摘要:

Clinically healthy human gingivae from deciduous molar regions were transplanted to subcutaneous sites of nude mice (nu/nu NC). Transplants were harvested after posttransplantation periods of 5, 6, 7, 8.5, 10.5 and 12 weeks and examined histologically after staining with hematoxylin‐eosin (H.E.), bisbenzimide, and a panel of mouse monoclonal anti‐keratin antibodies in an indirect fluorescence technique. Central parts of transplants contained human connective tissue covered by human stratified squamous epithelium which were unkeratinized in 5‐ to 7‐wk‐old transplants and most frequently (75%) parakeratinized in 8.5‐wk to 12‐wk transplants. Comparison of keratin expression before and after transplantation revealed a progressive keratin reconstitution, i.e., keratin markers of basal/suprabasal cells preceded those of suprabasal/spinous cell layers and immunohistochemical markers of keratinization preceded routine histologically observed parakeratinization. Original keratin staining and essential features of histodifferentiation were reconstituted and maintained after 8.5 wk but graft recovery rate decreased drastically 12 wk after transplantation. This study shows that the human gingiva/nude mouse model is useful in experimental studies of the gingival keratin profile in the period 8.5 to 10.5 wk after tr

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1991.tb01619.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Considerable research effort has been directed at preparing root surfaces in a fashion that would promote cell attachment leading to periodontal regeneration; however, no methods have proven to be clinically predictable. Identification of attachment protein(s) associated with the root surface matrix of cementum may prove valuable for developing effective clinical treatments. In this study cementum proteins were extracted from bovine and human teeth by sequential chaotropic extraction using guanidine followed by guanidine/EDTA. The guanidine/EDTA extract, but not guanidine extract, was found to promote attachment of fibroblasts. This attachment activity was inhibitable with synthetic peptide containing the attachment sequence arginine‐glycine‐aspartic acid (RGD). Fractionation of the guanidine/EDTA extract revealed several fractions with attachment activity. Immunoblot analysis demonstrated that two of these fractions contain the bone‐associated RGD containing attachment protein, bone sialoprotein‐II (BSP‐II). In addition, attachment activity was also noted in other fractions that could not be attributed to BSP‐II or fibronectin. These studies indicate that a component of the attachment activity of cementum is likely to be due to BSP‐II and that cementum contains additional, as yet undetermined, attach

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1991.tb01620.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Four rough‐surfaced (R) and three smooth‐surfaced (S) clinical isolates ofCapnocytophagaobtained from the subgingival plaque of periodontitis patients were studied for their peptidase and protease profiles. The results were compared with those obtained withC. gingivalis(which has a smooth morphology). All cell extracts obtained by ultrasonic treatment displayed high peptidase activity towardN‐aminoacyl‐2‐naphthylamines, the best substrates being the arginyl, aspartyl, and leucyl derivatives. The R and S isolates did not differ in these enzyme activities. Also the protease profiles studies with 4‐phenylazobenzyloxy‐carbonyl‐L‐prolyl‐L‐leucylglycyl‐L‐prolyl‐D‐arginine (PZ‐PLPGA) and casein were similar. All extracts also hydrolyzed furylacryloyl‐L‐leucylglycyl‐L‐prolyl‐L‐alanine (FALGPA), reconstituted type I [3H]‐collagen, and gelatin. NaBenzoyl‐DL‐arginyl‐2‐naphthylamine was hydrolyzed faster by the R than the S strains. Comparison between cell suspensions and cell extracts ofC. gingivalisshowed the suspensions to be enzymatically more active than the extracts. In general, peptidase substrates and PZ‐PLGPA were hydrolyzed at a higher rate by suspensions than by extracts, while protease substrates (such as casein) were hydrolyzed faster by the extracts. Gelatin and FALGPA were hydrolyzed by cell extracts only. Fast protein liquid chromatography of peptidases on a gel column was found to be a suitable method to differentiate between R and S isolates in diagnostics, while the chromatographic p

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1991.tb01621.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

This investigation analyzed, in a cross‐sectional study, the possible relationship between gingival crevicular fluid (GCF) elastase‐like protease (ELP) levels and the periodontal clinical parameters or the presence of specific bacteria in subgingival plaque. A total of 388 periodontal sites from 8 adult periodontitis patients were examined for plaque index (P1I), gingival index (GI), pocket depth (PD) and alveolar bone loss (ABL). GCF ELP levels were determined as ELP alpha‐1 protease inhibitor (ELP‐α1‐PI) complex levels with a commercially available ELISA. Subgingival plaque samples were tested for the presence ofBacteroides gingivalis, B. intermedius and Actinobacillus actinomycetemcomitansby indirect immunofluorescence (IF) microscopy. GCF ELP‐α1‐PI levels were then correlated with clinical periodontal indices and proportions of IF‐positive bacteria per site. Statistically significant positive correlations were found between GCF ELP‐α1‐PI concentrations and subgingivalBacteroides proportions. When the sites examined were analyzed depending on the level of each clinical parameter, the levels of these correlations changed.A. actinomycetemcomitancorrelated highly (r = 0.716) with ABL for sites with low GI score. The correlations between GCF ELP‐α1‐PI and B.gingivalis(r = 0.642) orB. intermedius(r = 0.774) were the highest for ABL ≤ 20% and PD ≤ 3 mm, respectively. The strong association between GCF ELP‐α1‐PI concentrations and subgingival bacteria previously associated with advancing periodontitis indicates that measurement of GCF ELP‐α1‐PI concentrations may be useful in the evaluation of periodontal sites, especially those

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1991.tb01622.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

The recognition that destructive periodontal diseases may be caused by specific microorganisms in periodontal pockets has led to an increased interest in and usage of antimicrobial agents in periodontal therapy. Recently, a new controlledrelease insert containing ofloxacin, a synthetic antibiotic, has been developed. In this study, the controlled‐release insert (PT‐01) was microbiologically evaluated in combination with or without subgingival mechanical debridement. PT‐01 was applied in the periodontal pockets of 27 patients with chronic periodontitis. Three sites with a deep probing pocket depth (≥5 mm) were randomly selected in different quadrants of each patient, and were assigned into three groups, i.e., PT01 applied (T), placebo applied (P) and control sites (C). Periodontal treatments consisted of supragingival scaling with oral hygiene instruction for the first 2 weeks followed by root planing and subgingival scaling. PT‐01 was applied weekly on day 0 to 35, and the subgingival plaque samples from each site were collected on d 0, 14, 21 and 42. The dynamics of the subgingival microflora was investigated by dark field microscopy and by anaerobic and aerobic cultivation. In the supragingival scaling period, significant reduction in percentages of spirochetes and motile rods and significant increase of the percentage of coccoid cells were observed only at T sites. In addition, the total viable counts of bacteria, black‐pigmentedBacteroidesandFusobacteriumspecies were significantly reduced at T sites. After mechanical subgingival debridement, significant shifts in the proportion and reduction of the viable counts in the subgingival microflora were found at all sites. Although PT‐01 applied sites showed some further shift in the proportion and reduction in subgingival microorganisms, statistically no significant differences in the microbiological results between the three groups of experimental sites were found. These results suggested that weekly application of PT‐01 in the periodontal pocket could have significant effects on both qualitative and quantitative changes in the subgingival microflora. However, the mechanical subgingival debridement, consisting of root planing and subgingival scaling, was very effective in eliminating the subgingival microflora by itself. Then, in the combination with mechanical subgingival debridement, statistically no additional effects could be found. Consequently, it was suggested that the application of PT‐01 might have an ameliorating effect as an adjunct in conventional pe

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1991.tb01623.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Recent experimental evidence has led to the Interpretation that “enamel‐like” material is deposited along the forming mouse molar root surface by cells of Hertwig's epithelial root sheath (HERS cells) and that this material is integral to the developmental program for cementogenesis. The experimental strategy described in this study was to examine selected developmental stages of root formation for mouse first and second mandibular molars in order to localize the cellular sites ofamelogeningene transcripts using high resolutionin situhybridization. Amelogenin is the major structural protein of coronal enamel and is highly conserved among mammalian species at the DNA and amino acid sequence level. Within the limits of sensitivity forin situhybridization and utilizing either cRNAs or oligodeoxynucleotide probes, we were unable to localizeamelogenintranscripts within HERS cells from selected developmental stages associated with mouse molar root formation. In contrast, previous studies using antipeptide antibodies have provided immuno‐histochemical localization of amelogenin domains in HERS cell‐derived products. For these HERS cell‐derived proteins to contain both amelogenin epitopes and yet fail to yield nucleic acid hybridization Signals suggests that either gene rearrangement and/or alternative processing of messenger RNAs from the structural gene locus operate to produce immunologically related motifs sharing insufficient complementarity at the nucleotide level to permit efficient detection by hybridization. It is postulated that HERS cells synthesize proteins which contain amelogenin domains and that these proteins participate during cementogenesis. However, these enamel‐related proteins are neither identical to, nor collinear with coronal canonicalamelogen

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1991.tb01624.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1991.tb01625.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Tetracycline inhibition of neutrophil‐associated collagenolysis has been the focus of a number of investigations. Evidence has suggested that this inhibition results from the ability of this family of antimicrobial drugs to bind divalent cations such as Ca2+and Zn2+, two cations that are required for full expression of activity of metalloproteinases such as collagenase and gelatinase. Data presented in this study demonstrate that tetracyclines can also inhibit neutrophil‐mediated RBC lysis, superoxide anion synthesis, degranulation and migration. To some extent, tetracycline inhibition of neutrophil functions is mimicked by the Ca2+binding agents, EDTA and TMB‐8. However, Ca2+enrichment restored full function to EDTA‐ and TMB‐8‐treated cells but not to tetracycline‐treated neutrophils. This suggests that Ca2+binding plays a role but is not the critical effect leading to tetracycline suppression of neutrophil functions. It has been suggested that tetracyclines can suppress leukocyte‐associated tissue damage. Host tissues are protected from neutrophil‐mediated damage by two mechanisms: 1. Neutrophil granule‐associated enzymes are secreted in an inactive state; and, 2. tissues are protected from these enzymes by a potent inhibitor shield. Neutrophils can bypass these protective elements by activating enzymes and by destroying the shield through the synthesis of oxygen radicals. Therefore, tetracyclines may suppress neutrophil‐mediated tissue damage by inhibiting their migration and degranulation and, potentially more importantly, by suppressing synthesis of oxygen radicals. Before the anti‐inflammatory properties of the tetracyclines can be most safely and effectively used in treating conditions where inflammatory tissue damage is a significant part of the disease process, a more complete understanding of the mechanisms involved in their inhibition of PMN fu

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1991.tb01626.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1991.tb01627.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY