No abstract

The objective of this study was to evaluate growth and attachment of human gingival fibroblasts on nonresorbable sol-gel-derived nanoporous titania (TiO2) coated discs and noncoated commercially pure titania (cpTi) discs in vitro. The strength of attachment was evaluated using serial trypsinization. The number of cells detached from TiO2-substrates was 30% +/- 3%, whereas those detached from the cpTi was 58% +/- 4% indicating a stronger cell attachment on the coated surfaces. In scanning electron microscopy (SEM) images fewer cells, with more rounded shape, were seen with cpTi than with TiO2 after the detachment assay. Fibroblasts grew more efficiently on TiO2 than on cpTi substrates, showing significantly higher cell activities at all times. In transmission electron microscopy (TEM), a continuous layer of two to three cells thick covered the coated and noncoated discs after 7 days of culture. The plasma membrane of cells in contact with the coating was in close opposition and the cytoplasm was ultrastructurally similar to the cells grown on noncoated discs with well-preserved organelles. In conclusion, we demonstrated that the sol-gel-derived TiO2 coatings can facilitate cell growth and attachment of human gingival fibroblasts on titanium in vitro. This in vitro study is in line with our previous in vivo observations of improved soft tissue attachment of TiO2 coatings in comparison with cpTi.

Aims: The manufacturing processes have been reported to influence the properties of probiotics with potential impact on health properties. The aim was to investigate the effect of different growth media and inactivation methods on the properties of canine-originated probiotic bacteria alone and in combination mixture. Methods and Results: Three established dog probiotics, Lactobacillus fermentum VET9A, Lactobacillus plantarum VET14A and Lactobacillus rhamnosus VET16A, and their combination mixture were evaluated for their adhesion to dog mucus. The effect of different growth media, one reflecting laboratory and the other manufacturing conditions, and inactivation methods (95°C, 80°C and UV irradiation) on the mucus adhesion of the probiotic strains was characterized. Evaluation of dog probiotics was supported by cell visualization using transmission electron microscopy (TEM). Higher adhesion percentage was reported for probiotic strains growing in laboratory rather than in manufacturing conditions (P < 0Á05). Inactivation by heat (95°C, 80°C) decreased the adhesion properties when strains were cultivated in soy-based growth media compared with those grown in MRS broth (P < 0Á05). TEM observations uncovered differences in cell-surface components in nonviable forms of probiotic strains as compared with their viable forms. Conclusions: Manufacturing process conditions such as growth media and pretreatment methods may significantly affect the adhesive ability of the tested strains. Significance and Impact of the Study: Growth conditions, growth media, pretreatment methods and different probiotic combinations should be carefully considered for quality control of existing probiotics and for identification of new probiotics for dogs. These may also have an impact on health benefits for the host.

Lysinuric protein intolerance (LPI) is an autosomal recessive disease characterized by defective transport of cationic amino acids. Patients have an increased incidence of fractures and their skeletal radiographs show osteoporosis. The aim of the study was to characterize the osteopenia in LPI. Twenty-nine Finnish LPI patients (age range 3.7-44.4 years) were screened for parameters of bone metabolism. Morphometric analysis of bone was carried out in specimens of 9 patients. Collagen synthesis was studied with cultured skin fibroblasts (4 patients) and collagen fibril sizes (3 patients) were measured using electron microscopy. Most histological bone specimens (8/9) showed osteoporosis. Osteomalacia was excluded. Routine clinical laboratory tests were unrevealing. The concentrations of free hydroxyproline and type III procollagen N-propeptide in serum and the urinary excretion of hydroxyproline were increased in almost all patients during their growth and in about half of adult patients. Collagen synthesis in LPI fibroblast cultures was significantly decreased compared with that in age-matched controls at 5 (p < 0.01), 14 (p < 0.01) and still at 30 years (p < 0.01), whereas no difference was observed at the age of 44 years (p = N.S.). Osteoporosis in LPI might reflect defective matrix protein synthesis caused by protein deprivation and deficiency of cationic amino acids. Increased collagen turnover can also contribute to the osteoporosis.

Changes in the structure and organization of collagen fibrils were recently described in the skin of aspartylglycosaminuria patients. The skin of the patients contained a normal amount and distribution of glycosaminoglycans, but the dermatan sulfate of aspartylglycosaminuria skin was more sensitive to chondroitinase AC digestion, resulting in unsaturated 4-sulfated disaccharides which were not detected in controls. Isolated dermatan sulfate chains as well as the chains present in the intact core protein synthesized by skin fibroblasts from an aspartylglycosaminuria patient were also digestible with chondroitinase AC, while those of a control fibroblast culture could be digested with chondroitinase ABC only. This is indirect evidence for abnormal epimerization of dermatan sulfate in the skin of aspartylglycosaminuria patients, which may be associated with the changes in collagen fibril formation.