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Biomedical subjects

J de Graaff

Publications and source records attributed to J de Graaff.

At least 19 recordsLinked to original sources
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

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↗
PubMed1992

Microbiological and clinical results of metronidazole plus amoxicillin therapy in Actinobacillus actinomycetemcomitans-associated periodontitis.

We report on the microbiological and clinical effects of mechanical debridement in combination with metronidazole plus amoxicillin therapy in 118 patients with Actinobacillus actinomycetemcomitans-associated periodontitis. Patients were categorized into 3 groups: 28 had localized periodontitis; 50 had generalized periodontitis, and 40 had refractory periodontitis. After initial treatment and metronidazole plus amoxicillin therapy 114 of 118 (96.6%) patients had no detectable A. actinomycetemcomitans. Significant reduction in pocket probing depth and gain of clinical attachment were achieved in almost all patients. Four patients were still positive for A. actinomycetemcomitans after therapy. Metronidazole resistance (MIC greater than 25 micrograms/ml) was observed in 2 of 4 strains from these patients. Patients still positive for A. actinomycetemcomitans or Porphyromonas gingivalis showed a significant higher bleeding tendency after therapy. It was concluded that mechanical periodontal treatment in combination with the metronidazole plus amoxicillin therapy is effective for subgingival suppression of A. actinomycetemcomitans in patients with severe periodontitis.

Adult↗
PubMed1991

[Chronic conjunctivitis caused by oral anaerobic germs].

A patient with chronic, unilateral conjunctivitis is presented. The predominant bacterial flora consisted mainly of Prevotella intermedia (formerly Bacteroides intermedius) and Peptostreptococcus micros. Restriction endonuclease fingerprinting of genomic DNA demonstrated that P. intermedia most probably originated from the oral cavity. In the oral cavity this species was recovered from the dorsum of the tongue, the tonsillar area and the periodontal pockets. Topical treatment with various antibiotics had failed to cure the infection in the past. The condition was cured after systemic therapy with metronidazole and amoxicillin.

Adult↗
PubMed1991

Microbiology in the management of destructive periodontal disease.

This paper summarizes the rationale for the application of microbiology in the management of destructive periodontal diseases. The subgingival microbiota in patients with severe periodontitis is complex and contains high numbers of obligate anaerobic bacteria as well as facultative micro-organisms. It has become clear that major differences exist in the composition of the subgingival microflora. These differences are not only quantitative but also qualitative. Difference in plaque composition is the basis for the application of clinical microbiology in the management of periodontal disease. Several bacterial species have emerged as useful indicators for progressive periodontitis. In this respect, the importance of Actinobacillus actinomycetemcomitans, Bacteroides gingivalis and Bacteroides intermedius has been shown in a number of studies. It has become clear that A. actinomycetemcomitans is not specifically associated with the local form of juvenile periodontitis, but this micro-organism is probably also of importance in severe periodontitis in adult patients. Selection of individuals with an A. actinomycetemcomitans associated periodontitis is essential since successful treatment in these patients needs an adjunctive antibiotic therapy. Microbiological testing can be useful in patients showing a poor response to periodontal treatment (refractory periodontitis). Factors which may be responsible include poor oral hygiene, poor subgingival debridement, the patient's susceptibility and a subgingival microflora resistant to therapy. In this patient category, microbiological testing is capable of diverting continuing periodontal treatment. Furthermore, microbiology can be useful in evaluating periodontal treatment. Successful elimination of specific periodontopathic microorganisms can be used to determine recall intervals.

Bacteria↗
PubMed1991

Synergistic effects between amoxicillin, metronidazole, and the hydroxymetabolite of metronidazole against Actinobacillus actinomycetemcomitans.

Interactions between metronidazole and amoxicillin, metronidazole and its hydroxymetabolite, and amoxicillin and the hydroxymetabolite of metronidazole were investigated with checkerboard titrations in combination with accurately determined MICs and MBCs. Actinobacillus actinomycetemcomitans was used as the test organism. Synergism was found for all three combinations. Fractional inhibitory concentration indices and fractional bactericidal concentration indices varied from 0.3 to 0.7. These synergistic interactions between these antibiotics may explain the efficacy of the combination of metronidazole and amoxicillin in various bacterial infections, including periodontal disease.

Actinobacillus↗
PubMed1991

Chronic conjunctivitis caused by oral anaerobes and effectively treated with systemic metronidazole plus amoxicillin.

In this study, we report on a case of refractory, unilateral anaerobic conjunctivitis. The predominant anaerobic flora consisted of Prevotella intermedia (formerly Bacteroides intermedius) and Peptostreptococcus micros. By using the technique of restriction endonuclease fingerprinting of genomic DNA, it was shown that the P. intermedia likely originated from the oral cavity. Topically applied antibiotics had failed to suppress the infection in the past. Successful treatment was achieved after systemic administration of metronidazole plus amoxicillin.

Adult↗
PubMed1991

Differences in cariogenicity between fresh isolates of Streptococcus sobrinus and Streptococcus mutans.

Streptococcus sobrinus is known to possess cariogenic properties in vitro. It can produce acid in large amounts and it has the capacity to adhere to enamel and other surfaces. However, most studies on cariogenicity have been performed with laboratory strains that have been subcultured over long periods of time. Therefore, the cariogenicity and acidogenicity of 9 fresh isolates of both S. sobrinus and Streptococcus mutans from human dental plaque were compared. The bacteria were inoculated into the oral cavity of rats. The rats were fed diet SSP 20/5, containing 20% sucrose and 5% glucose. After the experimental period of 42 days, the amount of caries was assessed and bacterial counts were determined using monoclonal antibodies. Four out of 9 S. sobrinus strains and 3 out of 9 S. mutans strains did not colonize the rats. Colonizing strains constituted 39-78% of the total anaerobic cultivable microflora. The numbers of advanced dentinal lesions in the fissures of the rats colonized with S. mutans were significantly lower than those colonized with S. sobrinus (p less than 0.05). S. sobrinus produced acid more rapidly than S. mutans in a pH-stat system at pH values between 6.5 and 5.0 (p less than 0.01). The results indicate that fresh isolates of S. sobrinus are more cariogenic in rats than fresh isolates of S. mutans. This is possibly due to differences in glycolytic properties of these two species.

Animals↗
PubMed1991

Comparison of the physicochemical surface properties of Streptococcus rattus with those of other mutans streptococcal species.

Mutans streptococci comprise a group of seven closely related, yet distinct species. The distinction between the four species used in this study, namely Streptococcus sobrinus, Streptococcus cricetus, Streptococcus rattus, and Streptococcus mutans, has been made only recently on the basis of DNA homologies. In order to determine if there is a difference in the physicochemical surface properties of these species, strains were characterized by contact angles, zeta potentials and isoelectric points (IEP), elemental surface compositions by X-ray photoelectron spectroscopy, and molecular moieties by infrared spectroscopy. Contact angles, particularly when measured with water, can be considered a measure of cell surface hydrophobicity; zeta potentials reflect the charge of the outermost cell surface; X-ray photoelectron spectroscopy yields the relative abundance of carbon, oxygen, nitrogen, and phosphorus over the outer 5 nm of the bacterial cell surface; infrared spectroscopy enables a molecular characterization in terms of proteins, phosphates, and polysaccharides. All four species were homogeneous with regard to their physicochemical surface properties. However, the S. rattus species were clearly different from the others on the basis of the low water contact angle (21 +/- 2 vs. 26-31 degrees), highly negative zeta potential and lack of IEP, and high oxygen/carbon (0.50 +/- 0.02 vs. 0.41-0.43) and phosphorus/carbon (0.016 +/- 0.001 vs. 0.006-0.008) surface concentration ratios. Amongst the other differences observed, each species had a characteristic pH dependence of their zeta potential measured in phosphate buffer, yielding an IEP of 1.7, 2.1, and 2.5 for S. cricetus, S. sobrinus, and S. mutans, respectively. However, a cluster analysis on the zeta potential data showed only an isolated cluster for the S. rattus species. Thus it is likely that the higher cariogenicity of S. sobrinus with respect to S. cricetus and S. mutans is, in addition to a higher acidogenicity, due to the smaller negative surface charge, giving an increased adhesion to negatively charged tooth surfaces. S. rattus is expected to be the least adherent strain in the oral cavity as it carries a relatively high negative surface charge.

Cell Membrane↗
PubMed1991

Competition between fluoride-resistant and fluoride-sensitive Streptococcus mutans in rat dental plaque.

The experiments were designed to study the effects of fluoride on the competition between a fluoride-sensitive strain of Streptococcus mutans (C180-2) and a fluoride-resistant mutant (S. mutans C180-2FR) in rat dental plaque. Competition was induced either by superinfecting rats or by co-caging rats infected with either strain with non-infected rats. Sodium fluoride was applied in diet and drinking water (60 ppm F), as daily brushings with a 1% F solution, or as a combination of both administrations. The fluoride applications favoured S. mutans C180-2FR, but not enough to outcompete the parent strain successfully under all conditions. Fluoride protected rat dental plaque harbouring S. mutans C180-2FR against colonization by the parent strain. In rats not previously infected with S. mutans, the fluoride in diet and drinking water in combination with the fluoride brushings favoured S. mutans C180-2FR in colonizing rat dental plaque. However, the fluoride applications did not benefit S. mutans C180-2FR in colonizing plaque in which the parent strain was already present. Human dental plaque may be colonized by fluoride-resistant S. mutans strains after spontaneous mutation in response to a fluoride pressure. Our data suggest that this pressure may also provide an ecological advantage to this mutant to colonize the dental plaque.

Animals↗
PubMed1991

Microflora and bacterial DNA restriction enzyme analysis in young adults with periodontitis.

As a result of an epidemiological survey on the periodontal status of young adults, a school was found with a relatively high number of subjects showing loss of attachment (18 out of 87). In 10 of these subjects the microflora of one pocket and of the dorsum of the tongue was investigated with special reference to black-pigmented species and Actinobacillus actinomycetemcomitans. Prevotella intermedia was the most prevalent species, being found in 9 patients. A. actinomycetemcomitans was isolated from 3 subjects and Porphyromonas gingivalis from 2 subjects. To determine whether cross-infection had occurred, the P. intermedia, P. gingivalis, and A. actinomycetemcomitans isolates were examined by restriction endonuclease analysis of the DNA after digesting with one or a combination of the endonucleases Pst I, Bam HI, and Hind III. Evaluation of the restriction endonuclease typing method showed it to be sensitive and useful for the typing of P. intermedia, P. gingivalis, and A. actinomycetemcomitans. Using this restriction endonuclease typing method, all isolates of A. actinomycetemcomitans, P. gingivalis, and P. intermedia obtained from single individuals showed different digest patterns. We conclude that in the present study bacterial cross-infection did not occur among subjects in this school.

Actinobacillus↗
PubMed1990

Identification of mutans streptococci with monoclonal antibodies.

Mutans streptococci have been correlated with dental caries. The identification of the species within this group is still a problem. The characterization of a monoclonal antibody (Mab) OMVU10 against S. sobrinus as well as the isolation and characterization of Mabs against S. mutans (OMVU30 and OMVU31), S. cricetus (OMVU40) and mutans streptococci (OMVU2) is described. The epitope specificity for OMVU10 and OMVU31 was cell-wall antigen B in both cases although both Mabs recognized different species-specific epitopes. OMVU40 was cross reactive with Streptococcus sanguis taxon 3. All other Mabs were specific for one species. Using these Mabs, a key to the identification of mutans streptococci is developed. This key was tested for 85 wild type isolates of mutans streptococci and proved to be highly reliable and easy to perform.

Antibodies, Monoclonal↗
PubMed1990

Aggregation of oral bacteria by human salivary mucins in comparison to salivary and gastric mucins of animal origin.

Seventeen strains of oral bacteria of the genera Actinomyces (5), Bacteroides (3), and Streptococcus (9) were tested for aggregation by the human whole salivary mucin fraction (HWSM) in comparison to three types of animal mucin preparations from submandibular glands of cow (BSM) and sheep (OSM), and from the stomach of pig (PGM). Considerable variation was seen with respect to the rate and titer of aggregation induced by these mucins. The aggregating activity of HWSM varied widely among the different bacterial strains. The Bacteroides group showed hardly any induced aggregation, whereas the final aggregation titers varied for S. sanguis (3 strains) between 12 and 48, for S. oralis (3 strains) between 6 and 48, for the S. mutans group (3 strains) between 6 and 96, and for the five Actinomyces strains even between 6 and 192. For a particular strain, similar differences in titer were seen between the four mucins. For a human salivary mucin (MG-2) it has been described that sialic acid in the sequence NeuAc (alpha 2,3)Gal(beta 1,3)GalNac- was specifically involved in the interaction with S. sanguis strains, in contrast to S. rattus BHT. Our results, however, indicate that this sugar sequence is not a prerequisite for the aggregation of S. sanguis, as animal mucins, devoid of this structure, were equally well or even better capable of inducing aggregation. On the other hand, desialization of BSM and OSM largely abolished their aggregating capability towards S. rattus BHT. Moreover, it was found that BSM and OSM, which are comparable with respect to their major oligosaccharide structure, show considerable differences in aggregating activity towards the same bacterial strain.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Involvement of human mucous saliva and salivary mucins in the aggregation of the oral bacteria Streptococcus sanguis, Streptococcus oralis, and Streptococcus rattus.

The contribution of human parotid (Par) and submandibular/sublingual (SM/SL) saliva and of the human whole salivary mucin fraction (HWSM) to saliva-induced bacterial aggregation was studied for S. sanguis C476, S. oralis I581, and S. rattus HG 59. The mucous SM/SL saliva showed a much higher aggregation potency towards the S. sanguis and S. oralis strain than did the serous Par saliva. The SM/SL saliva-induced aggregation was observed after 30 min, at 60 min followed by the Par saliva-induced aggregation, and showed a 4-fold higher aggregation titer of 128 for S. sanguis, and an 8-fold higher titer of 516 for S. oralis. In contrast, the Par saliva showed a slightly higher aggregation activity than the SM/SL saliva towards S. rattus as judged by a twofold higher titer of 64. Morphologically, however, the SM/SL saliva-induced aggregation of S. rattus was far more pronounced as was also found for S. sanguis. Finally, the HWSM-induced aggregation showed a 4 to 8-fold higher titer than the originating salivary source, measuring 2048 for S. oralis and 128 for S. rattus. Moreover, no difference was observed in aggregation activity between the HWSM from whole saliva of a blood group O donor and the HWSM from SM/SL saliva of a blood group A donor. All the data point to an important, though not exclusive role of the human salivary mucin fraction in the saliva-induced aggregation of these strains.

Blood Group Antigens↗
PubMed1990

Influence of the blood group reactive substances in saliva on the aggregation of Streptococcus rattus.

The interaction of blood group reactive substances in saliva with bacteria was investigated by testing saliva from persons with different blood groups in a bacterial aggregation assay with Streptococcus rattus HG 59, originally S. rattus BHT. For blood group A, saliva from 10 persons out of 11 aggregated S. rattus and for blood group O, saliva from 10 persons out of 16 aggregated S. rattus. For blood group B, saliva from 6 persons out of 8 aggregated S. rattus weakly and the average aggregation activity of blood group B was much lower than for blood group A or O. In addition, saliva from 3 non-secretors did not aggregate S. rattus. The role of blood group antigens in bacterial aggregation was confirmed by inhibition studies with blood group specific sugars and various other sugars. GalNAc, specific for blood group A, inhibited bacterial aggregation by saliva whereas D-galactose, specific for blood group B, and D-fucose, specific for blood group O, did not. In addition, sialic acid, a major terminal sugar residue in mucins, also inhibited the bacterial aggregation. This study shows that the blood group and secretor status of a person may influence the interaction of saliva with bacteria in the oral cavity.

Acetylgalactosamine↗