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R C Page

Publications and source records attributed to R C Page.

At least 145 records · Page 8Linked to original sources
PubMed1986

Effects of donor age on protein and collagen synthesis in vitro by human diploid fibroblasts.

Diploid fibroblast strains were established from explants of normal gingiva from donors ranging in age from 12 to 68 years. By using labeled amino acid precursors, we measured protein and collagen production, and intra- and extracellular protein degradation. Qualitative assessment of the patterns of protein production was performed by two-dimensional gel electrophoresis and detection of labeled components by fluorography. Protein and collagen production decreased more than 5-fold as a function of increasing donor age over the age range studied while protein degradation remained unaffected by donor age. The pattern of proteins produced was unaffected by donor age. These data demonstrate a large statistically significant slowdown in general protein synthesis with increasing donor age. This slowdown is not selective, but appears to affect all of the proteins being produced.

Adult↗
PubMed1985

A microdetermination method for assaying glycosaminoglycans and proteoglycans.

A simple and reliable method is described for the determination of glycosaminoglycans and proteoglycans in tissue extracts as well as during preparative and analytical procedures for these molecules. It is particularly useful because it requires much less starting material for the identification of glycosaminoglycans or proteoglycans and, in addition, is several fold more sensitive than the currently used uronic acid assays. The procedure allows separation of macromolecules by ion-exchange chromatography, density gradient centrifugation, or molecular sieve chromatography and involves spotting onto cellulose acetate membrane, reaction with Alcian blue, and quantitation of color in a spectrophotometer. This method is particularly appropriate to use for the analysis of proteoglycans and glycosaminoglycans in tissues which are available in limited amounts or have low levels of these macromolecules.

Alcian Blue↗
PubMed1985

Transcriptional regulation of fibroblast collagen synthesis by activated mononuclear cell supernatants.

Mononuclear cells elaborate effector substances which regulate growth and synthetic activities of fibroblasts. We have studied the mechanism by which activated mononuclear cell supernatants inhibit collagen production. Activated supernatants were prepared by culturing human peripheral mononuclear cells with phytohemagglutinin. Human fibroblasts were exposed to the activated supernatants and total cellular RNA was isolated. Collagen mRNA levels were measured using a pro alpha [I] probe and poly(A+) mRNA was assayed using polyuridylic acid as the probe. Collagen production was measured as collagenase-digestible radioactivity. The results showed that pro alpha 1 [I] mRNA levels were decreased in cells incubated with the activated mononuclear cell supernatants and that the decrease was dose and time dependent. The reduction in the pro alpha 1 [I] mRNA correlated with the decrease in collagen production. No inhibition in the poly(A+) message was observed. We conclude that inhibition of collagen production by activated mononuclear cell supernatant occurs primarily at the transcriptional level and that the inhibition may be selective to collagen.

Collagen↗
PubMed1985

An improved multimembrane microassay for quantitating the motility of granulocytes and monocytes labeled with chromium-51.

Various modifications of the Boyden chamber chemotaxis assay have been used to screen patients for abnormalities in granulocyte or monocyte motility. In most cases, cell motility has been assessed by quantitating the fraction of cells that migrates from an upper chamber through a filter toward a lower chamber containing chemoattractant. Existing versions of the assay have several shortcomings. They are labor-intensive, require relatively large numbers of cells and lengthy incubation, or they require visual cell counting and do not permit assessment of cells which may drop off the filter into the attractant medium. We have improved the accuracy and efficiency of existing microchamber assays by using 51Cr-labeled cells to eliminate microscopic cell counting, shortening the incubation time, adjusting the assay sensitivity, and accounting for cells which drop off into the attractant well. The modified method uses Neuroprobe multiwell microchambers and two 10 microns polycarbonate filters with 3 microns pores on top of one 100 microns nitrocellulose filter. The optimal incubation period is 60 min, and the assay requires about one-fifth as many cells as the standard Boyden chamber methods. Cell drop-off can be measured accurately by harvesting the attractant wells with detergent, and the assay sensitivity is comparable to that of existing radiometric assays using large chambers. The data indicate that the range of chemotactic and random motility of normal granulocytes and monocytes measured in the modified assay system is comparable to that reported for studies which have used established motility assays.

Cell Adhesion↗
PubMed1985

Mononuclear cell supernatants inhibit prolyl hydroxylation.

The effect of phytohemagglutinin(PHA)-activated human peripheral mononuclear cell supernatant (AS) on collagen production by human fibroblasts was examined. The AS inhibited collagen production in a dose- and time-dependent manner. Labeling and pulse chase experiments showed that it did not block collagen secretion, but a greater proportion of molecules synthesized in its presence accumulated within the cells. Amino acid analysis showed that when labeling was done at 24 degrees C prolyl hydroxylation in fibroblasts exposed to the AS was reduced to two-thirds of the cultures treated with control supernatant (CS), however it was not different at 37 degrees C. These results indicate that the AS inhibits collagen hydroxylation, that the un-(under)hydroxylated collagen molecules are degraded at physiological temperature and that suppression of collagen hydroxylation may be a mechanism by which the AS inhibits collagen production.

Cells, Cultured↗
PubMed1985

Synthesis of type V collagen by fibroblasts derived from normal, inflamed and hyperplastic human connective tissues.

Increased type V collagen content is a feature of many inflammatory and fibroproliferative diseases. In order to understand the mechanism responsible for this increase we have studied type V collagen synthesis by fibroblasts obtained from normal, inflamed and phenytoin-hyperplastic human gingivae. Cultures were immunostained with antibodies to type V and I collagens to determine the proportion of cells producing type V collagen. In addition, cells were metabolically labeled with radioactive amino acids, and type V procollagen and collagen were fractionated and quantitated. Results showed that all the cells were stained by both anti-type V and type I antibodies. Anti-type V staining was observed outside the cells whereas anti-type I staining was localized intracellularly. The proportion of radioactive type V collagen in the individual cell strains ranged from 0-5.2% of the total collagens; however, differences among the three cell types were not statistically significant. No differences were observed in the procollagen [V] levels, which accounted for 6.5-15.1% of the total procollagens. We conclude that changes in fibroblast population may not be a significant factor contributing to increased type V collagen in inflammation and hyperplasia, and that the increase may be due to other factors such as modulation of synthesis activities by environmental ligands and resistance of type V collagen to degradation.

Cell Line↗
PubMed1985

Metastatic melanoma of the lacrimal sac.

The case history of a patient with metastatic melanoma obstructing the lacrimal sac is presented. To our knowledge, this case represents a unique metastatic pattern that has not been previously reported. The patient was first treated for a melanoma of the left arm, which was excised in continuity with the axillary lymph glands. She was free of disease for 3 years until she developed metastatic disease causing obstruction of the ipsilateral lacrimal sac. Anatomical details of the metastasis were provided by computed axial tomography. Treatment consisted of excision of the metastatic lesion with reconstruction using forehead and intranasal mucosal flaps, followed by irradiation, hyperthermia, and multiple-drug chemotherapy. Emphasis is placed here on the differential diagnosis of orbital adnexal tumors.

Aged↗
PubMed1985

Defective neutrophil and monocyte motility in patients with early onset periodontitis.

Several studies have documented suppressed polymorphonuclear neutrophil (PMN) chemotaxis in most patients with juvenile periodontitis. In contrast, data regarding PMN chemotaxis in patients with rapidly progressive periodontitis are very limited, and monocyte (MN) chemotaxis and random migration of PMNs or MNs from these patients have not been studied previously. Accordingly, we examined cell motility of PMNs and MNs from 27 patients with rapidly progressive periodontitis, 5 patients with juvenile periodontitis, and 37 normal control subjects by using a microchamber technique and the synthetic peptide N-formylmethionyl-leucyl-phenylalanine (FMLP) as the chemoattractant. As a group, PMNs and MNs from patients with rapidly progressive periodontitis manifested significantly enhanced random migration relative to control cells (P less than 0.001), suppressed directed migration (chemotaxis) at FMLP doses of 10(-9) and 10(-8) M (P less than 0.05), and enhanced directed migration at a dose of 10(-6) M FMLP (P less than 0.01). In contrast, PMNs from patients with juvenile periodontitis exhibited normal random migration, and directed migration was significantly suppressed at all doses of FMLP tested (P less than 0.05). An abnormality of either PMN or MN motility was observed in 26 of 27 patients with rapidly progressive periodontitis. Enhanced random migration was seen in PMNs in 63%, MNs in 39%, and both cell types in 26% of the patients. Suppressed chemotaxis was seen in PMNs in 85%, in MNs in 74%, and in both cell types in 69% of the patients. The prevalence and magnitude of abnormalities in motility were somewhat lower in treated than in untreated patients. Thus, most, if not all, of this subgroup of patients with early onset, highly destructive periodontitis have abnormalities in PMN or MN motility, and these defects may differ from those seen in cells from patients with the juvenile form of the disease.

Adolescent↗
PubMed1985

Assessment of serum antibody patterns and analysis of subgingival microflora of members of a family with a high prevalence of early-onset periodontitis.

In a study of members of a large family with a high prevalence of early-onset periodontitis, we sampled the subgingival microflora and characterized 40 isolates from each sample. We surveyed serum samples by enzyme-linked immunosorbent assay for antibodies reacting with any of a panel of 21 periodontal bacteria. The mother and 7 of her 13 children had early-onset periodontitis. Bacteroides gingivalis was not detected in the subgingival flora of any affected or unaffected family member, and Actinobacillus actinomycetemcomitans was isolated from only one affected child. Capnocytophaga ochracea was isolated from five of seven affected children and from none of their normal siblings. We found no significant differences among the floras from family members who had rapidly progressive, juvenile, and prepubertal forms of periodontitis. Elevated levels of serum antibody reacting with one or more of the bacteria tested were found in all family members with disease, but in only one periodontally normal family member. Both children with prepubertal periodontitis had antibodies reacting with C. sputigena, a species not found in their subgingival floras, but with none of the other bacteria tested. All remaining affected family members had antibodies to one or more serotypes of A. actinomycetemcomitans, and four had antibodies reacting with additional bacteria, including C. sputigena, Eikenella corrodens, Fusobacterium nucleatum, and Haemophilus aphrophilus. Sera from patients contained antibodies specific for putative periodontal pathogens not found in their pocket flora, and conversely, putative periodontal pathogens for which no serum antibodies were found frequently comprised a large proportion (10% or more) of the pocket flora. In no case were both the bacterium and its antibody found. These observations are suggestive of sequential infection in the early-onset forms of periodontitis and of induction of protective immunity against reinfection by the same microorganism.

Actinobacillus↗
PubMed1985

Clinical and laboratory studies of a family with a high prevalence of juvenile periodontitis.

The form of periodontitis with onset at puberty and affecting predominantly the first molars and incisors is called juvenile periodontitis (JP). The disease has been the object of intense study because from its analysis may come insights into understanding other, more common, forms of periodontitis. We recently had the opportunity to study an unusual family in which both parents developed JP in their teens. We did clinical examinations, measured leukocyte chemotaxis, analyzed the pocket microflora, looked for serum antibodies against a large panel of putative periodontal pathogens and correlated the results. The couple had two affected and two unaffected children. One of the unaffected children was not available for study. Neutrophil chemotaxis was abnormal in both parents and in the two affected children, but not in the unaffected child. Actinobacillus actinomycetemcomitans accounted for 17.5% of the pocket flora isolated from one affected child and 2.5% of that from the unaffected child, but was not detected in the remaining family members. Antibodies specific for A. actinomycetemcomitans, Hemophilus aphrophilus and Eikenella corrodens were present in the serum of both affected children and for Capnocytophaga sputigena and C. ochracea in the father, but no antibodies directed against any of the species studied were found in the mother and the unaffected child. The distribution of disease in this family was more compatible with an X-linked dominant than with an autosomal recessive mode of inheritance. The correlations among presence or absence of disease, abnormal neutrophil chemotaxis and presence of serum antibodies reacting with A. actinomycetemcomitans were excellent.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

A new look at the etiology and pathogenesis of early-onset periodontitis. Cementopathia revisited.

For more than 20 years, investigators have unanimously agreed that human periodontitis is caused by bacterial colonization of the surfaces of the teeth and their extension apically. Recently, several investigators have demonstrated that most, if not all, individuals manifesting the early-onset, aggressive forms of periodontitis have abnormalities in their peripheral blood phagocytes which can be detected as abnormal cell motility or adherence. Because of the major role of these cells, especially the neutrophilic granulocytes, in host defense against the microbial onslaught at the gingival sulcus, these leukocyte abnormalities have been considered to be the major determinant of susceptibility to microbial infection and invasion of the periodontal tissues. In recent years the possibility that other etiologies may be involved has not been seriously considered. The purpose of the present communication is to focus attention on the idea that factors other than bacteria and host defense mechanisms may be of significance. We specifically want to call attention to a potentially important role for root cementum.

Adolescent↗
PubMed1985

Clinical studies of one family manifesting rapidly progressive, juvenile and prepubertal periodontitis.

We report clinical, radiographic and historical data on a large family with an unusually high prevalence of periodontitis. The proband, a 20-year-old black male, had the classic features of juvenile periodontitis (JP). His father was periodontally normal, while his mother had lost all her teeth at age 27 because of rapidly progressive periodontitis (RP). In addition to the 13 living children the couple had had 2 miscarriages. Of the children, one had RP, five had JP and two had prepubertal periodontitis (PP). Both maternal grandparents of the proband had become edentulous at an early age, presumably because of early-onset periodontitis. Four of 10 siblings of the proband's mother had early-onset periodontitis. In contrast, the paternal grandparents did not have early-onset periodontitis nor was periodontitis unusually prevalent in the siblings of the proband's father. The pedigree for this family is consistent with, but does not prove, an X-linked dominant pattern of genetic transmission. The natural history of early-onset periodontitis and the relationship among PP, JP and RP are not understood. The fact that the mother of the proband had RP and she had offspring with RP, JP and PP indicates a close relationship among these diseases and argues in favor of a common underlying mechanism. JP was not preceded by PP in the proband nor his affected 21-year-old brother, but one sister had PP, and at age 15 manifested JP. In her case, the alveolar bone around the deciduous molars had been destroyed, but it regenerated as the permanent premolars erupted.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

Studies of a family manifesting premature exfoliation of deciduous teeth.

We report observations made on a family in which the children manifested premature exfoliation of the deciduous incisors and canines beginning as early as 1.5 years of age. We observed gingival recession, alveolar bone resorption, tooth loosening and exfoliation without apical root resorption in the absence of clinical signs of inflammation. The children's mother, age 26, had a normal periodontium, but the father, age 30, had periodontitis of moderate severity. Exfoliated deciduous teeth from one of the children were examined histologically and features characteristic for hypophosphatasia were seen. However, localized prepubertal periodontitis could not be ruled out from these data alone. The differential diagnoses for this type of condition are discussed.

Adult↗
PubMed1984

An improved method for assessing the incorporation of labeled precursors into DNA by human mononuclear cells.

The blastogenic responsiveness of activated lymphoid cells is usually assessed in vitro by measuring the incorporation of radioactive thymidine or iododeoxyuridine, a thymidine analog, into DNA. The accuracy of this method is compromised by the presence in activated and unactivated lymphocytes and in some of the substances used to activate them, of degradative enzymes which compete with DNA synthetase, the incorporation efficiency of exogenous precursor is inherently low. We have done studies aimed at improving both the efficiency and the accuracy of the assay system by selectively inhibiting the enzymes responsible for thymidylate synthesis de novo and DNA precursor degradation. Culture conditions were investigated and potential inhibitors were tested using human peripheral blood mononuclear cells activated with phytohemagglutinin. Nucleoside-degrading activity of mammalian and bacterial cells is due largely to nucleoside phosphorylases, enzymes that require orthophosphate for activity. We partly inhibited DNA precursor degradation by lowering the phosphate concentration in the culture medium and lowering the pH, thereby reducing the orthophosphate concentration. To reduce precursor degradation further, we tested several potential nucleoside phosphorylase and thymidylate synthetase inhibitors at various concentrations. Our data show that the addition of 1 mM fluorouracil and 1 mM deoxyuridine to the culture medium largely prevents degradation of radioactive thymidine and iododeoxyuridine without unduly compromising the DNA-labeling efficiency of cells activated with mitogens or bacterial homogenates. Under these conditions, label incorporation increases linearly as the number of blast cells or the labeling time increases.

Adolescent↗
PubMed1984

Heterogeneity of normal human diploid fibroblasts: isolation and characterization of one phenotype.

Cultures of human diploid fibroblasts contain cells that respond to exposure to the first component of complement (C1) by initiating DNA synthesis and growth. The plasma membranes of these cells have specific binding sites for the C1q subcomponent of C1. A fluorescence-activated cell sorter was used to isolate a subset of cells with a high affinity for C1q, and the growth and synthesis activities of these high-affinity cells were studied after numerous replications in vitro. These cells synthesize DNA and grow faster than the parent cultures and low-affinity cells, and they produce two to three times as much protein. About 40 percent of their total protein synthesis activity is directed to collagen production, unusually high proportions of collagen types III and V being produced. These properties and the high affinity of the cells for C1q are retained for at least six cell transfers. This phenotype has the properties expected of fibroblasts in healing wounds and inflamed tissues.

Carrier Proteins↗