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Biomedical subjects

J Uitto

Publications and source records attributed to J Uitto.

At least 523 records · Page 29Linked to original sources
PubMed1978

Verrucous lesion in patients with discoid lupus erythematosus. Clinical, histopathological and immunofluorescence studies.

Seven cases of classical discoid lupus erythematosus of the face associated with hyperkeratotic, papulo-nodular lesions on the arms and hands were studied. Clinically the hyperkeratotic lesions resembled keratoacanthomas or hypertrophic lichen planus. The clinical course was marked by chronicity, an absence regression of the lesions, and resistance to treatment. Histopathologically, a lichenoid cellular reaction seemed to play a key role in the development of the hypertrophic lesions which resembled either keratoacanthomoas or hypertrophic lichen planus. Elastic fibres were prominent in the upper dermis, the lower levels of the epidermis and in the hyperkeratotic horny layer. Immunofluorescence of the papulo-nodular lesions demonstrated the deposition of IgG and IgM in a globular pattern at the dermal-epidermal junction. Discontinuous deposition of these antibodies was also seen at the basement membrane zone. On the basis of the immunofluorescence, histopathological and clinical studies, we suggest that the verrucous, hyperkeratotic lesions on the upper extremities represent an unusual, but distinct, form of discoid lupus erythematosus.

Adult↗
PubMed1976

Characterization of procollagen synthesized by matrix-free cells isolated from chick embryo tendons.

The genetic type and molecular structure of the precursor forms of collagen synthesized by matrix-free tendon cells isolated from 17-day old chick embryos were examined by chromatographic and electrophoretic techniques. The [14C]proline-labeled collagenous proteins secreted by the cells resolved on diethylaminoethylcellulose into two peaks, A and B. Both peaks contained type I collagenous proteins since on chromatography on carboxymethylcellulose, after limited pepsin proteolysis, both peaks contained alpha1 and alpha2 chains of collagen in a 2:1 ratio, and cyanogen bromide peptide maps of the 14C-labeled protein in both peaks were similar to cyanogen bromide peptide maps derived from authentic type I collagen. Enzymatic digestion with purified mammalian collagenase demonstrated that the collagen precursor in peak B contained noncollagenous peptide extensions at both the amino- and carboxy-terminal ends of the molecule, while peak A had only carboxy-terminal extension peptides. Although both the amino- and carboxy-terminal extensions incorporated radioactive cystine, only the carboxy-terminal extensions contained interchain disulfide bonds. The carboxy-terminal extensions were also shown to incorporate radioactive tryptophan. Since most of the precursor forms of collagen recovered in the incubation medium chromatographed in peak B, it is concluded that matrix-free tendon cells secrete only type I procollagen with extension peptides at both the amino- and carboxy-terminal ends of the molecule.

Animals↗
PubMed1976

Defects in the biochemistry of collagen in diseases of connective tissue.

The collagens are the major structural glycoproteins of connective tissues. A unique primary structure and a multiplicity of post-translational modification reactions are required for normal fibrillogenesis. The post-translational modifications include hydroxylation of prolyl and lysyl residues, glycosylation, folding of the molecule into triple-helical conformation, proteolytic conversion of precursor procollagen to collagen, and oxidative deamination of certain lysyl and hydroxylysyl residues. Any defect in the normal mechanisms responsible for the synthesis and secretion of collagen molecules or the deposition of these molecules into extracellular fibers could result in abnormal fibrillogenesis; such defects could result in a connective tissue disease. Recently, defects in the regulation of the types of collagen synthesized and in the enzymes involved in the post-translational modifications have been found in heritable diseases of connective tissue. Thus far, the primary heritable disorders of collagen metabolism in man include lysyl hydroxylase deficiency in Ehlers-Danlos syndrome type VI, p-collagen peptidase deficency in Ehlers-Danlos syndrome type VII, decreased synthesis of type III collagen in Ehlers-Danlos syndrome type IV, lysyl oxidase deficency in S-linked cutis laxa and Ehlers-Danlos syndrome type V, and decreased synthesis of type I collagen in osteogenesis imperfecta.

Aortic Diseases↗
PubMed1975

Retention of nonhelical procollagen containing cis-hydroxyproline in rough endoplasmic reticulum.

Fibroblasts freshly isolated from embryonic tendons were incubated with a proline analog, cis-4-hydroxy-L-proline, which is incorporated into protein and which leads to the intracellular accumulation of nonhelical procollagen. Evidence is presented here that the nonhelical procollagen containing the analog is retained within the rough endoplasmic reticulum and does not pass to the smooth endoplasmic reticulum or Golgi vacuoles at a normal rate.

Animals↗