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Biomedical subjects

I Ericsson

Publications and source records attributed to I Ericsson.

At least 73 records · Page 4Linked to original sources
PubMed1985

Alterations in mitochondrial aconitase activity and respiration, and in concentration of citrate in some organs of mice with experimental or genetic diabetes.

Mouse islets (not used for respiration), kidneys and liver were studied in early and manifest alloxan diabetes, and in genetic diabetes. In these organs the mitochondrial aconitase activity was lower, state 3 respiration with citrate or pyruvate plus malate (but not with succinate) was decreased, and the concentration of citrate was increased, compared with non-diabetic control mice. The alterations suggest a role of lowered activity of mitochondrial aconitase in alloxan diabetes, and probably also in genetic diabetes.

Aconitate Hydratase↗
PubMed1984

Inhibition by alloxan of mitochondrial aconitase and other enzymes associated with the citric acid cycle.

Considerable variations were found in the in vitro effect of alloxan on mouse liver enzymes associated with the citric acid cycle. The following approximative alloxan concentrations induced 50% inhibition of enzyme activity: 10(-6)M for aconitase, 10(-4)M for NAD-linked isocitrate dehydrogenase, glutamate dehydrogenase, alpha-ketoglutarate dehydrogenase, succinyl-CoA synthetase and fumarase, and 10(-3)M for citrate synthase and NADP-linked isocitrate dehydrogenase. Pyruvate dehydrogenase, succinate dehydrogenase and malate dehydrogenase were not inhibited by 10(-3)M alloxan. The inhibition of aconitase was competitive both when using mouse liver and purified porcine heart enzyme. The Ki values for the purified enzyme in the presence of 5 microM alloxan were 0.22 microM with citrate, 4.0 microM with cis-aconitate and 0.62 microM with isocitrate as substrate. The high sensitivity of aconitase for inhibition by alloxan probably plays a prominent role for the toxic effects of alloxan.

Aconitate Hydratase↗
PubMed1984

Recession in sites with inadequate width of the keratinized gingiva. An experimental study in the dog.

The present investigation was performed to assess the inflammatory response in gingival units subsequent to the placement of restorations with subgingivally located margins. 3 beagle dogs were used. Cotton floss ligatures were placed around the neck of the mandibular third and fourth premolars of all dogs. The ligatures were exchanged once a month during the first 6 months of experiment. When 40-50% of the height of the supporting tissues had been lost in an experimental periodontitis the ligatures were removed but the animals allowed to accumulate deposits for another 60 days. The inflamed periodontal tissues were subsequently excised using either an "apically placed flap" procedure or a "gingivectomy" procedure. In the flap procedure the main part of the keratinized gingiva was preserved while in the gingivectomy procedure the keratinized part of the gingiva was removed in toto. Following scaling and root planing the animals were during a maintenance period of 4 months placed on a program involving chlorhexidine application and mechanical tooth cleaning twice daily. On Day 0 a notch was prepared in the buccal surface of each root at the level of the gingival margin. Furthermore, steel bands were placed along the buccal surface of each root of the third and fourth premolars and secured with an apical margin at the level of 1 mm apical to the notch. The bands were cemented to the root surfaces by a cement. The dogs were allowed to accumulate plaque and calculus for 6 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Lack of significance of increased tooth mobility in experimental periodontitis.

This experiment was carried out in order to study the rate of progression of experimentally produced periodontal tissue breakdown in teeth which prior to the placement of cotton floss ligatures either had a normal or a permanently increased tooth mobility. Six beagle dogs were used. Trauma from occlusion of the jiggling type was produced on test teeth using a model previously described. Four months later experimental periodontal tissue breakdown was induced around both control and test teeth by placing cotton floss ligatures around the necks of the teeth. The ligatures which were exchanged once every 4 weeks during a 4-month period were replaced at the level of the gingival margin. Tooth mobility measurements and radiographic examinations were performed on Days 0, 30, 60, 90, 120, 160, 240 and 300. One dog was killed on Day 120 and the remaining 5 dogs on Day 300. Biopsies of the test and control teeth were fixed in formalin, decalcified, embedded in paraffin and mesiodistal sections cut with the microtome set at 4 micron. The results demonstrated that the degree of periodontal breakdown, initiated and maintained by ligature placement and plaque accumulation, was similar around teeth with a wide periodontal ligament space and in teeth with a normal width of the periodontium. In other words, progression of the plaque-associated lesions appeared to be unrelated to the width of the periodontal ligament space, i.e., to the degree of horizontal tooth mobility.

Animals↗
PubMed1983

Differentiation between gram-negative anaerobic bacteria by pyrolysis gas chromatography of lipopolysaccharides.

Lipopolysaccharides extracted by phenol-water from nine strains of Gram-positive anaerobic bacteria (Bacteroides. Fusobacterium and Veillonella), have been examined by means of pyrolysis gas chromatography. Lipopolysaccharides were fragmented into a group of low molecular weight components and four characteristic high molecular fractions probably consisting of hydrocarbons from the lipid part of the material. The latter fractions were specific for each of the genera tested. At the species level characteristic differences were also found although a limited number of strains were tested. Due to the high reproducibility of the technique, the potential of using the method in differentiating Gram-negative anaerobic bacteria was indicated.

Bacteroides↗
PubMed1982

The capacity of reduced periodontal tissues to support fixed bridgework.

The total area of periodontal ligament around the abutment teeth in 60 fixed bridges, inserted in patients treated for advanced periodontal disease, was calculated and compared with the total "periodontal ligament area" of the teeth replaced by pontics. The calculations revealed that only in 8% of the bridge restorations did the periodontal ligament area of the abutment teeth equal or exceed that of the replaced teeth. In 57% of the bridge material the periodontal ligament area of the abutments was less than 50% of the anticipated normal ligament area of the pontics. Despite the fact that the periodontal support for the restorations was dramatically reduced, all bridges have functioned properly for 8-11 years and the periodontal tissues around the abutment teeth have not suffered further loss of attachment during the period of maintenance care.

Denture, Partial, Fixed↗
PubMed1982

Effect of longstanding jiggling on experimental marginal periodontitis in the beagle dog.

The aim of the present experiment was to study the effect of a prolonged period of jiggling force application on the rate of progression of ligature-induced, plaque-associated marginal periodontitis in the beagle dog. The experiment was performed on eight dogs fed a diet which permitted dental plaque accumulation. On Day 0 a phase of periodontal tissue breakdown was initiated around the mandibular fourth premolars (4P; P4) by the placing of plaque retention ligatures around the neck of the teeth. The ligatures were exchanged once a month throughout the entire study. On Day 60 trauma from occlusion of the jiggling type was produced in the P4 region and maintained for 300 days. The animals were sacrificed on Day 360. Following sacrifice tissue sections comprising 1M, 4P, 3P and P3, P4, M1 were produced and subjected to microscopic analysis. The experiment revealed that in the dog jiggling forces applied to teeth which ae also subjected to ligature-induced and plaque-associated marginal periodontitis, may enhance the rate of destruction of the periodontium.

Animals↗
PubMed1982

The effect of elimination of jiggling forces on periodontally exposed teeth in the dog.

The aim of the present investigation in dogs was to analyze the effect on periodontal disease induced by a combination of ligatures and jiggling trauma, when the jiggling forces are eliminated. The experiment was performed in six dogs. On Day 0 a phase of periodontal tissue breakdown was initiated around the mandibular fourth premolars (4P; P4) by placing plaque retention ligatures around the necks of the teeth. The ligatures were changed once a month during a 90-day period. On Day 90 the ligatures were removed. On Day 0 trauma from occlusion (jiggling) was also produced in the 4P and P4 region. On Day 90 the jiggling trauma was removed from the 4P-region (test) while it was maintained in the P4-region (control). Tooth mobility measurements and radiographic examinations were carried out on experimental Days 0, 30, 60, 90, 180, and 360. One dog was sacrificed on Day 90 and the remaining five on day 360. Following sacrifice, tissue sections comprising 1M, 4P, 3P, P3, P4, M1 were obtained and subjected to microscopic analysis. Removal of the jiggling trauma from the test teeth resulted in a markedly decreased tooth mobility, but the loss of connective tissue attachment on Day 360 was similar in the test and control sites. This means that although the control teeth had an increased mobility and a widened periodontal ligament space, the height of the remaining periodontal tissue support was similar in the test and control tooth regions.

Animals↗
PubMed1981

Manifestations and treatment of periodontal disease in a patient suffering from cyclic neutropenia.

A case of severe periodontitis in a young man suffering from cyclic neutropenia is reported. The periodontal status as evaluated from oral radiographs at the age of 13 reveals advanced periodontal breakdown around the molars and the incisors in both jaws. At the age of 21, when clinical examination was performed, all teeth were found to be periodontally involved. The treatment was divided into three phases: (1) a causative treatment phase (oral hygiene phase) aimed at achieving the highest possible level of oral cleanliness, (2) a corrective phase including periodontal surgery and prosthetic rehabilitation and (3) a maintenance phase aimed at prevention of recurrence of periodontal disease. The oral hygiene phase was markedly extended both in time (2 years) and intensity. Several reexaminations were carried out during the course of this phase to evaluate the patient's ability to exercise proper plaque control and the response of the tissues to treatment. The progression of the periodontal disease could be arrested and the prosthetic treatment indicated was successfully performed. Following the corrective treatment phase a maintenance care program was designed including frequent recall appointments in order to prevent disease recurrence. Four years after active treatment no further periodontal breakdown could be observed as evaluated from pocket depth, attachment level and bone height measurements. The result of the treatment of this patient shows that treatment, designed to eliminate plaque infection, is effective also in an individual with defective host defense against bacterial infections, but the demand on the patient's cooperation must be extraordinary high as well as the demand on the effectiveness of the maintenance care program.

Adult↗