237 research outputs found

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

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    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

    Evaluation of New Herbicide Options for the Control of Foxtail Barley (Hordeum jubatum) in Spring Wheat

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    Foxtail barley (Hordeum jubatum) is a perennial grass increasing in prevalence in western Canadian cereal fields. Seedling, over-wintering-juvenile and mature stages makes herbicide timing and selection challenging for producers. Field experiments were conducted at six sites over two years to characterize the response of established seedling and mature foxtail barley populations to combinations of short residual herbicides applied PRE and POST seeding with glyphosate. Experiment one evaluated PRE short residual herbicides: Propoxycarbazone-sodium (2), flucarbazone-sodium/tribenuron and pyroxasulfone at rates of 7.5, 10, 21.79 and 150 g ai ha-1 respectively, tank-mixed with glyphosate at 450 and 900 g ae ha-1. Experiment two evaluated combinations of propoxycarbazone, flucarbazone/tribenuron and pyroxasulfone with the high rate of glyphosate followed by a POST application of thiencarbazone-methyl at 4.94 g ai ha-1. Foxtail barley seedling and mature populations varied among sites, Scott having the highest mature population at 76 mature plants m-2, while St. Albert had the highest seedling population at 81 seedlings m-2. Visual control, seedling emergence density, foxtail barley biomass, wheat biomass and wheat seed yield were quantified. Herbicides applied pre-seeding in the absence of glyphosate failed to control mature foxtail barley. However, propoxycarbazone at 10 g ai ha-1, flucarbazone/tribenuron and pyroxasulfone applied in combination with the high rate of glyphosate increased control to 73.9%, 72.1% and 74.4% at Lethbridge 2016, Olds and Scott, respectively. Moreover, at Lethbridge 2015, Vermilion and St. Albert control increased to 90.4%, 90.8% and 89.3%, respectively. Pyroxasulfone tank-mixed with the high and low rate of glyphosate reduced foxtail barley seedling emergence compared to rates of glyphosate applied alone (29 to 4 seedlings m-2). Glyphosate at both rates applied with and without residual herbicides reduced foxtail barley biomass compared to the non-treated check. However, the high rate of glyphosate did not significantly reduce foxtail barley biomass more than the low rate (49.91 to 27.45 g m-2). The addition of residual herbicides to the high rate of glyphosate did not increase wheat biomass or seed yield. Tank-mixing propoxycarbazone at 10 g ai ha-1 with the high rate of glyphosate followed by thiencarbazone reduced foxtail barely biomass compared to the high rate of glyphosate applied alone (28.67 to 4.53 g m-2). Seedling emergence was observed over an extended period in spring and post-harvest, suggesting that both pre-seeding and post-emergent control timings along with a multi-year strategy may be required to reduce future foxtail barley populations. This research indicates that by adding a short-residual soil applied herbicide to glyphosate at a pre-seeding timing, followed by a post-emergent herbicide application, producers can control foxtail barley for the growing season in spring wheat

    A Critical Review of Oxazolidinones: An Alternative or Replacement for Glycopeptides and Streptogramins?

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    OBJECTIVE: To review the available data on the oxazolidinones linezolid and eperezolid.DATA SELECTION: Published reports were obtained by searching MEDLINE for articles published between 1992 and 2000, inclusive. References of published papers were also obtained and reviewed. Abstracts from scientific proceedings were reviewed.DATA EXTRACTION: Due to the limited data available regarding these agents, the criteria for study inclusion were not restrictive.DATA SYNTHESIS: The oxazolidinones (eg, linezolid) are a new antimicrobial class with a unique mechanism of action. They are active against resistant Gram-positive cocci including methicillin-susceptible and -resistant Staphylococcus aureus (MRSA), methicillin-susceptible and -resistant Staphylococccus epidermidis, vancomycin-resistant enterococci (VRE) and penicillin-resistant Streptococcus pneumoniae (PRSP). Linezolid is active against anaerobes and displays modest activity against fastidious Gram-negative pathogens such as Haemophilus influenzae, but is not active against Enterobacteriaceae. Linezolid is available both orally and parenterally, and has a bioavailability of 100%. Clinical trials comparing linezolid with standard therapy have demonstrated similar bacteriological and clinical cures rates to standard therapy in community- and hospital-acquired pneumonia, uncomplicated and complicated skin and soft tissue infections, and infections caused by MRSA and VRE. Adverse effects have been minor and infrequent; however, platelets should be monitored in patients who have received more than two weeks of linezolid therapy. It is expected that these agents will have a bright future due to their excellent spectrum of activity against antibiotic-resistant Gram-positive organisms, such as MRSA, VRE and PRSP, and their excellent bioavailability.CONCLUSION: The oxazolidinones represent a new class of antimicrobials with a unique mechanism of action. They have excellent activity against susceptible and resistant Gram-positive organisms such as MRSA, methicillin-susceptible S epidermidis, VRE and PRSP, and a good adverse effect profile; they can be administered both intravenously and orally. Their potential use in Canada may be as an intravenous and oral alternative to glycopeptides and streptogramins.Peer Reviewe

    A Critical Review of Oxazolidinones: An Alternative or Replacement for Glycopeptides and Streptogramins?

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    OBJECTIVE: To review the available data on the oxazolidinones linezolid and eperezolid. DATA SELECTION: Published reports were obtained by searching MEDLINE for articles published between 1992 and 2000, inclusive. References of published papers were also obtained and reviewed. Abstracts from scientific proceedings were reviewed. DATA EXTRACTION: Due to the limited data available regarding these agents, the criteria for study inclusion were not restrictive. DATA SYNTHESIS: The oxazolidinones (eg, linezolid) are a new antimicrobial class with a unique mechanism of action. They are active against resistant Gram-positive cocci including methicillin-susceptible and -resistant Staphylococcus aureus (MRSA), methicillin-susceptible and -resistant Staphylococccus epidermidis, vancomycin-resistant enterococci (VRE) and penicillin-resistant Streptococcus pneumoniae (PRSP). Linezolid is active against anaerobes and displays modest activity against fastidious Gram-negative pathogens such as Haemophilus influenzae, but is not active against Enterobacteriaceae. Linezolid is available both orally and parenterally, and has a bioavailability of 100%. Clinical trials comparing linezolid with standard therapy have demonstrated similar bacteriological and clinical cures rates to standard therapy in community- and hospital-acquired pneumonia, uncomplicated and complicated skin and soft tissue infections, and infections caused by MRSA and VRE. Adverse effects have been minor and infrequent; however, platelets should be monitored in patients who have received more than two weeks of linezolid therapy. It is expected that these agents will have a bright future due to their excellent spectrum of activity against antibiotic-resistant Gram-positive organisms, such as MRSA, VRE and PRSP, and their excellent bioavailability. CONCLUSION: The oxazolidinones represent a new class of antimicrobials with a unique mechanism of action. They have excellent activity against susceptible and resistant Gram-positive organisms such as MRSA, methicillin-susceptible S epidermidis, VRE and PRSP, and a good adverse effect profile; they can be administered both intravenously and orally. Their potential use in Canada may be as an intravenous and oral alternative to glycopeptides and streptogramins

    The behavior of osteoblast-like cells on various substrates with functional blocking of integrin-β1 and integrin-β3

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    This study was designed to examine the influence of integrin subunit-β1 and subunit-β3 on the behavior of primary osteoblast-like cells, cultured on calcium phosphate (CaP)-coated and non coated titanium (Ti). Osteoblast-like cells were incubated with specific monoclonal antibodies against integrin-β1 and integrin-β3 to block the integrin function. Subsequently, cells were seeded on Ti discs, either non coated or provided with a 2 μm carbonated hydroxyapatite coating using Electrostatic Spray Deposition. Results showed that on CaP coatings, cellular attachment was decreased after a pre-treatment with either anti-integrin-β1 or anti-integrin-β3 antibodies. On Ti, cell adhesion was only slightly affected after a pre-treatment with anti-integrin-β3 antibodies. Scanning electron microscopy showed that on both types of substrate, cellular morphology was not changed after a pre-treatment with either antibody. With quantitative PCR, it was shown for both substrates that mRNA expression of integrin-β1 was increased after a pre-treatment with either anti-integrin-β1 or anti-integrin-β3 antibodies. Furthermore, after a pre-treatment with either antibody, mRNA expression of integrin-β3 and ALP was decreased, on both types of substrate. In conclusion, osteoblast-like cells have the ability to compensate to great extent for the blocking strategy as applied here. Still, integrin-β1 and β3 seem to play different roles in attachment, proliferation, and differentiation of osteoblast-like cells, and responses on CaP-coated substrates differ to non coated Ti. Furthermore, the influence on ALP expression suggests involvement of both integrin subunits in signal transduction for cellular differentiation

    The association between geographic proximity to a dialysis facility and use of dialysis catheters

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    Abstract Background Residing remotely from health care resources appears to impact quality of care delivery. It remains unclear if there are differences in vascular access based on distance of one’s residence to dialysis centre at time of dialysis initiation, and whether region or duration of pre-dialysis care are important effect modifiers. Methods We studied the association of distance from a patients’ residence to the nearest dialysis centre and central venous catheter (CVC) use in an observational study of 26,449 incident adult dialysis patients registered in the Canadian Organ Replacement Registry between 2000–2009. Multivariate logistic regression was used to assess the association between distance in tertiles and CVC use, adjusted for patient demographics and comorbidities. Geographic region and duration of pre-dialysis care were examined as potential effect modifiers. Results Eighty percent of patients commenced dialysis with a CVC. Incident CVC use was highest among those living > 20 km from the dialysis centre (OR 1.29 (1.24-1.34)) compared to those living < 5 km from centre. The length of pre-dialysis care and geographic region were significant effect modifiers; among patients residing in the furthest tertile (>20 km) from the nearest dialysis centre, incident CVC use was more common with shorter length of pre-dialysis care (< 1 year) and residence in central regions of the country. Conclusion Residing further from a dialysis centre is associated with increased CVC use, an effect modified by shorter pre-dialysis care and the geographic region of the country. Efforts to reduce geographical disparities in pre dialysis care may decrease CVC use.Peer Reviewe

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

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    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
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