1,721,012 research outputs found
Exogenous UDP-xylose can inhibit UDP-glucose dehydrogenase activity of cultured human skin fibroblasts.
No full textAzione demineralizzante di soluzioni chelanti: analisi quantitativa
No full textAim: the purpose of this study was to evaluate the effect of four chelating agents on the structure of dentin of extracted teeth: Smear Clear (Sybron Endo), Largal Ultra (Septodont), Tubuliclean (OGNA Laboratori Farmaceutici), EDTA: 17% (OGNA Laboratori Farmaceutici).
Methodology: slices of bovine teeth were dried in a Virtis Automatic Free- ze-Dryer for 5 days, weighed (Mettler AE 163 Dual Range Balance) and randomly distributed in nine groups.
The speciments were subsequently exposed to the chelating agents for 3 or 9 min. Then the speciments were washed with distilled water, dried for 5 days and weighed again. Difference between pre- and post-operative weight were recorded. Results were statistically analysed using the Kruskal-Wallis test, the Mann-Whitney test as post-hoc test with P < 0.05.
Results: loss of weight increased significantly with increasing time of contact of the chelating agents with dentine. There were significant difference between the four chelating agents for loss of weight. Largal Ultra chelating ability was significantly better than EDTA 17% followed by Tubuliclean and Smear Clear.
Conclusions: under the circumstances of this in vitro study, there were significant differences between the four chelating agents for loss of weight. The EDTA concentration, only in part, influences the chelating activity. The extent of demineralization is related to the time of exposure to these solutions
Biochemical changes in the articular cartilage of the patella and femoral condyles in the lateral hyperpatellar syndrome.
No full textThe biochemical changes in the articular cartilage of the femoral condyles and the patella were studied during the earliest stage of patello-femoral arthrosis, with particular reference to chondromalacia of the patella in the "lateral hypertension syndrome", with the object of comparing them with the results obtained by Boni et al. (1977) in the initial phases of experimental arthrosis induced in rabbits by means of vitamin A. The biochemical determinations were done on samples of cartilage removed at operation from the medial and lateral femoral condyles and the medial and lateral patellar articular facets in ten patients. The biopsy samples were fixed in 80% alcohol and dried in the oven at 50 degrees C for twenty-four hours. The hexosamine and hydroxyproline content was then determined. This investigation demonstrated significant biochemical changes in this syndrome in the four areas examined. The data obtained indicate that only the mucopolysaccharide component of the joint cartilage is involved at this stage. The most interesting finding was marked diminution in the galactosamine/glucosamine ratio, which was markedly diminished - the opposite of what occurs in established arthrosis. These data appear to be identical with those found in the early phases of vitamin A induced arthrosis in experimental rabbits. The diminution of hexosamine content and the diminished galactosamine/glucosamine ratio were more marked in the femoral condyles, which appeared to have few lesions macroscopically. These changes were also present in both articular facets of patella, but were less marked, probably because the degeneration was more advanced in those areas, thus more closely resembling frank arthrosis
Biosynthesis of glycosaminoglycan precursors: the role of UDP-N-acetylglucosamine 4'-epimerase in bovine cornea.
No full text
Fluoride release and uptake abilities of conventonal glass ionomer cements affected by ultrasonic curing.
No full textObjective: the objective of the study was to assess the effect of ultrasonic cur- ing on the fluoride release/uptake ca- pacities of two conventional glass ionomer cements (Fuji II and Fuji IX GP; GC Corporation, Tokyo, Japan). Methods : twenty discs of each materi- al were prepared and stored in deion- ized water at 37 °C. Two different cur- ing methods were investigated: stan- dard conditions and ultrasonic excita- tions.
Cumulative fluoride release was meas- ured on days 1, 2, 3, 5, 7, 21, 35, and 49, then fluoride gel was applied to all the groups tested, and fluoride release (after reuptake) was measured on days 56, 70, 84, and 224 using a ion analyzer. Results : no significant differences were found between standard and ultrason- ic curing for Fuji II cement, whereas us- ing the Fuji IX GP cement a remarkable increase of fluoride release was report- ed when ultrasonic curing was per- formed. After exposure to fluoride gel, fluoride release increased significantly for all the groups tested.
Significance: Ultrasonic curing does not affect fluoride release of Fuji II, whereas significantly increase fluoride release of Fuji IX GP
Solubility of root-end-filling materials: a comparative study.
No full textThis study tested solubility of 3 root-end filling materials (IRM, Pro Root, and Superseal) and an endodontic sealer (Argoseal) used as positive control. The test was performed according to the International Standards Organization 6876 standard and the American Dental Association specification #30. Six specimens of each material were prepared and immersed in water. Solubility was determined after 24 hours and 2 months and analyzed statistically with a one-way analysis of variance test. All retrograde filling materials were of low solubility. Under the conditions of the present study, IRM, Superseal, and Pro Root are virtually insoluble; this is an adequate physical property for use as rootend filling materials
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