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Biomedical subjects

I L Hansen

Publications and source records attributed to I L Hansen.

32 records · Page 2Linked to original sources
PubMed1982

Multiple collagen gene expression with type III predominance in rat mucosal keratinocytes.

Collagen synthesis in serially propagated cultures of rat mucosal keratinocytes (line RTK-I) was investigated. Analysis of biosynthetically labeled cell and media proteins retrieved after limited pepsin digestion revealed seven or eight collagen chains originating from four distinct collagens (types I, III, IV, V). Type III collagen was identified as the predominant species based on its electrophoretic and chromatographic behavior in the reduced and unreduced states, on the peptide pattern generated by limited cleavage with CNBr and with trypsin, and on the immunofluorescent detection of intracellular, collagen type III-reactive material. Evidence for the synthesis of two type IV collagen chains (155 k and 160 k after limited pepsin digestion) was provided by immunofluorescent and electrophoretic studies. Type V collagen was revealed by immunofluorescence, and two, possibly three, component chains were resolved in native type V collagen isolated from the harvest medium. Type I collagen, identified by comigration with authentic carriers, was a constant but quantitatively variable synthetic product. This study provides evidence that keratinocytes produce collagens normally found in mesenchymal matrices (type I and III) in addition to collagens characteristic of basement membranes (type IV) and of pericellular structures (type V). These findings reveal a hitherto unrecognized complexity and heterogeneity of the collagens synthesized by a highly differentiated epithelial cell type.

Animals↗
PubMed1981

Growth and differentiation of an established rat keratinocyte line in serial culture.

This paper describes the growth and differentiation of an established, feeder layer independent line of rat keratinocytes originally developed from tongue epithelium. The cells grew from any seeding density with a population doubling time of 14 to 16 h and a plating efficiency of 60 to 90%. The cells were kept in continuous culture for more than 3 yr and were cloned several times during this period. After more than 700 population doublings the cultures maintained typical expressions of the keratinocyte phenotype such as desmosomes and tonofilaments. The cells required 10 to 15% fetal bovine serum but no additional supplement of growth factors. Single colonies, as well as confluent multilayers, keratinized and displayed the whole complement of keratinization markers including keratin filaments, cornified envelopes, increased plasma membrane permeability, and destruction of cytoplasmic and nuclear components. However, the ability to stratify in a regular manner was lost although sporadic attempts of stratification were present. In suspension culture the cells terminally differentiated in 1 or 2 wk and developed highly cross-linked cornified envelopes that were resistant to boiling detergent solutions under reducing conditions. Chromosome numbers were in the diploid range (2N = 38 to 46), but aberrations were frequent.

Acid Phosphatase↗
PubMed1976

Bioenergetics in clinical medicine. IX. Gingival and leucocytic deficiencies of coenzyme Q10 in patients with periodontal disease.

The specific activities of the succinate dehydrogenase-coenzyme Q10 reductase in mitochondria were determined for patients from a normal periodontal practice. The criteria for selection were patients having a bone score of 1.0-4.0 and a pocket depth of 2.5-5.2 mm. All 29 patients showed a deficiency of 20-63% of CoQ10-enzyme activity in gingival biopsies. The mean value was elevated (P less than 0.001) over that of controls. For corresponding blood samples, 24/28 (86%) showed deficiencies of 20-66% and a higher (P less than 0.001) mean value than that of controls. Periodontal patients frequently have significant gingival and leucocytic deficiencies of CoQ10. The leucocytic deficiency indicates a systemic nutritional imbalance and is not likely caused by neglected oral hygiene. A gingival deficiency could predispose this tissue to periodontitis and this disease could even augment the deficiency. These results support previously suggested adjunctive use of CoQ10 with oral hygiene for improved treatment presumably through bioenergetics.

Adult↗