Allergic contact dermatitis due to vitamin K1 contained in a cosmetic cream.
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Biomedical subjects
Publications and source records attributed to Alicia Prieto.
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The structure of acidic fungal polysaccharides isolated from the cell wall of Plectosphaerella cucumerina, Verticillium dahliae, and V. albo-atrum has been investigated by chemical analysis, methylation analysis, and 1D and 2D 1H and 13C NMR spectroscopy. The polysaccharides have an idealized repeating block of the type: [carbohydrates: see text] linked to a small mannan core (<15%), where n=13, m=13, p=5, and q=8 for P. cucumerina, and n=16, m=16, p=6, and q <1 for both Verticillium species.
The alkali extractable and water-soluble cell wall polysaccharides F1SS from Aspergillus wentii and Chaetosartorya chrysella have been studied by methylation analysis, 1D- and 2D-NMR, and MALDI-TOF analysis. Their structures are almost identical, corresponding to the following repeating unit: [--> 3)-beta-D-Gal f -(1 --> 5)-beta-D-Gal f-(1 -->]n --> mannan core. The structure of this galactofuranose side chain differs from that found in the pathogenic fungus Aspergillus fumigatus, in other Aspergillii and members of Trichocomaceae: [--> 5)-beta-D-Gal f-(1 -->]n --> mannan core. The mannan cores have also been investigated, and are constituted by a (1 --> 6)-alpha-mannan backbone, substituted at positions 2 by chains from 1 to 7 residues of (1 --> 2) linked alpha-mannopyranoses.
The type 1 HIV presents a conical capsid formed by approximately 1500 units of the capsid protein, CA. Homodimerization of CA via its C-terminal domain, CA-C, constitutes a key step in virion assembly. CA-C dimerization is largely mediated by reciprocal interactions between residues of its second alpha-helix. Here, we show that an N-terminal-acetylated and C-terminal-amidated peptide, CAC1, comprising the sequence of the CA-C dimerization helix plus three flanking residues at each side, is able to form a complex with the entire CA-C domain. Thermal denaturation measurements followed by circular dichroism (CD), NMR, and size-exclusion chromatography provided evidence of the interaction between CAC1 and CA-C. The apparent dissociation constant of the heterocomplex formed by CA-C and CAC1 was determined by several biophysical techniques, namely, fluorescence (using an anthraniloyl-labeled peptide), affinity chromatography, and isothermal titration calorimetry. The three techniques yielded similar values for the apparent dissociation constant, in the order of 50 microM. This apparent dissociation constant was only five times higher than was the dissociation constant of both CA-C and the intact capsid protein homodimers (10 microM).
Paracoccidioides brasiliensis is a pathogenic dimorphic fungus causing paracoccidioidomycosis, the most widespread systemic mycosis in Latin America. We have studied the structure of the alkali-extracted water-soluble cell wall polysaccharides (F1SS) from both mycelial and yeast phases of this fungus by using chemical analysis and NMR spectroscopic techniques. The F1SS polysaccharide from the mycelial phase consists of a trisaccharidic repeating unit of -->6)-[alpha-Galf -(1-->6)-alpha-Manp-(1-->2)]-alpha-Manp-(1-->. The F1SS polysaccharide of the yeast phase maintains 10% of the structure of the mycelium phase, but the main structure contain a disaccharide repeating unit of -->6)-[-alpha-Manp-(1-->2)]-alpha-Manp-(1-->, alternating with a trisaccharide repeating block of -->6)-[beta-Galf -(1-->6)-alpha-Manp-(1-->2)]-alpha-Manp-(1-->.
The alkali-extracted water-soluble galactomannan F1SS isolated from the cell wall of two species each of Geotrichum, Galactomyces, and Dipodascus have been studied by methylation analysis and NMR spectroscopy, and their structure is established as the following: [carbohydrate structure: see text]
The alkali-extractable water-soluble polysaccharide (F1SS) isolated from the cell wall of Apodus deciduus has been studied by methylation analysis and NMR spectroscopy, and its structure established as:where n approximately 130+/-10.
Alkali-extractable and water-soluble polysaccharides were purified from cell walls of five species of Sesquicillium or its teleomorphs, Nectria lasiacidis and Nectria impariphialis, and from Nectria cinnabarina, the type species of Nectria, a heterogeneous genus that belongs to the Hypocreales. Methylation and NMR analyses for determination of linkage types and structure were performed and indicated differences between the polysaccharides purified during the present study and those isolated from other nectrioid fungi, namely the presence of 5-O-substituted galactofuranose (-->5)-Galf-(1-->) in the main chain together with 2,6-di-O-substituted galactofuranose (-->2,6)-Galf-(1-->) residues in Sesquicillium buxi and Sesquicillium pseudosetosum. The polysaccharide from N. impariphialis was similar to those obtained from the above species, although an additional residue of 6-O-substituted glucopyranose (-->6)-Glcp-(1-->), was detected in some side chains. In N. lasiacidis and Sesquicillium candelabrum the polysaccharide contained an additional branching point of 5,6-di-O-substituted galactofuranose (-->5,6)-Galf-(1-->) linked to terminal N-acetylglucosamine GlcNAc-(1-->). These chains were linked to a small mannan core. All these polysaccharides showed major differences to the polysaccharide of N. cinnabarina, which was formed by a main chain of (1-->6)-beta-linked galactofuranose units almost fully branched at positions 2-O by either single residues of glucopyranose or acidic chains containing glucuronic acid and mannose.