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Biomedical subjects

V Lassila

Publications and source records attributed to V Lassila.

34 records · Page 2Linked to original sources
PubMed1986

Alizarin red S-stained bone and cartilage in calcium deficiency provoked by experimental liver injury in rats.

Experimental liver injury with different stages was provoked in rats with daily injected doses of thioacetamide (ThAA). The dose recommended for both male and female rats was 50 mg/kg body weight. The liver damages caused were acute, subacute, cirrhotic and necrotic, with a traumatization period of 2, 7, 14 and 21 days. The loss of body weight under traumatization, indicating osteopenia, was in the case of female rats during the first experimental week markedly accelerated, and in the two subsequent weeks apparently inhibited when compared to male rats. The loss of body weight of male rats revealed a progressive fall. Vital staining was made giving intraperitoneally 200 mg/kg body weight of alizarin red S (ARS). The staining intensity was improved in the acute stage for both calvaria and tibia and in the necrotic stage for tibia only. It was impaired in the subacute stage for calvaria and tibia and in the necrotic stage for calvaria only. Prolonged traumatization with ThAA causes pathological defects in the liver and kidneys. Furthermore, the epiphyseal cartilage of necrotic-stage rats was bright red without any ARS staining.

Animals↗
PubMed1986

Influence of thioacetamide-provoked liver injury on female rat blood and alveolar bone under stress.

Experimental liver injury with different stages was induced to adult female test rats with daily injection of thioacetamide (ThAA). The doses administered intraperitoneally were 50 mg/kg body weight. In the liver sections progressive changes of damage, regeneration and fat substitution were noticed. Kidney sections revealed enhanced glomerular atrophy, particularly in the cortical tubules, provoked in the 3-week traumatization period. The influence of ThAA on female rat blood was assayed using standard biochemical methods. The analyses done were: the percentage of blood obtainable and the serum/blood ratio; the serum alanine transferase; serum alkaline phosphatase; serum creatinine; serum hydroxyproline and serum beta-glucuronidase activity in the acute, subacute, chronic and highly chronic stage of liver injury. The biochemical findings show continuously progressing damages when traumatization proceeds. In the 3-week test period the histological findings processed showed an increase in osteoclastic resorption in the alveolar bone around the occlusally stressed tooth simultaneously with a horizontal bone loss. Some indications of recovering incidents were seen, too. Only in the histological findings was no difference seen in the deterioration between both sexes, contrarily to the biochemical results also discussed in this study.

Alveolar Process↗
PubMed1985

Bite force and its correlations in different denture types.

Maximal bite force was measured and intraoral condition was examined in 89 patients at the Institute of Dentistry, University of Turku. These patients formed three different denture groups: those with complete dentures, those with full maxillary denture and partial mandibular denture, and those with natural dentition or skeleton-supported partial maxillary denture and partial mandibular denture. There were three age groups: greater than or equal to 70, 60-69, and less than or equal to 59 years old. Maximal bite force was recorded with an appliance at seven different measuring points by placing a biting fork between the antagonistic teeth while at the same time the occlusion was stabilized contralaterally with a plastic tube. Maximal bite force had a correlation with age and sex (P less than 0.01). In partial-denture groups high bite force had a correlation with the breaking of dentures (P less than 0.001 and P less than 0.05, respectively). Satisfied patients had a higher bite force than dissatisfied ones. When there was some disturbance in occlusion, the bite force was smaller, especially in full-denture groups (P less than 0.001). Full-denture wearers also had a good bite force, but the best biting area was located more posteriorly than in patients who still had some natural teeth left in both jaws. Changes in the denture-bearing mucosa in patients with complete dentures and negative height of the mandibular alveolar process decreased the bite force slightly.

Age Factors↗
PubMed1984

Influence of experimental liver injury on rat blood and alveolar bone under stress.

Experimental liver injury was induced to test rats with a daily injection of thioacetamide (ThAA). The doses used for intraperitoneal administrations were 50 mg/kg body weight. The loss of body weight in the 3-week test period was 15%. In the liver there was seen progressive changes which displayed cell necrosis and regeneration. The influence of ThAA on rat blood and serum was checked using standard biochemical assays consisting of the percentage of blood obtainable and the serum/blood ratio and analysis of serum alanine transferase, serum alkaline phosphatase, serum creatinine, and hydroxyproline in the acute, subacute, chronic, and necrotic stage of liver injury. With ThAA injections, the stimulated rate of glycosaminoglycan synthesis had its association to the serum calcium content. It decreased continuously as function of traumatization time. In the 3-week test period, histological findings show in the alveolar bone, around the teeth, when under occlusal stress and ThAA traumatization, the distinct decrease in osteoblastic activity and less osteoids indicating thus the decreased formation of new bone. Conspicuous osteoclastic resorption was also seen in the same area.

Acetamides↗
PubMed1982

Effect of occlusal disorder on the gingiva in rats with experimental arteriosclerosis. Enzyme histochemical and biochemical study.

This histochemical study showed that experimentally arteriosclerotic rats, subjected to an occlusal stress of six weeks' duration, showed an inflammation-related increase of chloride-activated arginine aminopeptidase and acid phosphatase activity in the basal cells of the gingival epithelium. The activity of chloride-activated arginine aminopeptidase and acid and alkaline phosphatase in the gingival connective tissue was slight and suggestive of chronic inflammation. Biochemical comparison of gingival specimens from the stressed and unstressed sides of the jaw in the experimental animals failed to reveal any difference in the rate of N-L-arginyl-2-naphthylamide hydrolysis induced by the C1-ion in connection with occlusal disorder. On the other hand, the mean value of the enzyme activity was lower in the experimental animals than the controls (p less than 0.5). The difference was assumed to be associated with degenerative tissue changes. The hydrolysis of p-nitrophenyl phosphate at acidic and alkaline pH in the gingiva was higher in the experimental animals than in the controls, and in the alkaline pH range the difference between the mean values was statistically significant (p less than 0.01). This finding, which may be associated not only with gingival inflammation but also with other tissue changes, requires further investigation.

Acid Phosphatase↗
PubMed1982

Periodontium and occlusal disorders in rats with experimental arteriosclerosis. A histological study.

Rats with arteriosclerosis induced by a hypercholesterolic diet were over a period of six weeks submitted to occlusal disorders. Hyperfunction was established by a high filling in the first mandibular molar, and hypofunction was achieved by removing the antagonist tooth. Histological examination revealed an increased number of inflammatory cells in the gingiva surrounding the disordered tooth, both in the experimental and the control animals. During the six weeks of occlusal disorder, however, a marked increase in the number of inflammatory cells, as well as epithelial proliferation and deepening of the gingival pocket in the gingival sulcus area, was observed in one-third of the experimental animals. This frequency was statistically higher than that found in the controls at the p less than 0.05 level. In all the experimental animals the gingival connective tissue showed degenerative changes. The apposition of alveolar bone had diminished and osteoclastic resorption had increased. In the control animals the periodontal effects of the occlusal disorders were slight.

Animals↗
PubMed1980

Deteriorating effect of occlusal disorders on the periodontium of rats with experimental arteriosclerosis.

The periodontal effects of food consistency and of experimental occlusal stresses were clinically studied with healthy and arteriosclerotic rats. Experimental arteriosclerosis was induced with a hypercholesterolemic diet continued for 6 -- 12 months. By using food that was finely powdered and moistened, mechanical irritation of the periodontium was reduced to a minimum. The special occlusal and gingival irritants lasting six weeks were an occlusal overload with an overhigh amalgam filling, or an occlusal hypofunction caused by extracting the antagonist tooth. The arteriosclerotic animals with experimental occlusal stress had gingival changes adjacent to the loaded tooth distinctly more often than around the control tooth on the contralateral side of the mandible of the same animal (P less than 0.001). The changes seen were local redness and inflamation, and an excessive hyperplastic growth of the gingiva. The gingival changes on the stressed side in control animals were generally slight and the difference compared to the contralateral side was not statistically significant. The control animals showed recession of the gingiva more often than hyperplastic growth of same. In both groups of animals food impaction and deposit of calculus had increased around the teeth that were in occlusal hypofunction. The inflammatory changes were more frequent in the arteriosclerotic animals than in the controls. The cause of the deterioration in the ability to repair tissue damage in arteriosclerotic animals is discussed.

Animals↗