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261.
Alternative therapy for refractory leukemic patients is being increasingly adopted. Circumvention of multidrug resistance represents a strategy that has been taken into account when conventional chemotherapy failed. In this work a group of 15 refractory, heavily pretreated, patients was enrolled in a circumvention protocol including etoposide (ETO) and cyclosporin A (CSA). All patients received etoposide prior to this schedule. Toxicity to circumvention protocol was acceptable and only one serious side-effect was observed. Two hematological clinical responses were seen, both of which were positive to P-glycoprotein immunostaining and exhibited in vitro modulation by CSA in cultures using the thymidine incorporation assay. Three out of four patients negative for P-glycoprotein achieved a minor response. Three out of six clinical failures were also negative for Pgp immunostaining one of which exhibited sinergistic effect between ETO and CSA. Our study suggests that hematological response to ETO and CSA association can be obtained in intensely pretreated leukemic patients. Several factors may affect the response such as clinical status before this therapy. Additionally, it also suggests that not all CSA effects on the combination ETO-CSA can be attributed to Pgp modulation. 相似文献
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263.
MV Wagster JC Hedreen CE Peyser SE Folstein CA Ross 《Canadian Metallurgical Quarterly》1994,127(1):70-75
Excitatory amino acid neurotoxicity has been proposed to cause the neostriatal neuronal degeneration of Huntington's disease (HD); N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA), and kainate receptors have been hypothesized to play important roles in this process. We have recently reported a loss of neurons in layer VI of the cerebral cortex in HD. Using quantitative autoradiographic methods, we have now measured NMDA, AMPA, and kainate receptor binding in the frontal cerebral cortex of the brains of controls and individuals with HD. We find no change in NMDA receptor binding but a selective decrease in kainate and AMPA receptor binding in layer VI. These data suggest that cerebral cortical neurons possessing kainate or AMPA receptors may be selectively vulnerable in individuals with HD. 相似文献
264.
D de Silva A Osborne SA Simpson JC Dean A Seaton 《Canadian Metallurgical Quarterly》1998,53(2):149-50; discussion 148
A 64 year old woman presented with persistent and severe symptoms due to recurrent aspiration pneumonias associated with oesophageal reflux. She had had multiple miscarriages and her son at birth had widely spaced eyes (hypertelorism), hypospadias, bilateral undescended testes, and an imperforate anus. Her daughter has mild hypertelorism and her daughter's son had neonatal inspiratory stridor, hypospadias and hypertelorism, all features now recognised as typical of the Opitz oculo-genito-laryngeal syndrome. This syndrome is genetically heterogeneous with autosomal dominant (linked to chromosome 22q21) and X-linked (linked to Xp22) inheritance. This family's history and genetic linkage data are consistent with linkage to Xp22. The proband is a manifesting carrier of this syndrome; her history of recurrent aspiration is probably secondary to pharyngeal neuromuscular incoordination aggravating gastro-oesophageal reflux. Obtaining a family history gives a vital clue to the diagnosis of Opitz oculo-genito-laryngeal syndrome. It is also suggested that this condition should be included in the differential diagnosis of recurrent aspiration pneumonia. 相似文献
265.
CM Serre M Papillard P Chavassieux JC Voegel G Boivin 《Canadian Metallurgical Quarterly》1998,42(4):626-633
The induction of a calcifying matrix is of great interest in the restoration of bone defects. In a previous in vitro study we demonstrated that a collagen sponge constituted of type I collagen fibrils, chondroitin sulfates, and hydroxyapatite crystals induces an earlier and a more abundant synthesis of a new extracellular calcifying matrix than do other biomaterials such as collagen or hydroxyapatite alone. Bone mineral contains various amounts of magnesium ions, either adsorbed at the surface of apatite crystals or incorporated inside the crystal structure. Magnesium is known to reduce the degradation rate of tricalcium phosphate ceramics and to influence the crystallization of mineral substance. Thus we evaluated two sponges modified with different substituted apatites. The substituted low magnesium-containing apatite sample decreased the osteoinductive properties of the sponge whereas the substituted high magnesium-containing apatite sample had a toxic effect on bone cells and prevented the formation of any extracellular matrix. Such a toxic effect can be explained by the presence of large numbers of magnesium ions released into the culture medium even though at physiological level magnesium is able to promote bone mineralization and to control the growth of hydroxyapatite crystals. Thus collagen sponges containing hydroxyapatite remain one of the most appropriately evaluated biomaterials used for the restoration of periodontal pockets and bone defects. 相似文献
266.
JM Zapata M Krajewska S Krajewski RP Huang S Takayama HG Wang E Adamson JC Reed 《Canadian Metallurgical Quarterly》1998,47(2):129-140
Low molecular mass polypeptides (LMP) 2 and LMP7 and transporter associated with antigen processing (TAP) subunits TAP1 and TAP2 play a crucial role in antigen processing and cell surface expression of HLA class I molecules. Since monoclonal antibodies (mAb) to these molecules will facilitate the analysis of their expression, structure and function in normal and transformed cells, in the present study we have developed these reagents. Specifically anti-LMP2 and LMP7 mAb were generated from BALB/c mice immunized with specific peptides, and anti-TAP1 and TAP2 mAb from BALB/c mice immunized with respective recombinant proteins. mAb VF101-39F7 and VF101-39G5 were shown to be specific for LMP2, mAb VF103-5D5 and VF103-8C2 for LMP7, mAb VF108-1B3 and VF108-12D6 for TAP1 and mAb VF118-1E4 and VF118-2C5 for TAP2, since they reacted specifically with the corresponding immunogens in ELISA and with the corresponding LMP and TAP subunits when tested in Western blotting with human lymphoid cell extracts. Furthermore, the mAb immunoprecipitated components with the characteristic electrophoretic mobility from lymphoid cells. Both anti-LMP and anti-TAP mAb stained keratinocytes and infiltrating lymphocytes in frozen and formalin-fixed, paraffin embedded sections of normal skin in indirect immunoperoxidase reactions. Furthermore, all the mAb except mAb VF103-5D5 stained the cytoplasm of lymphoid cells in an intracytoplasmic staining reaction. The specificity and reactivity pattern of the mAb we have characterized indicate that they will be valuable reagents to analyze the cellular expression and tissue distribution of LMP and TAP subunits. 相似文献
267.
JC van der Voet RB Keus AA Hart FJ Hilgers H Bartelink 《Canadian Metallurgical Quarterly》1998,42(2):247-255
Low frequency impedance measurements of pure egg lecithin (phosphatidylcholine) bilayers have revealed the presence of four layers which can be attributed to the acyl chain, carbonyl, glycerol bridge and phosphatidylcholine regions of the lecithin molecule. Measurements on bilayers formed in the presence of unoxidised-cholesterol revealed that cholesterol molecules were located in the hydrocarbon region of the bilayer with its hydroxyl groups aligned with the carbonyl region of the lecithin molecules. Measurements of oxidised-cholesterol lecithin bilayers revealed that these molecules protruded less into the hydrocarbon region and their polar hydroxyl group aligned with the glycerol bridge region of the lecithin molecule. 相似文献
268.
269.
JK Osbourn JC Earnshaw KS Johnson M Parmentier V Timmermans J McCafferty 《Canadian Metallurgical Quarterly》1998,16(8):778-781
The seven trans-membrane chemokine receptor CCR-5 is a coreceptor for macrophage tropic HIV-1 strains. CCR-5 responds to a number of chemokines, including macrophage inflammatory protein (MIP)-1 alpha. We describe the use of MIP-1 alpha in a biotin tyramine-mediated proximity selection to guide the selection of CCR-5-specific phage antibodies from a large phage display human library. Proximity based selections resulted in a population of antibodies recognizing CCR-5 on primary CD4+ lymphocytes, none of which blocked MIP-1 alpha binding to cells. The selected population of phage antibodies were subsequently used as guide molecules for a second phase of selection that was carried out in the absence of MIP-1 alpha. This generated a panel of CCR-5-binding antibodies, of which around 20% inhibited MIP-1 alpha binding to CD4+. The single chain Fvs (scFv) generated by this step-back selection procedure also inhibited MIP-1 alpha-mediated calcium signaling. 相似文献
270.