摘要:

Phagocytosis ofBacteroides melaninogenicus(five strains) andBacteroides gingivalis(two strains) was studied by electron microscopy. The chemiluminescent response of bacteria‐challenged polymorphonuclear leukocytes was also measured. There was a correlation between the ability of the bacteria to induce chemiluminescence in polymorphonuclear leukocytes and the cellular uptake of the bacteria. Four of the fiveB. melaninogenicusstrains were phagocytized within 10 min, while for one strain the phagocytic response was delayed. Cells of this strain were surrounded by a loosely bound layer of intermediate electron density. One of theB. gingivalisstrains was phagocytized to the same extent as theB. melaninogenicusstrains. The otherB. gingivalisstrain resisted phagocytosis. Cells of this strain were surrounded by an electron dense layer. When comparing previous results on the pathogenicity of these strains in experimental polymicrobial infections in guinea pigs with the present results on phagocytosis, it is apparent that all the pathogenicB. metaninogenicusstrains were phagocytized in vitro, while the non‐pathogenic strain ofB. gingivaliswas phagocytized and the pathogenic strain was

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1982.tb01137.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Bone resorbing activity and the presence of antigens ofBacteroides gingivaliswere assessed in plaque, calculus, cementum, and dentin obtained from roots of teeth previously exposed to periodontitis. Each fraction was obtained by scaling the root surface. The fractions were extracted by stirring and sonication, and the soluble extracts centrifuged, sterilized, dialyzed, and adjusted to equivalent protein concentrations. Cementum and dentin extracts from impacted teeth were prepared similarly and served as controls. Stimulation of bone resorption by each extract was assessed in organ cultures of fetal rat bones by measurement of release of previously‐incorporated45Ca from the bone into the medium. In some groups of teeth, calculus and cementum were treated with citric acid prior to scaling. Citric acid washes were recovered and dialyzed. An enzyme‐linked immunosorbent assay (ELISA) was used to assess the extracts for the presence of antigens reactive with an anti‐serum toB. gingivalis.Significant stimulation of bone resorption was found in all calculus and periodontally‐involved cementum preparations. ELISA showed significant levels ofB, gingivalisantigens in plaque, calculus, and cementum of periodontally‐involved teeth, but not in involved dentin nor in cementum or dentin of impacted teeth. Treatment with citric acid removed essentially allB. gingivalisantigens from cementum but not calculus.The results suggest that substances which stimulate bone resorption and substances which react withB. gingivalisantiserum are present in surface plaque, calculus, and cementum of periodontally‐involved teeth. These substances are not present in cementum and dentin of impacted teeth nor in dentin of periodontally‐involved teeth. Treatment by both scaling and citric acid demineralization will remove most of these substances from cementum of teeth previously exposed to

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1982.tb01138.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

The clinical, microbiologic, and histopathologic features ofShigella flexneri‐associated periodontal disease of rhesus monkeys were examined. Eighteen subgingival plaque samples and 17 gingival biopsy specimens were taken from 8 rhesus monkeys harboringS. flexneriorally. All plaque samples and three of the biopsy specimens were processed aerobically and anaerobically on selective and nonselective media. The remaining biopsy specimens were prepared for light or electron microscopic observation. An additional 11 subgingival plaque samples from 6 monkeys not suspected of orally harboringS. flexneriwere also processed microbiologically.In the monkeys harboringShigellaorally,S. flexneriserotype 4 was isolated from 16 of the 18 subgingival plaque samples. It constituted a minor plaque component in all 16 positive sites, usually less than 0.1 % of the recoverable flora.S. flexneriwas not detected in any of the subgingival plaques from control monkeys. Gingival sites harboringS. flexneriwere characterized by extremely intense clinical inflammation. Histopathologic observations included ulceration of the pocket wall and heavy lymphocytic and plasma cell infiltration of the connective tissue. At the ultrastructural level, unidentified bacteria were occasionally observed between, and possibly within, intact epithelial cells adjacent to areas of ulceration.The results suggest thatS. flexneri, though a numericallyminor componentof the plaque flora, may be important in the pathogenesis of the periodontal disease observed in this stud

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1982.tb01139.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

The enzyme‐linked immunosorbent assay (EL1SA) was used for the detection of circulating antibodies in human sera to antigens of three serotypes ofTreponema denticola. The antigens used in the assay were obtained by a sodium deoxycholate extraction procedure. Sera obtained from totally edentulous patients, patients with advanced periodontitis, as well as dental students who were in good to excellent periodontai health were tested for antibodies to these antigens by ELISA. Significantly elevated antibody levels were detected in 10/11 patients with advanced periodontitis towards the antigens of all 3 serotypes. In contrast, ll/ 13 edentulous patients were negative for antibodies to serotypes W and TT and 9/13 were negative against serotype 11. In the mild gingival inflammation group, 11/14 individuals were negative against serotypes W and 11, and all were found to be negative against serotype TT. Adsorption studies carried out with 4 highly reactive sera indicated that the IgG antibodies detected by ELISA were specific for these antigens ofT. denticola.The results of these studies are at variance with those of previous investigators who reported the total absence of detectable antibodies to T. denticola in sera from patients with advanced periodontai diseas

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1982.tb01140.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Normal human fibroblasts were inhibited from attaching to a culture surface that was coated with endotoxic lipopolysaccharide (LPS) isolated from oral strains ofBacteroidesorFusobacterlum. The LPS fromFusobacteriuminhibited cell attachment to a greater degree (p<0.001) than that of the LPS fromBacteroides, and at a concentration as low as 12.5 ng/cm2(p<0.001), When LPS‐coated culture dishes (12.5 ng/cm2) were incubated with concentrations of plasma fibronectin as low as 50 μg/ml for at least 15 min, the fibronectin significantly enhanced cell attachment, returning it to control levels (p<0.001). Futhermore, when plasma fibronectin (50 μg/ml) was compared to other agents such as bile acids, citrated serum, and human plasma fraction IV1(Cohn), which have been shown to affect the toxicity of LPS, fibronectin led to significantly more cell attachment in the presence of LPS than any other treatment (p<0.001). Evidence is presented by means of transmission electron microscopy (TEM) that LPS may bind to fibronectin. Subsequently, the cell surface interacts with the fibronectin‐LPS and internalizes it via phagocytosis. This mechanism provides for the clearance of LPS from the culture su

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1982.tb01141.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Several biopsies of human marginal gingiva were collected from clinically healthy and from slightly inflamed sites. The biopsies from one given site were divided and treated as follows: one portion was immediately fixed and used as a reference; the others were incubated for two hours either in culture medium alone, or in the same medium with different concentrations of elastase purified from human polymorphonuclear leukocytes. The biopsies were then fixed and examined by electron microscopy. It was found that elastase caused an enlargement of the intercellular spaces of the oral gingival epithelium, interruptions of the basement lamina, and loss of collagen in the underlying connective tissue.Biopsies collected from severely inflamed sites were also studied in the electron microscope. Some of the ultrastructural alterations observed in these inflamed tissues were similar to those experimentally induced by elastase.

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1982.tb01142.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Explants of human gingiva obtained during periodontal surgery and maintained in tissue culture synthesized three metalloproteinases which degraded collagen, gelatin, and proteoglycan respectively. Collagenase and gelatinase were present in both active and latent forms suggesting that collagen degradation was taking place. Proteoglycan degrading activity, however, was present only in the latent form.Human gingival fibroblasts in monolayer culture did not synthesize metalloproteinases, but did produce an inhibitor with properties similar to the purified inhibitor TIMP (Tissue Inhibitor of Metallo‐Proteinases) synthesized by rabbit bones in culture. Human gingival fibroblast inhibitor had an apparent molecular weight of 32,000 on gel filtration and blocked the activity of all three metalloproteinases.These findings indicate that further investigation of the factors that control or modify metalloproteinase and TIMP activity in gingival tissues should help clarify the pathogenic mechanisms responsible for connective tissue loss in periodontal diseas

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1982.tb01143.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

The effect of 1 to 5 doses of 15,000 I.U. of vitamin A on N‐acetyl neuraminic acid (NANA) concentration in gingival tissue from rats was studied. Increased sialic acid concentration was observed in those animals receiving up to 4 doses of the vitamin, while a decreased concentration was found in the 5 doses group. Also examined was the interrelationship between vitamin A‐cortisol and vitamin A‐ascorbic acid. The profile of NANA variation in the groups receiving vitamin A plus ascorbic acid was similar to that of animals receiving only ascorbic acid. The data obtained for the groups receiving both vitamin A and cortisol, did not differ from that obtained for the groups receiving only vita

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1982.tb01144.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

In order to examine the effect of pregnancy on the gingiva, the metabolism of progesterone in pregnant and non‐pregnant rats was studied. Homogenates and mitochondrial, microsomal, and soluble fractions were obtained with differential centrifugation. The subcellular preparations were supplemented with NADPH and incubated with14C‐progesterone for 30 min at pH 7.4 and 37°C. The metabolites were identified by column and multiple thin‐layer chromatography and radioautography and quantified with liquid scintillation counting. The metabolism was significantly reduced in homogenate, mitochondrial, and microsomal incubations of oral mucosae of pregnant rats when compared to those of non‐pregnant ones. The decrease of the metabolism in the soluble fraction incubations was not statistically significant. In all subcellular preparations the activities of 20et‐and 20β‐hydroxysteroid dehydrogenases, if present, remained rather constant, but the activities of steroid hydrogenases and 3α‐ and 3β‐hydroxysteroid dehydrogenases decreased markedly. The value of these findings as a contributing factor in pregnancy ging

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1982.tb01145.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

The aim of the present study was to investigate the sequence of events that takes place in ligature‐induced periodontal defects following removal of the ligature.In eight beagle dogs the dentogingival fibres around six lower premolars (2P2,3P3,4P4) were cut to the level of the alveolar bone. Closely adapted copper bands were then cemented around the teeth. After 3 weeks the copper bands were replaced by cotton floss ligatures which were left in place for 11 weeks.The dogs were sacrificed on different dates so that it was possible to analyse defects 3, 7, 15, or 31 weeks after ligature removal. Contralateral defects one week after ligature removal served as controls. Micrographic color slides of the histological sections were analyzed using a Ferranti‐Cetec digitizer.Mean values for loss of attachment in the 15 and 31 weeks specimens were greater than in the control defects, suggesting that apical positioning of the junctional epithelium was irreversible. However, alveolar bone height tended to increase with experimental time, indicating bone repair. In the 15 and 31 weeks specimens junctional epithelium was occasionally found between the root surface and the alveolar boneIt was concluded that the model does not show all the histological characteristics of naturally occurring periodontitis even in those dogs examined 31 weeks after removal of ligatu

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1982.tb01146.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY