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Biomedical subjects

R C Page

Publications and source records attributed to R C Page.

At least 199 records · Page 11Linked to original sources
PubMed1980

Effect of epidermal growth factor on the synthetic activity of human fibroblasts.

The influence of epidermal growth factor on DNA and protein synthesis by human gingival fibroblasts was studied. Synchronized cells treated with epidermal growth factor synthesized considerably greater amounts of DNA relative to 10% fetal calf serum and the peak of synthesis ocurred 6 h later than with serum. Epidermal growth factor caused a dose-dependent stimulation of protein synthesis (proline incorporation). Collagen synthesis remained unaffected and, as a result, the proportion of collagen synthesized decreased with increasing epidermal growth factor concentration. Aspirin and indomethacin did not abrogate these effects, indicating that prostaglandins may not be involved.

Cells, Cultured↗
PubMed1980

Complement-dependent induction of DNA synthesis and proliferation of human diploid fibroblasts.

The effects of fresh human serum (FHS) and heat-inactivated human serum (HHS) on the DNA synthesis and proliferation of human diploid fibroblasts were assessed. FHS activated significantly more quiescent fibroblasts to undergo DNA synthesis and proliferation than did HHS. The stimulatory effect occurred consistently over a serum concentration range of 0.1-10%. Using bromodeoxyuridine selective killing techniques, it was shown that this FHS stimulatory effect was on a specific subpopulation of fibroblasts unresponsive to HHS. The involvement of the complement system, and specifically of Cl, was shown by the inability of Clq-depleted FHS to support enhanced DNA synthesis whereas Clq-depleted serum reconstituted with purified Clq was effective. Purified Clq did not restore activity when added to heated serum, nor was it mitogenic when tested in basal medium without serum. The addition of purified Clq to fresh serum inhibited the enhancement of DNA synthesis, and at Clq concentrations of 4 microgram/ml and greater, the fresh serum effects were abrogated. Thus, it appears that binding of the assembled Cl complex to the fibroblast surface was required for FHS-mediated enhancement of fibroblast proliferation, with Clq subcomponent serving as the recognition site. The results from several experiments indicated that antibody was not required for the complement-dependent fibroblast activation. FHS was not cytotoxic, and autologous serum was as effective as allogeneic sera. A 20-fold molar excess of Fab' from pooled human IgG did not alter the FHS effects. FHS from which IgG was more than 99% depleted was still effective. These results suggested an antibody-independent role for complement in the activation of a subpopulation of human diploid fibroblasts.

Animals↗
PubMed1980

Marathon groups: counseling the imprisoned drug abuser.

This article describes how marathon group therapy can contribute to the rehabilitation of imprisoned drug abusers. Nine 16-hour marathon groups were facilitated with female drug abusers at a woman's prison. One purpose of these groups was to facilitate the discussion of the personal problems of the group members. A second purpose was to enable the participants to receive feedback about how they related to each other in the group. The manner in which these groups were facilitated is described. Member evaluations of these groups are included. Other settings in which these groups can be used with drug abusers are suggested.

Counseling↗
PubMed1978

Elastin cross-linking in vitro. Studies on factors influencing the formation of desmosines by lysyl oxidase action on tropoelastin.

The formation of isodesmosine and desmosine in vitro by the action of lysyl oxidase on tropoelastin was studied. The synthesis of desmosines occurred in the absence of additional substances. The formation of desmosines was not affected by removal of molecular O2 from the reaction medium nor was it affected by the lack of proline hydroxylation in tropoelastin. However, there was virtually no desmosine formation at 15 degrees C, a temperature not conducive to coacervation, indicating that coacervation is an important prerequisite for cross-linking.

Amino Acid Oxidoreductases↗
PubMed1978

Chronic inflammatory gingival and periodontal disease.

Gingivitis and periodontitis account for more than 95% of all inflammatory diseases of the tissues surrounding the teeth, comprising the principal cause of tooth loss in adults. Gingivitis is a relatively innocuous inflammation of the gums, with associated bleeding and exudation. Gingivitis may convert to periodontitis, a destructive aggressive disease with resorption of alveolar bone, destruction of collagen with fibrosis, and formation of deep pockets around the necks of the teeth. Gingivitis and periodontitis are caused by microorganisms populating the gingival sulcus and periodontal pocket. Treatment is directed toward arresting the progress of the disease through debridement and stabilization of the teeth. Toothbrushing and other measures by which the teeth are mechanically cleaned remain the most effective way to control plaque accumulation and periodontal disease.

Bacterial Infections↗
PubMed1978

Morphological features and functional properties of human fibroblasts exposed to Actinomyces viscosus substances.

Connective tissue fibroblasts undergo cytopathic degenerative changes during certain long-term inflammatory diseases such as rheumatoid arthritis and periodontitis. The failure of inflamed tissues to repair properly may result from functional alterations of fibroblasts within the affected tissues. Numerous previous studies indicate that direct cytotoxicity by bacterial or other substances may be responsible for the cellular alterations observed in vivo. We have tested this hypothesis by exposing cultures of human diploid fibroblasts to homogenates of Actinomyces viscosus (a microorganism associated with periodontitis and capable of causing other chronic inflammatory diseases) and analyzing the effects on cell viability, morphology, and function. The cells bind and subsequently engulf relatively large quantities of the bacterial substances. These substances do not appear to be toxic to fibroblasts as determined by 51Cr release and microcytotoxicity assays, although there is a slight but significant decrease in protein synthesis (P less than 0.01) as measured by the incorporation of [14C]proline. However, collagen production was not altered, and the cytopathic alterations observed in diseased tissues in vivo did not occur in the exposed cells. These findings suggest that A. viscosus substances do not directly cause injury to connective tissue fibroblasts in periodontal disease but may, through cell-surface binding, mark these cells for subsequent immune-mediated damage.

Actinomyces↗
PubMed1978

An alternative to radical surgery for cancer of the prostate.

We have used the technique of retropubic implantation of 125I seeds, as introduced by Whitmore and associates in 1972, in 12 selected patients with prostatic cancer. Morbidity has been minimal, and the tumor has been effectively controlled. This technique delivers more radiation and has fewer side effects than external cobalt irradiation, and it should be offered to the patient as an effective alternative to radical prostatectomy. It is best suited for patients with stage A, stage B, or small stage C lesions who have negative bone scans. Edema of the penis follows the lymphadenectomy but gradually subsides.

Humans↗
PubMed1978

Collagens synthesized in vitro by diploid fibroblasts obtained from chronically inflamed human connective tissue.

Collagen synthesis by fibroblasts obtained from healthy and diseased human gingiva was compared. The cells were labeled with radioactive amino acids and the collagenous proteins synthesized were characterized after NaCl fractionation by CM-cellulose chromatography and cyanogen bromide peptide analysis. Fourteen cell lines, six from healthy gingiva, six from gingiva with chronic inflammatory periodontitis, and two from acutely inflamed gingiva were studied. All of the cell lines synthesized predominantly type I collagen. Type III collagen was a minor product of all cell lines except one from diseased tissue. Five of six cell lines from diseased gingiva and two of two from acutely inflamed tissue synthesized a collagen that was soluble in 2.5 M NaCl. The alpha1/alpha2 ratio and cyanogen bromide peptide pattern indicated that this fraction contained a collagen of the type alpha1[I]3. The alpha1[I]3 collagen was not detectable in the fibroblast lines obtained from healthy gingiva. It appears that inflamed human gingivae contain fibroblasts which differ phenotypically from cells from normal tissue in that they are capable of synthesizing alpha1[I]3 collagen.

Cell Line↗