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1.
E Imbasciati R Gusmano A Edefonti P Zucchelli C Pozzi C Grassi M Della Volpe F Perfumo P Petrone M Picca et al. 《BMJ (Clinical research ed.)》1985,291(6505):1305-1308
In a multicentre, randomised, prospective trial 89 patients (67 children and 22 adults) with the minimal change nephrotic syndrome were treated with three intravenous pulses of methylprednisolone followed by low dose oral prednisone for six months (group given methylprednisolone) or with high dose oral prednisone for four weeks followed by low dose oral prednisone for five months (control group). Five patients in the group given methylprednisolone and one in the control group did not respond initially. The time to response was shorter in children treated with methylprednisolone. No significant differences between the two groups were observed in the number of patients who relapsed or number of relapses per patient per year. Patients given methylprednisolone tended to relapse earlier than patients in the control group. Side effects related to treatment were significantly fewer in the group given methylprednisolone than in the control group. These data suggest that a short course of methylprednisolone pulses followed by low dose oral prednisone is only marginally less effective than a regimen of high dose oral steroids but can improve the ratio of risk to benefit associated with treatment of the minimal change nephrotic syndrome. 相似文献
2.
Biosynthesis of immunoglobulin A (IgA). Secretion and addition of carbohydrate to monomer and polymer forms of a mouse myeloma protein 总被引:9,自引:3,他引:6
Cell suspensions of mouse plasma-cell tumour MOPC 315 secreting predominantly IgA (immunoglobulin A) monomer and dimer were incubated with radioactive leucine, mannose, galactose and fucose for various periods of time. The amounts of secreted and intracellular immunoglobulins were measured by co-precipitation with specific antibody, and the molecular species present were assessed by electrophoresis in polyacrylamide gels. Analysis of the secreted myeloma protein demonstrated that monomer and dimer IgA molecules are identical with respect to carbohydrate composition and rate of secretion. Within the cell, the myeloma protein is almost entirely accounted for by monomer units which either leave the cell as such or are polymerized with the addition of J chain close to the time of secretion. The results support the concept of a stepwise addition of carbohydrate residues to IgA immunoglobulin during the process of secretion. Similar patterns of carbohydrate assembly were found for the monomer or dimer molecules. Mannose residues are added at an early stage, whereas fucose is added close to the time of secretion. Galactose is also added early, but some may also be incorporated at a later stage. Control of IgA polymerization is considered unlikely to reflect regulation at the level of carbohydrate addition, and it is suggested that the critical controlling factor is the J chain. 相似文献
3.
Fiorenzo A. Peverali Maurizio D'Esposito Dario Acampora Giuseppe Bunone Mario Negri Antonio Faiella Anna Stornaiuolo Maria Pannese Enrica Migliaccio Antonio Simeone Giuliano Della Valle Edoardo Boncinelli 《Differentiation; research in biological diversity》1990,45(1):61-69
Mammalian genes containing a class-I homeobox (HOX genes) are highly expressed in the embryonic nervous system. As a first step towards the molecular analysis of the role these genes play in neural cells, we studied the expression of four human HOX genes in five neuroblastoma (NB) cell lines - SK-N-BE, CHP-134, IMR-32, SK-N-SH and LAN-1 - during the process of differentiation induced by treatment with retinoic acid (RA). The four genes, HOX1D, 2F, 3E and 4B, located at corresponding positions in the four HOX loci, share a high degree of sequence similarity with the Drosophila Deformed homeotic gene and constitute a homology group, group 10. One of these genes, HOX1D, is not expressed in the cells used, whereas the other three are highly expressed in untreated and RA-induced NB cells, even though the expression pattern in the various lines is slightly different for the three genes. Our analysis reveals a complex and specific expression pattern in these lines, paving the way to an identification of different NB-cell populations by means of specific HOX gene expression schemes. On the other hand, in every line studied, morphological maturation toward a neuronal differentiated phenotype appears to be associated with increased HOX gene expression. 相似文献
4.
5.
V Della Bianca M Grzeskowiak P De Togni M Cassatella F Rossi 《Biochimica et biophysica acta》1985,845(2):223-236
Verapamil inhibits in human neutrophils the respiratory burst, the secretion and the change of transmembrane potential induced by formylmethionylleucylphenylalanine, a Ca2+-dependent stimulus, and by phorbol myristate acetate, a Ca2+-independent stimulus. Besides the blocking of Ca2+ channels, many mechanisms are responsible for the inhibition of neutrophil responses. In fact, verapamil (i) increases the intracellular cAMP concentration, potentiates the cAMP response induced by the chemotactic peptide and induces the appearance of a cAMP response also when the stimulant is phorbol myristate acetate; (ii) causes a decrease of Ca2+ association to cell membranes, so depleting the pools of exchangeable Ca2+ and depressing the 'Ca2+ response' in terms of rise in [Ca2+]i monitored with Quin 2 and of rapid mobilization from cell membranes monitored by chlorotetracycline fluorescence change; (iii) inhibits the Ca2+-activated phospholipid-dependent protein kinase C. The data, discussed in relation to the biochemical mechanisms of the stimulus-response coupling, are compatible with the hypothesis of an involvement of the activation of protein kinase C as key step in the sequence of transduction events for the induction of many neutrophil functions. 相似文献
6.
P De Togni V Della Bianca P Bellavite M Grzeskowiak F Rossi 《Biochimica et biophysica acta》1983,755(3):506-513
Studies were carried out on the mechanism responsible for the enhancement of the respiratory and secretory responses to N-formylmethionylleucylphenylalanine (fMet-Leu-Phe) exhibited by human neutrophils suspended in Na+-free, high-K+ buffered solution. The results demonstrate that: (a) the variation of Na+ concentration in the suspending solution induces in human neutrophils a marked modification of the recognition apparatus for the chemotactic peptide fMet-Leu-Phe, the lack of or low concentration of this ion increasing the number of the receptors and their specific affinity for the ligand; (b) the greater respiratory burst and secretion induced by fMet-Leu-Phe in human neutrophils suspended in Na+-free, high-K+ medium are due to the increased formation of receptor-ligand complexes at the cell membrane; (c) the greater respiratory response is partially due also to a higher efficiency of these receptor-ligand complexes. The molecular mechanism by which Na+ exerts a regulative role on the properties of the recognition apparatus for the chemotactic peptide and its possible significance are discussed. 相似文献
7.
Properties of the xanthine oxidase from human liver 总被引:4,自引:0,他引:4
8.
G. Cassinelli E. Cotta G. D'Amico C. Della Bruna A. Grein R. Mazzoleni M. L. Ricciardi R. Tintinelli 《Archives of microbiology》1970,70(3):197-210
Summary A new microorganism, isolated in our laboratories and identified as Streptomyces michiganensis var. amylolyticus var. nova is described.Thaimycins can be obtained by submerged fermentation of this microorganism on a suitable culture medium.Three new related compounds, thaimycins A, B and C have been obtained and characterized by their physical and chemical properties.Data on the antiprotozoal and anthelmintic activities in vitro as well as in vivo are reported. 相似文献
9.
NAD(P) aldehyde dehydrogenases (EC 1.2.1.3) are a family of enzymes that oxidize a wide variety of aldehydes into acid or activated acid compounds. Using site-directed mutagenesis, the essential nucleophilic Cys 149 in the NAD-dependent phosphorylating glyceraldehyde-3-phosphate dehydrogenase from Escherichia coli has been replaced by alanine. Not unexpectedly, the resulting mutant no longer shows any oxidoreduction phosphorylating activity. The same mutation, however, endows the enzyme with a novel oxidoreduction nonphosphorylating activity, converting glyceraldehyde 3-phosphate into 3-phosphoglycerate. Our study further provides evidence for an alternative mechanism in which the true substrate is the gem-diol entity instead of the aldehyde form. This implies that no acylenzyme intermediate is formed during the catalytic event. Therefore, the mutant C149A is a new enzyme which catalyzes a distinct reaction with a chemical mechanism different from that of its parent phosphorylating glyceraldehyde-3-phosphate dehydrogenase. This finding demonstrates the possibility of an alternative route for the chemical reaction catalyzed by classical nonphosphorylating aldehyde dehydrogenases. 相似文献
10.
Two homologous genes, originated by duplication, encode the human hnRNP proteins A2 and A1. 总被引:2,自引:0,他引:2 下载免费PDF全文
Heterogeneous nuclear ribonucleoprotein (hnRNP) A2 belongs, with A1, B1 and B2, to the basic protein subset of the hnRNP complex in mammalian cells. All these proteins share a modular structure consisting of two conserved RNA binding domains linked to less conserved Gly-rich domains (2xRBD-Gly). In the framework of our studies on the genetic basis of hnRNP proteins structure and diversity we have isolated and sequenced the A2 gene and compared it to the previously described A1 gene. The A2 gene, which exists in a single copy on Ch. 7 band p15, is split in 12 exons including an alternatively spliced 36 nt mini exon specific for the human hnRNP protein B1. In this work we show that the intron/exon organisation of the A2 gene is identical to that of the A1 gene over the entire length, indicating a common origin by gene duplication. Moreover the comparison of corresponding exons evidences significant conservation also in the apparently divergent Gly-rich domains that could define previously unenvisaged structural and/or functional motifs. The A2 gene promoter is also analysed in comparison to that of the A1 gene. 相似文献