摘要:

A toxin isolated from the growth medium ofActinobacillus actinomycetemcomitansby ammonium sulfate precipitation was shown to inhibit irreversibly the multiplication of human gingival fibroblasts. DNA histograms from flow cytometric measurements showed that the cells accumulated preferentially in the G2 phase of the cell cycle. Such cells exhibited sheetlike protrusions, and an increased frequency of micronuclei was evident in cells treated with low concentrations of the toxin. Toxin‐treated cells were viable for several weeks, as shown by staining with trypan blue and fluorescein diacetate, and the general cell metabolism as measured by oxygen consumption was unimpaire

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1993.tb01064.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Numerous studies report that water fluoridation reduces caries in children, but little current evidence exists about fluoridation's effects on the periodontal health of adults. To address this issue, we estimated fluoridation effects on periodontal disease among 1066 Washington state employees and their spouses, aged 20 to 34, with current residences divided evenly between fluoridated and nonfluoridated communities. Subjects were interviewed by telephone to collect residence histories, personal characteristics and other data. Each subject's lifetime years of fluoridation exposure (YFE) was calculated from the person's residence history and the U.S. Centers for Disease Control'sFluoridation Census. Oral assessments were conducted to measure the extent of periodontal disease. Relative to adults with no exposure, continuous lifetime exposure reduced the probability of attachment loss from 0.87 to 0.72. Similar benefits were obtained for bleeding gingiva and calculus. The estimates of fluoridation's benefits were not influenced by selection bias due to subjects' nonparticipation in the oral assessments.

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1993.tb01065.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Three‐quarters of the patients with periodontal diseases surveyed in this study had one or more distinct types of hemolytic bacteria in their subgingival plaque. Twelve different species of bacteria were identified, belonging to five genera (Actinomyces, Streptococcus, Staphylococcus, Prevotella, andActinobacillus). Nine hemolytic isolates, consisting of fourPrevotella denticolastrains, twoActinomyces naeslundiigenospecies 2 strains, and one each ofP. melaninogenica, Streptococcus constellatus, andA. naeslundiigenospecies 1 strains were characterized. Incorporation of pronase into blood agar medium inhibited hemolysis by all of the isolates, suggesting a proteinaceous component for each of their hemolysins. With one exception, hemolysin production appeared to be regulated by the concentration of environmental iron: exogenous hemin was found to inhibit hemolysin production, and the iron scavenging compound, 2,2′‐dipyridyl, was found to promote hemolysin production by all of the strains except for theS. constellatusisolate. Genomic libraries of each of the hemolytic plaque isolates were prepared inEscherichia coliusing pBR322. Hemolytic clones were isolated on blood agar medium containing ampicillin at frequencies ranging from 1–6.7 × 10−4. Extensive restriction mapping revealed regions of homology in the case of clones derived from threeP. denticolastrains isolated from the same subject. Two of theP. denticola‐derived clones were virtually identical throughout the entirety of their>5 Kb inserts. The clone derived from the third strain showed good homology to the other two within a 1.3 Kb region, but the flanking DNA showed no homology even though all threeP. denticolaisolates were shown to be clonally related by ribotyping. The results indicate that hemolytic bacteria are frequently recovered from active disease sites of subjects with periodontal diseases. The hemolytic phenotype appears to be restricted to a small proportion of the total number of species normally resident in subgingival plaque. Restriction mapping suggested that a variety of hemolysin genes may be involved and that, at least in certain cases, they may be on mobile gene

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1993.tb01066.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

We have studied the relationship between perturbations of fibroblast turnover in inflamed gingiva of different severities. To perform detailed spatial analyses of gingival fibroblast progenitor cells, inflammatory cell infiltrates and blood vessels, 3 Cynomolgus monkeys with healthy periodontium and 2 with naturally occurring gingivitis and ligature‐induced periodontitis were pulse‐labeled with3H‐thymidine. Morphometric analyses of radioautographs from mid‐sagittal supra‐alveolar gingival connective tissues of incisors were performed in sites subjacent to junctional, sulcular and oral epithelium, in the body of the lamina propria and just superior to the alveolar crest. The percentage of fibroblasts incorporating3H‐thymidine label, expressed as the labeling index (LI), was higher subjacent to the sulcular epithelium in periodontitis (1.73±0.37) than in healthy sites (1.06±0.22). This was not statistically significant (0.05

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1993.tb01067.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

In the present series of investigations we first studied the local effects of exogenous substance P (SP) on the hallmarks of neurogenic inflammation, i.e. vascular permeability and blood flow, in the oral mucosa of the rat. Pretreatment with capsaicin was shown to attenuate the symptoms of neurogenic inflammation; therefore, the distribution of nerve fibers displaying substance P‐like immunoreactivity (SP‐IR) in the mandibular mucosa was also assessed in control rats and in animals pretreated with capsaicin both neonatally and in adulthood using immunohistochemical techniques. The application of SP at a dose of 7.5 nmol resulted in an almost 70% increase of vascular permeability (NS) and the administration of a four‐fold higher dose (30 nmol) produced about 150% increase in Evans blue extravasation compared with control values (p<0.05). A similar increase (ca 146%) in vascular permeability was observed in response to 45 nmol SP solution (p<0.05). While the 7.5 nmol SP‐solution failed to affect blood flow, the 30 nmol SP significantly increased it by ca. 38% (p<0.05). The administration of the 45 nmol SP solution resulted in a similar enhancement of blood flow (43%, p<0.05). Capsaicin pretreatment performed either neonatally or in adulthood has reduced the number of SP‐immunoreactive fibers in the oral mucosa. Our functional results suggest that SP may have a role in the experimentally‐induced neurogenic inflamation of the oral mucosa in the rat. This is also supported by our finding that capsaicin pretreatment, known to decrease the number of SP‐immunoreactive fibers in these tissues, reduced the symptoms of neurogenic

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1993.tb01068.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

We examined the oxidative burst (hydrogen peroxide‐dependent oxidative product formation) of polymorphonuclear leukocytes (PMNL) in the peripheral blood from the patients with various types of periodontal diseases including localized juvenile (LJP), generalized juvenile (GJP) and adult periodontitis (AP). Heparinized peripheral blood was obtained from 15 LJP. 13 GJP and 52 AP patients and from 30 healthy control subjects. The oxidative product (2′, 7′‐dichlorofluorescein: DCF) formation of PMNL by stimulation with phorbol myristate acetate was evalauted by a rapid quantitative assay using flow cytometry. The results indicated that all patient groups contained variable populations with normal or increased DCF formation, while the control subjects exhibited DCF formation as a single population. No significant differences in average DCF formation were found among the three patient groups. Although individual patients gave various values, the average DCF formation of the three patient groups was much higher than that of the control group. Statistical analysis revealed a significant positive correlation between DCF formation and the clinical periodontal parameters on an individual basis. Futhermore, after intial periodontal treatment, DCF formation decreased to normal levels. These results suggest that the capacity of peripheral blood PMNL to mount oxidative burst reactions might reflect the inflammotory status of periodontal

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1993.tb01069.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Subgingival plaque samples from patients with chronic periodontitis were exposed to light from a 7.3 mW Helium/Neon laser for 30 s in the presence and absence of 50μg/ml toluidine blue O as a photosensitizer. Viable counts of various groups and species of bacteria were carried out before and after irradiation. The median numbers of viable bacteria initially present in the 30‐μl aliquots irradiated were 1.13 × 105cfu (aerobes), 4.08 × 105cfu (anaerobes), 4.92 × 103cfu (black‐pigmented anaerobes), 4.75 × 102cfu (Porphyromonas gingivalis), 6.15 × 103cfu (Fusobacterium nucleatum) and 1.7 × 104cfu (streptococci). The dye/laser combination achieved significant reductions in the viability of these organisms, the median reductions in the viable counts being 91.1% for aerobes, 96.6% for anaerobes, 100% for black‐pigmented anaerobes,P. gingivalisandF. nucleatumand 94.2% for streptococci. Overall, the viability of bacteria in the 20 plaque samples was not significantly decreased by the dye alone. However, in a small minority of samples there were indications of light‐independent, dye‐induced toxicity. Low‐power lasers, in conjunction with appropriate photosensitizers, may be a useful adjunct to mechanical debridement in the treatment of inflammatory periodontal diseases if a similar effectiveness against subgingival plaque bacteria can

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1993.tb01070.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Lectins were used to characterize glycoconjugates on the cell surface ofTreponema denticola, a suspected periodontopathogen. Bacteria were first screened by light microscopy using fluorescein isothiocyanate‐coupled lectins. Wheat germ agglutinin (WGA) showed a high reactivity toT. denticola. While the WGA‐binding activity was accentuated following heating or detergent treatments of bacterial cells, the reaction was inhibited by incorporation of competing carbohydrates. Scanning and transmission electron microscope studies were conducted in order to characterize the distribution of the WGA‐binding sites on the cell surface ofT. denticola. Data from these studies confirmed that heat treatment increases the percentage of labeled profiles and suggest that the WGA‐binding sites are concentrated on specific regions on the spirochete surface. Initial biochemical analysis indicated that the high reactivity to WGA resides in a peptidoglycan f

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1993.tb01071.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

The aim of the present study was to analyze the adhesive and invasive potential of a number ofP. gingivalisstrains, in anin vitrosystem utilizing cultures of human oral epithelial cells (KB cell line, ATCC CCL 17).P. gingivalisstrains W50 and FDC 381 (laboratory strains) and OMGS 1738, 1743 and 1439 (clinical isolates) as well asE. colistrain HB 101 (non‐adhering, non‐invasive control) were used. Adherence was assessed by means of scintillation counting and light microscopy, after incubation of radiolabelled bacteria with epithelial cells. In the invasion assay, monolayers were infected with theP. gingivalisandE. colistrains and further incubated with an antibiotic mixture (metronidazole 0.1 mg/ml and gentamicin 0.5 mg/ml). Invasion was evaluated by (i) assessing presence of bacteria surviving the antibiotic treatment, and (ii) electron microscopy. AllP. gingivalisstrains adhered to and entered into the oral epithelial cells. After 3 hours of incubation, bacteria were frequently identified intracellularly by means of electron microscopy. The cellular membranes, encapsulating the microorganisms in early stages of the invasive process, appeared later to disintegrate. The presence of coated pits on the epithelial cell surfaces suggested that internalization ofP. gingivaliswas associated with receptor‐mediated endocytosis (RME). Formation of outer membrane vesicles (blebs) by intracellular bacteria indicated that internalizedP. gingivaliswas able to retain its viability.E. colistrain HB 101 neither adhered to nor invaded epithelial

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1993.tb01072.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

This study explored gingival crevicular fluid (GCF) volumes as measured by the Periotron in an attempt to find a more objective measure of gingival inflammation that could be used in dental compliance studies. The first step in this process was to assess the realiability of the method of collecting and determining GCF volumes as described by the manufacturer. Collections of GCF from both the buccal and lingual surfaces of 6 teeth from 18 subjects with good to moderate plaque accumulation was accomplished. At a later time these same surfaces were retested for a comparison with the initial value for reliability determination. We found that only 23% of the tooth surface pairs varied by less than 20% and 57% of these pairs differed by at least 50%. These values were similar for both good and moderate plaque accumulation subjects. In these subjects, reliability measurements at individual tooth surfaces did not approach acceptable levels of reliability. However, when the GCF values from the 12 tooth surfaces were averaged for each subject, differences between the two measurements improved markedly. Sixty‐one percent of these subject pairs differed by less than 20%. Therefore, the average GCF value from subjects with good to moderate plaque accumulations may be compared with reasonable accurac

ISSN:0022-3484    

DOI:10.1111/j.1600-0765.1993.tb01073.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY