Micron 2001; 32:571-8. [PMID: 11166577 DOI: 10.1016/s0968-4328(00)00054-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Different detection methods for F-actin labeling were compared on a range of plant specimens: cultured cells, whole organ mounts and sectioned material. For cultured cells, microinjection of labeled phalloidin yielded the most detailed picture but careful permeation methods come close, while immunocytochemical methods always gave relatively poor detail, especially on the level of the fine filaments. For whole organ mounts and sectioned material, permeation methods and immunolocalization are the methods of choice, however never reaching the level of resolution of permeation methods in single cells. It is clear that there is no general and universal good method and multiple techniques are needed, especially when working with different specimens and with different aims.
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Huber VC, Lynch JM, Bucher DJ, Le J, Metzger DW. Fc receptor-mediated phagocytosis makes a significant contribution to clearance of influenza virus infections. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:7381-8. [PMID: 11390489 DOI: 10.4049/jimmunol.166.12.7381] [Citation(s) in RCA: 267] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Fc receptors for IgG expressed on macrophages and NK cells are important mediators of opsonophagocytosis and Ab-dependent cell-mediated cytotoxicity. Phagocyte-mediated opsonophagocytosis is pivotal for protection against bacteria, but its importance in recovery from infection with intracellular pathogens is unclear. We have now investigated the role of opsonophagocytosis in protection against lethal influenza virus infection by using FcR gamma(-/-) mice. Absence of the FcR gamma-chain did not affect the expression of IFN-gamma and IL-10 in the lungs and spleens after intranasal immunization with an influenza subunit vaccine. Titers of serum and respiratory Abs of the IgM, IgG1, IgG2a, and IgA isotypes in FcR gamma(-/-) mice were similar to levels seen in FcR gamma(+/+) mice. Nevertheless, FcR gamma(-/-) mice were highly susceptible to influenza infection, even in the presence of anti-influenza Abs from immune FcR gamma(+/+) mice. NK cells were not necessary for the observed Ab-mediated viral clearance, but macrophages were found to be capable of actively ingesting opsonized virus particles. We conclude that Fc receptor-mediated phagocytosis plays a pivotal role in clearance of respiratory virus infections.
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MESH Headings
- Animals
- Antibodies, Viral/biosynthesis
- CD3 Complex
- Cell Line
- Cytokines/biosynthesis
- Genetic Predisposition to Disease
- Humans
- Immune Sera/administration & dosage
- Immunization, Passive
- Immunoglobulin Isotypes/biosynthesis
- Influenza A virus/immunology
- Influenza, Human/genetics
- Influenza, Human/immunology
- Influenza, Human/prevention & control
- Influenza, Human/virology
- Injections, Intraperitoneal
- Lung/immunology
- Lung/metabolism
- Macrophages/immunology
- Macrophages/virology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Inbred CBA
- Mice, Knockout
- Mice, Transgenic
- Phagocytosis/immunology
- Receptors, Antigen, T-Cell/genetics
- Receptors, Fc/deficiency
- Receptors, Fc/genetics
- Receptors, Fc/physiology
- Spleen/immunology
- Spleen/metabolism
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Tugores A, Le J, Sorokina I, Snijders AJ, Duyao M, Reddy PS, Carlee L, Ronshaugen M, Mushegian A, Watanaskul T, Chu S, Buckler A, Emtage S, McCormick MK. The epithelium-specific ETS protein EHF/ESE-3 is a context-dependent transcriptional repressor downstream of MAPK signaling cascades. J Biol Chem 2001; 276:20397-406. [PMID: 11259407 DOI: 10.1074/jbc.m010930200] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Exon trapping and cDNA selection procedures were used to search for novel genes at human chromosome 11p13, a region previously associated with loss of heterozygosity in epithelial carcinomas. Using these approaches, we found the ESE-2 and ESE-3 genes, coding for ETS domain-containing transcription factors. These genes lie in close proximity to the catalase gene within a approximately 200-kilobase genomic interval. ESE-3 mRNA is widely expressed in human tissues with high epithelial content, and immunohistochemical analysis with a newly generated monoclonal antibody revealed that ESE-3 is a nuclear protein expressed exclusively in differentiated epithelial cells and that it is absent in the epithelial carcinomas tested. In transient transfections, ESE-3 behaves as a repressor of the Ras- or phorbol ester-induced transcriptional activation of a subset of promoters that contain ETS and AP-1 binding sites. ESE-3-mediated repression is sequence- and context-dependent and depends both on the presence of high affinity ESE-3 binding sites in combination with AP-1 cis-elements and the arrangement of these sites within a given promoter. We propose that ESE-3 might be an important determinant in the control of epithelial differentiation, as a modulator of the nuclear response to mitogen-activated protein kinase signaling cascades.
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32
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Zhao YH, Le J, Abraham MH, Hersey A, Eddershaw PJ, Luscombe CN, Butina D, Beck G, Sherborne B, Cooper I, Platts JA, Boutina D. Evaluation of human intestinal absorption data and subsequent derivation of a quantitative structure–activity relationship (QSAR) with the Abraham descriptors. J Pharm Sci 2001; 90:749-84. [PMID: 11357178 DOI: 10.1002/jps.1031] [Citation(s) in RCA: 357] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The human intestinal absorption of 241 drugs was evaluated. Three main methods were used to determine the human intestinal absorption: bioavailability, percentage of urinary excretion of drug-related material following oral administration, and the ratio of cumulative urinary excretion of drug-related material following oral and intravenous administration. The general solvation equation developed by Abraham's group was used to model the human intestinal absorption data of 169 drugs we considered to have reliable data. The model contains five Abraham descriptors calculated by the ABSOLV program. The results show that Abraham descriptors can successfully predict human intestinal absorption if the human absorption data is carefully classified based on solubility and administration dose to humans.
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Leonard AW, Hyne RV, Lim RP, Leigh KA, Le J, Beckett R. Fate and toxicity of endosulfan in Namoi River water and bottom sediment. JOURNAL OF ENVIRONMENTAL QUALITY 2001; 30:750-759. [PMID: 11401264 DOI: 10.2134/jeq2001.303750x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Endosulfan (6,7,8,9,10,10,-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepine-3-oxide) sorption (standardized to 1% total organic carbon and dry weight) was significantly (P < 0.05) more concentrated on the large (>63 microm) particle fraction compared with smaller size fractions (<5 microm and 5-24 microm) of bottom sediments from the Namoi River, Australia. Following completion of the particle size fractionation (6 to 12 wk) and a sediment toxicity assessment (2 wk), the sediments showed large decreases in concentrations of alpha-endosulfan that coincided with an increase in endosulfan sulfate concentrations and minimal changes in beta-endosulfan concentrations. In the Namoi River, similar patterns were observed in the composition of total endosulfan in monthly measurements of bottom sediments and in passive samplers placed in the water column following runoff from cotton (Gossypium hirsutum L.) fields. The toxicity of endosulfan sulfate in river water indicated by the nymphs of the epibenthic mayfly Jappa kutera, was more persistent than the alpha- and beta-endosulfan parent isomers due to its longer half-life. This suggests that endosulfan sulfate would contribute most to previously observed changes in population densities of aquatic biota. Measured concentrations of total endosulfan in river water of up to 4 microg L(-1) following storm runoff, exceed the range of the 96-h median lethal concentration (LC50) values in river water for both alpha-endosulfan (LC50 = 0.7 microg L(-1); 95% confidence interval [CI] = 0.5 to 1.1) and endosulfan sulfate (LC50 = 1.2 microg L(-1); 95% CI = 0.4 to 3.3). In contrast, the 10-d LC50 value for total endosulfan in the sediment toxicity test (LC50 = 162 microg kg(-1); 95% CI = 120 to 218 microg kg(-1)) was more than threefold higher than the highest measured concentration of total endosulfan in field samples of bottom sediment (48 microg kg(-1)). This suggests that pulse exposures of endosulfan in the water column following storm runoff may be more acutely toxic to riverine biota than in contaminated bottom sediment.
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Xie JP, Le J, Wang HH. [Harnessing the microbial genome to develop novel antibiotics]. YAO XUE XUE BAO = ACTA PHARMACEUTICA SINICA 2001; 36:396-400. [PMID: 12584867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
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Abstract
OBJECTIVE To evaluate clinical information on Implanon as a long-term method of contraception and, specifically, to review the efficacy and adverse effect profile of Implanon. DATA SOURCES A MEDLINE search (from 1966 through June 1999) was performed to retrieve primary and review articles. The search was limited to data on human subjects. Some references were identified through secondary sources. STUDY SELECTION AND DATA EXTRACTION Pharmacokinetic and pharmacodynamic studies, and clinical trials assessing the efficacy and safety of desogestrel implants were reviewed. Relevancy and consistency of information was assessed for each trial. DATA SYNTHESIS Implanon is the newest contraceptive implant system that has completed worldwide Phase III clinical trials. It is a single rod that contains a core of 68 mg of 3-keto-desogestrel with a membrane of ethylene vinyl acetate. Inhibition of ovulation occurs within one day of implantation, and effective contraception lasts for three years. Fertility returns within one month after implant removal. Insertion and removal by trained medical professionals is simple, and only minor complications have been documented. Adverse effects are mild and primarily consist of abnormal bleeding, weight gain, acne, breast pain, and headache. CONCLUSIONS The data on Implanon indicate that it provides effective long-term contraception with limited adverse effects. It appears to be a good addition to the currently available contraceptives.
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Zhang Z, Sun M, Wang H, Le J. [Protective effect of erigeron injections on hepatotoxicity induced by intestinal ischemia-reperfusion in mice]. WEI SHENG YAN JIU = JOURNAL OF HYGIENE RESEARCH 2001; 30:86-8. [PMID: 11321958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
The liver injury was induced by intestinal ischemia-reperfusion and the protective effect of erigeron injection (EI) was studied in mice. The results showed that serum alanine transaminase (ALT) and glutathione S-transferase (GST) activity increased while the root of superior mesenteric artery was blocked with non-injury artery clap for 20 minute and reperfusion for 1 hour. EI could protect the above changes induced by intestinal ischemia-reperfusion. EI could reduce the activities of serum ALT and GST, decrease the content of hepatic MDA and significantly increase the activity of SOD. The pathological changes of hepatocytes induced by intestinal ischemia-reperfusion were less in EI groups. These results suggested that EI could protect the liver of mice from injury induced by intestinal ischemia-reperfusion. One of the mechanisms of hepatoprotective action was related to the antioxidative function of erigeron.
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Le J, Vandenbussche F, Van Der Straeten D, Verbelen JP. In the early response of Arabidopsis roots to ethylene, cell elongation is up- and down-regulated and uncoupled from differentiation. PLANT PHYSIOLOGY 2001; 125:519-22. [PMID: 11161008 PMCID: PMC1539361 DOI: 10.1104/pp.125.2.519] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
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38
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Le J, Vandenbussche F, Van Der Straeten D, Verbelen JP. In the early response of Arabidopsis roots to ethylene, cell elongation is up- and down-regulated and uncoupled from differentiation. PLANT PHYSIOLOGY 2001. [PMID: 11161008 DOI: 10.1104/pp.125.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
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39
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Le J, Vandenbussche F, Van Der Straeten D, Verbelen JP. In the early response of Arabidopsis roots to ethylene, cell elongation is up- and down-regulated and uncoupled from differentiation. PLANT PHYSIOLOGY 2001. [PMID: 11161008 DOI: 10.1104/pp.125.1.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
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40
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Arulanandam BP, Raeder RH, Nedrud JG, Bucher DJ, Le J, Metzger DW. IgA immunodeficiency leads to inadequate Th cell priming and increased susceptibility to influenza virus infection. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:226-31. [PMID: 11123296 DOI: 10.4049/jimmunol.166.1.226] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
IgA is considered to be the principal Ab involved in defense against pathogens in the mucosal compartment. Using mice with a targeted disruption in IgA gene expression (IgA(-/-) mice), we have examined the precise role of IgA in protective anti-influenza responses after intranasal vaccination. IgA(-/-) mice immunized intranasally with soluble hemagglutinin (hemagglutinin subtype 1) and neuraminidase (neuraminidase subtype 1) vaccine in the absence of adjuvant were found to be more susceptible to influenza virus infection than IgA(+/+) mice (13 vs 75% survival after virus challenge). Inclusion of IL-12 during immunization restored the protective efficacy of the vaccine to that seen in IgA(+/+) animals. IgA(-/-) mice had no detectable IgA expression, but displayed enhanced serum and pulmonary IgM and IgG Ab levels after IL-12 treatment. Assessment of T cell function revealed markedly depressed splenic lymphoproliferative responses to PHA in IgA(-/-) animals compared with IgA(+/+) mice. Furthermore, IgA(-/-) animals displayed impaired T cell priming to the H1N1 subunit vaccine, with concomitant reduction in recall memory responses due to a defect in APC function. Collectively, these results provide evidence that a major role of IgA is to facilitate presentation of Ag to mucosal T cells. IL-12 treatment can overcome IgA deficiency by providing adequate T cell priming during vaccination.
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MESH Headings
- Administration, Intranasal
- Animals
- Antibodies, Viral/biosynthesis
- Antibodies, Viral/blood
- Cells, Cultured
- Genetic Predisposition to Disease
- HN Protein/administration & dosage
- HN Protein/immunology
- IgA Deficiency/genetics
- IgA Deficiency/immunology
- IgA Deficiency/virology
- Immunity, Innate/genetics
- Immunoglobulin A/biosynthesis
- Immunoglobulin A/blood
- Immunologic Memory/genetics
- Influenza A virus/immunology
- Influenza Vaccines/administration & dosage
- Influenza Vaccines/immunology
- Interleukin-12/therapeutic use
- Lymphocyte Activation/genetics
- Lymphoproliferative Disorders/genetics
- Lymphoproliferative Disorders/immunology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Orthomyxoviridae Infections/genetics
- Orthomyxoviridae Infections/immunology
- Orthomyxoviridae Infections/prevention & control
- T-Lymphocytes, Helper-Inducer/immunology
- T-Lymphocytes, Helper-Inducer/metabolism
- T-Lymphocytes, Helper-Inducer/virology
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Bachmaier K, Le J, Penninger JM. "Catching heart disease": antigenic mimicry and bacterial infections. Nat Med 2000; 6:841-2. [PMID: 10932199 DOI: 10.1038/78561] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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42
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Merewether LA, Le J, Jones MD, Lee R, Shimamoto G, Lu HS. Development of disulfide peptide mapping and determination of disulfide structure of recombinant human osteoprotegerin chimera produced in Escherichia coli. Arch Biochem Biophys 2000; 375:101-10. [PMID: 10683254 DOI: 10.1006/abbi.1999.1636] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recombinant human osteoprotegerin chimera is a 90-kDa protein containing a human IgG Fc domain fused to human osteoprotegerin. The molecule is a dimer linked by two intermolecular disulfide bonds and contains eleven intramolecular disulfide bonds per monomer. A cysteine-rich region in osteoprotegerin contains nine disulfide bridges homologous to the cysteine-rich signature structure of the tumor necrosis factor receptor/nerve growth factor receptor superfamily. In this report, we have developed peptide mapping procedures suitable to generate disulfide-containing peptides for disulfide structure assignment of the fusion molecule. The methods employed included proteolytic digestion using endoproteinases Glu-C and Lys-C in combination followed by LC-MS analyses. Disulfide linkages of peptide fragments containing a single disulfide bond were assigned by sequence analysis via detection of (phenylthiohydantoinyl) cystine and/or by MS analysis. Disulfide bonds of a large, core fragment containing three peptide sequences linked by four disulfides were assigned after generation of smaller disulfide-linked peptides by a secondary thermolysin digestion. Disulfide structures of peptide fragments containing two disulfide bonds were assigned using matrix-assisted laser desorption ionization mass spectrometry with postsource decay. Both the inter- and intramolecular disulfide linkages of the chimeric dimer were confirmed.
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Bachmaier K, Krawczyk C, Kozieradzki I, Kong YY, Sasaki T, Oliveira-dos-Santos A, Mariathasan S, Bouchard D, Wakeham A, Itie A, Le J, Ohashi PS, Sarosi I, Nishina H, Lipkowitz S, Penninger JM. Negative regulation of lymphocyte activation and autoimmunity by the molecular adaptor Cbl-b. Nature 2000; 403:211-6. [PMID: 10646608 DOI: 10.1038/35003228] [Citation(s) in RCA: 522] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The signalling thresholds of antigen receptors and co-stimulatory receptors determine immunity or tolerance to self molecules. Changes in co-stimulatory pathways can lead to enhanced activation of lymphocytes and autoimmunity, or the induction of clonal anergy. The molecular mechanisms that maintain immunotolerance in vivo and integrate co-stimulatory signals with antigen receptor signals in T and B lymphocytes are poorly understood. Members of the Cbl/Sli family of molecular adaptors function downstream from growth factor and antigen receptors. Here we show that gene-targeted mice lacking the adaptor Cbl-b develop spontaneous autoimmunity characterized by auto-antibody production, infiltration of activated T and B lymphocytes into multiple organs, and parenchymal damage. Resting cbl-b(-/-) lymphocytes hyperproliferate upon antigen receptor stimulation, and cbl-b(-/-) T cells display specific hyperproduction of the T-cell growth factor interleukin-2, but not interferon-gamma or tumour necrosis factor-alpha. Mutation of Cbl-b uncouples T-cell proliferation, interleukin-2 production and phosphorylation of the GDP/GTP exchange factor Vav1 from the requirement for CD28 co-stimulation. Cbl-b is thus a key regulator of activation thresholds in mature lymphocytes and immunological tolerance and autoimmunity.
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Rattner A, Sabido O, Le J, Vico L, Massoubre C, Frey J, Chamson A. Mineralization and alkaline phosphatase activity in collagen lattices populated by human osteoblasts. Calcif Tissue Int 2000; 66:35-42. [PMID: 10602842 DOI: 10.1007/s002230050007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Adult human osteoblastic cells were grown in a native type I collagen gel. Proliferation and viability analyses showed that cells rapidly stopped dividing and became blocked in the G0G1 phase (91% on day 13). Carboxyfluorescein diacetate cell staining and flow cytometry showed that osteoblasts were viable for the first 16 days and then viability decreased (58% viable cells on day 22). Osteoblasts were able to retract the matrix. Betaglycerophosphate (betaGP) stimulated the deposition of mineral particles in the collagen network, and electron probe microanalysis showed that they were principally calcium and phosphorus, with a Ca/P ratio of about 1.7. Various times of betaGP supply were tested. We compared 10 mM betaGP added only once at day 0, or continuously from day 0, day 8, or day 21. Mineralization was observed in conditions where betaGP was added at day 0. Furthermore, 10 mM betaGP added once during gel preparation was sufficient to induce mineralization with mineral accumulation up to day 15 whereas the speed of the gel contraction decreased. In every condition, cultures expressed high alkaline phosphatase (ALP) levels as early as day 3, which decreased afterwards. These kinetics might explain why the other conditions did not prove favorable to the mineralization process. The model was used to study the influence of blocking gel retraction. Blocking retraction delayed the ALP activity decrease, but had no effect on mineralization. In conclusion, human adult osteoblasts cultured in native collagen gel stopped proliferation and underwent mineralization very early. This model should be used to investigate the influence of effectors on the early stages of culture.
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Le J, Perier C, Peyroche S, Rascle F, Blanchon MA, Gonthier R, Frey J, Chamson A. Urine glycyl-L-proline increase and skin trophicity. Amino Acids 1999; 17:315-22. [PMID: 10582130 DOI: 10.1007/bf01366930] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Glycyl-L-proline (gly-pro) is an end product of collagen metabolism that is further cleaved by prolidase (EC 3.4.13.9); the resulting proline molecules are recycled into collagen or other proteins. We postulated a relationship between defective gly-pro hydrolysis, increased collagen degradation and skin destruction. This relationship was tested using HPLC to measure the gly-pro in urine. 24 hour urine samples were collected from 27 old people (86 +/- 6 years old), of whom 15 were suffering from skin pressure sores of the sacrum or calcaneus. The urine from patients with pressure sores contained significantly more gly-pro than the urine from the control. A cut-off at 7 mumol/mmol creatinine gave the test a positive predictive value of 70%. Collagen breakdown was also increased as indicated by the increase of hydroxyproline (hyp) in the urine. But this breakdown seemed to stop at the gly-pro step.
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Abraham MH, Le J. The correlation and prediction of the solubility of compounds in water using an amended solvation energy relationship. J Pharm Sci 1999; 88:868-80. [PMID: 10479348 DOI: 10.1021/js9901007] [Citation(s) in RCA: 218] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The aqueous solubility of liquids and solids, as log S(W), has been correlated with an amended solvation equation that incorporates a term in Sigma alpha(2)(H) x Sigma beta(2)(H), where the latter are the hydrogen bond acidity and basicity of the solutes, respectively. Application to a training set of 594 compounds led to a correlation equation with a standard deviation, SD, of 0.56 log units. For a test set of 65 compounds, the SD was 0.50 log units, and for a combined correlation equation for 659 compounds, the SD was 0.56 log units. The correlation equations enable the factors that influence aqueous solubility to be revealed. The hydrogen-bond propensity of a compound always leads to an increase in solubility, even though the Sigma alpha(2)(H) x Sigma beta(2)(H) term opposes solubility due to interactions in the liquid or solid. Increase in solute dipolarity/polarizability increases solubility, whereas an increase in solute excess molar refraction, and especially, volume decrease solubility. The solubility of Bronsted acids and bases is discussed, and corrections for the fraction of neutral species in the saturated solution are graphically presented.
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Gevins A, Smith ME, McEvoy LK, Leong H, Le J. Electroencephalographic imaging of higher brain function. Philos Trans R Soc Lond B Biol Sci 1999; 354:1125-33. [PMID: 10466140 PMCID: PMC1692636 DOI: 10.1098/rstb.1999.0468] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
High temporal resolution is necessary to resolve the rapidly changing patterns of brain activity that underlie mental function. Electroencephalography (EEG) provides temporal resolution in the millisecond range. However, traditional EEG technology and practice provide insufficient spatial detail to identify relationships between brain electrical events and structures and functions visualized by magnetic resonance imaging or positron emission tomography. Recent advances help to overcome this problem by recording EEGs from more electrodes, by registering EEG data with anatomical images, and by correcting the distortion caused by volume conduction of EEG signals through the skull and scalp. In addition, statistical measurements of sub-second interdependences between EEG time-series recorded from different locations can help to generate hypotheses about the instantaneous functional networks that form between different cortical regions during perception, thought and action. Example applications are presented from studies of language, attention and working memory. Along with its unique ability to monitor brain function as people perform everyday activities in the real world, these advances make modern EEG an invaluable complement to other functional neuroimaging modalities.
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Doumit J, Le J, Frey J, Chamson A, Perier C. A comparison of 15N proline and 13C leucine for monitoring protein biosynthesis in the skin. Amino Acids 1999; 16:107-11. [PMID: 10319183 DOI: 10.1007/bf01321530] [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: 10/25/2022]
Abstract
The tracers L 15N-proline and L(1-13C)-leucine were used to explore the synthesis of skin proteins in vivo in rabbits. They orally received a single dose containing an equimolecular mixture of L(1-13C)-leucine and L 15N-proline. The changes in the amounts of these tracers in blood and skin were monitored for a total of 8 h. The data showed the appearance of the two tracers in blood within 15 min and their clearance in 8 h. They were both rapidly (15 min) incorporated into skin proteins, but more proline was incorporated than leucine. We therefore consider L 15N-proline to be a better tracer than L(1-13C)-leucine for studying protein metabolism in the skin.
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Abstract
In most instances, traditional EEG methodology provides insufficient spatial detail to identify relationships between brain electrical events and structures and functions visualized by magnetic resonance imaging or positron emission tomography. This article describes a method called Deblurring for increasing the spatial detail of the EEG and for fusing neurophysiologic and neuroanatomic data. Deblurring estimates potentials near the outer convexity of the cortex using a realistic finite element model of the structure of a subject's head determined from their magnetic resonance images. Deblurring is not a source localization technique and thus makes no assumptions about the number or type of generator sources. The validity of Deblurring has been initially tested by comparing deblurred data with potentials measured with subdural grid recordings. Results suggest that deblurred topographic maps, registered with a subject's magnetic resonance imaging and rendered in three dimensions, provide better spatial detail than has heretofore been obtained with scalp EEG recordings. Example results are presented from research studies of somatosensory stimulation, movement, language, attention and working memory. Deblurred ictal EEG data are also presented, indicating that this technique may have future clinical application as an aid to seizure localization and surgical planning.
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Penninger JM, Fischer KD, Sasaki T, Kozieradzki I, Le J, Tedford K, Bachmaier K, Ohashi PS, Bachmann MF. The oncogene product Vav is a crucial regulator of primary cytotoxic T cell responses but has no apparent role in CD28-mediated co-stimulation. Eur J Immunol 1999; 29:1709-18. [PMID: 10359126 DOI: 10.1002/(sici)1521-4141(199905)29:05<1709::aid-immu1709>3.0.co;2-o] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The guanine nucleotide-exchange factor Vav is a regulator of antigen-mediated cytoskeletal reorganization required for receptor clustering, proliferation and thymic selection. Moreover, Vav has been identified as a major substrate in the CD28 signal transduction pathway and overexpression of Vav enhances TCR-mediated IL-2 secretion in T cells. Here we show that CD3- plus CD28-mediated proliferation and IL-2 production were reduced in vav gene-deficient T cells. However, Vav had no apparent role in phorbol 12-myristate 13-acetate-plus CD28-mediated proliferation and IL-2 production, suggesting that Vav acts downstream of the TCR/CD3 complex. In vivo, Vav expression was crucial to generate primary vesicular stomatitis virus (VSV)-specific cytotoxic T cell responses. In contrast, vav-/- mice exhibited a reduced but significant footpad swelling after lymphocytic choriomeningitis virus (LCMV) infections and mounted a measurable primary cytotoxic T cell response to LCMV. Upon in vitro restimulation, cytotoxic T cell responses of both VSV- and LCMV-infected mice reached near normal levels. Our data provide the first genetic evidence that Vav is an important effector molecule that relays antigen receptor signaling to IL-2 production and activation of cytotoxic T cells.
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