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J Sodek

Publications and source records attributed to J Sodek.

At least 109 records · Page 6Linked to original sources
PubMed1989

Transforming growth factor-beta regulation of collagenase, 72 kDa-progelatinase, TIMP and PAI-1 expression in rat bone cell populations and human fibroblasts.

Quiescent cultures of normal fetal rat calvarial bone cell populations (RC I and RC IV) and human fibroblasts were incubated with 1.0 ng/ml TGF-beta and the conditioned culture media were processed individually to separate collagenase and 72 kDa-progelatinase from TIMP, the tissue inhibitor of matrix metalloendoproteinases, using mini-columns of heparin- and gelatin-Sepharose. Collagenase synthesis was decreased progressively by TGF-beta in fibroblasts despite a 1.6-fold increase in secreted protein levels and a approximately 1.8-fold increase in 72 kDa-progelatinase synthesis. The human fibroblasts and the osteoblast-enriched RC IV cells showed a greater TGF-beta-induced stimulation in 72 kDa-progelatinase levels over controls compared with the RC I cells. In contrast to RC IV cells, in which TIMP mRNA levels were increased 2.9-fold by TGF-beta, the constitutive level of TIMP transcripts in the RC I cells was greater than 20-fold over that of the RC IV cells, but was not elevated by TGF-beta. TGF-beta also increased TIMP expression in fibroblasts approximately 1.7-fold and PAI-1 levels approximately 5-fold in RC IV cells, and greater than 10-fold in fibroblasts.

Animals↗
PubMed1988

Mineral-binding proteoglycans of fetal porcine calvarial bone.

To provide a more definitive characterization of the hydroxylapatite-associated proteoglycans (HAPG) of bone, proteins were extracted from the mineralized matrix of fetal porcine calvaria with 0.5 M EDTA in the absence of guanidine HCl. The small proteoglycans obtained in the extract were fractionated by gel filtration on Sepharose CL-6B, purified by ion-exchange chromatography on Polyanion matrix (fast protein liquid chromatography), and then separated into three major populations of chondroitin sulfate proteoglycans by chromatography on hydroxylapatite, all in the presence of 7 M urea. Based on immunological and chemical properties, two classes of bone proteoglycan were resolved. In one class (HAPG1), the proteoglycan and specific CNBr-derived peptides cross-reacted with three monoclonal antibodies that recognize different epitopes of the protein core of bovine skin proteodermatan sulfate. The other class of proteoglycan included two species (HAPG2, HAPG3) which were not recognized by these antibodies. In addition, these proteoglycans did not stain with Coomassie Blue R-250 nor with silver stain nor did they bind to nitrocellulose membranes used in Western blots. However, the cationic dye Stains-all stained both HAPG2 and HAPG3; the protein cores of these proteoglycans were stained a characteristic turquoise blue, whereas the protein core of HAPG1 was stained pink. The average Mr values of the bone proteoglycans, from gradient sodium dodecyl sulfate-polyacrylamide gel electrophoresis were: HAPG1, 120,000, with a protein core (chondroitinase AC-digested) of 45,000; HAPG2 and HAPG3, 110,000, with protein cores of 37,000-38,000. On 15% polyacrylamide gel electrophoresis, the protein cores of HAPG2 and HAPG3 migrated with an Mr 30,000, while HAPG1 protein core was unchanged (Mr 45,000). Based on amino acid analysis, the protein chains of HAPG2 and HAPG3 appear to be identical, although minor differences in the relative amount of glucosamine were evident. In contrast, the composition of HAPG1 was quite different, with higher relative amounts of hydrophobic and aromatic residues and lower amounts of Asx and Glx. The presence of 360 residues/1,000 of Asx and Glx in HAPG2 and HAPG3 may in part explain the characteristic staining and immunotransfer properties of these proteoglycans. The unique amino-terminal sequence of HAPG2 (Asn-Pro-Val-Ala-Arg-Tyr-Gln), together with the immunological and chemical properties, would indicate that HAPG2 and HAPG3 are novel proteoglycans and, unlike HAPG1, could be unique to mineralized tissues.

Amino Acids↗
PubMed1988

Characterization of porcine osteonectin extracted from foetal calvariae.

Osteonectin, extracted from foetal porcine calvariae with 0.5 M-EDTA, was purified to homogeneity by using gel filtration and polyanion anion-exchange fast protein liquid chromatography under dissociative conditions without the need of reducing agents. The purified protein migrated with an Mr of 40,300 on SDS/polyacrylamide gels and was similar to bovine osteonectin in both amino acid composition and in its ability to bind to hydroxyapatite in the presence of 4 M-guanidinium hydrochloride (GdmCl). However, unlike the bovine protein, porcine osteonectin did not bind selectively to hydroxyapatite when EDTA tissue extracts were used. In addition, purified porcine osteonectin did not show any apparent affinity for either native or denatured type I collagen, but did bind to serum albumin. Primary sequence analysis revealed an N-terminal alanine residue, with approximately one-half of the subsequent 35 residues identified as small hydrophobic amino acids and one-quarter as acidic amino acids. The only significant difference between the N-terminal sequences of the bovine and porcine proteins was the deletion of the tripeptide Val-Ala-Glu in porcine osteonectin. In contrast with bovine osteonectin, far-u.v.c.d. of porcine osteonectin revealed considerable secondary structure, of which 27% was alpha-helix and 39% was beta-sheet. Cleavage of the molecule with CNBr under non-reducing conditions generated five fragments, of which two major fragments (Mr 27,900 and 12,400) stained blue with Stains All, a reagent that stains sialic-acid-rich proteins/phosphate-containing proteins and/or Ca2+-binding proteins blue while staining other proteins pink. The 12,400-Mr fragment bound 45Ca2+ selectively, indicating a Ca2+-binding site in this part of the molecule. The 27,900-Mr fragment did not bind Ca2+, and since biosynthetic studies with 32PO4(3-) did not show phosphorylation of porcine osteonectin, this fragment is likely to be highly acidic. The incomplete cleavage of the molecule with CNBr and the ability of the molecule to regain its secondary structure after exposure to 7 M-urea are features consistent with the molecule having a compact structure that is stabilized by numerous disulphide bridges. The chemical and binding properties of porcine osteonectin are closely similar to the recently described 'culture shock', SPARC and BM-40 proteins, indicating that these are homologous proteins.

Amino Acid Sequence↗
PubMed1988

Bone formation in vitro by stromal cells obtained from bone marrow of young adult rats.

Cells from fetal or neonatal skeleton can synthesize bone-like tissue in vitro. In contrast, formation of bone-like tissue in vitro by cells derived from adult animals has rarely been reported and has not been achieved using cells from bone marrow. We have explored development of bone-like tissue in vitro by bone marrow stromal cells. Marrow stromal cells obtained from 40-43-day-old Wistar rats were grown in primary culture for 7 days and then subcultured for 20-30 days. Cells were cultured in either alpha-minimal essential medium containing 15% fetal bovine serum, antibiotics, and 50 micrograms/ml ascorbic acid, or the above medium supplemented with either 10 mM Na-beta-glycerophosphate, 10(-8) M dexamethasone, or a combination of both. Cultures were examined using phase-contrast microscopy, undemineralized and demineralized tissue histology, histochemistry (for alkaline phosphatase activity), immunohistochemistry (for collagen type, osteonectin, and bone Gla-protein), scanning and transmission electron microscopy, energy dispersive X-ray microanalysis, and X-ray diffraction. Collagenous, mineralized nodules exhibiting morphological and ultrastructural characteristics similar to bone were formed in the cultures, but only in the presence of both beta-glycerophosphate and dexamethasone. Cells associated with the nodules exhibited alkaline phosphatase activity. The matrix of the nodules was composed predominantly of type-I collagen and both osteonectin and Gla-protein were present. X-ray microanalysis showed the presence of Ca and P, and X-ray diffraction indicated the mineral to be hydroxyapatite. The nodules were also examined for bone morphogenetic protein-like activity. Paired diffusion chambers containing partly demineralized nodules and fetal muscle were implanted intraperitonealy in rats. Induction of cartilage in relation to muscle was observed histologically after 40 days in the chambers. This finding provided further support for the bone-like nature of the nodules. The observations show that bone-like tissue can be synthesized in vitro by cells cultured from young-adult bone marrow, provided that the medium contains both beta-glycerophosphate and, particularly, dexamethasone.

Aging↗
PubMed1988

Cell attachment of human gingival fibroblasts in vitro to porous-surfaced titanium alloy discs coated with collagen and platelet-derived growth factor.

The influence of biological coating, with or without the incorporation of growth factor, on the migration, attachment and orientation of human gingival fibroblasts in relation to porous-surfaced titanium alloy (Ti6AI4V) discs, was measured. Comparison was made between coating the discs with collagen and with collagen incorporating platelet-derived growth factor (PDGF); controls comprised porous-surfaced discs coated with agar or collagen containing bovine serum albumin (used as a carrier for the PDGF), uncoated porous-surfaced Ti6AI4V discs (with or without additional protein additives) exhibited significantly higher attachment indices (AI) and orientation indices (OI) compared with naked control discs (p less than 0.01); OI was also significantly higher than that of surface-demineralized root slices (p less than 0.001) on days 1, 2 and 3. Addition of PDGF to the collagen resulted in a further enhancement in OI on days 1 and 2 (p less than 0.01) over that shown by discs coated with collagen incorporating the bovine serum albumin vehicle. There was no cell attachment and consequently, no cell orientation, in relation to Ti alloy discs that had been coated with agar. These data suggest that attachment and orientation of cells following migration in relation to porous-surfaced Ti6AI4V discs can be modified by the application of biological molecules to the surface of the disc. This may have a useful application in clinical implantology.

Alloys↗
PubMed1988

Collagen remodelling in rat periodontal tissues: compensation for precursor reutilization confirms rapid turnover of collagen.

Measurement of collagen turnover is complicated by the reutilization of isotopic precursors used to label the collagen. In an earlier study a novel approach was used to circumvent the problems of precursor recycling and unusually short half-lives were determined for collagen in adult rat periodontal tissues (Sodek, 1977). To verify these results we have used an alternate procedure devised by Poole (1971) in which the decay profile for the radiolabelled protein is corrected in accordance with the decay of the radiolabelled precursor. In this manner real half-lives for mature, neutral salt-insoluble collagen were determined as 3 days in the molar periodontal ligament, 6 days in the continuously erupting incisor ligament and approximately 10 days in the lamina propria of the gingiva, compared to apparent half-lives for these tissues of 6, 12 and approximately 20 days, respectively. The values calculated for actual half-lives are, therefore, approximately two-fold faster than values determined without compensating for reutilization, a difference that is in agreement with other protein turnover studies in which the effects of precursor reutilization have been measured. Although the real half-lives determined in this study indicate turnover rates for the periodontal tissues that are slightly slower than reported previously, the relative differences between the tissues in the rates of collagen turnover are similar. Moreover, the study confirms the existence of a remarkably high rate of collagen remodelling in these tissues.

Animals↗
PubMed1988

Identification of small collagenous proteins with properties of procollagen alpha 1 (I) pN-propeptide in fetal porcine calvarial bone.

Several small collagenous apatite binding (SCAB) proteins have been extracted from the mineralized matrix of fetal porcine calvarial bone. One protein (SCAB 3), released on demineralization of bone with 0.5 M EDTA, appears to represent the alpha 1 pN-propeptide that is normally released during proteolytic processing of type I procollagen. The 28 Kd protein, which stains blue with "Stains-all", is reduced to a 19 Kd fragment by bacterial collagenase digestion, but is not susceptible to cyanogen bromide. The amino acid composition, blocked amino-terminus and immunological properties are all consistent with properties of alpha 1 (I) pN-propeptide. Fractionation on hydroxylapatite in the presence of urea has revealed a nonbinding (SCAB 3a) and a binding (SCAB 3b) form. Extraction of the demineralized matrix of bone with 4 M GuHCl revealed a third form (G2-28) which was similar to SCAB 3a on hydroxylapatite chromatography but showed differences on FPLC "Mono Q" resin. The occurrence of these different forms of pN-propeptide in bone may be of significance in collagen fibril-associated hydroxylapatite formation and in the regulation of osteoblastic function during bone resorption.

Amino Acids↗
PubMed1988

Differential effects of transforming growth factor-beta on the synthesis of extracellular matrix proteins by normal fetal rat calvarial bone cell populations.

To determine the effects of transforming growth factor-beta (TGF-beta) on the different cell types that exist in bone, cell populations (I-IV), progressively enriched in osteoblastic cells relative to fibroblastic cells, were prepared from fetal rat calvaria using timed collagenase digestions. TGF-beta did not induce anchorage-independent growth of these cells, nor was anchorage-dependent growth stimulated in most populations studied, despite a two- to threefold increase in the synthesis of cellular proteins. In all populations the synthesis of secreted proteins increased 2-3.5-fold. In particular, collagen, fibronectin, and plasminogen activator inhibitor synthesis was stimulated. However, different degrees of stimulation of individual proteins were observed both within and between cell populations. A marked preferential stimulation of plasminogen activator inhibitor was observed in each population, together with a slight preferential stimulation of collagen; the effect on collagen expression being directed primarily at type I collagen. In contrast, the synthesis of SPARC (secreted protein acidic rich in cysteine/osteonectin was stimulated approximately two-fold by TGF-beta, but only in fibroblastic populations. Collectively, these results demonstrate that TGF-beta stimulates matrix production by bone cells and, through differential effects on individual matrix components, may also influence the nature of the matrix formed by different bone cell populations. In the presence of TGF-beta, osteoblastic cells lost their polygonal morphology and alkaline phosphatase activity was decreased, reflecting a suppression of osteoblastic features. The differential effects of TGF-beta on bone cell populations are likely to be important in bone remodeling and fracture repair.

Animals↗
PubMed1988

Biochemical comparison of fibroblast populations from different periodontal tissues: characterization of matrix protein and collagenolytic enzyme synthesis.

To compare the expression of extracellular matrix components by fibroblasts from different periodontal tissues, rat molar periodontal ligament fibroblasts (RPL) and rat gingival fibroblasts (RGF) were isolated and cultured from individual animals. Pulse-chase experiments using [35S]methionine as a precursor revealed that confluent populations of early passage cells of both cell types synthesized similar amounts of collagen, fibronectin, and SPARC/osteonectin. Qualitative and quantitative differences were apparent in the relative proportions of type III collagen, in the rates of procollagen processing, and in the synthesis of a small number of unidentified proteins observed by sodium dodecyl sulphate--polyacrylamide gel electrophoresis. Collagen constituted 24-26% of the radiolabelled proteins secreted by both cell types, type I being the predominant collagen, with lower amounts of type III (3-8% RGF, 8-18% RPL) and type V (approximately 1%) collagens. Procollagen processing in the culture medium of RPL cells was more rapid than for RGF cells, but was increased in multilayered cultures of both RPL and RGF. In multilayered cultures, collagen TCA fragments, indicative of tissue collagenase activity, were also identified. Active and latent tissue collagenases and a latent form of a novel collagenolytic enzyme (matrix metalloendoproteinase-V) that cleaves native TCA fragments were demonstrated in these cultures. Addition of either concanavalin A (10(-6) M) or retinoic acid (10(-5) M) to the culture medium stimulated the secretion of the latent collagenolytic enzymes. Collagenase inhibitor was also synthesized by both RGF and RPL cells. SPARC/osteonectin, a 40-kilodalton glycoprotein, represented 0.5-1.0% of the secreted radiolabelled proteins of both cell types.

Animals↗
PubMed1987

1,25-Dihydroxyvitamin D3 increases epidermal growth factor receptors and transforming growth factor beta-like activity in a bone-derived cell line.

To investigate possible mechanisms through which 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) affects cell proliferation and differentiation, we have studied the effects of 1,25-(OH)2D3 on the binding and mitogenic activity of epidermal growth factor (EGF) in RCJ 1.20 cells, an established, non-tumorigenic cell line derived from 21-day-old fetal rat calvaria. 1,25-(OH)2D3 caused a dose- and time-dependent 2- to 3-fold increase in the number of receptors for EGF. The 25-hydroxyvitamin D3 and 24,25-dihydroxyvitamin D3 metabolites of vitamin D3 were ineffective in eliciting changes in EGF binding. Saturation and Scatchard analyses indicated that an increase in available unoccupied high affinity EGF binding sites was responsible for the 1,25-(OH)2D3-induced EGF binding. In addition, 1,25-(OH)2D3 enhanced EGF-dependent growth of RCJ 1.20 cells in soft agar. The potentiation of EGF effects on RCJ 1.20 cell growth by 1,25-(OH)2D3 may be related to the 1,25-(OH)2D3 regulation of EGF binding. However, the induction of anchorage-independent growth by 1,25-(OH)2D3 appears to be due to the stimulation of transforming growth factor beta-like activity. These results provide a possible explanation for the mechanism whereby the effects of 1,25-(OH)2D3 on cell proliferation and bone metabolism may be mediated.

Animals↗
PubMed1987

Characterization of a monoclonal antibody recognizing small collagenous proteins in fetal bone.

A monoclonal antibody (MBP-322) that recognizes two small collagenous, apatite-binding (SCAB) proteins associated with the mineral phase of fetal bone, has been prepared. The SCAB proteins, which are quantitatively extracted from bone with EDTA, have been shown by immunotransfer analyses to have MrS of 28K and 25K and both were selectively degraded by bacterial collagenase. Amino acid analysis of the collagenase-digested protein revealed a hypro:pro:gly ratio of approximately 0.5:1:0.7 for both proteins and indicated that one-third of the protein could have a collagen-like sequence. The SCAB proteins, unlike other collagens and collagen fragments tested bound quantitatively to hydroxylapatite in the presence of 4M guanidine hydrochloride and appear to be unique to bone. The antibody, however, was not specific for the SCAB proteins and showed comparable immunoreactivity against denatured alpha 1 chains of types I, II and III collagens and the alpha 2 chains of types I and V collagens but not type IV collagen nor native collagens I-V. The epitope was further localized to the CB6 fragment in the alpha 1(I) chain and the CB5 fragment of alpha 1(III) chain, and was present in both the TCA and TCB fragments of alpha 2(I). Despite the immunological reactivity, the properties of the SCAB proteins were not consistent with their being derived from known collagen types. Immunocytochemical staining of permeabilized bone cells with MPB-322 showed a perinuclear, punctate staining pattern in most cells with some cells showing specific nuclear staining. In non-permeabilized cells, the antibody stained various sized spherical particles, many of which were closely associated with the cell surface. Immunoblots of cell proteins revealed a number of immunoreactive proteins sensitive to collagenase digestion including two proteins with MrS similar to the SCAB proteins. The MBP-322 antibody appears useful for identifying sequence homology in various collagens, and for recognizing denatured collagen and specific collagen fragments in tissues, as well as being important for the further characterization of the SCAB proteins.

Amino Acids↗
PubMed1987

Initial characterization of a neutral metalloproteinase, active on native 3/4-collagen fragments, synthesized by ROS 17/2.8 osteoblastic cells, periodontal fibroblasts, and identified in gingival crevicular fluid.

Analysis of collagenolytic activity in gingival crevicular fluid (GCF) has revealed the presence of an enzyme capable of fragmenting native 3/4- and 1/4-collagen cleavage products generated by collagenase. An enzyme with similar activity was also identified in media conditioned by fibroblasts from rat periodontal ligament and gingiva, and by rat osteoblastic cells (ROS 17/2.8, 17/2A, 17/2B). In culture, the enzyme was secreted in a latent form that could be activated by organomercurials. For further characterization of this novel enzyme (MMP-V), the osteoblast proteinase was partially purified. ROS 17/2.8 conditioned medium was harvested daily and the 25%-60% sat. ammonium sulfate fraction chromatographed on an AcA 54 gel filtration column. Latent forms of MMP-V (apparent Mr approximately 54 k) and collagenase (Mr approximately 54 k) were resolved from gelatinase (Mr approximately 76 k) and two collagenase inhibitors (Mr approximately 62 k, approximately 36 k). Activated MMP-V degraded native 3/4-collagen fragments from collagen types I and II in a step-wise manner and was active on denatured collagen. MMP-V showed a divalent cation requirement, was active at neutral pH, and was inhibited by collagenase inhibitor and fetal bovine serum, but not by serine, thiol, or carboxyl proteinase inhibitors. These properties indicate that MMP-V is a member of the matrix-degrading, neutral-metalloproteinase family of enzymes which include collagenase, gelatinase, stromelysin, and telopeptidase. The enzyme may function in the degradation of collagen fibrils by cleaving proteinase-resistant 3/4-collagen fragments that are stabilized by association with neighboring collagen molecules.

Adult↗
PubMed1986

The effects of platelet-derived transforming growth factor beta on normal human diploid gingival fibroblasts.

Studies of the effects of transforming growth factor (TGF) beta on normal human diploid gingival fibroblasts (HGF) have been carried out to determine possible physiological effects of this growth factor. Responses distinctly different from those characterized using established cell lines were observed. Whether alone, or in combination with EGF (2.5 ng/ml), human platelet-derived TGF-beta (0.1 ng/ml or 1.0 ng/ml) did not induce anchorage-independent growth of HGFs in soft agar assays. However, TGF-beta with EGF acted synergistically in promoting a 1.8-fold increase in anchorage-dependent proliferation of quiescent HGFs. At the same concentrations TGF-beta alone stimulated the incorporation of [35S]methionine into both cellular (cell-layer) and matrix (medium) proteins by as much as 3-fold and 1.7-fold respectively. Densitometric analysis of fluorographs of radiolabeled media proteins separated by SDS-PAGE revealed that the TGF-beta-stimulated protein synthesis was selective. However, synthesis of collagen, the major protein synthesized and secreted by HGFs, was stimulated by TGF-beta to the same extent as the average secreted protein. Protein synthesis and cell proliferation were significantly greater in subconfluent cells compared to confluent and multilayered cells. These effects are likely to reflect physiological activity of platelet-derived TGF-beta which may act to promote the wound healing response.

Amino Acids↗
PubMed1986

Phenotypic differences in subclones and long-term cultures of clonally derived rat bone cell lines.

Previous studies with clonally derived populations of cells have shown that cells released from embryonic rat calvaria by enzymatic digestion are heterogeneous with respect to their hormone responsiveness, morphology, and production of matrix components [Aubin JE et al; J. Cell Biol 92:452, 1982]. Several of these clonal populations have been used to study the effects of long-term culture and inter- and intraclonal cell heterogeneity. During continuous subculture, marked changes in collagen synthesis were observed in two clonal populations. Both of these clones were originally responsive to parathyroid hormone (PTH) and synthesized primarily type I collagen with small amounts of type III and V collagens, although one clone (RCJ 3.2) had a fibroblastic morphology whereas the second clone (RCB 2.2) displayed a more polygonal shape. Following routine subculture over 3 yr, clone RCB 2.2 was found to synthesize exclusively alpha 1(I)-trimer and not other interstitial collagens. When the same cells were maintained at confluence for 1-2 wk, however, they also synthesized type III collagen. Whereas RCJ 3.2 did not show such dramatic changes in collagen synthesis after long-term subculture, two subclones derived from RCJ 3.2 were found to synthesize almost exclusively either type III collagen (RCJ 3.2.4.1) or type V collagen (RCJ 3.2.4.4). Immunocytochemical staining indicated that both subpopulations also produced type IV collagen, laminin, and basement membrane proteoglycan, proteins that are typically synthesized by epithelial cells. The differences in collagen expression by the various clonal cell populations were accompanied by qualitative and quantitative differences in other secreted proteins and differences in cell morphology. The results demonstrate both the inter- and intraclonal heterogeneity of connective tissue cells and their diverse potentiality with respect to extracellular matrix synthesis.

Animals↗
PubMed1986

Correlation of collagenolytic enzymes and inhibitors in gingival crevicular fluid with clinical and microscopic changes in experimental periodontitis in the dog.

The quadrants of the jaw in 2 beagle dogs had various forms of periodontal disease induced by ligatures placed around second, third and fourth premolars in one quadrant and, 2.5 months later, around the same teeth in a second quadrant; gingivitis was allowed to develop in a third quadrant after 4 months; the fourth quadrant served as a healthy control. Crevicular fluid flow, plaque index, gingival index, attachment levels and recession were determined at intervals and collagenolytic activity measured in the fluid. The dogs were killed after 5 months and sections of each site prepared for histomorphometry. Clinically-inflamed and degenerating sites had significantly higher collagenolytic activities (p less than 0.001), lower collagenase inhibitor activities and greater fluid flow than control sites which showed abundant inhibitor activity and minimal active enzyme. Periodontitis sites had higher active enzyme, compared to latent enzyme activities, whereas latent collagenase was predominant in control and gingivitis sites. The collagenolytic activities in periodontitis sites fluctuated with time, suggesting a cyclical pattern. Active enzyme activities correlated strongly with gingival crevicular fluid flow and attachment loss. Periodontitis sites had much more inflammatory-cell infiltration than control and gingivitis sites (p less than 0.001). Thus periodontal disease may be monitored by examination of crevicular fluid collagenolytic enzymes, inhibitors and fluid flow, and these criteria may prove more meaningful than current clinical criteria.

Animals↗