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Biomedical subjects

M Knuuttila

Publications and source records attributed to M Knuuttila.

60 records · Page 4Linked to original sources
PubMed1979

Concentrations of Ca, Mg, Mn, Sr and Zn in supra- and subgingival calculus.

The concentrations of Ca, Mg, Mn, Sr and Zn in supra- and subgingival calculus collected from mandibular anterior teeth mainly of the same persons were analyzed with atomic absorption spectrophotometry. The results showed highly significantly (P less than 0.001) greater Zn and Sr concentrations in subgingival samples. The mean value of Zn was 5.4 times higher in subgingival calculus than in supragingival calculus. In contrast, the concentration of Mn was significantly (P less than 0.01) higher in supragingival calculus. The difference in the concentration of Mg in supra- and subgingival calculus was highly significant (P less than 0.001) only when samples from the same person were compared. The concentration of Ca was very similar in both types of calculus and individual variations were very small.

Adult↗
PubMed1978

The interaction of collagenase with hydroxyapatite and related materials and enzymatic properties of the adsorbed enzyme.

The commercial collagenase from Clostridium histolyticum was adsorbed on hydroxyapatite, on bovine femur shaft and on enamel and dentin powders. The substrate specificity of the adsorbed enzyme tested, with chromophore substrate, azocoll and native collagen, differed from that obtained with the soluble enzyme. The adsorption and the substrate specificity was also dependent on the adsorbent used. A pretreatment of hydroxyapatite with chondroitin sulphate, hyaluronate and DNA lowered the adsorption of collagenase. Phosphate ion caused desorption of the enzyme from hydroxyapatite. Sodium fluoride caused partial desorption of the enzyme from hydroxyapatite and enamel and dentin powders. Colangenase adsorbed on root surfaces of teeth liberated hydroxyproline containing material.

Adsorption↗
PubMed1977

Effect of chlorhexidine on the hamster cheek pouch. Microcirculation and penetration studies.

The application of chlorhexidine gluconate on the intact cheek pouch of hamsters led to an immediate increase of flow velocity determined in venules beneath the epithelium. The application of [14C]chlorhexidine on the intact cheek pouch led to accumulation of labeled material in the liver and kidneys. Both findings indicate that penetration of the drug occurred through the epithelium of the cheek pouch.

Absorption↗
PubMedDate not supplied

Cadmium content of human cancellous bone.

The cadmium content of human cancellous bone was related to age, sex, bone loss, physical properties, and elemental composition. Bone specimens from the anterior iliac crest were collected from 889 cadavers with a normal mineral status, and from 50 cadavers which had bone loss from chronic diseases and immobilization. The element concentrations were analyzed using atomic absorption spectrophotometry. Bone fluoride levels ere determined with the ion specific electrode, the mineral density with the gamma ray attenuation method, and the compressive strength with a strain transducer. The data were analyzed using multiple linear regression analysis. The mean cadmium content of 0.22 +/- 9.16 micrograms/g dry weight (+/- SD) in the samples did not change with age and its content was slightly greater in males than in females. Furthermore, no statistically significant relation was found in cadmium content to bone loss changes or to the calcium content of bone. The cadmium content had a high statistically significant positive correlation with the strontium and nickel content.

Adolescent↗
PubMedDate not supplied

Controlled study of the association of smoking with lactobacilli, mutans streptococci and yeasts in saliva.

The effect of smoking on salivary microbe levels was studied in 780 subjects by multivariate analysis, taking into account some confounding factors. Lactobacilli, mutans streptococci and yeasts were detected with Dentocult-LB, Dentocult-SM and Oricult-N tests. The explanatory variables considered were gender, presence of natural teeth, presence of removable denture, presence of decayed teeth, toothbrushing frequency, use of sugar in coffee or tea, consumption frequency of sugary products, secretion rate of stimulated and unstimulated saliva, buffering capacity of saliva, pH of saliva, oral hygiene and tobacco smoking habits. Smoking was strongly associated with higher lactobacilli counts and presence of yeasts, independently of oral status, hygiene or salivary factors. The relation between smoking and mutans streptococci was weaker. The overall associations of lactobacilli and yeasts with the study variables followed a very similar pattern.

Colony Count, Microbial↗