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Biomedical subjects

G Murphy

Publications and source records attributed to G Murphy.

At least 379 records · Page 21Linked to original sources
PubMed1986

Increasing simple toy play in profoundly mentally handicapped children: II. Designing special toys.

The purpose of this study was to increase simple toy play in profoundly mentally handicapped children by presenting them with specially designed toys. Twenty children (mean chronological age 14 years, mean mental age less than 1 year) were observed while playing with the special toys, which emitted stimuli (vibration, light, or sound) when appropriately operated. They were also observed with the toys when the stimuli were unavailable. There were large individual differences, but, in general, children interacted significantly more with the experimental toys than with the control toys and engaged in significantly less stereotyped behavior when the experimental toys were available. The implications for clinical and research work are discussed.

Adolescent↗
PubMed1986

Characterization of a specific antiserum to rabbit stromelysin and demonstration of the synthesis of collagenase and stromelysin by stimulated rabbit articular chondrocytes.

An antiserum to rabbit bone stromelysin (proteoglycanase) was raised in sheep and characterized as specific, recognizing the enzyme from both different tissue sources and different species. This antiserum and a specific antiserum to rabbit bone collagenase were used in the study of metalloproteinase production by rabbit articular chondrocytes stimulated with either interleukin 1 or mononuclear cell-conditioned medium. It was shown by electroimmunoblotting that the apparently co-ordinate (mole:mole) induction of collagenase and stromelysin activity with time correlated in either case with an increase in enzyme protein. The stimulated production of both enzymes could be modified in parallel by a variety of compounds. Immunohistochemical studies confirmed that although most cells were producing both metalloproteinases simultaneously, some chondrocytes produced detectable levels of only one. The data are discussed in relation to the mechanisms of breakdown in connective tissues.

Animals↗
PubMed1986

Commitment to expression of the metalloendopeptidases, collagenase and stromelysin: relationship of inducing events to changes in cytoskeletal architecture.

Agents that alter the morphology of rabbit synovial fibroblasts induce synthesis of the metalloendopeptidases, collagenase and stromelysin. We studied the relationship of cytoskeletal changes to the commitment to expression of these metalloendopeptidases. Cells treated with cytochalasin B (CB) or 12-O-tetradecanoylphorbol-13-acetate rounded, and only cells that had lost their stress fibers expressed collagenase and stromelysin, as determined by immunofluorescence. We concentrated on the effects of CB because of its rapid reversibility. When CB was added for 1-24 h, then removed, the cells respread within 30-60 min. The minimum period of CB treatment that committed cells to the subsequent synthesis of collagenase and stromelysin was 3 h. After initial treatment with 2 micrograms/ml CB for 3-24 h, or with various concentrations of CB (0-2 micrograms/ml) for 24 h, both enzyme activity and biosynthesis of the proenzymes showed a graded increase when measured at 24 h. Even after treatment with 2 micrograms/ml CB for only 3 h, greater than 85% of all cells were positive for both collagenase and stromelysin when cells were monitored by immunofluorescence. In contrast, when the dependence of collagenase and stromelysin expression on the inducing concentration of CB was examined, there was a dose-dependent increase in the number of cells positive for collagenase and stromelysin, as determined by immunofluorescence. Thus, at low concentrations of CB (less than 0.5 micrograms/ml), a heterogeneous population response was observed. These results suggest that the commitment of fibroblasts to induction of the metalloproteinases is a stochastic process in which a second signal that correlates with the disruption of the actin cytoskeleton may be rate-limiting for collagenase and stromelysin gene expression.

Actins↗
PubMed1986

Early treated hypothyroidism: development at 3 years.

Eighty children from the North West and North East Thames Regional Health Authorities who had been identified as having congenital hypothyroidism either by neonatal screening (76 cases) or by clinical symptoms (four) were seen for psychological assessments at 1 (60 cases), 3 (58), and/or 5 (20) years of age. Almost all the children's scores were in the normal range, and comparisons with matched controls suggested that they were doing only slightly less well than normal children in overall development. They were significantly slower, however, on a motor skills task. Moreover, a low initial serum thyroxine and triiodothyronine value, considerable delay in initial bone age, and an absence of thyroid tissue on isotope scan seemed to be associated with a somewhat poorer prognosis.

Child Development↗
PubMed1986

Double-blind assessment of potential pergolide-induced cardiotoxicity.

Possible pergolide-induced cardiotoxicity has been reported in open trials. Over a 6-month period of observation, we prospectively analyzed ECGs and 24-hour ambulatory ECG in 23 patients with Parkinson's disease who were randomized in a double-blind fashion to pergolide or placebo treatments. Pergolide therapy was associated with a mild and transient bradycardiac effect, but no clinically significant cardiotoxicity.

Aged↗
PubMed1986

Characterization of a specific antiserum for mammalian collagenase from several species: immunolocalization of collagenase in rabbit chondrocytes and uterus.

A specific antiserum to rabbit bone collagenase was raised in a sheep and shown to react with collagenase from several mammalian species. This antiserum was used to demonstrate that only active collagenase binds to and can be immunolocalized on collagen fibrils and, by indirect immunofluorescence, the secretion of latent collagenase by stimulated rabbit chondrocytes and cells of the post-partum involuting rabbit uterus. The ionophore monensin was used to demonstrate intracellular accumulation of collagenase in the Golgi apparatus of both stimulated chondrocytes and involuting uterine cells. Collagenase was not detectable in either normal cartilage or non-gravid uterus. These results are discussed in relation to other studies of collagenase immunolocalization reported in the literature.

Animals↗
PubMed1985

Stromelysin, a connective tissue-degrading metalloendopeptidase secreted by stimulated rabbit synovial fibroblasts in parallel with collagenase. Biosynthesis, isolation, characterization, and substrates.

Rabbit synovial fibroblasts induced to undergo a specific switch in gene expression by agents that alter cell morphology secreted the neutral proteinase precursor procollagenase (apparent Mr of 53,000 and 57,000). A major Mr = 51,000 polypeptide that was always induced coordinately with procollagenase has now been identified as the proenzyme form of a metal-dependent proteinase active at neutral pH. We have named this proteinase stromelysin. Prostromelysin and procollagenase were the most prominent [35S]methionine-labeled secreted proteins of the induced fibroblasts. By the use of casein degradation as an assay for enzyme activity, stromelysin was isolated with high yield from the conditioned culture medium of 12-O-tetradecanoylphorbol 13-acetate-treated fibroblasts and migrated as an active form of Mr = 21,000 that was immunologically identical to the proteoglycan-degrading proteinase purified from rabbit bone. Immunoglobulin G from antiserum raised to purified rabbit bone proteoglycanase immunoprecipitated the Mr = 51,000 proenzyme form from conditioned medium of induced rabbit cells and also immunoprecipitated an Mr = 55,000 polypeptide from induced human fibroblasts. When rabbit prostromelysin was activated by trypsin or 4-aminophenylmercuric acetate, the proenzyme was converted to an active form of Mr = 41,000. During the course of the purification, prostromelysin was converted to an additional activatable form of Mr = 35,000 and additional active forms of Mr = 21,000-25,000, which had related peptide maps distinct from collagenase. All of these forms were immunologically cross-reactive. Purified stromelysin degraded casein, cartilage proteoglycans, fibronectin, alpha 1-proteinase inhibitor, and immunoglobulin G2a and had limited activity on laminin, elastin, type IV collagen, and gelatin, but did not degrade type I collagen. Stromelysin was inhibited by EDTA, 1,10-phenanthroline, and the specific glycoprotein tissue inhibitor of metalloproteinases isolated from human amniotic fluid and was therefore classified as a metalloproteinase.

Animals↗
PubMed1985

Purification and characterization of a bone metalloproteinase that degrades gelatin and types IV and V collagen.

A third metalloendopeptidase activity, gelatinase, has been completely separated from the collagenase and proteoglycanase activities of rabbit bone culture medium. Although the proteinase could not be purified to homogeneity in large amounts, it was possible to obtain accurate molecular weight values and activity after electrophoresis on non-reduced SDS/polyacrylamide gels. The latent form had an Mr of 65 000 which could be activated with 4-aminophenylmercuric acetate, APMA, to a form of Mr 61 000; under reducing conditions the latent and active forms had Mr of 72 000 and 65 000, respectively. Trypsin was a very poor activator of the latent enzyme. Gelatinase degraded gelatins derived from the interstitial collagens and it also had low activity on native types IV and V collagen and on insoluble elastin. Gelatinase acted synergistically with collagenase in degrading insoluble interstitial collagen. The specific mammalian tissue inhibitor of metalloproteinases inhibited gelatinase by forming a stable inactive complex. Comparison of the properties of gelatinase with those of collagenase and proteoglycanase suggest that the three proteinases form a family which together are capable of degrading all the major macromolecules of connective tissue matrices.

Animals↗
PubMed1985

Tissue inhibitor of metalloproteinases. Identification of precursor forms synthesized by human fibroblasts in culture.

Precursor forms of the glycoprotein tissue inhibitor of metalloproteinases (TIMP) synthesized by human fibroblasts in culture have been identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of specific immunoprecipitates. Translation of mRNA extracted from fibroblasts in the cell-free rabbit reticulocyte lysate system yielded a single immunoprecipitable precursor of tissue inhibitor of metalloproteinases, Mr 22000. Intact fibroblasts cultured in the presence of tunicamycin synthesized an Mr 20 000 form of tissue inhibitor of metalloproteinases, detectable intracellularly and extracellularly. This is in contrast to the predominantly intracellular Mr 24 000 form synthesized during monensin treatment of cells and the normal secreted form of tissue inhibitor of metalloproteinases, Mr 29 000. Isoelectric focusing of the various immunoprecipitable precursor forms showed a progressive increase in positive charge and microheterogeneity of the protein during cellular processing. The data suggest that the inhibitor protein core, of basic pI, is glycosylated initially by the addition of mostly neutral sugars and subsequently by acidic sugars, prior to secretion.

Cells, Cultured↗
PubMed1985

Biosynthesis of tissue inhibitor of metalloproteinases by human fibroblasts in culture. Stimulation by 12-O-tetradecanoylphorbol 13-acetate and interleukin 1 in parallel with collagenase.

Biosynthesis of the glycoprotein tissue inhibitor of metalloproteinases (TIMP) by human fibroblasts in culture has been characterized by functional assays, immunoprecipitation, and immunocytochemistry with a monospecific antiserum. As determined by radiolabeling with [35S]methionine, immunoprecipitation, and analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the secreted form of TIMP had an Mr of 29,000, whereas the form associated with the cell layer had an Mr of 24,000. Unstimulated human lung fibroblasts (HFL-1) secreted TIMP at the rate of approximately 2 micrograms/10(6) cells/24 h, and normal foreskin fibroblasts (HS 27) and skin fibroblasts from a patient with Hurler's disease (GM 1391) secreted TIMP at 0.3 and 0.2 micrograms/10(6) cells/24 h, respectively. Secretion of TIMP was stimulated up to 10-fold by treating the cells with 20-100 ng/ml of 12-O-tetradecanoylphorbol 13-acetate or 10 units/ml of human interleukin 1. In the stimulated HFL-1 cells, TIMP accounted for 0.03-0.09% of the total [35S]methionine incorporated into protein, and 0.3-0.8% of the [35S]methionine in secreted protein. Although TIMP accounted for a relatively small proportion of total protein synthesis of the fibroblasts, greater than 80% of untreated and greater than 95% of stimulated fibroblasts synthesized TIMP, as determined by indirect immunofluorescence. The treatments of the human fibroblasts that increased TIMP secretion also induced synthesis and secretion of proenzyme forms of collagenase, indicating that degradative enzymes and their controlling inhibitors may be synthesized in parallel under certain conditions.

Animals↗
PubMed1985

Increasing simple toy play in profoundly mentally handicapped children. I. Training to play.

The purpose of this study was to increase simple toy play in profoundly mentally handicapped children. Twenty children (mean chronological age, 14 years; mean mental age, less than 1 year) were trained to play with ordinary toys, half by a behavior modification technique and half by a control procedure. The operant training led to some increases in total toy contact but did not appear to be significantly more effective than the control technique in promoting independent constructive play. The possible reasons for the relative lack of success of the behavioral training are discussed.

Adolescent↗
PubMed1985

Inhibition of type I collagen film degradation by tumour cells using a specific antibody to collagenase and the specific tissue inhibitor of metalloproteinases (TIMP).

Rabbit VX2 tumour cells in culture produced a collagenolytic activity which was shown to be immunologically identical to collagenase from rabbit articular chondrocytes and bone. VX2 cells degraded type I collagen films spontaneously and did not produce detectable levels of the tissue inhibitor of metalloproteinases (TIMP). Chondrocytes, however, required both stimulation of collagenase synthesis and activation to effect lysis and were observed to make appreciable amounts of TIMP. The degradation of type I collagen films by VX2 tumour cells was significantly inhibited by both a specific antibody to rabbit collagenase and by purified TIMP, thus demonstrating the unequivocal role of collagenase in this model system.

Animals↗
PubMed1985

Prostaglandin production and zinc depletion in human pregnancy.

An association between zinc depletion and intrauterine growth retardation might occur through disturbed prostaglandin (PG) synthesis. The zinc content and PG metabolism of leucocytes from control, nonpregnant women and mothers 24-48 h after delivery, were measured and related to fetal growth and maternal smoking. Mothers of small for gestational age babies had lower polymorphonuclear and mononuclear cell zinc contents than mothers of appropriate for gestational age babies or nonpregnant controls. Monocytes were the major leucocytes producing PGs. Mothers of small for gestational age babies had higher PGE2:F2 alpha ratios than mothers of appropriate for gestational age babies. PGF2 alpha production and PGE2:F2 alpha ratio were correlated with tissue zinc status. Monocytes from nonsmokers tended to produce more PGs than those from smokers but the differences were not significant. Mild maternal zinc depletion is not significantly sufficient to alter absolute PG production, but is associated with altered differential production of PGs in human leucocytes. Zinc depletion or malnutrition may contribute to intrauterine growth retardation by affecting placental and/or umbilical PG production.

Adolescent↗
PubMed1985

Immunolocalization of tissue inhibitor of metalloproteinases (TIMP) in human cells. Characterization and use of a specific antiserum.

A specific antiserum to pure human amniotic fluid metalloproteinase inhibitor (TIMP) was raised in a sheep. This antiserum was used to demonstrate: firstly, the immunological identity of the TIMP activities from amniotic fluid and culture medium of human foetal lung fibroblasts; and secondly, by indirect immunofluorescence, the secretion of TIMP by human foetal lung fibroblasts, chondrocytes, epithelial cells and smooth muscle cells. The phorbol ester, 12-O-tetradecanoylphorbol-13-acetate, was used to stimulate secretion of TIMP by human foetal lung fibroblasts and the ionophore monensin was used to demonstrate intracellular accumulation of TIMP in the Golgi apparatus of these cells. These results are discussed in relation to other inhibitors of collagenase reported in the literature, which are probably identical to TIMP.

Amniotic Fluid↗