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Biomedical subjects

F Urbina

Publications and source records attributed to F Urbina.

14 recordsLinked to original sources

Circumscribed palmar hypokeratosis: clinical evolution and ultrastructural study after prolonged treatment with topical calcipotriol.

Circumscribed palmar hypokeratosis is a recently described condition that consists of a solitary area of depressed skin affecting the palm (or sole). Its histopathological features include a thinned horny layer, a slightly diminished granular cell layer, and intraepidermal vacuolated cells. Prolonged treatment with topical calcipotriol resulted in complete recovery of the affected zone in the case reported here. A second biopsy of the lesion taken at around the fourth year of therapy showed a normalization of the granular layer, a reduction in the intraepidermal vacuolated cells, and a somewhat thicker horny layer. An ultrastructural study carried out at the same time showed a reduction in keratin bundles and keratohyalin granules, and an increase in lipid droplets up to the horny layer. These findings and the therapeutic response to topical calcipotriol support the concept that circumscribed palmar hypokeratosis is a focalized abnormal keratinization defect morphologically expressed at the granular and horny layers.

Administration, Cutaneous↗

Structure elucidation of the O-antigenic polysaccharide from the enteroaggregative Escherichia coli strain 62D1.

The O-antigen polysaccharide of the lipopolysaccharide from the enteroaggregative Escherichia coli strain 62D1 has been determined. Sugar and methylation analysis together with 1H and 13C NMR spectroscopy revealed the components of the repeating unit. Two-dimensional NOESY and heteronuclear multiple-bond correlation experiments were used to deduce the sequence. 1H and 13C NMR spectra indicate heterogeneity in the polysaccharide. Methylation analysis and 1H NMR spectra of native and Smith-degraded material show that the majority (65%) of the repeating units has the following structure: Minor resonances in the NMR spectra are consistent with the presence of repeating units which lack the alpha-d-Galp terminal residue (35%).

Carbohydrate Conformation↗

Structural elucidation of the O-antigenic polysaccharides from Escherichia coli O21 and the enteroaggregative Escherichia coli strain 105.

The structure of the O-antigen polysaccharide of the lipopolysaccharide from an enteroaggregative Escherichia coli (strain 105) has been elucidated, using primarily one-dimensional and two-dimensional NMR experiments. The sequence of residues was deduced with heteronuclear multiple-bond correlation and NOESY experiments. The structure of the repeating unit of the polysaccharide from the enteroaggregative E. coli is as follows:[sequence: see text] The structure of the O-antigen from enteroaggregative E. coli strain 105 was shown to be identical with that of E. coli O21 by sugar and methylation analyses as well as by 1H-NMR and 13C-NMR spectroscopy.

Bacterial Adhesion↗

Structure determination of the O-antigenic polysaccharide from the enterotoxigenic Escherichia coli (ETEC) O101.

The O-antigenic polysaccharide of the lipopolysaccharide from the enterotoxigenic Escherichia coli O101 has been investigated. The composition and sequence of the repeating units was established by sugar and methylation analysis together with 1H and 13C NMR spectroscopy. The sequence was corroborated using the computer program CASPER. The structure of the repeating unit of the polysaccharide from E. coli O101 is as follows: -->6)-alpha-D-GlcpNAc-1-->4-alpha-D-GalpNAc-(1-->.

Carbohydrate Conformation↗

Structural analysis of the O-antigenic polysaccharide from the enteropathogenic Escherichia coli O125.

The structure of the polysaccharide part of the lipopolysaccharide obtained from the enteropathogenic Escherichia coli O125 has been investigated. Methylation analysis, 1H-NMR spectroscopy and 13C-NMR spectroscopy revealed that the polysaccharide is composed of repeating hexasaccharide units. Smith degradation of the native O-polysaccharide resulted in a polysaccharide with four sugar residues in the repeating unit. Information on the sequence of the native O-polysaccharide and the Smith-degraded product was obtained by two-dimensional techniques, namely heteronuclear-multiple-bond-connectivity and NOESY experiments. The structure of the repeating unit of the O-polysaccharide of E. coli strain O125, which has two adjacent branch-point residues, is [sequence: see text].

Carbohydrate Conformation↗

Mal de Meleda.

A case of mal de Meleda originating in Chile is reported. The patient had no history of consanguinity and cases could not be detected in four generations of the patient's family. The palmoplantar keratoderma was progrediens and transgrediens, with distant hyperkeratotic plaques of the knees and elbows. The nails, hair, and teeth were normal.

Adult↗

Pigmented follicular cyst.

A pigmented follicular cyst is an infrequent variant of an epithelial cyst which has rarely been reported since it was first described about 10 years ago. The condition consists of a single pigmented lesion which occurs predominantly in adult men, and is usually located on the head and neck region. We report an example of a pigmented follicular cyst, which was located in the axilla.

Adult↗

Malignant cutaneous mixed tumor. A new case with unusual clinical features.

We report the case of an ulcerated malignant cutaneous mixed tumor occurring on the nose of a 75-year-old woman. Malignant cutaneous mixed tumor (CMT) is a rare neoplasm. Of the 14 previously reported cases, 10 occurred on the extremities, three on the trunk, and one on the scalp. This contrasts with the benign CMT which is found mainly on the head and neck region, the nose being the most commonly affected site. Although eight of the cases of malignant CMT recurred and 10 metastasized, the primary lesion never ulcerated.

Aged↗

Self-inflicted tongue ulcer: an unusual form of factitious disorder.

Factitious disorders in the buccal cavity are infrequent. A 9-year-old boy with a 5-year history of an artefact ulcer of the tongue is described. Psychiatric evaluation revealed an altered personality structure with a background of psychotic traits. Complete remission was observed with psychiatric management.

Anti-Anxiety Agents↗