Primary cutaneous nocardiosis with multiple, subcutaneous abscesses in a patient with sarcoidosis.

A case of multiple subcutaneous nocardial abscesses is reported in a patient who received systemic corticosteroids over a period of about 4 years for the treatment of visceral sarcoidosis. The diagnosis of subcutaneous abscess caused by Nocardia asteroides was made based on bacteriological examination. It could not be determined before treatment whether the abscesses represented primary or secondary nocardiosis. Surgical drainage and systemic administration of minocycline hydrochloride dramatically resolved the cutaneous lesions. To the authors' knowledge, this is the first reported case in Japan of primary cutaneous nocardiosis in a patient with sarcoidosis.

The conformational study of chitin and chitosan oligomers in solution.

The inter-residual dihedral angles phi and phip of chitin and chitosan oligomers were determined from experimental 3J(C-H) constants and ROESY cross peaks.

The conformation of alpha-(1-->4)-linked glucose oligomers from maltose to maltoheptaose and short-chain amylose in solution.

The conformation of maltose-type oligomers in water and in dimethylsulfoxide (Me2SO) was studied using two-dimensional NMR spectra. In Me2SO all of the oligomers have a 1a-type conformation. In water, they tend to adopt the same conformation, but the oligomers are looser and more flexible than in Me2SO.

NMR study of the galactomannans of Trichophyton mentagrophytes and Trichophyton rubrum.

Around 90% of chronic dermatophyte infections are caused by the fungi Trichophyton mentagrophytes and Trichophyton rubrum. One of the causes of the chronic infection resides in the immunosuppressive effects of the cell-wall components of these organisms. Therefore we have attempted to identify the chemical structure of galactomannan, one of the major cell-wall components. The cell-wall polysaccharides secreted by T. mentagrophytes and T. rubrum were isolated from the culture medium and fractionated into three subfractions by DEAE-Sephadex chromatography. Analysis of each subfraction by NMR indicated that there are two kinds of polysaccharides present, i.e. mannan and galactomannan. The mannan has a linear backbone consisting of alpha1,6-linked mannose units, with alpha1,2-linked mannose units as side chains. The core mannan moiety of the galactomannan was analysed by a sequential NMR assignment method after removing the galactofuranose units by acid treatment. The result indicates that the mannan moiety has a linear repeating structure of alpha1,2-linked mannotetraose units connected by an alpha1,6 linkage. The H-1 signals of the two intermediary alpha1, 2-linked mannoses of the tetraose unit showed a significant upfield shift (Deltadelta=0.05-0.08 p.p.m.), due to the steric effect of an alpha1,6-linked mannose unit. The attachment point of the galactofuranose units was determined at C-3 of the core mannan by the assignment of the downfield-shifted 13C signals of the galactomannan compared with those of the acid-modified product. In these galactomannans there were no polygalactofuranosyl chains which have been found in Penicillium charlesii and Aspergillus fumigatus.

Existence of novel branched side chains containing beta-1,2 and alpha-1,6 linkages corresponding to antigenic factor 9 in the mannan of Candida guilliermondii.

Isolation of beta-linkage-containing side chain oligosaccharides from the mannan of Candida guilliermondii IFO 10279 strain has been conducted by acetolysis under mild conditions. A structural study of these oligosaccharides by one- and two-dimensional NMR and methylation analyses indicated the presence of extended oligosaccharide side chains with two consecutive beta-1,2-linked mannose units at the nonreducing terminal of alpha-linked oligosaccharides. The linkage sequence present in this mannan, Man beta 1-->2Man alpha 1-->3Man alpha-->, has also been found in the mannan of Saccharomyces kluyveri but not in the mannan of Candida species. Furthermore, these oligosaccharides are branched at position 6 of the 3-O-substituted mannose units as follows. (Carbohydrate sequence in text) Structure 1 and (Carbohydrate sequence in text) Structure 2 The H-1 signals of the mannose units substituted by a 3,6-di-O-substituted unit showed a significant upfield shift (delta delta = 0.04-0.08 ppm) due to a steric effect. The inhibition of an enzyme-linked immunosorbent assay between the mannan of C. guilliermondii and factor 9 serum with oligosaccharides obtained from several mannans indicated that only the oligosaccharides with the above structure were active, suggesting that these correspond to the epitope of antigenic factor 9.

Existence of branched side chains in the cell wall mannan of pathogenic yeast, Candida albicans. Structure-antigenicity relationship between the cell wall mannans of Candida albicans and Candida parapsilosis.

Isolation of side chain oligosaccharides from mannans of Candida albicans NIH B-792 (serotype B) and Candida parapsilosis IFO 1396 strains has been conducted by acetolysis under mild conditions. Structural study of these oligosaccharides by 1H and 13C NMR and methylation analyses indicated the presence of novel branched side chains with the following structures in C. albicans mannan. [sequence: see text] It was observed that the H-1 proton chemical shifts of the second and the third mannose units from the reducing terminus in each oligosaccharide are shifted upfield by substitution with an alpha-linked mannose unit at position 6 of the 3-O-substituted mannose unit. An agglutination inhibition assay between factor 4 serum and cells of Candida stellatoidea IFO 1397 lacking the beta-1,2-linked mannose unit, with oligosaccharides obtained from these mannans, indicated that only the branched oligosaccharides were active. This finding suggests that the branched oligosaccharides correspond to the epitope of antigenic factor 4. The presence of the branched structure in other mannans was detected by the characteristic H-1-H-2-correlated cross-peak of the alpha-1,2-linked mannose unit connected with the 3,6-di-O-substituted one by two-dimensional homonuclear Hartmann-Hahn spectroscopy.

Expression of alpha-1,3 linkage-containing oligomannosyl residues in a cell-wall mannan of Candida tropicalis grown in yeast extract-Sabouraud liquid medium under acidic conditions.

We investigated the cell-wall mannan obtained from Candida tropicalis IFO 1647 strain cells grown in yeast extract-Sabouraud medium at pH 3.0 by two-dimensional homonuclear Hartmann-Hahn spectroscopy. The results indicate that the phosphate group and the side chains containing a beta-1,2-linked mannopyranose unit decreased compared to those of mannan from cells grown under conventional conditions (pH 5.9) with concomitant expression of alpha-1,3 linkage-containing oligomannosyl side chains. The results of acetolysis of these mannans indicated that the presence of alpha-1,3-linked mannopyranose unit existed in side chains corresponding to pentaose and hexaose, Manp alpha 1-3 Manp alpha 1-2Manp alpha 1-2 Manp alpha 1-2Man, and Manp alpha 1-2Manp alpha 1-3Manp alpha 1-2Manp alpha 1-2Manp alpha 1-2Man, in the mannan from cells grown at pH 3.0.

Complete assignment of 1H and 13C nuclear magnetic resonance chemical shifts of beta-1,2-linked mannooligosaccharides isolated from the phosphomannan of the pathogenic yeast Candida albicans NIH B-792 strain.

To confirm correctness of the previous assignment study of H-1 protons of beta-1,2-linked mannooligosaccharides provided by Shibata et al. (Biochemistry 31, 5680-5686, 1992), another type of nonempirical assignment of the H-1 signals of the same oligosaccharides was achieved by adopting a sequential NMR assignment method that combines two-dimensional 1H-13C correlated spectroscopy, two-dimensional 1H-1H correlated spectroscopy, and two-dimensional heteronuclear multiple-bond connectivity. Based on the above results, all of the 1H and most of the 13C signals in each oligosaccharide could also be assigned. The results of the proton assignment study provided sufficient evidence to confirm the correctness of that obtained in the previous H-1 proton assignment study. Furthermore, the existence of a regularity rule between the order of mannose units and its 1H and 13C chemical shifts has been revealed.

Sequential nuclear magnetic resonance assignment of beta-1,2-linked mannooligosaccharides isolated from the phosphomannan of the pathogenic yeast Candida albicans NIH B-792 strain.

The H-1 and H-2 signals of beta-1,2-linked mannooligosaccharides isolated from the phosphomannan of Candida albicans NIH B-792 strain by mild acid hydrolysis were assigned by a sequential NMR assignment method that combines two-dimensional 1H-1H correlated spectroscopy (COSY) and two-dimensional nuclear Overhauser enhancement and exchange spectroscopy (NOESY). The results indicated that the H-1 and H-2 of each beta-1,2-linked mannopyranose unit show largely different signals compared with those of the alpha-linked ones and that the correlation between linkages and signals could not be explained by a conventional additivity rule. Furthermore, a regular proportional downfield shift of the H-1 signal was observed in the order of the mannose unit from the reducing terminal except those of the reducing and nonreducing terminal positions. Although the 1H NMR spectra of these oligosaccharides were complicated due to the presence of a large portion of the beta-anomer from the reducing terminal mannose unit, reduction of the oligosaccharides with NaBH4 to the corresponding alcohols gave simple and more readily interpretable 1H NMR spectra. Unexpectedly, however, a shift of H-1 signals by this reduction occurred not only on the second mannose unit but also on the third and fourth mannose units from the modified reducing terminal group of each oligosaccharide alcohol. This result indicates that the reducing terminal mannose unit is able to affect up to the fourth mannose unit from the reducing terminal. The presence of a long-distance interresidue NOE also suggests that the beta-1,2-linked mannooligosaccharides have a compactly folded conformation in solution.

Structural study on a phosphorylated mannotetraose obtained from the phosphomannan of Candida albicans NIH B-792 strain by acetolysis.

A mixture of phosphorylated manno-oligosaccharides was isolated from the acid-stable domain of phosphomannan of Candida albicans NIH B-792 strain (serotype B) by acetolysis and was fractionated on a column of Bio-Gel P-2 equilibrated with 50 mM pyridine-CH3COOH buffer, pH 5.0. A monophosphorylated mannotetraose was isolated as the major constituent. Structural analyses of this phosphate-containing tetraose and its reduction product with NaBH4 by 1H, 13C, and two-dimensional homonuclear Hartmann-Hahn NMR spectroscopies, subsequently, gave results consistent with the structure described below (where Manp represents the mannopyranose unit): [formula: see text] It was unexpected that the major phosphorylated branch in the acid-stable domain of the parent phosphomannan of this C. albicans strain is a relatively short mannotetraosyl residue containing solely alpha-1,2-linked mannopyranose units, and a phosphate group as a 6-O-ester on the intermediary unit adjacent to the nonreducing terminal group. These findings indicate that the size of the major phosphorylated branch of this phosphomannan is the same as that of Saccharomyces cerevisiae.