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A Frandsen

Publications and source records attributed to A Frandsen.

51 records · Page 3Linked to original sources
PubMed1979

Juvenile periodontitis. Localization of bone loss in relation to age, sex, and teeth.

The distribution of bone loss in 156 patients, 12-32 years old, with juvenile periodontitis was analyzed according to age, sex, and teeth affected. The criteria for bone loss were: vertical or horizontal bone loss involving more than one-third of the root as judged by radiographs. Three age groups were established: 12-18, 19-25, and 26-32 years old. Three types of bone loss localization were defined: I. First molars and/or incisors. II. First molars, incisors and some additional teeth (total less than 14 teeth). III. General involvement . There was a dominance of female patients. The ratio females: males decreased from 5.3:1 in the youngest age group to 1.5:1 in the oldest. The mean number of involved teeth increased with age from 5.3 teeth in the youngest group to 11.6 in the oldest. The frequency of type I bone loss decreased from 55% in the youngest group to 7% in the oldest. Type II occurred with the same frequency (55-58%) in all three age groups. Type III was not seen in the youngest group whereas it increased from 17% in the middle to 35% in the oldest group. Of the total number of involved teeth, the first molars were most frequently affected, followed by the incisors. Maxillary teeth were involved to a slightly higher degree than mandibular teeth, and there was a strong "mirror effect" between involved teeth of right and left jaw halves.

Adolescent↗
PubMed1978

Autologous tooth transplantation to replace molars lost in patients with juvenile periodontitis.

A method is described to replace perodontally destroyed first molars in patients with juvenile periodontitis by auto-transplantation of third molars. Fifteen molars which had been extracted due to periodontal destruction were replaced by autologous third molars with incomplete root formation. The patients were then observed for a period up to 7 years. In all cases complete regeneration of the alveolar bone took place and radiographically a normal periodontal membrane was extablished. All of the transplanted teeth continued their root formation and there was no radiographic evidence for root resorption, ankylosis or necrosis of the pulp. None of the transplanted teeth displayed pocket depths over 3 mm and no abnormal mobility was detectable.

Adolescent↗
PubMed1978

Ultrastructure of the subgingival microflora in juvenile periodontitis.

The ultrastructure of the subgingival deposits on the root surfaces of teeth affected by juvenile periodontitis was studied on 12 teeth from nine individuals, 15--30 years of age. The deposits consisted of either microbial masses associated with a pellicle, or of a cuticular material almost free of bacteria. Gram-negative rods and filaments were the predominant microorganisms. "Corncob" configurations consisting of filamentous bacteria surrounded by Gram-positive cocci, and "bristle brush" formations comprising corncobs surrounded by long rods were observed in the superficial layer of the plaque. Spirochetes and flagellated rods constituted a major segment of the microflora. The present data indicated that the deep pockets in juvenile periodontitis harbor a sparse but relatively characteristic microbial population.

Adolescent↗
PubMed1978

Microbiota of gingivitis in man.

A study on the predominant cultivable microorganisms inhabiting gingival crevices affected with a chronic gingivitis was carried out using the roll tube culture technique. Samples were obtained from nine individuals 25--42 years of age. Gram-positive rods make up 29.1% of the isolates and included mainly Actinomyces naeslundii, Actinomyces israelii, and Actinomyces viscosus. Streptococcus mitis and Streptococcus sanguis together made up 26.8% of the cultivable organisms. Peptostreptococcus averaged 3.0% of the organisms recovered. Gram-negative anaerobic rods constituted 25.0% of the total isolates with Fusobacterium nucleatum, Bacteroides melaninogenicus ss. intermedius. Bacteriodes ochraceus, other Bacteroides species, Selenomonas sputigena, and Campylobacter sputorum as the most predominant isolates. Haemophilus parainfluenzae averaged about 14% and Veillonella species 4.3% of the cultivable microflora. The data presented indicate that the subgingival microflora of a chronic gingivitis differs from those of healthy periodontium and advanced adult and juvenile periodontis. This might suggest that different infectious processes may be operative in various clinical entities of periodontal disease.

Actinomyces↗
PubMed1973

[Dental education].

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Education, Dental↗
PubMedDate not supplied

Pharmacological and functional characterization of excitatory amino acid mediated cytotoxicity in cerebral cortical neurons.

The cytotoxic action of the excitatory amino acids (EAAs) glutamate, N-methyl-D-aspartate (NMDA), quisqualate (QA), kainate (KA) and (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionate (AMPA) was studied in cerebral cortical neurons in culture. The pharmacological profile of these actions was characterized using the NMDA selective antagonist D-(-)-2-amino-5-phosphonopentanoate (APV) and the non-NMDA selective antagonists 6,7-dinitroquinoxaline-2,3-dione (DNQX), 2-amino-3[3-(carboxymethoxy)-5-methylisoxazol-4-yl]-propionate (AMOA) and 2-amino-3-[2-(3-hydroxy-5-methylisoxazol-4-yl)methyl-5-methyl-3- oxoisoxazolin-4-yl]propionate (AMNH). The role of intracellular Ca++ homeostasis and cGMP production for development of EAA mediated cytotoxicity was assessed by measurements of changes in [Ca++]i using the fluorescent Ca++ chelator Fluo-3 and in cGMP concentrations using a conventional radioimmune assay. It was found that glutamate toxicity involves both NMDA and non-NMDA receptor activation and that aberrations in Ca++ homeostasis brought about by Ca++ influx and/or liberation of Ca++ from internal stores are important for development of toxicity. The drug dantrolene which prevents release of Ca++ from such stores can prevent toxicity induced by glutamate, NMDA and QA completely but has no effect on KA and AMPA toxicity. Changes in cGMP levels appear to play a role for development of glutamate, NMDA and KA toxicity but does not seem to be involved in that triggered by QA and AMPA.

Amino Acids↗
PubMedDate not supplied

Pharmacology and toxicology of ATOA, an AMPA receptor antagonist and a partial agonist at GluR5 receptors.

(RS)-2-Amino-3-[3-(carboxymethoxy)-5-tert-butyl-4-isoxazolyl]propi onic acid (ATOA) has previously been described as an antagonist at (RS)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) receptors with an IC50 value of 150 microM towards AMPA-induced depolarisation in the rat cortical wedge preparation. ATOA has now been shown also to be a partial agonist at recombinant GluR5 receptors, expressed in Xenopus oocytes, with an EC50 value of 170 microM and a relative efficacy of 0.17 +/- 0.04 compared with responses produced by kainic acid (1.0). Using cultured cerebral cortical neurones as a test system and leakage of lactate dehydrogenase (LDH) as an indicator of cell damage, ATOA was shown to be cytotoxic (ED50 > 300 microM), though much less toxic than the structurally related dual AMPA and GluR5 agonist, (RS)-2-amino-3-(3-hydroxy-5-tert-butyl-4-isoxazolyl)propionic acid (ATPA) (ED50 = 14 +/- 2 microM). The toxic effect of ATPA was sensitive to 6,7-dinitroquinoxaline-2,3-dione (DNQX) but was not significantly reduced by the selective AMPA receptor antagonist, (RS)-2-amino-3-[3-(carboxymethoxy)-5-methyl-4-isoxazolyl]propionic acid (AMOA). The toxicity of ATOA (1 mM) could not be significantly attenuated by co-administration of AMOA (300 microM) or DNQX (25 microM). A structure-activity analysis indicates that the tert-butyl group of ATPA and ATOA facilitates the interaction of these compounds with GluR5 receptors.

Alanine↗