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51.
Cecilio CA Costa EH Ucelli P Chaves CA Toffoli MC Flores CA Cunha FQ Ferreira SH Tamashiro WM 《Mediators of inflammation》1997,6(1):46-52
Macrophages harvested from the peritoneal cavities of rats release a neutrophil chemotactic factor (MNCF) in response to stimulation with Gram-negative bacterial lipopolysaccharide (LPS). MNCF has been shown to be active in rats treated with dexamethasone, a glucocorticoid that usually inhibits the neutrophil migration induced in this species by interleukin (IL)-1, tumour necrosis factor alpha (TNFalpha), IL-8, C5a and leukotriene B(4) (LTB(4)). Here we report that macrophages harvested from peritoneal cavities of mice, and stimulated in vitro with LPS, also release a factor that induces neutrophil migration in dexamethasone-treated animals. This chemotactic activity was neutralized by the incubation of the LPS-stimulated macrophage supernatants with a purified polyclonal IgG anti-mouse TNFalpha. In addition, significant amounts of TNF were detected in the supernatants. The neutrophil migration induced by intraperitoneal administration of recombinant murine TNFalpha was also unaffected by pretreatment of the mice with dexamethasone. Moreover, neutrophil migration induced by intraperitoneal injection of LPS was completely blocked by pretreatment of the mice with a monoclonal antibody against murine TNFalpha. In conclusion, our results support the hypothesis that, in contrast to the role of TNF in rats (where it indirectly induces neutrophil migration), in mice, it may be an important mediator in the recruitment of neutrophils to inflammatory sites. 相似文献
52.
Characterization of novel long-chain 1,2-diols in Thermus species and demonstration that Thermus strains contain both glycerol-linked and diol-linked glycolipids.
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R Wait L Carreto M F Nobre A M Ferreira M S da Costa 《Journal of bacteriology》1997,179(19):6154-6162
In this study, we purified and characterized tetra- and triglycosyl glycolipids (GL-1 and GL-2, respectively) from two different colonial forms of Thermus scotoductus X-1, from T. filiformis Tok4 A2, and from T. oshimai SPS-11. Acid hydrolysis of the purified glycolipids liberated, in addition to the expected long-chain fatty acids, two components which were identified by gas chromatography-mass spectrometry as 16-methylheptadecane-1,2-diol and 15-methylheptadecane-1,2-diol. Fast atom bombardment mass spectrometry of the intact glycolipids indicated that a major proportion consisted of components with glycan head groups linked to long-chain 1,2-diols rather than to glycerol, although in all cases glycerol-linked compounds containing similar glycan head groups were also present. As in other Thermus strains, the polar head group of GL-1 from T. filiformis Tok4 A2 and from T. scotoductus X-1 colony type t2 was a glucosylgalactosyl-(N-acyl)glucosaminylglucosyl moiety. However, GL-2 from T. scotoductus X-1 colony type t1 and from T. oshimai SPS-11 was a truncated analog which lacked the nonreducing terminal glucose. Long-chain 1,2-diols have been previously reported in the polar lipids of Thermomicrobium roseum and (possibly) Chloroflexus aurantiacus, but to our knowledge, this is the first report of their detection in other bacteria and the first account of the structural determination of long-chain diol-linked glycolipids. 相似文献
53.
An autosomal dominant retinitis pigmentosa family with close linkage to D7S480 on 7q 总被引:7,自引:0,他引:7
José M. Millán Francisco Martínez Concha Vilela Magdalena Beneyto Félix Prieto Carmen Nájera 《Human genetics》1995,96(2):216-218
Retinitis pigmentosa is the most prevalent inherited disorder of the retina. It can be autosomal dominant (adRP), autosomal recessive (arRP) or X-linked (XLRP). A form of adRP mapping to chromosome 7q was reported in a large Spanish pedigree. We have typed DNA from the members of another Spanish family for polymorphic markers from the known candidate genes. Positive lod scores were obtained only for the markers located on 7q31-35, giving a maximum lod score of 2.98 (3.01 by multipoint analysis) at = 0.00 for D7S480. A brief clinical evaluation is given. 相似文献
54.
We have recently described the purification of a 54 kDa acidic protein, identified as macrophage-derived neutrophil chemotactic factor (MNCF). This protein causes in vitro chemotaxis as well as in vivo neutrophil migration even in animals treated with dexamethasone. This in vivo chemotactic activity of MNCF in animals pretreated with dexamethasone is an uncommon characteristic which discriminates MNCF from known chemotactic cytokines. MNCF is released in the supernatant by macrophage monolayers stimulated with lipopolysaccharide (LPS). In the present study, we describe some biological characteristics of homogenous purified MNCF. When assayed in vitro, MNCF gave a bell-shaped dose-response curve. This in vitro activity was shown to be caused by haptotaxis. Unlike N-formyl-methionylleucyl- phenylalanine (FMLP) or interleukin 8 (IL-8), the chemotactic activity of MNCF in vivo and in vitro, was inhibited by preincubation with D-galactose but not with D-mannose. In contrast with IL-8, MNCF did not bind to heparin and antiserum against IL-8 was ineffective in inhibiting its chemotactic activity. These data indicate that MNCF induces neutrophil migration through a carbohydrate recognition property, but by a mechanism different from that of the known chemokines. It is suggested that MNCF may be an important mediator in the recruitment of neutrophils via the formation of a substrate bound chemotactic gradient (haptotaxis) in the inflamed tissues. 相似文献
55.
An increase in nitric oxide produced by rat peritoneal neutrophils is not involved in cell apoptosis
Fierro IM Barja-Fidalgo C Canedo RM Cunha FQ Ferreira SH 《Mediators of inflammation》1995,4(3):222-228
Polymorphonuclear neutrophils (PMN) obtained from carrageenin-stimulated peritoneal cavities of rats, but not blood PMN, spontaneously produced nitric oxide (NO) when incubated in vitro. Incubation of the cells with the NO synthase inhibitors, L-imino-ethyl-L-ornithine (L-NIO) or N(G)-monomethyl-L-arginine (L-NMMA), inhibited NO production. This inhibition could be reversed by L-arginine. Incubation of PMN with lipopolysaccharide (LPS) failed to enhance NO production. Pretreatment of the rats with dexamethasone (DEXA) prior to carrageenin injection or incubation of PMN with the glucocorticoid in vitro partially inhibited the spontaneous release of NO. On the other hand, when PMN obtained from DEXA pretreated rats were incubated in vitro with DEXA, NO synthase activity and hence NO generation were almost abolished. A similar inhibition was also observed following the addition of L-NIO or cycloheximide to cultures of carrageenin-elicited PMN. The NO production by PMN did not appear to be related to cell viability or apoptosis. Indeed, neither the blockade of NO generation by L-NIO nor the incubation of the neutrophils with a NO donor, S-nitroso-acetylpenicillamine (SNAP) modified the pattern of LDH release or DNA fragmentation. In summary, it appears that PMN migration triggers a continuous NO synthesis, and that NO produced by these cells is not related to their apoptosis. 相似文献
56.
Summary A mutant strain of Rhodococcus australis CSIR-236.457 which accumulates 3a-H-4-(3-propionic acid)-5-hydroxy-7a-methylhexahydro-indan-1-one--lactone from cholesterol, stigmasterol and -sitosterol was studied. The product is produced in a 60% molar yield in a dilute black strap molasses medium containing 6–12g/l cholesterol after a 72 hour fermentation period. 相似文献
57.
Custódio D. Santos Alberto F. Ribeiro Clélia Ferreira Walter R. Terra 《Cell and tissue research》1984,237(3):565-574
Summary Columnar cells of the larval midgut of the cassava hornworm, Erinnyis ello, display microvilli with vesicles pinching off from their tips (anterior and middle midgut) or with a large number of double membrane spheres budding along their length (posterior midgut). Basal infoldings in columnar cells occur in a parallel array with many openings to the underlying space (posterior midgut) or are less organized with few openings (anterior and middle midgut). Goblet cells have a cavity, which is formed by invagination of the apical membrane and which occupies most of the cell (anterior and middle midgut) or only its upper part (posterior midgut). The infolded apical membrane shows modified microvilli, which sometimes (posterior midgut) or always (anterior and middle midgut) contain mitochondria. The cytoplasmic side of the membrane of the microvilli that contain mitochondria are studded with small particles. The results suggest that the anterior and middle region of the midgut absorbs water, whereas the posterior region secretes it. This results in a countercurrent flux of fluid, which is responsible for the enzyme recovery from undigested food before it is expelled. Intermediary and final digestion of food probably occur in the columnar cells under the action of plasma membrane-bound and glycocalix-associated enzymes. 相似文献
58.
J. D. Ferreira 《Antonie van Leeuwenhoek》1982,48(1):1-24
Stained cells of Saccharomyces rosei prepared from 4 to 10-day-old cultures were studied under the light microscope. Mitotic and meiotic divisions involving a ring-like structure as well as preceding and subsequent stages were observed. Cells presenting supernumerary mitoses in a varying number were frequent. These mitoses, having terminated their multiplication activity, suspended the process shortly before its conclusion and, in a development which was identical at all, assumed a curious arrangement forming a mitoses-ring. Meiosis-buds were detected. These especial buds, where karyogamy and meiosis took place, resulted from the development of the mitoses-ring, whose mitoses upon resuming their activity moved toward the cell wall giving rise to the appearance of these appendices. Each one of these buds received the corresponding pair of daughter nuclei, diploidization occurring subsequently. Meiosis was usually processed in a single bud (effective-meiosis-bud) and all four meiotic nuclei migrated to the mother cell, and gave rise to a tetra-nucleate spore or binucleate spores if two were formed.Other modalities of sporulation were observed. These may result either from the association of two cells, in which one assumed the function of meiosis-bud (false-meiosis-bud), or from a cell association in which this function was performed for several linearly arranged cells forming a protuberance.Conjugation between mother cell and an attached bud, or between independent cells, was not observed. 相似文献
59.
Osvaldo A. Sant'Anna Olga M. Ibanez Vera C. A. Ferreira Marisa Gennari Denise Mouton 《Immunogenetics》1983,18(4):359-364
High (H/s) and low (L/s) antibody responder lines of mice selected according to their response to the somatic (s) antigen of Salmonella (Selection IV) have unexpected inverse capacity for antibody production to rabbit gamma globulin (RGG): H/s mice are low or even nonresponders to this antigen, whereas L/s mice are high responders. It was shown that the phenotypic variability within each line is due to environmental factors. RGG was a selection antigen in Selection V; the high (H/p) and low (L/p) responder mice are therefore considered as homozygous for the RGG genes. Responsiveness to RGG was investigated in F1 and F2 hybrids obtained by crossing the phenotypically similar RGG responder or nonresponder mice of Selections IV and V. The results support the hypothesis that the same genes control the response to RGG in L/s and H/p lines as well as in H/s and L/p lines. This means that the genes specific for RGG responsiveness were independent from those regulating responses to the s antigen. Unaffected by the selective breeding in Selection IV, they have been fixed by chance in an inverse way in H/s and L/s lines. 相似文献
60.
A strong interaction between iron(III) and calf thymus DNA at pH 7.4 was demonstrated in the present study by separation of the complex by column chromatography and by the slow kinetics of iron(III) removal from DNA by disodium-1,2-dihydroxybenzene-3,5-disulfonate (Tiron). An equilibrium constant of 2.1 x 10(14) was calculated by measurements of bound iron(III) by flame atomic absorption spectroscopy and assuming a one iron to two nucleotide stoichiometry. Graphic analysis of the interaction however, indicated that DNA has two binding sites for iron(III) characterized by a stoichiometry of one iron to 12 nucleotides and one iron to 2 nucleotides, and association constants of 4.8 x 10(12) and 2.3 x 10(11), respectively. The DNA-iron(III) complex isolated by column chromatography was shown to catalyze the oxidation of both 2-phenylethylhydrazine and methylhydrazine by spin-trapping experiments with alpha-(4-pyridyl 1-oxide)-N-tert-butylnitrone (POBN). By contrast, oxidation of 1,2-dimethylhydrazine was not catalyzed. Catalysis of 2-phenylethylhydrazine oxidation was confirmed by oxygen consumption studies. The results suggest that iron chelated to DNA may be significant in DNA damage induced by oxidizable chemicals. 相似文献