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Biomedical subjects

E Vuorio

Publications and source records attributed to E Vuorio.

At least 145 records · Page 8Linked to original sources
PubMed1987

Differential expression of fibrillar collagen genes during callus formation.

An experimental fracture healing model in the rat tibio-fibular bone was employed to study the appearance of messenger RNAs for types I, II and III collagens during endochondral fracture repair. Total RNA was extracted from normal bone and from callus tissue at various time points. The total RNAs were analyzed in Northern hybridization for their contents of procollagen mRNAs using specific cDNA clones. The results show that during the first week of fracture repair type III collagen mRNA is increased to the greatest extent, followed by type II collagen mRNA during the second week. The 28-day callus resembles bone by containing mainly type I collagen mRNAs and very little type II or III collagen mRNA.

Animals↗
PubMed1987

Coordinated regulation of type I and type III collagen production and mRNA levels of pro alpha 1(I) and pro alpha 2(I) collagen in cultured morphea fibroblasts.

Fibroblast cultures were started from affected and unaffected skin areas of six patients with localized scleroderma in an active stage. The cell lines were studied for synthesis of procollagens and fibronectin by metabolic labeling with 3H-proline and for their contents of mRNAs for pro alpha 1(I) and pro alpha 2(I) collagen. For this purpose a cDNA clone for human pro alpha 1(I) collagen mRNA was constructed. The clone was identified by restriction site mapping and hybridization to the specific mRNAs. All the scleroderma fibroblast lines produced increased amounts of type I and type III collagens and fibronectin during the early passages. The cell lines gradually reduced their elevated synthesis of collagen and fibronectin to normal or near normal levels by the tenth passage. The ratios of alpha 1(I) and alpha 2(I) chains and of type I and type III collagens, and the extent of type I procollagen processing, remained relatively unchanged in all the cultures. The cellular levels of type I procollagen mRNAs were increased in all the cells exhibiting an increased synthesis of collagen. The results suggest that in localized scleroderma the fibroblasts have undergone a coordinated activation of collagen synthesis at transcriptional level.

Collagen↗
PubMed1987

Collagen synthesis in the vaginal connective tissue of patients with and without uterine prolapse.

The insufficiency of connective tissue in pelvic relaxation was studied in five patients with uterine descent and in five age-related controls. Samples from vaginal fascias were first studied by histology. Fibroblast cultures started from each sample were analysed for their collagen synthesis and content of type I procollagen messenger RNAs (mRNAs). The cellularity of the fascias in histological specimens and the biosynthesis of collagen in fibroblast cultures decreased with increasing age in both groups. Fibroblasts grown from patients with uterine descent exhibited rates of collagen synthesis similar to or slightly higher than those from age-matched controls. The histological and biochemical changes observed in connective tissue of uterine descent are most likely related to the age and hormonal status of the patients. The findings suggest that uterine descent is not related to defects in the capacity of vaginal fibroblasts to synthesize or process procollagen.

Adult↗
PubMed1987

Localization of types I, II, and III collagen mRNAs in developing human skeletal tissues by in situ hybridization.

Paraffin sections of human skeletal tissues were studied in order to identify cells responsible for production of types I, II, and III collagens by in situ hybridization. Northern hybridization and sequence information were used to select restriction fragments of cDNA clones for the corresponding mRNAs to obtain probes with a minimum of cross-hybridization. The specificity of the probes was proven in hybridizations to sections of developing fingers: osteoblasts and chondrocytes, known to produce only one type of fibrillar collagen each (I and II, respectively) were only recognized by the corresponding cDNA probes. Smooth connective tissues exhibited variable hybridization intensities with types I and III collagen cDNA probes. The technique was used to localize the activity of type II collagen production in the different zones of cartilage during the growth of long bones. Visual inspection and grain counting revealed the highest levels of pro alpha 1(II) collagen mRNAs in chondrocytes of the lower proliferative and upper hypertrophic zones of the growth plate cartilage. This finding was confirmed by Northern blotting of RNAs isolated from epiphyseal (resting) cartilage and from growth zone cartilage. Analysis of the osseochondral junction revealed virtually no overlap between hybridization patterns obtained with probes specific for type I and type II collagen mRNAs. Only a fraction of the chondrocytes in the degenerative zone were recognized by the pro alpha 1(II) collagen cDNA probe, and none by the type I collagen cDNA probe. In the mineralizing zone virtually all cells were recognized by the type I collagen cDNA probe, but only very few scattered cells appeared to contain type II collagen mRNA. These data indicate that in situ hybridization is a valuable tool for identification of connective tissue cells which are actively producing different types of collagens at the various stages of development, differentiation, and growth.

Cartilage, Articular↗
PubMed1987

Alterations in scleroderma fibroblast surface glycoproteins associated with increased collagen synthesis.

Fibroblasts were cultured from affected and unaffected skin sites of 6 patients with localized scleroderma. As a parameter of fibroblast activation, collagen synthesis and cellular pro alpha 1(I)collagen mRNA levels were measured. Cell surface glycoproteins were labelled with the periodate/borohydride method and fractionated electrophoretically. A distinct reduction in the relative amount of surface glycoproteins in the 120 kDa region was observed in two affected cell lines producing increased amounts of collagen and in one affected cell line with normal collagen production when compared to unaffected fibroblast lines. Other, non-systematic alterations in the surface glycoproteins of the affected cell lines were also detected. Compared to unaffected and healthy control fibroblasts no alterations in the surface protein profiles were seen in the other three affected cell lines. These cells did not show an increase in collagen production either. The results suggest that the activation of collagen synthesis found in scleroderma fibroblasts might be connected with alterations in the normal cell surface glycoprotein pattern.

Adult↗
PubMed1986

Type I collagen messenger RNA levels in experimental granulation tissue and silicosis in rats.

A complementary DNA (cDNA) clone was constructed for chick pro alpha 2(I) collagen mRNA. This and previously constructed cDNA clones for chick and human pro alpha 1(I) collagen mRNAs were used to measure levels of type I procollagen messenger RNAs in two experimental models: viscose cellulose sponge-induced experimental granulation tissue and silica-induced experimental lung fibrosis in rats. Both Northern RNA blot and RNA dot hybridizations were used to quantitate procollagen mRNAs during formation of granulation tissue. The period of rapid collagen synthesis was characterized by high levels of procollagen mRNAs, which were reduced when collagen production returned to a low basal level. The rate of collagen synthesis and the levels of procollagen mRNAs during the period of rapid reduction in collagen production did not, however, parallel with each other. This suggests that translational control mechanisms are important during this time in preventing overproduction of collagen. In silicotic lungs, the early stages of fibroblast activation follow a similar path but appear faster. At a later stage, however, the RNA levels increase again and permit collagen synthesis to continue at a high rate, resulting in massive collagen accumulation.

Animals↗
PubMed1985

Construction and identification of a cDNA clone for human type II procollagen mRNA.

Double-stranded cDNA was constructed for poly(A)-containing RNA isolated from foetal human articular cartilage known to contain small amounts of pro alpha 1 (II) collagen mRNA. A 585 base pair PstI-EcoRI cDNA fragment was isolated and cloned into plasmid pBR322. A resulting recombinant plasmid pHCAR1 was shown to hybridize specifically to a 5.4 kilobase mRNA in cartilage but not in calvarial RNA. Definite identification of clone pHCAR1 was based on sequence analysis; marked homology with the corresponding chick gene and complete agreement with the human gene sequences available were observed.

Base Sequence↗
PubMed1985

Activation of type I collagen genes in cultured scleroderma fibroblasts.

Fibroblasts cultured from affected skin areas of five patients with cutaneous scleroderma were found to produce increased amounts of collagen when compared with nonaffected control cells. Total RNA was isolated from the cultures and analyzed for its level of pro alpha 1 (I)collagen mRNA by hybridization of RNA blots with a cloned cDNA probe. The levels of pro alpha 1 (I)collagen mRNAs relative to total RNA were two- to sixfold higher in the samples from affected cells, accounting for the increased synthesis of type I collagen. Cytoplasmic dot hybridizations were performed to measure the cellular content of pro alpha 1 (I)collagen mRNA: up to ninefold increases in the level of this mRNA per cell were found. Upon subculturing, scleroderma fibroblasts were found to reduce gradually the increased synthesis of collagen to the level of nonaffected controls by the tenth passage. The levels of type I collagen mRNAs were also reduced, but more slowly. The results suggest that in scleroderma fibroblasts the genes for type I collagen are activated at procollagen mRNA level or that they are more stable and that the activating factors are lost during prolonged cell culture because cells from affected areas lose their activated state.

Adolescent↗
PubMed1984

Identification of messenger RNA for human type II collagen.

Total RNA was purified from human fetal calvaria and articular cartilage. Messenger RNAs for type I and II collagens were identified by hybridization using cDNA clones for chicken pro alpha 1(I)-, pro alpha 2(I)- and pro alpha 1(II)collagen mRNAs and by analysis of cell-free translation products of these RNAs by polyacrylamide gel electrophoresis. The size of human pro alpha 1(II)collagen mRNA is approx. 5100 bases. Translatability of cartilage specific type II collagen mRNA was found to be concentration dependent: with increasing total RNA concentrations the relative translation of type II collagen mRNA was reduced with respect to type I mRNAs.

Animals↗
PubMed1984

Increased type I collagen mRNA levels in cultured scleroderma fibroblasts.

Pro alpha 1(I)collagen mRNA levels in fibroblasts cultured from affected and non-affected skin areas of two scleroderma patients were measured by hybridization of RNA blots with a specific cDNA clone. Collagen synthesis was estimated with an inhibition ELISA for type I collagen and with densitometric scans of fluorograms of [3H]proline-labelled medium proteins. Affected scleroderma fibroblasts exhibited 2-7-fold higher levels of pro alpha 1(I)collagen mRNAs to account for the increased synthesis of collagen by the same cells. This suggests that the control of collagen synthesis in scleroderma is altered at transcriptional level.

Cells, Cultured↗
PubMed1984

Characterization of trimethoprim resistance by use of probes specific for transposon Tn7.

Transposon Tn7 codes for resistance to trimethoprim and streptomycin. For detection of Tn7 by DNA-DNA hybridization, two recombinant plasmids were constructed. The former contained a 1-kilobase BamHI fragment and the latter contained a 4.3-kilobase EcoRI-BamHI fragment of Tn7. These DNA fragments, which did not include the drug resistance genes, were used as probes for detecting Tn7-like sequences in bacterial strains by colony hybridization. They hybridized strongly to bacterial DNA known to carry Tn7 but not to DNA known to carry transposons other than Tn7. These probes were used to study the occurrence of Tn7 in bacterial strains isolated in the Turku City Hospital in Finland. Transposon Tn7 was present in 47.2% of 199 trimethoprim-resistant enterobacteria (MIC greater than or equal to 8 micrograms/ml). Among the 69 Proteus mirabilis strains studied, 75% contained Tn7, although none of these strains transferred trimethoprim resistance in conjugation tests. The reliability of colony hybridization was further confirmed by Southern hybridization to detect the Tn7-specific 2.6-kilobase HindIII restriction fragment. Colony hybridization proved to be a sensitive and rapid method for detecting Tn7-determined sequences.

Bacteria↗
PubMed1984

Characterization of plasma membranes and rough endoplasmic reticulum of synovial cells cultured from rheumatoid arthritis patients.

[35S]methionine-labelled plasma membrane (PM) and rough endoplasmic reticulum (RER) proteins were analysed from synovial cell cultures derived from rheumatoid arthritis (RA) and reference patients. Pure RER was prepared by a modification of CsCl-containing sucrose-cushion method. The PM proteins were resolved into 30-35 bands using sodium dodecyl sulphate-electrophoresis in polyacrylamide gradient gels. The major polypeptides had apparent molecular masses of 170, 140, 110, 60, 40, 33, 23 and 14 kilodaltons. The major RER polypeptides had the apparent molecular masses of 170, 74, 58 and 35 kD. No reproducible differences were demonstrated in the polypeptide patterns or in the specific activities of the PM and ER (endoplasmic reticulum) marker enzymes between cells from RA and reference patients. The results reflect similarities of membrane structures in RA and reference cells, although differences have been reported in their metabolism.

Arthritis, Rheumatoid↗
PubMed1983

The effect of rheumatoid synovial fluid macrophages on DNA, glycosaminoglycan and collagen synthesis by synovial fibroblasts.

The effects of soluble factors secreted by peripheral blood monocytes and rheumatoid synovial fluid macrophages were tested on human synovial fibroblast cultures. Both monocytes and macrophages liberated factors which reduced DNA synthesis (3H-thymidine incorporation) by synovial fibroblasts. Monocyte and macrophage factors stimulated hyaluronic acid synthesis. The activation obtained with rheumatoid synovial macrophages was considerably greater than that with monocytes. Foetal bovine serum was found to have a clear stimulatory effect on the synthesis of collagen and other proteins by fibroblasts. The effects of monocyte and macrophage factors on protein synthesis in synovial fibroblasts were small: collagen synthesis was slightly increased relative to other extracellular proteins.

Arthritis, Rheumatoid↗
PubMed1983

Plasma membrane glycoproteins of cultured rheumatoid synovial fibroblasts.

Fibroblast cultures were started from synovial tissue samples of 12 rheumatoid arthritic, 9 non-rheumatoid synovitic and 6 control patients. External galactose units of plasma membrane glycoproteins of confluent cells were labelled using the galactose oxidase-tritiated borohydride method. These surface-labelled cells were analyzed for possible differences in their glycoproteins by electrophoresis in SDS-containing polyacrylamide gradient gels. Total cell lysates were separated into 50-60 polypeptide bands. Fluorography of the gels revealed about 20 labelled plasma membrane glycoproteins. Some strain-specific differences were detected between the samples in all the groups, but no correlation with rheumatoid arthritis could be demonstrated.

Arthritis, Rheumatoid↗
PubMed1982

Construction and partial characterization of two recombinant cDNA clones for procollagen from chicken cartilage.

Type II procollagen mRNA has been partially purified from embryonic chick sternal cartilage by guanidine hydrochloride extraction, sucrose gradient sedimentation and Sepharose 4B chromatography. Double stranded cDNA was synthesized using AMV reverse transcriptase and E. coli DNA polymerase I, tailed using terminal transferase and inserted into the Pst I site of pBR322. Two putative type II procollagen cDNA clones have been characterized. Both plasmids hybridize to 2 sternal RNA species, a major species of 5.3 kb and a minor species of 7 kb. These RNAs are present in total RNA from sterna and differentiated limb bud cultures but are not detected in RNA from stage 24 limb bud which has not yet differentiated to cartilage or in RNA from calvaria. The time of appearance of these RNAs during the differentiation of limb mesenchyme in culture parallels the appearance of translatable type II procollagen mRNA.

Animals↗
PubMed1982

Synthesis of underpolymerized hyaluronic acid by fibroblasts cultured from rheumatoid and non-rheumatoid synovitis.

Fibroblast cultures were started from synovial tissue of normal controls and patients with seronegative and seropositive rheumatoid arthritis, juvenile rheumatoid arthritis and chronic non-rheumatoid synovitis. Glycosaminoglycan synthesis of the cultures was studied by metabolic labeling with 3H-glucosamine. Molecular weight of hyaluronic acid produced and secreted into culture medium by these fibroblast strains was studied by gel filtration in a Sepharose 2 B column. All fibroblast strains from joints with active inflammation produced hyaluronate with decreased molecular weight. The synthesis of underpolymerized hyaluronate thus appears to be a property of activated synovial fibroblasts common to rheumatoid and non-rheumatoid inflammation.

Adolescent↗