Mise en évidence d'un agent coagulant utilisable en fromagerie dans les fruits de Balanites aegyptiaca

Study of a Suitable Cheese Making Milk-clotting Agent from Balanites aegyptiaca Fruits. As slaughtering of zebu (Bos indicus) calves in Cameroon is forbidden, calf abomasa are rare on markets so it is diffi cult to prepare rennet. The aim of this study was to look for other sources of milk clotting extracts, especially from Balanites aegyptiaca fruits. B. aegyptiaca is a widespread tree in northern Cameroon. Its fruit is pulpy with a thin and hard epicarp, a dark brown mesocarp and a hard endocarp enclosing an oil seed. The fruits of B. aegyptiaca were harvested at Pitoa (9°23' N, 13°32 E). Milk clotting, determined by the Berridge method, was only obtained with mesocarp extracts. The experimental design of the extraction was a split-plot (5 4 4) with 5 mesocarp concentrations, 4 temperatures and 4 maceration times. Optimum extraction was performed when macerating 50 g mesocarp in 100 ml water at 4 °C during 9 h. Protein content (91 14 mg. ml-1) was determined by bicinchoninic acid assay. Five proteins of respective molecular masses 27, 30, 42, 44 and 90 kg.mole-1 were observed by SDS-PAGE under reducing conditions. The force of the extract was determined by comparing its milk clotting time to that obtained with rennet. Proteolytic activity of the extract was measured by hydrolysis of bovine haemoglobin and titration of free NH2 using l'ophthaldialdehyde reagent. Counting of coliforms was carried out on DCL gelose, that of the total aerobic mesophil fl ora on PCA and that of the sulfi to-reducing fl ora on TSN. The extract only contained coliforms and aerobic mesophil fl ora. Fresh cheese was made with zebu milk using rennet or B. aegyptiaca mesocarp extract. Indemnes of Specifi que Pathogen Organism mice were fed with these cheeses then with crude B. aegyptiaca mesocarp extract. No abnormality, nor toxicity were observed on mice. A panel was allowed to appreciate these cheeses. Statistical analysis was conducted using SASsoftware. It was concluded that B. aegyptiaca mesocarp extract is suitable for cheese manufacture

Bone Tissue Response to Porous and Functionalized Titanium and Silica Based Coatings

Background: Topography and presence of bio-mimetic coatings are known to improve osseointegration. The objective of this study was to evaluate the bone regeneration potential of porous and osteogenic coatings. Methodology: Six-implants [Control (CTR); porous titanium coatings (T1, T2); thickened titanium (Ti) dioxide layer (TiO2); Amorphous Microporous Silica (AMS) and Bio-active Glass (BAG)] were implanted randomly in tibiae of 20-New Zealand white rabbits. The animals were sacrificed after 2 or 4 weeks. The samples were analyzed histologically and histomorphometrically. In the initial bone-free areas (bone regeneration areas (BRAs)), the bone area fraction (BAF) was evaluated in the whole cavity (500 mm, BAF-500), in the implant vicinity (100 mm, BAF-100) and further away (100–500 mm, BAF-400) from the implant. Bone-to-implant contact (BIC-BAA) was measured in the areas where the implants were installed in contact to the host bone (bone adaptation areas (BAAs)) to understand and compare the bone adaptation. Mixed models were used for statistical analysis. Principal Findings: After 2 weeks, the differences in BAF-500 for different surfaces were not significant (p.0.05). After 4 weeks, a higher BAF-500 was observed for BAG than CTR. BAF-100 for AMS was higher than BAG and BAF-400 for BAG was higher than CTR and AMS. For T1 and AMS, the bone regeneration was faster in the 100-mm compared to the 400-mm zone. BIC-BAA for AMS and BAG was lower after 4 than 2 weeks. After 4 weeks, BIC-BAA for BAG was lower than AMS and CTR. Conclusions: BAG is highly osteogenic at a distance from the implant. The porous titanium coatings didn’t stimulate bone regeneration but allowed bone growth into the pores. Although AMS didn’t stimulate higher bone response, it has a potential of faster bone growth in the vicinity compared to further away from the surface. BIC-BAA data were inconclusive to understand the bone adaptation.status: publishe

Histological evaluation of different Ca-P sputter coatings implanted in goals

Item does not contain fulltex

A histological evaluation of TiO2-gritblasted and Ca-P magnetron sputter coated implants placed into the trabecular bone of the goat: part 2

Item does not contain fulltex

A mechanical evaluation of TiO2-gritblasted and Ca-P magnetron sputter coated implants placed into the trabecular bone of the goat: part 1

Item does not contain fulltex

Development and characterization of a biodegradable polyphosphate

A biodegradable polyphosphate polymer (M n = 18,000, M w /M n = 3.2) matrix system was developed as a potential delivery vehicle for growth factors. As a model system, release of recombinant human osteogenic protein-1 (OP-1) from this polymer was evaluated. The polyphosphate was synthesized using a triethylamine catalyst in an argon environment, and characterized using elemental analysis, gel permeation chromatography (GPC), and Fourier transform infrared spectroscopy (FTIR). Degradation kinetics of the polyphosphate polymer in phosphate-buffered saline (PBS) were represented by a second-order polynomial while degradation in bovine serum was linear with time. The polymer degraded faster in PBS than in bovine serum. In vitro release of OP-1 was also faster in PBS than in serum. Release kinetics of OP-1 in PBS and serum were represented by second-order polynomials. The OP-1 release from this physically dispersed polymeric matrix may be described by several possible mechanisms: diffusion, bulk polymer degradation, ion complexation, and interactions among the protein (OP-1), polymer, proteins, and enzymes in the media. This polyphosphate may be an effective carrier for morphogens, growth factors, or other classes of bioactive molecules. © 1997 John Wiley & Sons, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38013/1/13_ftp.pd