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Biomedical subjects

V Lassila

Publications and source records attributed to V Lassila.

At least 19 recordsLinked to original sources
PubMed1989

Impact of streptozotocin-induced diabetes on rat blood and alveolar bone affected by occlusal stress.

Adult male and female rats were used as test animals. The experimental diabetes mellitus was provoked with one dose of i.v. injection of streptozotocin (65 mg/kg body weight), which interferes with the insulin release mechanism in pancreatic beta cells. After a follow-up period of 10 wk an average loss of 10% of body weight and an increase of 25% in the amount of blood obtained by decapitation was recorded in the test animals. The biochemical assays performed on the serum of the diabetic rats showed, for both sexes, a fourfold rise in the plasma glucose level, a threefold rise in plasma alkaline phosphatase activity and plasma alanine transferase activity as well as a 1.5-fold rise in plasma creatine value. The two latter values indicated systematic disorders reflected in the liver and the kidneys. An increase in serum total calcium and hydroxyproline values was also detected. The clinical studies of the gingiva showed diminished tissue resistance in diabetic rats. The histologic studies of alveolar bone revealed retarded formation of bone matrix and new bone in diabetic animals. However, the stimulated metabolism in alveolar bone, due to the artificially induced stress, increased marginal bone cell activity in both the diabetic and the control group, resulting in increased crestal resorption in the former group. The differences in tissue response observed among the diabetic animals affected and unaffected by stress originated from the disturbed recovering mechanism typically found in diabetic animals.

Animals↗
PubMed1989

Effect of splenectomy on hepasor treatment in allyl-alcohol-traumatized rat liver.

Experimental liver injury was provoked in test rats with and without spleen intraperitoneally with allyl alcohol injections. The rats without spleen were used for tests 2 months after the splenectomy. Traumatized rats received further intraperitoneal injections of Hepasor, a protoberberine alkaloid mixture from Enantia chlorantha (Annonaceae). Biochemical assays from blood plasma, serum alanine transferase, serum alkaline phosphatase, serum creatinine, serum hydroxyproline and serum calcium were done and the total amount of blood obtained by decapitation was measured. Liver and kidney samples for histological processing were taken. The biochemical results obtained show significant changes in serum hydroxyproline which increases cumulatively due to traumatization, Hepasor treatment and splenectomy. In case of spenectomy, the absolute volume of circulating blood enhanced under Hepasor treatment. The histological findings in the liver sections show that a 2-week Hepasor therapy of the 2-week pretraumatized rats greatly furthers the healing process during prolonged traumatization. The preventive effect of Hepasor was seen as a diminished occurrence of Kupffer cells, improved cell architecture and promoted mitotic activity. The sedative effect of Hepasor was pivotally evaluated, when massive intra- and extracellular damages were provoked with allyl alcohol in splenectomized rats. This indicate the high regeneration potency of Hepasor on experimentally provoked liver dysplasia.

1-Propanol↗
PubMed1988

Natural protoberberine alkaloids from Enantia chlorantha, palmatine, columbamine and jatrorrhizine for thioacetamide-traumatized rat liver.

Experimental liver injury was provoked experimentally in rats with intraperitoneal injections of thioacetamide. Traumatized rats received further intraperitoneal injections of Hepasor, a protoberberine alkaloid extract from Enantia chlorantha (Annonaceae) containing palmatine, columbamine and jatrorrhizine. The development of body weight was kept under continuous control. Biochemical assays of blood plasma, serum alanine transferase (S-ALT), serum alkaline phosphatase (S-AP), serum creatinine S-CREAT, serum hydroxyproline (S-OH-PROL) and serum calcium (S-Ca) were done and liver samples for histological processing were taken. The biochemical results obtained indicate Hepasor exerted a marked influence on the S-ALT activities and S-OH-PROL values in female rats, but more incidental one in male rats. Some reduction in S-AP activity and S-CREAT values, which was also dependent on sex, was also found. The histological findings in the liver sections of female rats show that Hepasor improves the blood flow and mitotic activity in thioacetamide-traumatized livers.

Acetamides↗
PubMed1988

Regeneration of D-galactosamine-traumatized rat liver with natural protoberberine alkaloids from Enantia chlorantha.

Experimental liver injury was provoked in test rats with intraperitoneal injections of D-galactosamine. Traumatized rats received further intraperitoneal injections of Hepasor, a protoberberine alkaloid mixture from Enantia chlorantha (Annonaceae). Biochemical assays from blood plasma, serum alanine transferase, serum alkaline phosphatase, serum creatinine, serum hydroxyproline and serum calcium were done and liver and kidney samples for histological processing were taken. The biochemical results obtained indicate a marked influence by Hepasor on the serum alanine transferase activities and serum hydroxyproline values in female rats, but more accidental ones in male rats. A reduction in serum alkaline phosphatase activity and the serum creatinine values was also found, being also dependent on sex. The histological findings in the liver sections of female rats show that 1 week Hepasor therapy greatly furthers the healing process in a D-galactosamine-pretraumatized liver, eliminating megalocytosis, contraction of chromatines and other disorders in the cell architecture. The inhibitory effect of Hepasor on proceeded traumatization caused by D-galactosamine was nearly complete.

Alanine Transaminase↗
PubMed1986

Comparison of five interocclusal recording materials.

The initial resistance of interocclusal recording materials to closure changed from 0.5 N to 13.8 N, and a rapid rise in the working time was seen in all elastomers. The resistance exhibited by wax at 60 degrees C was about 7 N. The volumetric contraction of elastomers in polymerization was clinically slight. The dimensional stability of rigid materials, acrylic resin, and zinc oxide pastes was good. Elastomers maintained their reliability for a relatively long time when stored in a tightly sealed plastic bag.

Chemical Phenomena↗
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↗