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71.
Jean-Pierre Monthard Marcel Camps Ahmed Belfkira Michel Chatzopoulos Robert Granger Luc Jorat Grard Noyel 《Macromolecular chemistry and physics.》1985,186(7):1519-1532
The relations between structure and isothermal, dielectric properties of poly(α-acetoxystyrene)s substituted in para position by ? OCOCH3 ( 1a ), ? OCOCH2CH3 ( 1b ), ? OCOCH2CH2CH3 ( 1c ), ? OCOC6H5 ( 1d ), ? OCOCH2CH2Cl ( 1f ) and ? OCOOCH3 ( 1g ) were studied. The dielectric constants, at 105 Hz and 20 ± 2°C, were found to be: 3,79 ( 1a ), 3,36 ( 1b ), 3,18 ( 1c ), 3,51 ( 1d ), 3,36 ( 1e ), 3,65 ( 1f ) and 3,07 ( 1g ). The polymers 1a – 1g do not show any α- or β-transition. Increasing bulkiness of the para substituent gives rise to a decreasing dielectric constant due to an increase of the degree of syndiotacticity, as determined from 1H and 13C NMR spectra. 相似文献
72.
Pierre Moine Colette Sauve Eric Vallee Jean-Pierre Bedos Esther Azoulay-Dupuis 《Clinical microbiology and infection》1997,3(6):608-615
Objective: To compare cefotaxime (CTX) to amoxicillin (AMO) (usually considered the definitive therapy for penicillinsusceptible Streptococcus pneumoniae infections) in an immunocompromised mouse pneumonia model.
Methods: Three S. pneumoniae clinical isolates were used: two serotype 19 strains, a penicillin-susceptible (Ps ) strain (penicillin MIC = 0.03 μ/mL) and a highly penicillin-resistant (Pr ) strain (penicillin MIC = 4 μ/mL), and one serotype 23F strain, a penicillin-cephalosporin-resistant (CFTR) strain (CTX MIC = 4 μ/mL).
Results: CTX activity in this mouse model of pneumonia induced by the highly penicillin-resistant strain of S. pneumoniae was lower than expected from its low MIC against this organism. Furthermore, AMO had greater efficacy than CTX against a CFTR S. pneumoniae strain.
Conclusion: Our data suggest that there is no major difference in the in vivo efficacy of the two agents, cefotaxime and amoxicillin, against penicillin-resistant and penicillin-cephalosporin-resistant S. pneumoniae. 相似文献
Methods: Three S. pneumoniae clinical isolates were used: two serotype 19 strains, a penicillin-susceptible (P
Results: CTX activity in this mouse model of pneumonia induced by the highly penicillin-resistant strain of S. pneumoniae was lower than expected from its low MIC against this organism. Furthermore, AMO had greater efficacy than CTX against a CFTR S. pneumoniae strain.
Conclusion: Our data suggest that there is no major difference in the in vivo efficacy of the two agents, cefotaxime and amoxicillin, against penicillin-resistant and penicillin-cephalosporin-resistant S. pneumoniae. 相似文献
73.
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75.
Jean-Claude Brouet William Vainchenker Dominique Blanchard Ugo Testa Jean-Pierre Cartron 《European journal of immunology》1983,13(4):350-352
The Tn (or polyagglutinability) syndrome corresponds to a human nonmalignant acquired condition which results from a somatic mutation occurring at the level of bone marrow stem cells. This model offers therefore a unique opportunity to study the contribution of multipotential stem cells to the maintenance of cells from the lymphoid lineage. We found that the Tn mutation is expressed by both myeloid and lymphoid mature blood cells. Whereas a large proportion of surface IgM-bearing B cells carry the Tn mutation, only a small percentage of T cells and IgA- or IgG-bearing B cells are defective, showing that under physiological conditions the penetration of stem cells into the various myeloid and lymphoid compartments is variable. 相似文献
76.
Jean-Pierre Laussac 《Molecular and chemical neuropathology / sponsored by the International Society for Neurochemistry and the World Federation of Neurology and research groups on neurochemistry and cerebrospinal fluid》1990,12(1):37-54
Thymulin (formerly called FTS) is a well-defined nonapeptide hormone produced by thymic epithelial cells. Its biological activity and antigenicity depend on the presence of the metal zinc in the molecule. The interaction between this metal ion and thymulin has been investigated by means of one- and two-dimensional NMR experiments. These experiments were performed in dimethyl-d 6 sulfoxide solution and in aqueous medium with different metal: peptide ratios. The results are compared with those obtained for complexes of thymulin with other metal ions (Cu2+ and Al3+) and for the [Ala4]- and [Ala8]-analogs in terms of biological activity. These comparative studies suggest that the 1∶1 complex is the only conformation recognized by the antibodies. From the NOESY data, a spatial conformation has been proposed for this complex. This conformation should be the physiological one and could lead to a better insight into the conformation requirements at receptor sites. 相似文献
77.
Hideki Morimoto Paola Princine Jean-Pierre Robin Colette Broquet Jean Michel Mencia-Huerta Pierre Braquet Benjamin Bonavida 《Cancer chemotherapy and pharmacology》1993,32(4):293-300
The in vitro cytotoxic properties of a newly synthesized demethylpodophyllotoxin derivative, 4-o-butanoyl-4-demethylpodophyllotoxin (BN 58705), were determined by using several human tumor cell lines of different histological origin and of different sensitivity to conventional chemotherapeutic drugs (Adriamycin andcis-diammine-dichloride platinum). BN 58705 is shown to be cytotoxic against various human tumor cell lines as assessed by the MTT assay. Furthermore, BN 58705 is shown to be cytotoxic against several drug-resistant tumor cell lines. BN 58705 is cytotoxic at concentrations 100- to 1000-fold lower than those of Adriamycin orcis-diammine-dichloride platinum required to achieve similar cytotoxicity. BN 58705 did not mediate DNA fragmentation of target cells, whereas the epipodophyllotoxin-like etoposide induced DNA cleavage by stabilizing the DNA-enzyme intermediate. Like vinca alkaloids, BN 58705 induced a block in the mitotic phase of the cell cycle. By comparison, BN 58705 exerted a stronger cytotoxic activity in vitro than did either etoposide, an epipodophyllotoxin, or vincristine, a vinca alkaloid. When BN 58705 was applied in vivo in mice, it resulted in low toxicity (50% lethal dose, 150 mg/kg). These results demonstrate than BN 58705 is cytotoxic to drug-resistant human tumor cell lines and is manyfold more potent than conventional drugs. The cytotoxic potency and low toxicity of BN 58705 are important criteria to establish its potential chemotherapeutic efficacy in vivo.Abbreviations cpm
counts per minute
- BN 58705
4-o-butanoyl-4-demethylpodophyllotoxin
- MTT
3-(4,5-dimethyl-thiazoyl-2-yl)-2,5-diphenyl-tetrazolium bromide
- OD
optical density
- TRIS
TRIS (hydroxymethyl) aminomethane
- EDTA
ethylenediaminetetraacetic acid
- FITC
fluoresceinisothiocyanate
- PI
propidium iodide
This work was supported by a grant from Institut Henri Beaufour, France 相似文献
78.
Tumor necrosis factor-{alpha} up-regulates Bcl-2 expression and decreases calcium-dependent apoptosis in human B cell lines 总被引:7,自引:0,他引:7
Genestier Laurent; Bonnefoy-Berard Nathalie; Rouault Jean-Pierre; Flacher Monique; Revillard Jean-Pierre 《International immunology》1995,7(4):533-540
Group I and Epstein–Barr virus-negative Burkitt's lymphomacell lines and the B104 lymphoma cell line which expresses aphenotype of immature B cells undergo apoptosis after cross-linkingof their surface Ig receptors or after exposure to a calciumionophore. We show here that tumor necrosis factor (TNF)- protectsthese B cell lines against Ca2+-dependent apoptosis. Protectionwas associated with up-regulatlon of bcl-2 mRNA and proteinexpression. The increase of Bcl-2 expression induced by TNF-was inhibited by chelerythrine, a specific inhibitor of proteinkinase C (PKC), suggesting that Bcl-2 expression was dependenton PKC activation. Furthermore, we show that phorbol estersand cyclosporin A (CsA), which prevent Ca2+-dependent apoptosis,up-regulated Bcl-2 expression. The effect of CsA on Bcl-2 expressionis controlled by calcineurin since we have shown that FK506but not rapamycin had the same effect on Bcl-2 expression, whereasokadaic acid, an inhibitor of phosphatases 1, 2A and 2C, wasineffective. These data provide direct evidence that TNF- preventsCa2+-dependent apoptosis by a Bcl-2-dependent mechanism mediatedby PKC. 相似文献
79.
Jean-Luc Fellahi Bruno Valtier Alain Beauchet Jean-Pierre Bourdarias François Jardin 《Journal canadien d'anesthésie》1999,46(5):423-428