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Biomedical subjects

J de Graaff

Publications and source records attributed to J de Graaff.

At least 109 records · Page 6Linked to original sources
PubMed1990

Microbiology in diagnosis and treatment of severe periodontitis. A report of four cases.

The purpose of this report is to illustrate the use of microbiology in the diagnosis and treatment in four cases of severe adult periodontitis. All four patients were subgingivally infected with Actinobacillus actinomycetemcomitans which was the basis for an adjunct minocycline therapy. Scaling and root planing plus minocycline were not able to establish a clinically stable periodontal condition. A. actinomycetemcomitans was not eliminated from the pockets in any of the patients. Good clinical and microbiological results were obtained after continuous conventional treatment with an adjunct therapy of metronidazole plus amoxycillin. With a 7 day course of this antibiotic therapy, the pockets of all four patients became free of A. actinomycetemcomitans and were still negative on repeated sampling on recall visits. Microbiological monitoring of severe periodontitis in adults seems to be a valuable adjunct to clinical examination. Furthermore, effective antibiotic therapy in A. actinomycetemcomitans-associated periodontitis appears of paramount importance in obtaining a stable periodontal situation.

Actinobacillus↗
PubMed1990

[Microbiological aspects in the treatment planning of periodontal disease].

A large number of bacterial species are found in the periodontal pocket. It has been shown that the composition of the subgingival microbiota can differ significantly between individual pockets in one patient, as well as between different subjects. These different types of microfloras can be characterized by indicator bacteria. These indicator bacteria are strongly associated with active periodontal breakdown. Therefore, these microorganisms can be useful in the periodontal treatment of individual patients. It also supports the use of antibiotics in specific forms of periodontal disease. The application of microbiological data in diagnosis and treatment planning in four severe periodontitis patients is illustrated.

Actinobacillus↗
PubMed1989

Importance of steroid receptors and aromatase activity in the prognosis of ovarian cancer: high tumor progesterone receptor levels correlate with longer survival.

The presence of steroid receptors (82 tumors) and aromatase activity (39 tumors) in ovarian carcinomas was correlated with patient survival. No statistically significant correlation was found between the presence or absence of estrogen receptors (ER, 56.1%), progesterone receptors (PR, 57.3%), androgen receptors (AR, 91.5%), or aromatase activity (33.3%) and survival. However, high levels of PR were associated with better survival (P less than 0.05). Furthermore, there was a tendency for patients with advanced disease and PR-positive tumors to have better survival than those with advanced disease and PR-negative tumors (P = 0.13). Patients with tumors that did not contain any of the receptors and those in which ER and AR were absent, or in which PR and AR were absent, had poor survival. It is concluded that receptor status, especially of PR, may be of prognostic importance and that status of receptors and aromatase activity may become useful in selecting ovarian cancer patients for endocrine therapy.

Adenocarcinoma↗
PubMed1989

Metronidazole plus amoxycillin in the treatment of Actinobacillus actinomycetemcomitans associated periodontitis.

The potential use of an adjunctive therapy of metronidazole plus amoxycillin for the subgingival elimination of Actinobacillus actinomycetemcomitans in periodontitis patients was investigated. 22 patients participated in this study, 11 with localized juvenile periodontitis (LJP) and 11 with rapidly progressive periodontitis (RPP). 14 patients had received periodontal treatment in the past. All patients were subgingivally infected with A. actinomycetemcomitans. After mechanical subgingival debridement in combination with the antibiotic treatment, elimination of A. actinomycetemcomitans was achieved in all patients but one. With this one exception, clinical improvements were observed in all patients, resulting in reduced pocket probing depths as well as in a significant reduction in bleeding on probing. Re-examination of 16 patients after 9-11 months revealed that A. actinomycetemcomitans was still undetectable and further clinical improvement was observed. It was concluded that the combination of metronidazole plus amoxycillin is a valuable adjunct to mechanical therapy in A. actinomycetemcomitans associated periodontal infections.

Actinobacillus↗
PubMed1989

Periodontal condition and microbiology of healthy and diseased periodontal pockets in type 1 diabetes mellitus patients.

On the basis of glycosylated hemoglobin (HbA1c) values, 22 type 1 (insulin-dependent) diabetic adults were grouped into patients with near normal (HbA1c less than or equal to 7.7%) and poor (HbA1c greater than or equal to 9.9%) metabolic control. A total of 44 subgingival sites were examined for Actinobacillus actinomycetemcomitans, black-pigmented Bacteroides species and Capnocytophaga species. No significant difference could be demonstrated between patients in the 2 test groups with regard to periodontal condition. Neither age of diabetic patients nor duration of diabetes mellitus influenced the periodontal parameters. In both test groups, pocket depth of 4 mm or more (greater than or equal to 4 mm) was found to be significantly associated with increased swelling, bleeding after probing and amount of marginal plaque. Proportionally high %s of cultivable A. actinomycetemcomitans (mean 4.3%; range 2.8-5.8%), Bacteroides gingivalis (33.2% and 34.6%) and Bacteroides intermedius (mean 4.2%; range 0.001-13.5%) were isolated from diseased periodontal pockets. In diabetic patients with poor metabolic control, B. intermedius was isolated from diseased periodontal pockets with a mean % of 7.2%, range 0.3-12.5%. Independent of the degree of metabolic control, low %s of Capnocytophaga species were isolated from diseased and healthy periodontal pockets, mean 0.9% (range 0.003-3.9%) and mean 1.4% (range 0.04-4.9%), respectively. It was concluded from this study that metabolic control seems to have no direct effect on the periodontium. Furthermore, the rôle of Capnocytophaga species in the pathogenesis of infectious periodontal disease in type 1 diabetic patients seems to be overestimated.(ABSTRACT TRUNCATED AT 250 WORDS)

Actinobacillus↗
PubMed1989

Acidogenesis by oral streptococci at different pH values.

Streptococcus mutans is known to be one of the most cariogenic oral microorganisms. Recently, organisms classified as S. mutans have been shown to be genotypically heterogeneous and to form at least six separate species. In this study, differences in acid production between the mutans streptococci and Streptococcus sanguis were investigated at pH values from 5.0 to 7.0. While all of the species investigated were able to produce acids, Streptococcus sobrinus was found to be significantly more acidogenic than the others. S. sobrinus was capable of sustained acid production at pH levels below 6.0, while acid production by other species ceased or was strongly inhibited. These results indicate that S. sobrinus deserves more attention as a potentially cariogenic microorganism.

Acids↗
PubMed1988

Microbial succession in recolonizing deep periodontal pockets after a single course of supra- and subgingival debridement.

In the present study, the effect of supra and subgingival plaque debridement on the dynamics of the subgingival microflora in deep pockets was investigated. 8 adult periodontitis patients participated in the study. In each patient, 4 clinically diseased sites were investigated microbiologically by phase contrast microscopy for the determination of both the %s as well as the total numbers of spirochetes and motile rods and by anaerobic cultivation for the determination of the different black-pigmented Bacteroides species. After base-line examination, patients were treated by mechanical removal of supra- and subgingival plaque deposits. 2 and 8 weeks after treatment, clinical and microbiological parameters were re-evaluated. During the experimental period, no oral hygiene procedures were performed in order to achieve fast recolonization of the pockets. Treatment resulted in a significant reduction in probing pocket depth and gain of probing attachment. 2 weeks after treatment, no further improvements could be observed. A positive correlation was found between the reduction in probing pocket depth and decrease in Bacteroides gingivalis (P less than 0.009) and between gain in probing attachment and reduction in the % of B. gingivalis (P less than 0.009). No correlation between these clinical parameters and B. intermedius, spirochetes or motile rods was apparent. An inverse relationship between B. gingivalis and B. intermedius was observed. We found that changes in %s of spirochetes and motile rods are not correlated with changes in total numbers of these bacterial groups. It was concluded that monitoring of %s of micro-organisms may not supply rational information on the microbiological conditions of the subgingival area.

Adult↗
PubMed1988

The role of black-pigmented Bacteroides in human oral infections.

Today, 10 black-pigmented Bacteroides (BPB) species are recognized. The majority of these species can be isolated from the oral cavity. BPB species are involved in anaerobic infections of oral and non-oral sites. In the oral cavity, BPB species are associated with gingivitis, periodontitis, endodontal infections and odontogenic abscesses. Cultural studies suggest a specific role of the various BPB species in the different types of infection. Bacteroides gingivalis is closely correlated with destructive periodontitis in adults as well as in juveniles. Bacteroides intermedius seems to be less specific since it is found in gingivitis, periodontitis, endodontal infections and odontogenic abscesses. The recently described Bacteroides endodontalis is closely associated with endodontal infections and odontogenic abscesses of endodontal origin. There are indications that these periodontopathic BPB species are only present in the oral cavity of subjects suffering from periodontal breakdown, being absent on the mucosal surfaces of subjects without periodontal breakdown. BPB species associated with healthy oral conditions are Bacteroides melaninogenicus, Bacteroides denticola and Bacteroides loescheii. There are indications that these BPB species are part of the normal indigenous oral microflora. Many studies in the past have documented the pathogenic potential and virulence of BPB species. This virulence can be explained by the large numbers of virulence factors demonstrated in this group of micro-organisms. Among others, the proteolytic activity seems to be one of the most important features. Several artificial substrates as well as numerous biological proteins are degraded. These include anti-inflammatory proteins such as alpha-2-macroglobulin, alpha-1-antitrypsin, C3 and C5 complement factors and immunoglobulins. B. gingivalis is by far the most proteolytic species, followed by B. endodontalis. Like other bacteria, the lipopolysaccharide of B. gingivalis has shown to be active in bone resorption in vitro and is capable in stimulating interleukin-1 production in human peripheral monocytes. Based on the well documented association with periodontal disease and the possession of relevant virulence factors, BPB species must be considered as important micro-organisms in the etiology of oral infections. B. gingivalis seems to be the most pathogenic and virulent species.

Bacteroides↗
PubMed1988

Rapid characterization of oral and nonoral pigmented Bacteroides species with the ATB Anaerobes ID system.

The ATB Anaerobes ID system (API SYSTEM, La Balme Les Grottes, France) was evaluated for its ability to differentiate between species of the pigmented Bacteroides group. This identification system is based on the degradation of chromogenic substrates in combination with sugar fermentation reactions. The results showed that the ATB system can be useful for differentiation between the 10 pigmented Bacteroides species. However, additional tests may be necessary.

Bacteriological Techniques↗
PubMed1988

Bacterial involvement in denture-induced stomatitis.

Denture and mucosal plaque samples were collected from eight full-denture wearers of whom four suffered from denture-induced stomatitis (DIS). Cultures were made, and a proportional identification to species level was carried out of bacteria and yeasts. An inventory was made of the predominant flora. Results showed that the predominant microflora of both groups, both on dentures and the denture-bearing mucosa, consisted mainly of Gram-positive bacteria. Differences in the proportions of cocci were found between the predominant bacterial flora on the dentures. In the control group, 69% of the denture flora consisted of cocci, while on the dentures of the DIS group a mean of 33% cocci was found. Neither group of palates revealed any differences in the proportions of cocci. On these locations a mean of 69% was found. The plaque of dentures and the palates of the healthy group showed means of 35% and 31%, respectively, of obligate anaerobic bacteria, while in the DIS group these percentages were 56% and 43%, respectively. No obligately aerobic bacteria were found. Candida species was detected in both groups, both on dentures and palates in very low numbers (DIS group, median palates 0.02%, median dentures 0.25%). The predominant organisms were Streptococcus species, of which S. salivarius was mostly present on the palates of both groups. Other species which were regularly found at different locations were Veillonella parvula and species of Lactobacillus, Bacteroides, and Actinomyces.

Bacteria↗
PubMed1987

Androgen receptor predominance in human ovarian carcinoma.

Cytosols of 94 untreated common epithelial ovarian cancer tissues were analysed for the presence of estrogen-, progesterone- and androgen receptors. Androgen receptors clearly predominated (90%) over and above estrogen- (55%) and progesterone receptors (52%). Further characterisation particularly of the androgen receptor revealed steroid-receptor complex with the sedimentation coefficient similar to ovalbumin (3,6 S). Only androgens, natural and synthetic, were able to alter the sedimentation profile. Estrogen appeared to slightly lower the peak, while progesterone and cortisol did not alter the profile at all. No difference in receptor concentrations between tumor tissues from pre-, peri- and postmenopausal women was found. The serum hormone levels (estradiol-17 beta, testosterone, FSH, LH) measured preoperatively in 20 postmenopausal patients did not correlate with the receptor status. Majority of the ovarian carcinomas studied contained androgen receptors. We therefore suggest consideration of the addition of anti-androgens to the therapeutic strategies applicable to ovarian cancer.

Adolescent↗
PubMed1987

Spontaneous rupture of the spleen in third trimester of pregnancy. Report of a case and review of the literature.

A case of idiopathic spontaneous rupture of the spleen in the third trimester of pregnancy is presented. The cause remains an enigma; the diagnosis is difficult, but echography may prove to be helpful. The treatment requires early exploration to enhance fetal as well as maternal survival. In this case mother and child did not survive. The etiology and clinical picture are discussed. The literature relating to rupture of the spleen is reviewed, including one particular case of a rupture in the third trimester of pregnancy.

Adult↗
PubMed1987

Short-chain fatty acids produced by anaerobic bacteria alter the physiological responses of human neutrophils to chemotactic peptide.

The effect of some short-chain fatty acids (SCFA) produced by anaerobic bacteria, namely acetic, propionic, isobutyric, butyric, isovaleric and succinic acids, on production of light and release of lysozyme by human neutrophils exposed to chemotactic peptide fMet-Leu-Phe was investigated. A short period of incubation of neutrophils with SCFA led to marked inhibition of both granulocytic chemiluminescence and degranulation (P less than 0.001). Ultrastructural studies of neutrophils, incubated with concentrations of SCFA inhibiting the chemotactic response, chemiluminescence and release of lysozyme (30 mmol/l), effected alterations in cellular morphology with formation of protrusions of varying shape. The data reported indicate that SCFA might be regarded as important pathogenicity factors. The observed effect on neutrophils could also partially explain the ability of anaerobes to inhibit their own phagocytosis and killing as well as that of the aerobic species present in mixed infections.

Bacteria, Anaerobic↗
PubMed1987

Identification of Streptococcus sobrinus with monoclonal antibodies.

Identification of Streptococcus sobrinus is often difficult to perform because of the great resemblance of the organism to other oral streptococcal species. Therefore, monoclonal antibodies were prepared which were shown to be highly specific for S. sobrinus. Cross-reactivity with other oral microorganisms has not been observed in an enzyme-linked immunosorbent assay and an immunofluorescence assay. These monoclonal antibodies belonged to the subclass immunoglobulin G2b. To be certain that the strains used in cross-reactivity tests were S. sobrinus, their DNA base composition was measured as a golden standard. Additional tests like colony morphology and sugar fermentation with the API 20 Strep system (Analytab Products, Montalieu-Vercieu, France) were performed. These additional tests turned out to be necessary because 100% correct identification could not be obtained by separate tests. Immunological characterization with the clones OMVU10 and OMVU11 proved to be discriminative between S. sobrinus and other streptococcal species.

Antibodies, Monoclonal↗
PubMed1986

Enzymatic characterization of oral and non-oral black-pigmented Bacteroides species.

The purpose of this study was to investigate the production of various enzymes by oral and non-oral black-pigmented Bacteroides species using chromogenic substrates. The 19 substrates present in the API ZYM system did not differentiate between B. melaninogenicus, B. denticola, B. loescheii and B. levii. The asaccharolytic black-pigmented Bacteroides species showed each species specific enzyme activity, however, differences were based on one enzyme only as far as B. asaccharolyticus and B. endodontalis are concerned. An extended number of 40 chromogenic substrates were tested in order to find more species specific enzyme. With a set of 20 substrates it appeared to be possible to discriminate between all species tested. The possibility to use enzymes for the identification of black-pigmented Bacteroides is discussed.

Bacteroides↗