摘要:

Experiments were performed to provide information on the mechanisms of the formation of gingival fluid in rats and on the determinants of its flow and composition. For this purpose we studied the effect of increasing net capillary filtration by venous stasis induced by multiple ligations of the jugular vein or by hypoproteinemia induced through puromycine nephrosis. A 1 μl glass capillary was placed in the sulcus of the first maxillary molar for collection of gingival fluid (GF). Colloid osmotic pressure (COP) was determined in GF, in wick fluid from attached gingiva and buccal mucosa, and in plasma. Interstitial fluid hydrostatic pressure (Pi) was measured by micropuncture technique and the fractional removal rate of radiolabelled human serum albumin (kAlb) was recorded in attached gingiva and buccal mucosa. Duringvenous stasisthe gingival fluid flow increased from 1.7 μ1/h to 3.8 μ1/h, whereas COPGFfell from 14.1 mmHg to 8.8 mmHg. COP in wick fluid from gingiva was reduced from 10.3 to 4.3 mmHg. Piincreased from 6.8 to 13.1 mmHg, and kAlbin sham‐operated controls increased from 0.068 to 0.189 h‐1. In buccal mucosa COPiwas significantly decreased to 7.1 mmHg in rats with venous stasis, whereas Piand kAlbremained unchanged compared to the sham‐operated controls. Inhypoproteinemic ratsCOPGFwas 5.0 mmHg and COPpwas reduced from 18.9 to 8.0 mmHg. COPideclined from 8.9 mmHg to 2.4 mmHg in gingiva and from 8.1 mmHg to 2.7 mmHg in buccal mucosa. Piin attached gingiva increased from 6.1 mmHg to 9.0 mmHg, whereas Piin buccal mucosa showed no consistent change. The production of gingival fluid was increased about 3 times. We conclude that increased gingival fluid flow during venous stasis and hypoproteinemia is caused by increased capillary filtration, resulting in increased interstitital fluid volume and

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1995.tb02127.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

We investigated the expression of carbohydrate residues in regenerated junctional epithelium (JE) cells histopathologically with lectin staining to clarify the mechanisms responsible for the changes in their expression in JE cells derived from residual oral epithelium. Curettage and root planing procedures were performed on the buccal gingival sulci of rat first lower molars, and JE and connective tissues were completely removed. The mandibles were resected after 12 h and 1, 2, 3, 4, 5, 7, 10 and 14 days, fixed with paraformaldehyde, decalcified with EDTA and embedded in paraffin. Serial sections were stained histochemically with four kinds of lectins (PNA, DBA, GS I, UEA I) to clarify the expression patterns of carbohydrate residues in regenerating epithelium. No binding of PNA or DBA was observed even when the regenerating epithelium was attached to the root surface, and they showed the same negative reactions as the basal cells of oral gingival epithelium (OGE). Positive reactions were, however, observed on the more stratified regenerating epithelium along the root surface. Positive reactions with GS I and negative reactions with UEA I were observed throughout the regeneration process, and these were the same as those observed in the basal cells of OGE. Therefore, we concluded that the basal cells and regenerated epithelium derived from OGE expressed the same carbohydrate residues. Futher‐more, the expression of carbohydrate residues, one of the characteristics of JE, was related not only to the attachment to the tooth surface but also to changes of cell shape and cytoskeleton with stratification along the root surfac

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1995.tb02128.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Prevotella intermediahas recently been re‐defined and a new species,Prevotella nigrescenshas been proposed. However, there is little data available on the incidence of these new species in periodontal health or disease. Black‐pigmented anaerobes isolated from diseased and healthy subgingival sites were identified by serotyping, SDS‐PAGE and physiological tests. In adult periodontitis subjects, 64% of active sites, 35.7% of inactive sites and 38.5% of healthy sites yielded black‐pigmented anaerobes. Of these,Porphyromonas gingivaliswas found in 11% of active and 5% of healthy sites in diseased patients,Prevotella intermediain 15.5% of active and 20.5% of healthy sites,Prevotella nigrescensin 37.7% of active and 11.5% of healthy sites andPrevotella denticolain 3% of active and 1% of healthy sites. In healthy subjects, 50% of sites yielded black‐pigmented anaerobes.P. gingivaliswas not found in healthy subjects butP. intermediawas found in 18% andP. nigrescensin 31% of sites. SDS‐PAGE proved to be a useful method for routinely differentiatingP. intermediaandP. nigrescensand two sub‐types of the latter species were detected on the basis of band pattern. Only oneP. nigrescenssub‐type was found in any given individual and one type, typified by ATCC 25261, was more commonly found in deep pockets. However, overall bothP. nigrescensandP. intermediaas species were just as frequently found at healthy sites as diseased sites. Thus, these species, in contrast toP. gingivalis, appear to be common commensals but they may act as opportun

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1995.tb02129.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

The co‐aggregation characteristics betweenFusobacterium nucleatumand streptococci were examined to clarify the adherence factors participating in the co‐aggregation. Nineteen strains ofF. nucleatumwere classified into 8 groups according to co‐aggregation titer and inhibition by L‐arginine, L‐lysine and N‐acetyl‐D‐galactosamine (or lactose). The inhibition activity was, however, very different from strain to strain. With two fusobacterial strains, two inhibitors, which were both inhibition negative on their own, completely inhibited the co‐aggregation when used together in a mixture. In some co‐aggregation pairs, the protease treatment ofF. nucleatuminactivated one of the adherence factors, and resulted in the change of inhibition characteristics. These results indicate the multimodal co‐aggregation ofF. nucleatumwith streptococci mediated by L‐arginine‐sensitive, L‐lysine‐sensitive,N‐acetyl‐D‐galactosamine‐sensitive and some resistant factors, and that the adherence factor or factors participating in the co‐aggregation change a

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1995.tb02130.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

In thisin vitrostudy we compared high resolution computed tomography (HR‐CT) with dental radiographs regarding the interpretation of horizontal and vertical alveolar bone loss. After removal of the soft tissue and metallic restorations of 20 dentate upper and lower jaw segments 40 infra‐alveolar bony defects of different dimensions were experimentally produced. The specimens were examined radiographically with standardized dental radiographs and 1.0 mm thick contiguous axial CT‐scans. On the specimens, radiographs and CT‐scans the bone loss was measured between the cemento‐enamel junction and the adjacent alveolar bone level of 472 mesial and distal tooth surfaces; the identification, classification and vertical depth of the infra‐alveolar bony defects were also compared. An average underestimation of 0.6 mm of horizontal alveolar bone loss in the dental radiographs and an overestimation of 0.2 mm in CT‐scanning was shown. No significant differences between the imaging accuracy of horizontal alveolar bone loss between dental radiographs and CT‐scanning could be evaluated. In the dental radiographs 24 (60%) of the infra‐alveolar bony defects could be identified and the vertical depth was underestimated by a mean of 2.2 mm. In comparison, all 40 (100%) infra‐alveolar defects could be identified in the CT‐scans and the vertical depth was underestimated by an average of 0.2 mm. The HR‐CT‐technique offers a three‐dimensional interpretation of the alveolar morpholoy without overlying structures. This permits a high identification rate and classification of infra‐alveolar bone loss according to the number of surrounding bone walls into one‐, t

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1995.tb02131.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Expression of the interleukin‐2 receptor (IL‐2R) on T cells is the molecular mechanism that initiates the Goto G1transition and is the critical first step for T cell proliferation in response to antigen. The effect of whole periodontal bacteria and lipopolysaccharides (LPS) on peripheral blood mononuclear cell (PBMC) IL‐2R expression was examinedin vitro. LPS induced a modest but significant increase in high affinity lL‐2Rα/β (p55/p75 positive) expression on PBMC over untreated cells after 48 h culture. Addition of LPS to PBMC cultures depleted of monocytes had no effect on 1L‐2R expression compared to untreated cultures. Interleukin‐1 (IL‐1) caused a similar effect to LPS in 48 h PBMC cultures but IL‐1 also increased high affinity IL‐2R expression in cultures depleted of adherent mononuclear cells. When antibody to IL‐1 was simultaneously added with LPS to PBMC cultures, the high affinity IL‐2R inductive effect was reversed at 48 h, suggesting that the LPS effect on PBMC IL‐2R was indirect, via monocytes. Whole pathogenic oral bacteria cultured with PBMC at high (100:1), but not low (10:1) bacteria:PBMC ratios had a similar effect to LPS, inducing high affinity IL‐2R expression at 48 h. Increases in soluble IL‐2Rα were also measured in supernatants of PBMC incubated with periodontal bacteria compared to untreated controls. In this system, a critical threshold of bacteria was required to activate PBMC perhaps related to the quantity of cell‐surface LPS present

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1995.tb02132.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

We previously demonstrated the sequestration of nifedipine in gingival crevicular fluid (GCF), especially in patients exhibiting significant gingival overgrowth. The aim of the present study is to determine the role of site specific periodontal factors in this phenomenon. 10 adult patients exhibiting nifedipine induced gingival overgrowth were studied. In each patient GCF was harvested from two sites that demonstrated inflammation and increased probing depth as well as from two clinically healthy sites. The concentration of nifedipine was determined using gas chromatography. Drug concentrations were significantly increased in the presence of inflammation (p=0.004) and plaque (p=0.029) whilst increased probing depths and gingival overgrowth were not significantly related to drug sequestration. We can conclude that inflammatory changes in gingival tissues appear to be a significant determinant for the sequestration of nifedpine in the GCF.

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1995.tb02133.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

The present study was designed to examine whether systemic administration of a bisphosphonate, risedronate, could prevent alveolar bone resorption in rats with experimental periodontitis. On Day 1, an elastic ring was placed around the neck of the right mandibular 1st molar to induce inflammatory periodontitis. The animals were given daily injections of either 0.9% NaCl (control group), or 0.8, 1.6 or 3.2 Öoles/kg (s.c.) of risedronate (experimental groups) from Days 1 to 7, and were killed on Day 8. Histological examinations and determination of bone mineral density in the interdental area between the 1st and 2nd molars with an image analyzer revealed that the presence of the elastic ring induced a loss of attachment and bone resorption in the control group. Vigorous bone resorption, with appearance of a large number of osteoclasts, was observed in the interdental and bifurcation areas. In the experimental groups, however, the resorption of alveolar bone and the loss of bone mineral content in these areas were prevented in a dose‐dependent fashion, especially at doses of 1.6 and 3.2 Ömoles/kg. Many osteoclasts were detached from the surface of the alveolar bone and had degenerated appearances, such as rounded shapes, loss of polarity and pyknosis. These results suggest that administration of risedronate is effective in preventing bone resorption in periodonti

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1995.tb02134.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

The role of glycosaminoglycans (GAGs) and proteoglycans during cementogenesis is not known. In this study, we have analysed the temporal and spacial expression of GAGs in the cellular cementum of 10–30 weeks old rats, immunohistochemically using monoclonal antibodies 2B6 and 3B3, specific for chondroitin 4‐sulfate/dermatan sulfate and chondroitin 6‐sulfate, respectively. Both 2B6‐and 3B3‐epitopes were expressed at similar position and time in the rat cellular cementum. Two types of cellular cementum were identified; GAG‐positve and GAG‐negative cementum. The former corresponded to the lightly stained and the latter to the darkly stained cementum in sections stained with haematoxylin and eosin. The GAG‐positive cementum was seen at the distal side of dentine surface and appeared most thick at middle of the apical half roots, whereas the other parts of the cementum were the GAG‐negative. Distribution of GAG‐positive cementum showed changes with age of animals. In 10–15 week old rats, the GAG‐positive cementum occupied most of the cementum layer, covering a thin layer of the GAG‐negative cementum. The cellular cementum of 20–30 week old rats consisted of three layers; GAG‐negative, GAG‐positive and GAG‐negative cementum from dentine to cementum surface, reducing the GAG‐positive area. Because our previous study has demonstrated that the lightly stained cementum is uncalcified, the present result suggests a correlation between calcification and contents of GAGs in the cellular cementum. Further, time‐ and position‐specific expression of GAGs indicates their relation to the physiological tooth movement,

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1995.tb02135.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

We re‐evaluated several antibiotics including newer ones, for theirin vitrokilling activity, as well as their inhibitory activity, against clinical isolates of periodontopathic bacteria. Tetracyclines were active againstPorphyromonas gingivalis, and were highly active againstPrevotella intermedia, but demonstrated only a low killing activity againstActinobacillus actinomycetemcomitans. Rokitamycin. a new macrolide, and clindamycin were highly active againstP. gingivalisandP. intermedia, but showed very weak killing activity againstA. actinomycetemcomitans. Quinolones demonstrated excellent bactericidal activity againstA. actinomycetemcomitans, and good inhibitory and bactericidal activity againstP. gingivalisandP. intermedia. Metronidazole had an activity almost equivalent to quinolones againstP. gingivalisandP. intermedia; but it was the least active againstA. actinomycetemcomitan

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1995.tb02136.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY