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排序方式: 共有1327条查询结果,搜索用时 31 毫秒
1.
Neurotoxic Esterase in Human Nervous Tissue 总被引:1,自引:1,他引:0
2.
L. Manzocchi C. Tonelli G. Gavazzi N. Di Fonzo C. Soave 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1986,72(6):778-781
Summary This paper reports that the opaque-6 (o6) mutation of maize, which causes seedling lethality and interferes in the endosperm with the synthesis of zeins and b-32 protein, is a proline requiring mutant functionally allelic to proline-1 (pro-1). Furthermore, immunological studies on the b-32 content of ten independently originated o6 and pro-1 alleles demonstrated that four alleles contain an apparently normal b-32 protein while the others are either devoid of it or contain trace amounts of cross-reacting proteins of lower molecular weight. 相似文献
3.
Marcello Franco Eduardo Bagagli Marino Cunha Luiz Gastão Chamma Denise Fecchio 《Mycopathologia》1996,135(1):13-19
We investigated the occurrence of antigenic and biochemical variability among Paracoccidioides brasiliensis antigen batches prepared according to the same protocol. Initially (experiment #1), we analyzed two antigen lots of two human isolates (Bt1 & Bt2), cultured in two media (PYG: bactopeptone, yeast extract, glucose; MMM: McVeigh & Morton medium) in SDS-PAGE and in two immunological tests (imunodiffusion-ID and footpad swelling test-FPT). Afterwards (experiment #2), we compared the antigenic profile of three antigen batches from three human isolates (Bt1, Bt2 & Bt3) by two-dimensional immunoelectrophoresis (2 D-IEP) against a reference system for P. brasiliensis antigens. In experiment #1, there were important intra- and inter-strain antigenic differences between batches of the fungal isolates cultured on both media. The block titration of the antigen batches for the immunological tests revealed correlation between protein concentration and biological activity in ID and no correlation in FPT. In experiment #2, the reference system for P. brasiliensis showed 26 antigen peaks. There were important differences between batches prepared from the same isolate and between batches from different isolates. Our data suggested the occurrence of instability in the synthesis of antigenic components by a same P. brasiliensis isolate, under controlled incubation conditions. 相似文献
4.
M L Brandi G Weber A Svensson A Falchetti F Tonelli R Castello L Furlani S Scappaticci M Fraccaro C Larsson 《American journal of human genetics》1993,53(6):1167-1172
Families in which both parents are heterozygotes for the same autosomal dominant neoplasia syndrome are extremely unusual. Recently, we had the unique opportunity to evaluate three symptomatic siblings from the union between two unrelated individuals affected by multiple endocrine neoplasia type 1 (MEN1). When the three siblings and their parents and relatives were genotyped for 12 markers tightly linked to the MEN1 locus, at 11q13, two of the siblings were found to be homozygotes, and one a heterozygote, for MEN1. With regard to the MEN1 syndrome, no phenotypic differences were observed between the two homozygotes and the heterozygotes. However, the two homozygotes showed unexplained infertility, which was not the case for any of the heterozygotes. Thus, MEN1 appears to be a disease with complete dominance, and the presence of two MEN1 alleles with mutations of the type that occur constitutionally may be insufficient for tumor development. 相似文献
5.
Molecular homology among members of the R gene family in maize. 总被引:2,自引:0,他引:2
6.
Stefania Motta Marcello Monti Silvia Sesana Ruggero Caputo Stephana Carelli Riccardo Ghidoni 《生物化学与生物物理学报:疾病的分子基础》1993,1182(2):147-151
This paper investigates the ceramide composition of the psoriatic scale compared with that of normal human SC. A method was optimalized, based on TLC separation followed by densitometry, allowing the provision of good resolution and quantification of ceramide fractions from both normal and pathological specimens. Seven ceramide fractions were isolated and submitted to compositional analysis. The obtained results suggested a revisitation of previous ceramide designation. Therefore a simple classification is suggested, based on grouping ceramides carrying structural similarities under common codes. According to these rules, ceramides were grouped into five classes designated as: (1) Cer[EOS], which contains ester-linked fatty acids, ω-OH fatty acids and sphingosines; (2) Cer[NS], which contains non-OH fatty acids and sphingosines; (3) Cer[NP], which contains non-OH fatty acids and phytosphingosines; (4) Cer[AS], which contains α-OH fatty acids and sphingosines; (5) Cer[AP], which contains α-OH fatty acids and phytosphingosines. Analysis of ceramides from the psoriatic scale, compared to those from normal human SC, resulted in an impairment of the Cer[EOS] content as well as of the ceramides containing phytosphingosine, with concurrent increase in ceramides containing sphingosine, being the total amount maintained identical. Since one of the suggested pathways for phytosphingosine biosynthesis involves the water addition to the corresponding sphingosine double bond, we can speculate that the observed alterarion is due to a deranged water bioavailability, associated with psoriaris. 相似文献
7.
E. Gattavecchia D. Tonelli A. Breccia 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1981,224(3):465-471
A method for the determination of radiotherapeutic concentrations of metronidazole, misonidazole and its metabolite is described. The biological fluid (serum or urine) was deproteinized with acetone containing 2-nitroimidazole as internal standard, centrifuged and the supernatant evaporated under vacuum. The residue, dissolved in acetone, was applied to an HPTLC-RP-18 layer and, after development, quantitation was achieved with a scanning densitometer. The response was linear up to 180 μg/ml for all tested compounds and the detection limit was 0.5 μg/ml. Owing to its rapidity and sensitivity the method can be considered to be equivalent to high-performance liquid chromatography. 相似文献
8.
Vittoria Nuti Ronchi Lucia Giorgetti Mariagrazia Tonelli Guido Martini 《Plant Cell, Tissue and Organ Culture》1992,30(2):107-114
Cytological analysis of different carrot cell lines in culture has shown various cytogenetic anomalies generating new levels of ploidy and novel chromosome numbers. Polyploidy may be considered a reservoir of variability that can be released in the form of distinct new segregants of different ploidy. Mechanisms alternative to mitosis (reductional grouping, prophase chromosome reduction) operate from a polyploid state (possibly reached by means of endopolyploidy, endomitosis, nuclear fusion, or restitution nuclei) to generate new levels of ploidy and novel chromosome numbers necessary for selection to operate in vitro. The segregational phenomena require chromosome recognition in haploid set complements and abnormal behaviour of mitoses; the resulting chromosome variability suggests that chromosomes are arranged, in the resting nuclei, in an orderly and predictable manner.The knowledge of the molecular events governing these mechanisms, and how to control them, would be of great help for future applications of plant cell culture. 相似文献
9.
Although endogenous cannabinoid systems have been implicated in the modulation of the rewarding effects of abused drugs and food, little is known about the direct effects of endogenous ligands for cannabinoid receptors on brain reward processes. Here we show for the first time that the intravenous administration of anandamide, an endogenous ligand for cannabinoid receptors, and its longer-lasting synthetic analog methanandamide, increase the extracellular dopamine levels in the nucleus accumbens shell of awake, freely moving rats, an effect characteristic of most drugs abused by humans. Anandamide produced two distinctly different effects on dopamine levels: (1) a rapid, transient increase that was blocked by the cannabinoid CB1 receptor antagonist rimonabant, but not by the vanilloid VR1 receptor antagonist capsazepine, and was magnified and prolonged by the fatty acid amide hydrolase (FAAH) enzyme inhibitor, URB597; (2) a smaller delayed and long-lasting increase, not sensitive to CB1, VR1 or FAAH blockade. Both effects were blocked by infusing either tetrodotoxin (TTX, 1 microm) or calcium-free Ringer's solution through the microdialysis probe, demonstrating that they were dependent on the physiologic activation of dopaminergic neurotransmission. Thus, these results indicate that anandamide, through the activation of the mesolimbic dopaminergic system, participates in the signaling of brain reward processes. 相似文献
10.
Elisabetta Gianazza Francesco Chillemi Marcello Duranti Pier Giorgio Righetti 《Journal of biochemical and biophysical methods》1983,8(4):339-351
A new method for peptide analysis and purification is described, based on isoelectric focusing in immobilized pH gradients. On the analytical scale, the peptide zones can now be revealed by an stain for primary and secondary amino group (e.g. ninydrin, fluorescamine, dansyl chloride) since the buffering species, unlike conventional carrier ampholytes, contain only carboxyl and tertiary amino groups. For preparative purposes, conditions have been described to remove most contaminants (e.g. unreacted monomers, non-cross-linked, short polyacrylamide chains) from the gel matrix before the electrophoretic run. However, ca. 2% of the gel dry mass is still present as extractable material. The focused peptides can be recovered in higly yields (ca. 90%) with a fairly high degree of purity (75%), the contaminants being mostly components eluted from the polyacrylamide gel. 相似文献