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Biomedical subjects

T Modéer

Publications and source records attributed to T Modéer.

At least 73 records · Page 4Linked to original sources
PubMed1991

Regression of phenytoin-induced gingival overgrowth after withdrawal of medication.

The regression of phenytoin-induced gingival overgrowth after withdrawal of medication was studied in 10 children. After only one month a statistically significant (p less than 0.05) in buccolingual dimension of the marginal gingiva was observed in both the maxillary and mandibular incisor areas. Children diagnosed as responders (i.e. exhibiting pseudopockets) showed a more rapid and significantly greater decrease (p less than 0.05) in buccolingual dimension at 1 and 3 months after withdrawal of PHT medication than non-responders. Compared to a control group of children on other antiepileptic drugs, no significant differences could be found in the thickness of the marginal gingiva six months after withdrawal of medication.

Adolescent↗
PubMed1991

Oral health in adolescents with immigrant background in Stockholm.

Dental caries and periodontal health was studied in 225 18- and 19-year-old adolescents with different ethnic background. The results showed that immigrant adolescents exhibit an increased prevalence of periodontal disease compared to the Swedish control group whereas no differences were found concerning the prevalence of dental caries. Alveolar bone loss was diagnosed on one or more surfaces in 4.3% of the Swedish adolescents compared to 16.2% in the immigrant group. Subgingival calculus was found among 5.3% of the Swedish adolescents compared to 35.1% in the immigrant group. This study shows that immigrant adolescents must be considered at high risk to develop periodontal disease during adolescents while dental caries can be managed.

Adolescent↗
PubMed1990

Regulation of epidermal growth factor receptor metabolism in gingival fibroblasts by phenytoin in vitro.

Normal human gingival fibroblasts derived from five children between 8 and 12 yr of age were cultured under serum-free conditions in the presence of epidermal growth factor (EGF) either alone or in combination with 5,5-diphenylhydantoin (phenytoin; PHT). DNA-synthesis, binding of EGF to its cell-surface receptor and internalisation of EGF-receptor-ligand complexes were studied. In normal gingival fibroblasts treated solely with EGF for 48 h, DNA synthesis increased significantly, as in cells treated solely with PHT. When EGF binding data was calculated according to Scatchard, it was found that the number of EGF receptors in fibroblasts increased significantly after PHT treatment. The number of EGF-receptors in untreated gingival fibroblasts varied from 147,000 to 170,000 receptors per cell whereas in PHT-treated fibroblasts the range was from 181,000 to 280,000. The study indicates that PHT regulates EGF-receptor metabolism in human gingival fibroblasts by increasing the number of cell-surface EGF-receptors which may contribute to the alteration of gingival connective tissue observed in patients undergoing PHT medication.

Child↗
PubMed1990

Periodontal disease in children with Down's syndrome.

The occurrence of supra- and subgingival calculus, gingival inflammation, periodontal pockets (greater than or equal to 5 mm) and alveolar bone loss was determined in children (10-19 yr) with Down's syndrome (D-S) and in an aged- and sex-matched control group (n = 39). Of D-S children (n = 71), 39 of the patients (mean age 15.5 yr) cooperated in a clinical and roentgenologic examination. Alveolar bone loss was determined around incisors and first molars on intraoral radiographs when the distance between cementoenamel junction (CEJ) to alveolar crest (AC) exceeded 2.0 mm. Alveolar bone loss was diagnosed in 39% of the D-S children compared to 3% in the control group (P less than 0.001). Of the total number of sites examined on radiographs the distance from CEJ to AC exceeded 2.0 mm in 8% in the D-S group compared to 0.2% in the control group (P less than 0.001). The frequency of sites with alveolar bone loss in D-S children was significantly (P less than 0.001) higher around the mandibular incisors compared to first molars. The study shows that early signs of periodontitis are frequently seen in D-S children as early as 11 yr of age and the lesions are first diagnosed in the mandibular anterior region.

Adolescent↗
PubMed1990

Effect of phenytoin medication on the metabolism of epidermal growth factor receptor in cultured gingival fibroblasts.

Human gingival fibroblasts derived from 2 patients before and 9 months after the start of phenytoin (PHT) therapy were studied with respect to the effect of epidermal growth factor (EGF) on the incorporation of 3H-thymidine into DNA, binding of EGF to its cell-surface receptor, internalization of EGF-receptor-ligand complexes and, finally, with respect to EGF receptor mRNA levels. In fibroblasts derived from the patient who developed gingival overgrowth during the PHT medication (responder) as well as in the fibroblasts derived from the patient where gingival overgrowth did not develop (non-responder), the affinity of the EGF receptor for EGF was not significantly changed. In the non-responder patient the internalization of EGF receptor ligand was decreased, whereas it was increased in the fibroblasts derived from the responder patient after PHT therapy. The steady-state level of EGF-r mRNA increased significantly (p less than 0.001) in the cultured fibroblasts derived from the non-responder but decreased (p less than 0.05) in the responder patient following PHT therapy. Ligand affinity cross-linking studies revealed one major component of EGF receptor with a molecular weight of 170 KDa in fibroblasts from the non-responder as well as from the responder. The study indicates that PHT medication results in a down-regulation of EGF receptor metabolism in fibroblasts derived from a responder patient, whereas in the non-responder patient EGF receptor metabolism is up-regulated.

Cell Division↗
PubMed1990

Bradykinin-2 receptor-mediated release of 3H-arachidonic acid and formation of prostaglandin E2 in human gingival fibroblasts.

Bradykinin stimulated production of prostaglandin E2 (PGE2) and the release of 3H-arachidonic acid by gingival fibroblasts in a time- and dose-dependent manner. The effect on PGE2 biosynthesis was seen already after 15 seconds and was maximal after 5 minutes. Several structurally unrelated inhibitors of arachidonic acid metabolism via the cyclooxygenase pathway totally abolished the PGE2 response to bradykinin. The stimulation of PGE2 formation was seen at and above 10 nmol/l of bradykinin. Des-Arg9-bradykinin was 100-fold less potent compared to bradykinin. Des-Arg9-Leu8-bradykinin did not antagonize bradykinin-induced PGE2 formation. Met-Lys-bradykinin and Lys-bradykinin also enhanced PGE2 formation in gingival fibroblasts. The stimulatory action of bradykinin on 3H-arachidonic acid release was observed after 30 s and progressively increased for at least 15 min. The stimulatory effect on 3H-arachidonic acid release by bradykinin was seen at and above 10 nmol/l, whereas des-Arg9-bradykinin was without effect up to a concentration of 1 mumol/l. Indomethacin did not affect bradykinin-induced 3H-arachidonic acid release. These data show that bradykinin, via a B2-receptor-mediated pathway, can stimulate arachidonic acid release and subsequent prostanoid formation in gingival fibroblasts. Consequently, gingival fibroblasts may contribute, by a bradykinin-regulated reaction, to the enhanced amounts of prostanoids found in gingival tissues and crevicular fluids in patients with periodontal diseases.

Analysis of Variance↗
PubMed1990

Subpopulations of lymphocytes in connective tissue from adolescents with periodontal disease.

Mononuclear cell populations were studied in gingival biopsy specimens from adolescents (n = 10) with at least one periodontal pocket with an increased probing depth (greater than 5 mm). The marginal bone loss was measured on radiographs, subgingival plaque samples were collected from the lesions, and the microbial flora was identified. Specimens from gingivitis lesions (n = 5) were used as controls. The mononuclear cell populations in the specimens were detected by using monoclonal antibodies defining functional T-lymphocyte subpopulations, B lymphocytes, and monocytes. All gingival specimens from patients with increased probing depth showed large lymphocyte infiltrates, most of which were CD 3-antigen-positive cells (T lymphocytes). Few (2%) infiltrating T cells expressed receptors for interleukin-2. B cells were detected in most specimens from the periodontitis group and varied from less than 1% to 21%. This study indicates that lesions in adolescents with early signs of periodontitis are characterized predominantly by T-cell lesions with relatively few cell aggregates of B cells present.

Actinobacillus↗
PubMed1989

Phenytoin induces interleukin-1 production in vitro.

Human adherent mononuclear cells and subcloned cell lines established from the human histiocytic cell line U-937 were cultured with phenytoin (PHT) and/or lipopolysaccharide (LPS) purified from Bacteroides fragilis. After the cultivation period, the cell-free supernatants were tested for interleukin-1 (Il-1) activity. The results showed that PHT induces Il-1 activity and potentiates LPS-induced Il-1 production. In the monocytic cell line U-937, the induced Il-1 production was found to be clonally distributed indicating that the response to PHT may be exerted by a subpopulation of monocytes. The PHT-induced Il-1 activity may be of importance in the development of gingival overgrowth. The induced Il-1 could also contribute to other known side effects such as dermatologic reactions accompanied by transient fever seen in patients medicating the drug.

Adult↗
PubMed1989

Facial growth and morphology in long-term survivors after bone marrow transplantation.

A roentgen cephalometric investigation was used to study facial growth and morphology in 17 children who had undergone bone marrow transplantation (BMT) because of acute leukaemia and aplastic anaemia. The ages at BMT varied from 1.0 to 12.9 years. Preoperative treatment included high doses of cyclophosphamide and in children with acute leukaemia also 10 Gy total body irradiation (TBI). The median observation period following BMT was 3.9 years. The control group comprised 85 age and sex matched healthy children. In comparison to the controls, all linear measurements studied were found to be significantly diminished in children conditioned with TBI. For variables describing vertical dimensions, the degree of reduction appeared to be associated with the patients' ages at the time of irradiation. It was concluded that the disturbance in dental development, which is also a consequence of TBI, could be partly responsible for this association. Children who were not conditioned with TBI exhibited no significant differences when compared to controls in respect of the variables studied.

Bone Marrow Transplantation↗
PubMed1989

Effect of phenytoin on intracellular 45Ca2+ accumulation in gingival fibroblasts in vitro.

Effect of 5,5 diphenylhydantoin (phenytoin; PHT) alone or in combination with epidermal growth factor (EGF) on the intracellular accumulation of the radioisotope 45Ca2+ (4 min labelling period) was determined in gingival fibroblasts. EGF as well as PHT increased the intracellular accumulation of the radioisotope in normal gingival fibroblasts by approximately 2 and 1.6-fold, respectively. In contrast, in fibroblasts derived from the phenytoin-induced gingival overgrowth, neither EGF nor PHT stimulated intracellular accumulation of 45Ca2+. When normal gingival fibroblasts were treated in vitro with EGF in combination with PHT, the EGF-induced increase in intracellular accumulation of the radioisotope 45Ca2+ was abolished. The rate of efflux of the radioisotope 45Ca2+ in prelabelled normal gingival fibroblasts was decreased by PHT treatment in vitro to a level already present in fibroblasts derived from PHT-induced gingival overgrowth. This study indicates that PHT influences the cellular calcium metabolism in fibroblasts which may contribute to the pathogenesis of gingival overgrowth.

Adolescent↗
PubMed1989

Potentiation of fibroblast DNA synthesis by a phenytoin-induced mononuclear cell derived factor in vitro.

Human mononuclear cells purified by Lymphoprep flotation were incubated with phenytoin (PHT) (20 micrograms/ml) or its metabolite p-HPPH (2 micrograms/ml) in the presence of Concanavalin A (10 micrograms/ml) in vitro. The results indicate that phenytoin and its metabolite p-HPPH induce the release of a mononuclear cell factor(s) that activates quiescent human gingival fibroblast to synthesize DNA.

Cell Division↗
PubMed1989

Oral mucous membrane lesions in children treated with bone marrow transplantation.

Oral mucous membrane lesions were studied in 54 children below 12 yr of age treated with allogeneic bone marrow transplantation mainly because of hematological malignancies. Sixty-two percent of the children exhibited a wide range of oral side effects during therapy. Lesions observed during the first 2 wk prior to engraftment of the donor marrow were related to the chemo- and radiotherapy given. Oral ulcerations were seen in 34% of the children. Children given methotrexate as graft-versus-host disease (GVHD) prophylaxis exhibited oral ulcerations significantly (P less than 0.05) more often than those given cyclosporin. Oral lesions related to acute GVHD were only observed in two patients. Reactivating herpes simplex virus infection was seen in 35% of the children who were seropositive prior to BMT. An extensive oral candidiasis was observed in 15% of the patients. All six children with a chronic GVHD exhibited changes in the oral mucosa 2-4 yr after transplantation such as erythma of the mucous membranes, tongue atrophy and also lichenoid changes in the buccal mucosa.

Antineoplastic Agents↗
PubMed1989

Relation between sucking habits and dental characteristics in preschoolchildren with unilateral cross-bite.

The relationship between sucking habits and dental characteristics of unilateral cross-bite in 4-yr-old children (n = 76) was studied. The cross-bites were classified on the variables "number of teeth involved", incisor "overjet" and "overbite", "terminal plane shift", "midline shift", "asymmetric maxillary dental arch" and "max./mand. arch width difference". Type of sucking habit (dummy, finger) and its duration and intensity were analyzed from a questionnaire answered by the parents. The "max./mand. arch width difference" in the canine region was found to be negatively related to the intensity and duration of the sucking habit, and also negatively related to sucking a dummy compared to finger sucking. The study indicates that the "duration" and "intensity" of the sucking habit have a negative influence by reducing the transverse width of the maxillary arch in children with a unilateral cross-bite. Dummy sucking was more detrimental to the transverse dimension in the canine region than finger sucking.

Child, Preschool↗
PubMed1989

Effect of chemotherapy on dental maturity in children with hematological malignancies.

Dental maturity or dental age was determined in 44 children with hematological malignancies treated with chemotherapy. No significant difference was observed between the chronological and dental age in children treated with chemotherapy compared to healthy controls. With regard to the number of erupted permanent teeth, no significant differences could be found between the two groups. The results indicate that chemotherapy given to children with hematological malignancies did not interfere with dental maturity or eruption of permanent teeth.

Adolescent↗
PubMed1988

Disturbances in dental development after total body irradiation in bone marrow transplant recipients.

The dental status of 16 children who had been treated with bone marrow transplantation (BMT) for serious bone marrow diseases was followed for up to 6 years. Several types of disturbances in dental development were observed in children who had been conditioned with total body irradiation (TBI) at 10 Gy before BMT. Thus, impaired root development that caused short V-shaped roots was found in all patients, a complete failure of root development and premature apical closure were found in five patients, enamel hypoplasia was observed in four patients, and microdontia was observed in three patients conditioned with TBI. Patients younger than 6 years of age at BMT exhibited the most severe and extensive dental aberrations. The TBI at 10 Gy appeared to be the major cause of the disturbances found.

Abnormalities, Radiation-Induced↗
PubMed1988

Potentiation of fibroblast spreading by extracellular matrix from fibroblasts derived from phenytoin-induced gingival overgrowth.

Cell attachment and spreading appear when a cell, on contact with an appropriate substratum, adheres and changes its shape and accommodates to the substratum. The transition from a non-spreading to a spreading state is a prerequisite for growth. Cell-free extracellular matrix (ECM) was produced by fibroblast-like cells from normal gingiva (N-ECM) and phenytoin-induced gingival overgrowth (PHT-ECM). The effect of the ECM on cell attachment and spreading of human gingival fibroblasts was studied in the presence of 2% serum. Within 30 min after seeding 40% of the normal fibroblast cells showed an advanced flattening on PHT-ECM-prepared dishes, compared with 10% on normal ECM-prepared dishes and 5% on uncoated plastic dishes. The results indicate that cells derived from PHT-induced gingival overgrowth produce an ECM with special properties, which could regulate cell functions such as cell attachment and spreading.

Adolescent↗
PubMed1987

Effect of disease severity and pharmacotherapy of asthma on oral health in asthmatic children.

Oral health was studied in a group of asthmatic children (n = 61). The children were divided in two groups, 5-10 and 11-18 yr of age. The individuals with asthma were further subgrouped with respect to the disease severity. Severe asthma was defined as more than 10 asthmatic attacks per year. This patient group had daily medication compared to children with moderate asthma (less than 10 asthmatic attacks/yr) who medicated temporarily. 55 age matched children from the same area made up the control group. All children were examined clinically and two bitewing radiographs were taken. The results showed no statistically significant differences concerning caries prevalence and gingival condition in asthmatic children compared to a healthy control group. The study shows that neither the asthma per se nor the disease severity affected the caries prevalence and gingival condition in asthmatic children.

Adolescent↗