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J de Graaff

Publications and source records attributed to J de Graaff.

At least 73 records · Page 4Linked to original sources
PubMed1993

K-antigens in Porphyromonas gingivalis are associated with virulence.

We investigated antigens in spreading and non-spreading Porphyromonas gingivalis strains. On the basis of differences in virulence in the mouse model, 8 strains were selected for antiserum production in rabbits. Hyperimmune sera were tested by double immunoprecipitation and immunoelectrophoresis. Besides a common antigen, differences in antigenic composition were observed in the thermolabile antigens between all strains tested. Two different heat-stable antigens were found after heating at 120 degrees C. One such antigen was detected after sonication of the pellet fraction of autoclaved P. gingivalis cells. This antigen cross-reacted with 6 of the 8 immune sera. This somatic antigen was almost neutrally charged and sensitive to sodium periodate treatment, suggestive of lipopolysaccharide. A second heat-stable antigen was detected in the supernatant of autoclaved strains of W83, W50, HG184 and A7A1-28. These non-somatic antigens were strain-specific, i.e., no cross-reactivity was found with heterologous hyperimmune sera. An exception was strain W50, which had a non-somatic heat-stable antigen which was recognized by W83 antiserum. These antigens were resistant to DNAse, RNAse and proteinase-K treatment but were degraded by sodium periodate. In immunoelectrophoresis, these antigens appeared to be negatively charged. These properties are characteristics of a K-antigen, which likely represent a thermostable carbohydrate capsule. The presence of K-antigen correlates very well with the serum resistance, the low chemiluminescence, the resistance to phagocytosis and the need for opsonization with specific antibodies for complement-mediated killing of virulent P. gingivalis strains.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Mutans streptococci in caries-active and caries-free infants in Tanzania.

The occurrence of mutans streptococci species was investigated in Tanzanian infants aged between 1.0 and 3.5 years with rampant caries and without caries using biochemical and immunological techniques. These infants came from Turiani and Singida, where the caries prevalence for this age group was 12.8% and 1.6% respectively. Streptococcus mutans was found to be the only mutans streptococcal species. The other species, including the previously reported Streptococcus rattus, were not found. Consequently, the differences in caries experience observed between and within the two populations could not be explained by differences in mutans streptococcal species.

Child, Preschool↗
PubMed1993

Survival in transport media of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia in human subgingival samples.

The purpose of this study was to evaluate the survival in 3 transport media of 3 suspected periodontal pathogens, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia. Subgingival samples were taken from 10 patients with severe periodontitis, all harboring at least two of the above-mentioned species. The material was dispersed and aliquots were added to vials containing reduced transport fluid, reduced transport fluid containing 10% Fildes extract, or viability-maintaining microbiostatic medium, anaerobically prepared (VMGA III). Viable counts were determined after 1, 2, 4, 24 and 48 h of storage at 4 degrees C or at room temperature. The results showed that, for up to 4 h of storage, no significant differences existed for all parameters tested. A large increase of the total viable counts was found in VMGA III at room temperature after 24 and 48 h. This was due to an outgrowth of mainly streptococci. Incubation at 4 degrees C yielded often a significantly higher recovery compared to room temperature. After storage at room temperature, the tested bacteria were below detection level in some samples.

Aggregatibacter actinomycetemcomitans↗
PubMed1993

Classification and typing methods of black-pigmented gram-negative anaerobes.

Until recently, black-pigmented Gram-negative anaerobes were classified as 'black-pigmented Bacteroides'. At present, 11 distinct species are recognized in this group. Because of major differences with Bacteroides fragilis, the type species of the genus Bacteroides, new genera have been proposed: Porphyromonas for three asaccharolytic species, and Prevotella for the saccharolytic species. Typing methods have been developed for some species of black-pigmented Gram-negative anaerobes. These include biotyping and serotyping, but relatively few types can be distinguished with these methods. Recently, DNA restriction endonuclease analysis has been used for typing of P. gingivalis, Pr. intermedia and P. endodontalis strains. Great heterogeneity was observed within all three species. This typing method can be useful for epidemiological studies.

Bacterial Typing Techniques↗
PubMed1993

Transmission of Porphyromonas gingivalis between spouses.

Porphyromonas gingivalis has been associated with severe forms of periodontitis. The question can be raised about the origin of this suspected periodontal pathogen. The purpose of the present investigation was to study the possibility of transmission of P. gingivalis between spouses. 18 patients were selected with severe periodontitis and colonized with P. gingivalis. 10 of their spouses appeared to be colonized with P. gingivalis too. 8 of the patients and their spouses were investigated further clinically and microbiologically. Microbiological evaluation revealed mostly high %s of P. gingivalis in the pockets, not only of the patients (5-48% of the cultivable flora), but also in 7 of the 8 spouses (0.2-61%). Furthermore, this species was isolated often from the saliva, the tongue, the buccal mucosa and the tonsillar area from both patients and spouses. For typing purposes, bacterial DNA was isolated, treated with the restriction endonucleases Bam HI or Pst I, after which the DNA fragments were separated by agarose gelelectrophoresis. With one exception, each individual was colonized with only one clonal type of P. gingivalis. The DNA patterns of all P. gingivalis isolates from unrelated individuals were found to be distinct. In contrast, in 6 of the 8 couples, the DNA patterns of isolates from husband and wife were indistinguishable. From these data, it can be concluded that it is most likely, that P. gingivalis can be transmitted between spouses. It remains to be investigated whether transmission of P. gingivalis is a risk factor for developing periodontal destruction.

Adult↗
PubMed1993

Epidemiology and transmission of Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans among children and their family members. A report of 4 surveys.

The distribution and transmission of Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans in 4 families were studied. The families were included, based on the isolation of P. gingivalis from a young child or adolescent. The probands of these 4 families were: a 5-year old periodontally healthy boy; a 17-year old girl with severe generalized juvenile periodontitis; an 11-year old girl with prepubertal periodontitis; 2 sisters, 5 and 17-years old, with untreated severe periodontitis as a component of the Papillon-Lefèvre syndrome. All members of the 4 families were examined clinically and microbiologically for the presence of P. gingivalis and A. actinomycetemcomitans. Most of the parents appeared to be adult periodontitis patients; the parents of one proband were edentulous. Results showed that in all cases at least one of the parents was positive for P. gingivalis. On the basis of indistinguishable restriction endonuclease patterns (REPs) of P. gingivalis and A. actinomycetemcomitans isolates from parents and their children, and distinct REPs from unrelated individuals, the present study indicates that P. gingivalis and A. actinomycetemcomitans were transmitted between parents and their children.

Adolescent↗
PubMed1993

The effect of sibling relationship on the periodontal condition.

The purpose of this investigation was to study clinically as well as microbiologically the effect of sibling relationship on the periodontal condition in a young population with a relatively high prevalence of periodontal disease and deprived from regular dental care. In this study, 23 family units consisting of 3 more siblings were evaluated. In all, 78 subjects aged 15 to 25 years were included in the study. The mean interproximal amount of loss of attachment in this population was 0.29 mm. The individual mean ranged from 0 to 1.27 mm. In 33% of the subjects, > or = 1 sites with a probing depth of 5 mm or more in conjunction with 2 mm of attachment loss were present. The results show a significant sibship effect for: plaque, calculus, loss of attachment, spirochetes on the tongue and in the pocket, Porphyromonas gingivalis on the gingiva and in the saliva and Prevotella intermedia in the saliva. These results support the hypothesis that periodontitis aggregates in families.

Adolescent↗
PubMed1993

Effect of monoclonal antibodies on the colonization of rats by Streptococcus sobrinus.

Local passive immunization has been suggested as a method of preventing colonization of teeth by mutans streptococci. In this study we describe the effect of local application of monoclonal antibodies (Mabs) on the colonization of Streptococcus sobrinus. The rats, 37 days old, were divided in 4 groups: group 1 received Mab OMVU10 (Mab reactive with Antigen B of S. sobrinus, IgG2b), group 2 received Clone 24 (Mab reactive with lipid A of Escherichia coli, IgG2b), group 3 received uninoculated culture medium, and group 4 received phosphate-buffered saline (PBS). Mabs were applied 6 times on the surfaces of the molars and the labial surfaces of the incisors of the rats, on days 37, 40, 44, 46, 49 and 54 after birth. After the third application of Mabs, all rats were inoculated with S. sobrinus (day 45). Subsequently, the rats were fed a cariogenic diet containing 20% sucrose and 5% glucose. The rats were killed 34 days after inoculation and the maxillary molars were extracted and homogenized in order to determine the numbers of S. sobrinus. The proportions of S. sobrinus, expressed as a percentage of the total cultivable microflora, in rats which received OMVU10 (group 1) were 23.1 +/- 14.8%, whereas in rats which received Clone 24, culture medium or PBS the levels were 34.5 +/- 11.3%, 40.7 +/- 14.9% and 36.7 +/- 9.7%, respectively. Statistical analysis showed that the level of colonization of rats which received OMVU10 was significantly lower than that of rats which received Clone 24, culture medium or PBS (p < 0.001, p < 0.013 and p < 0.01, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1993

The effect of glass-ionomer cement on carious dentine: an in vivo study.

The effect of a glass-ionomer cement sealant on carious dentine was investigated clinically and bacteriologically. The study group consisted of 24 molar teeth, with small clinical visible occlusal dentine lesions, in 13 children (aged 7-18 years). Twenty of these molars were filled and sealed with a glass-ionomer cement (Fuji Ionomer Type III) and 4 with a resin sealant (Delton). From each molar, two dentine samples were collected aseptically with a time interval of 7 months. The first sample was taken after opening the lesion just beneath the dentino-enamel junction before application of the filling material (sample A), and the second beneath the removed filling material (sample B) 7 months later. Before collecting sample B the sealant was clinically evaluated and impressions were prepared in order to (re)evaluate the sealants later by scanning electron microscopy (SEM). After taking the second sample, the remaining fissures were opened to a standard depth, the caries which was still present was removed, and a composite resin restoration was applied. In all teeth, more glass-ionomer cement material was found by SEM compared to the clinical evaluation. In both the glass-ionomer- and the resin sealant-treated group, the median value of the total number of microorganisms (CFU) on blood agar was 100 times smaller in the B sample. Microorganisms were found in 90% of the B samples in the group treated with glass-ionomer cement; hard dentine was also found in 45% of the B samples from this group.(ABSTRACT TRUNCATED AT 250 WORDS)

Actinomyces↗
PubMed1993

Prediction of dental caries in pre-school children.

Data obtained in a longitudinal study of caries incidence and caries-related factors were analysed with a view to producing a model for the prediction of caries. In direct correlations, caries incidence was significantly associated with bacterial, dietary and salivary variables; but when the data were examined by stepwise regression the strongest variables were the baseline caries score and misuse of sugar. Counts of Streptococcus mutans entered into the analysis but only as a relatively minor component. Similar significant relationships were seen with the determination of odds ratios. A caries activity test was formulated combining the following caries-associated variables: high counts of S. mutans, or lactobacilli, or the misuse of sugar, or frequent consumption of paediatric medicines. Regular use of fluoride tablets could compensate for paediatric medicine use or misuse of sugar. Such a caries activity test if it had been applied to the children at baseline would have had a positive predictive value of 0.76, a negative predictive value of 0.82, a sensitivity of 0.8 and a specificity of 0.78. Combining tests made the prediction of caries more accurate and in the population for which it was intended gave a reliable means of detecting those children most in need of enhanced caries prevention.

Child↗
PubMed1993

Microbiological and clinical monitoring of non-localized juvenile periodontitis in young adults: a report of 11 cases.

It has been shown that patients with localized juvenile periodontitis (LJP) often harbor Actinobacillus actinomycetemcomitans in the subgingival area. However, little is known of the oral microflora in non-LJP juvenile periodontitis patients with less extensive disease. The purpose of this study was to describe the microflora and clinical parameters of young adults with minor to moderate periodontitis during treatment for a period of 1 year. Eleven patients 15 to 16 years of age were studied. All of them had 4 to 8 mm loss of attachment at minimally one site, but the typical clinical description of localized juvenile periodontitis was an exclusion criterion in this study. Microbiological examination of the deepest periodontal pocket and of the tongue revealed that 6 patients harbored Actinobacillus actinomycetemcomitans and 5 harbored Porphyromonas gingivalis. Almost all subjects showed relatively high proportions of Prevotella intermedia, Campylobacter rectus, motile organisms, and spirochetes. On the basis of clinical and microbiological parameters the 11 patients could be assigned to 1 of 2 groups. Six cases had moderate periodontal breakdown with loss of attachment at 7 to 44 sites. All harbored A. actinomycetemcomitans and 5 of them P. gingivalis. These 6 cases responded relatively well to initial treatment despite the continued presence of A. actinomycetemcomitans. The other group consisted of 5 cases with relatively minor periodontal breakdown; i.e, 1 or 2 sites with 4 to 6 mm loss of attachment. Neither A. actinomycetemcomitans nor P. gingivalis was detected in the deepest pocket of these patients. All 5 responded well to initial treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Familial ovarian cancer.

Familial ovarian cancer occurs in approximately 5% of all ovarian cancers. Since the relation between ovarian cancer and genetic heritage has drawn much attention lately, general gynaecologists will more and more be faced with the question how to survey patients from a family with the familial ovarian cancer syndrome. We describe a patient from a family with three daughters, of which two older sisters were known to have ovarian cancer. Although our patient was closely observed, a third-stage ovarian cancer developed. With this case in mind and after a review of the literature, we will in future closely survey patients from familial ovarian cancer families from their twentieth birthday on, and recommend prophylactic bilateral oophorectomy after child-bearing age. However, we are aware of the fact that it is impossible to diagnose ovarian cancer in a premalignant phase as yet, and the benefit of a close survey might be an earlier diagnosis and not prevention. Also, prophylactic oophorectomy does not prevent the occurrence of intra-abdominal malignancies histopathologically indistinguishable from ovarian cancer. Patients should be aware of these restrictions. If, in the future, the precise chromosomal defect in ovarian cancer families is localized, prevention of ovarian cancer, but not of intra-abdominal malignancies of the same histopathology, might be within reach.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1992

[Diathermy excision using a metal loop in the treatment of cervical intra-epithelial neoplasms; short-term results in 154 patients].

Intraepithelial neoplasia of the uterine cervix (CIN), proven in colposcopically guided biopsies, can be treated in several ways. With the destruction techniques the lesion is treated by laser evaporation or by cryocoagulation. With the excision methods the transformation zone is excised by cold knife conisation, by laser exconisation or by large loop excision (LLETZ). LLETZ was developed by Cartier in 1977 and can be performed under local anaesthesia on an outpatient basis. In the current investigation 154 women with CIN were treated by LLETZ. In four patients microinvasion was suspected after pathological examination and cold knife conisation was performed, so that 150 patients were available for cytological follow-up after three and six months. After 1989 larger loops and more loops of different sizes were used. Therefore the results in both groups are presented separately. In 22 women CIN residue was found. The treatment in the first period of the study (1985-1988) was effective in 36 of the 55 cases (65%), that in the second period (1989-1991) in 87 of the 95 cases (93%). In the first period the size and endocervical localisation of the lesion significantly affected predict the result of the LLETZ, in the second half of the study these were no longer relevant. Destruction methods lack the possibility of pathological investigation, which is possible with the excision methods. In this way underestimation by the colposcopist of a (micro)invasive carcinoma does not necessarily delay adequate treatment.

Adolescent↗
PubMed1992

Porphyromonas (Bacteroides) endodontalis: its role in endodontal infections.

Porphyromonas endodontalis (formerly Bacteroides endodontalis) is a black-pigmented anaerobic Gram-negative rod which is associated with endodontal infections. It has been isolated from infected dental root canals and submucous abscesses of endodontal origin. The presence of P. endodontalis in infected dental root canals has been correlated with symptoms of an acute infection. It is occasionally found on oral mucous membranes and periodontal pockets. P. endodontalis has shown relatively low virulence in experimental monoinfections. In anaerobic mixed infections it can play an essential role. Differences in virulence between strains have been related to capsular material. On the basis of different types of capsules, three serotypes have been described. P. endodontalis is sensitive to a wide range of antibiotics, including the penicillins, the tetracyclines, and metronidazole.

DNA Fingerprinting↗
PubMed1992

In vitro susceptibilities of Actinobacillus actinomycetemcomitans to a number of antimicrobial combinations.

The in vitro susceptibilities of Actinobacillus actinomycetemcomitans to 14 antimicrobial combinations were studied by using the checkerboard titration technique. The results, expressed as the range of the fractional inhibitory concentration indices, were as follows: for metronidazole or its hydroxymetabolite combined with cefixime, 0.2 to 0.6; for moxalactam, 0.2 to 0.6; for penicillin G, 0.3 to 0.6; for tobramycin, 0.8 to 2.0; for erythromycin, 0.8 to 1.7; for ciprofloxacin, 0.2 to 0.6; for tetracycline, 0.8 to 1.2. Our observations indicated that the beta-lactam antibiotics as well as ciprofloxacin act synergistically with both metronidazole and its hydroxymetabolite against A. actinomycetemcomitans. Synergistic interactions were independent of the individual MICs of the antibiotics tested. Erythromycin, tobramycin, and tetracycline combined with either metronidazole or its hydroxymetabolite showed additive to indifferent effects against the five strains of A. actinomycetemcomitans, with the fractional inhibitory concentration indices ranging from 0.8 to 2.0. A. actinomycetemcomitans was found to be highly susceptible to ciprofloxacin (MIC of ciprofloxacin for 90% of strains tested, 0.010 micrograms/ml) and cefixime (MIC of cefixime for 90% of strains tested, 0.8 micrograms/ml). The results indicate that in patients who are allergic to penicillin, cefixime and ciprofloxacin may be useful alternative antibiotics in combination with metronidazole for the treatment of A. actinomycetemcomitans-associated periodontitis.

Actinobacillus Infections↗
PubMed1992

Influence of saliva on aggregation and adherence of Streptococcus gordonii HG 222.

The influence of saliva on the aggregation and adherence of Streptococcus gordonii HG 222 was studied. The aggregation was measured spectrophotometrically, and the adherence of S. gordonii to microtiter plate wells was measured in an enzyme-linked immunosorbent assay system. The aggregation of HG 222 was induced primarily by mucous saliva, whereas the adherence of HG 222 to microtiter plates was mediated by both mucous and serous saliva. Fractions of submandibular saliva, obtained by gel filtration and containing low-molecular-weight mucins (MG-2), induced both bacterial aggregation and adherence. Purified MG-2 induced aggregation and promoted adherence, whereas high-molecular-weight mucins (MG-1) did not. After incubating clarified human whole saliva with HG 222, only MG-2, and not MG-1, was bound by the bacteria. Proline-rich proteins (PRPs) and proline-rich glycoprotein (PRG) promoted the adherence of HG 222. These proteins in solution bound to HG 222 but did not induce aggregation of the bacterial cells. PRPs and PRG in solution were not able to inhibit adherence to microtiter plate wells coated with the same components. Purified alpha-amylase hardly promoted adherence to microtiter plates but, in the soluble state, readily bound to HG 222. In conclusion, these results indicate that the aggregation of S. gordonii HG 222 is mediated primarily by MG-2. These mucins also promote adherence. Several other salivary components, such as PRPs and PRG, are also involved in the adherence of HG 222.

Adult↗