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Biomedical subjects

R Attström

Publications and source records attributed to R Attström.

At least 109 records · Page 6Linked to original sources
PubMed1979

Electron microscopic study of junctional and oral gingival epithelia in the juvenile and adult beagle dog.

A previous study demonstrated structural differences in the junctional epithelium between juvenile and adult dogs. In juveniles the junctional epithelium showed some resemblances to the oral gingival epithelium, and a cuticular structure at the dento-gingival junction was of particular interest. The oral gingival epithelium is considered to be less permeable than the junctional epithelium. As cytoplasmic filaments are held to be the main component in the process of keratinization, and to have a stabilizing influence on the cells and tissues, the present investigation was designed to study the relative amounts of cytoplasmic filaments in the junctional and the oral epithelia of beagle dogs during juvenile and adult stages. In addition, the ultrastructure of the dento-gingival junction was characterized. Six beagle dogs were used. The material consisted of gingival biopsies sampled when the dogs were 3 and 12 months old, respectively. On these occasions the gingiva was in excellent health. The biopsies were prepared for electron microscopic analysis and three randomly selected fields were recorded photographically from each of the following epithelial strata: basal and granular cell layers of the oral epithelium and basal and superficial cell layers of the junctional epithelium. Morphometric analysis was performed in order to estimate the density of cytoplasmic filaments of the cells in these epithelial strata. The amount of cytoplasmic filaments was considerably lower in the cells of the junctional epithelium than in those of the oral epithelium. In the oral epithelium the amount increased from basal towards superficial cells, whereas no such increase was seen in the junctional epithelium. The pattern was the same in the juvenile and the adult stage. At the dento-gingival junction all dogs had a thick, laminated layer of dental cuticle material in the juvenile stage. In the adult stage a similar structure was seen only infrequently, and it never attained the thickness observed in the juvenile stage.

Age Factors↗
PubMed1979

Effect of mechanical plaque control on development of subgingival plaque and initial gingivitis in neutropenic dogs.

Histologic, histometric and morphometric investigations were performed on the gingival tissues of three neutropenic dogs. Over a period of 4 d the animals had been subjected to daily toothcleaning of the left side of both jaws, whereas plaque accumulation and subsequent gingivitis occurred on the uncleaned teeth of the right side of both jaws. Observations and data revealed that subgingival plaque had formed in both sides and extended further apically (max. 0.6 mm) on the cleaned than on the uncleaned sides. In the responding gingival tissues, leukocytes of the junctional epithelium were more numerous and blood vessels of the marginal connective tissue occupied a greater volume on the cleaned sides when compared with the uncleaned sides. It is concluded that neutrophilic granulocytes normally help to prevent bacterial invasion into the dentogingival region, and that, in the presence of subgingival plaque, toothcleaning may aggravate the inflammatory response of the gingiva.

Agranulocytosis↗
PubMed1979

Effect of experimental neutropenia on initial gingivitis in dogs.

The role of neutrophilic granulocytes in the loss of gingival collagen has been studied by inducing experimental neutropenia during initial gingivitis in beagle dogs. Neutropenia was induced for 4 d in three animals with normal gingiva by repeated injections of rabbit anti-neutrophil serum. During neutropenia microbial plaque was allowed to form on the teeth. Samples of junctional (crevicular) leukocytes and gingival fluid were taken on days 0 and 4. Block biopsies of buccal gingiva were obtained on day 4. Stained semi- and ultrathin sections were used for histometric and stereologic tissue analysis. Gingival fluid flow increased from day 0 to day 4 in all dogs while junctional leukocytes increased in one dog only. Subgingival plaque had formed in most biopsies, and in the junctional epithelium very few neutrophilic granulocytes were present. In the coronal connective tissue subjacent to the junctional epithelium lymphoid cells, structurally abnormal neutrophilic granulocytes and monocytes/macrophages were diffusely scattered. The gingival collagen appeared mainly displaced by the inflammatory cells rather than dissolved. The data suggest that neutrophilic granulocytes may contribute to the loss of gingival collagen during initial gingivitis in dogs. The neutrophils also seem to be of importance for the limitation of subgingival plaque growth along the tooth surface.

Agranulocytosis↗
PubMed1978

Effect of experimental neutropenia on oral wound healing in guinea pigs.

The influence of experimental neutropenia on the wound healing process in standardized excisional palatal wounds was studied in 16 guinea pigs. Corresponding wounds in 15 normal animals were used as controls. Neutropenia was induced and maintained by daily injections of heterologous anti-neutrophil serum. One-micron sections from biopsies of palatal mucosa sampled 6, 24, 48 and 120 h after wounding were evaluated with special reference to the progress of epithelial wound repair and to the occurrence and location of inflammatory cells and bacteria. In animals treated with anti-serum, neutrophilic leukocytes disappeared from the wound cavity, whereas other inflammatory cells remained unchanged. Further bacterial invasion deep into the cavity was observed. The epithelial repair took place at a deeper level in the wounds of neutropenic animals compared with those of normal animals. The rate of re-epithelialization was the same in neutropenic and control wounds. The experiment indicates that the neutrophils in oral wounds provide a principal agency for host defense against microorganisms and probably thereby indirectly determine the direction and level of epithelial cell migration.

Agranulocytosis↗
PubMed1975

Complement factors in gingival crevice material from healthy and inflamed gingiva in humans.

The presence and levels of complement factors C3, C4, C5, and C3 proactivator, were determined by electroimmuno assay in gingival cervice material from five individuals with healthy gingiva and from six patients with chronically inflamed gingiva. Higher concentrations of C3 and C4 were found in samples from chronically inflamed gingiva when compared to those healthy gingiva. The amount of C3 in material from healthy as well as from inflamed gingiva was related to that in plasma, when the albumin in plasma and gingival crevice material was used as a reference. The same was found for C4 in samples from healthy gingiva but in those from inflamed gingiva, the values were significantly lower when related to plasma levels. C5 could not be found in material from healthy gingiva but was present in material from inflamed gingiva. C3 proactivator was present in material from inflamed gingiva in the converted form. No C3 proactivator was found in material from healthy gingiva with the methods used. Analysis of C3 in samples from inflamed gingiva, using crossed immunoelectrophoresis, showed that C3 was converted in these samples. The results indicate that the complement system may be activated in gingival crevice material from inflamed gingiva.

Adult↗
PubMed1975

Early formation of dental plaque on platic films. 1. Light microscopic observations.

In human subjects with healthy gingiva thin transparent plastic films were applied to the buccal surfaces of premolars in the upper and lower jaws. The films were left in place for peiods of 15, 30, 60, 120 and 240 minutes. The presence of coccoid bacteria, leukocytes and epithelial cells was investigated in an area adjacent to the gingival margin. The results showed that by 15 minutes coccoid bacteria had become attached to the artificial tooth surface. The number of microorganisms gradually increased during the time of the study. Large numbers of cocci and the formation of micro-colonies were observed after 120 and 240 minutes. Increasing numbers of leukocytes and epithelial cells were also found during the period of observation.

Adult↗