7 resultados para stannous fluoride
em Université de Lausanne, Switzerland
Resumo:
BACKGROUND: Dietary fluoride supplements were first introduced to provide systemic fluoride in areas where water fluoridation is not available. Since 1990, the use of fluoride supplements in caries prevention has been re-evaluated in several countries. OBJECTIVES: To evaluate the efficacy of fluoride supplements for preventing dental caries in children. SEARCH METHODS: We searched the Cochrane Oral Health Group's Trials Register (to 12 October 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 3), MEDLINE via OVID (1950 to 12 October 2011), EMBASE via OVID (1980 to 12 October 2011), WHOLIS/PAHO/MEDCARIB/LILACS/BBO via BIREME (1982 to 12 October 2011), and Current Controlled Trials (to 12 October 2011). We handsearched reference lists of articles and contacted selected authors. SELECTION CRITERIA: We included randomised or quasi-randomised controlled trials comparing, with minimum follow-up of 2 years, fluoride supplements (tablets, drops, lozenges) with no fluoride supplement or with other preventive measures such as topical fluorides in children less than 16 years of age at the start. The main outcome was caries increment measured by the change in decayed, missing and filled tooth surfaces (DMFS). DATA COLLECTION AND ANALYSIS: Two review authors, independently and in duplicate, assessed the eligibility of studies for inclusion, and carried out risk of bias assessment and data extraction. In the event of disagreement, we sought consensus and consulted a third review author. We contacted trial authors for missing information. We used the prevented fraction (PF) as a metric for evaluating the efficacy of the intervention. The PF is defined as the mean caries increment in controls minus mean caries increment in the treated group divided by mean caries increment in controls. We conducted random-effects meta-analyses when data could be pooled. We assessed heterogeneity in the results of the studies by examining forest plots and by using formal tests for homogeneity. We recorded adverse effects (fluorosis) when the studies provided relevant data. MAIN RESULTS: We included 11 studies in the review involving 7196 children.In permanent teeth, when fluoride supplements were compared with no fluoride supplement (three studies), the use of fluoride supplements was associated with a 24% (95% confidence interval (CI) 16 to 33%) reduction in decayed, missing and filled surfaces (D(M)FS). The effect of fluoride supplements was unclear on deciduous or primary teeth. In one study, no caries-inhibiting effect was observed on deciduous teeth while in another study, the use of fluoride supplements was associated with a substantial reduction in caries increment.When fluoride supplements were compared with topical fluorides or with other preventive measures, there was no differential effect on permanent or deciduous teeth.The review found limited information on the adverse effects associated with the use of fluoride supplements. AUTHORS' CONCLUSIONS: This review suggests that the use of fluoride supplements is associated with a reduction in caries increment when compared with no fluoride supplement in permanent teeth. The effect of fluoride supplements was unclear on deciduous teeth. When compared with the administration of topical fluorides, no differential effect was observed. We rated 10 trials as being at unclear risk of bias and one at high risk of bias, and therefore the trials provide weak evidence about the efficacy of fluoride supplements.
Resumo:
Introduction: Oseltamivir phosphate (OP), the prodrug of oseltamivir carboxylate (OC; active metabolite), is marketed since 10 years for the treatment of seasonal influenza flu. It has recently received renewed attention because of the threat of avian flu H5N1 in 2006-7 and the 2009-10 A/H1N1 pandemic. However, relatively few studies have been published on OP and OC clinical pharmacokinetics. The disposition of OC and the dosage adaptation of OP in specific populations, such as young children or patients undergoing extrarenal epuration, have also received poor attention. An analytical method was thus developed to assess OP and OC plasma concentrations in patients receiving OP and presenting with comorbidities or requiring intensive care. Methods: A high performance liquid chromatography coupled to tandem mass spectrometry method (HPLC-MS/MS) requiring 100-µL aliquot of plasma for quantification within 6 min of OP and OC was developed. A combination of protein precipitation with acetonitrile, followed by dilution of supernant in suitable buffered solvent was used as an extraction procedure. After reverse phase chromatographic separation, quantification was performed by electro-spray ionization-triple quadrupole mass spectrometry. Deuterated isotopic compounds of OP and OC were used as internal standards. Results: The method is sensitive (lower limit of quantification: 5 ng/mL for OP and OC), accurate (intra-/inter-assay bias for OP and OC: 8.5%/5.5% and 3.7/0.7%, respectively) and precise (intra-/inter-assay CV%: 5.2%/6.5% and 6.3%/9.2%, respectively) over the clinically relevant concentration range (upper limits of quantification 5000 ng/mL). Of importance, OP, as in other previous reports, was found not to be stable ex vivo in plasma on standard anticoagulants (i.e. EDTA, heparin or citrate). This poor stability of OP has been prevented by collecting blood samples on commercial fluoride/oxalate tubes. Conclusions: This new simple, rapid and robust HPLC-MS/MS assay for quantification of OP and OC plasma concentrations offers an efficient tool for concentration monitoring of OC. Its exposure can probably be controlled with sufficient accuracy by thorough dosage adjustment according to patient characteristics (e.g. renal clearance). The usefulness of systematic therapeutic drug monitoring in patients appears therefore questionable. However, pharmacokinetic studies are still needed to extend knowledge to particular subgroups of patients or dosage regimens.
Resumo:
The methylotrophic yeast Pichia pastoris is widely used for the expression of heterologous enzymes. While the purity of the desired expression product is of major importance for many applications, we found that recombinant enzymes produced in methanol medium were contaminated by a 37-kDa endogenous yeast protease. This enzyme was completely inhibited by phenylmethanesulfonyl fluoride (PMSF) but not by 1,10-phenanthroline, EDTA, and pepstatin A, suggesting the nature of a serine protease. Its secretion was abolished in P. pastoris strains GS115 and KM71 by specific mutagenesis of a subtilisin gene (SUB2) but not by inactivation of the gene encoding vacuolar proteinase B (PRB). Bioinformatic comparisons of Sub2 protein with subtilisins from other fungal genomes and phylogenetic analyses indicated that this enzyme is not an orthologue of the vacuolar protease cerevisin generally present in yeasts but is more closely related to another putative subtilisin found in a small number of yeast genomes. During growth of P. pastoris, Sub2 was produced as a secreted enzyme at a concentration of 10 microg/ml of culture supernatant after overexpression of the full-length SUB2 gene. During fermentative production of recombinant enzymes in methanol medium, 1 ml of P. pastoris culture supernatant was found to contain approximately 3 ng of Sub2, while the enzyme was not detected during growth in a medium containing glycerol as a carbon source. The mutant strain GS115-sub2 was subsequently used as a host for the production of recombinant proteases without endogenous subtilisin contamination.
Resumo:
The efficacy of treatments for osteoporosis does not become evident when evaluated by fracture incidence (FI). Vertebral FI decreased in all controlled studies on calcitonin, but not significantly. Small sample sizes and short periods of treatment may have masked a possible therapeutic benefit, but longer, controlled studies with sodium fluoride or etidronate in larger groups of patients also failed to show a decrease in FI. The present analysis of nine published, therapeutic studies which indicate the FI per year and the initial prevalence of vertebral fractures, examines the question of whether the initial prevalence of fractures has an effect on the subsequent incidence of new fractures and whether the therapeutic effects have to be evaluated as a function of the initial prevalence of fractures. Bearing in mind the differences in roentgenological evaluation and in the size and quality of the various studies, the analysis revealed (1) that in the control groups there was a higher FI in patients with more than three vertebral fractures at baseline (estimated odds ratio (OR) = 49, p = 0.011); (2) that a similar trend, although not statistically significant, was observed in treated patients; (3) that the groups of control patients treated for more than 1 year showed in general an increase in FI beyond the first year and that the reverse was true in treated patients. In conclusion, failure to allow for the initial prevalence of vertebral fractures at the individual level in therapeutic trials of calcitonin to treat osteoporosis and prevent new fractures might have contributed to the absence of a demonstrable benefit of the treatment in those studies.
Resumo:
BACKGROUND: Multivitamin/multimineral (MVM) supplements are commonly consumed by the general population, but little is known regarding their composition and compliance with local regulations. We assessed the composition and compliance with regulations [no indication in the label of vitamin/minerals amounting <15% of the acceptable daily intake (ADI)] of MVM available in Switzerland. METHODS: The composition of vitamin/minerals supplements was obtained from the Swiss drug compendium, the Internet, pharmacies, parapharmacies and supermarkets. MVM was defined as the presence of at least 5 vitamins and/or minerals. RESULTS: Of the 254 vitamin/mineral supplements collected, 95 (37%) were considered as MVM. The most frequent vitamins were B₆ (73.7%), C (71.6%), B₂ (69.5%) and B₁ (67.4%); the least frequent were K (17.9%), biotin (51.6%), pantothene (55.8%) and E (56.8%). Approximately half of MVMs provided >150% of the ADI for vitamins. The most frequent minerals were zinc (66.3%), calcium (55.8%), magnesium (54.7%) and copper (48.4%), and the least frequent were fluoride (3.2%), phosphorous (17.9%), chrome (22.1%) and iodine (25%). More than two thirds of MVMs provided between 50 and 150% of the ADI for minerals, and few MVMs provided >150% of the ADI. While few MVMs provided <15% of the ADI for vitamins, a considerable fraction did so for minerals (32.7% for magnesium, 26.1% for copper and 22.6% for calcium). CONCLUSION: There is a great variability regarding the composition of MVMs available in Switzerland. Several MVM do not comply with Swiss regulations, which calls for monitoring and corrective measures.
Resumo:
An analysis of latent fingermark residues by Sodium-Dodecyl-Sulfate PolyAcrylamide Gel Electrophoresis (SDS-PAGE) followed by silver staining allowed the detection of different proteins, from which two major bands, corresponding to proteins of 56 and 64 kDa molecular weight, could be identified. Two other bands, corresponding to proteins of 52 and 48 kDa were also visualizable along with some other weaker bands of lower molecular weights. In order to identify these proteins, three antibodies directed against human proteins were tested on western blots of fingermarks residues: anti-keratin 1 and 10 (K1/10), anti-cathepsin-D (Cat.D) and anti-dermcidin (Derm.). The corresponding antigens are known to be present in the stratum corneum of desquamating stratified epithelium (K1/10, Cat.D) and/or in eccrine sweat (Cat.D, Derm.). The two major bands were identified as consistent with keratin 1 and 10. The pro-form and the active form of the cathepsin-D have also been identified from two other bands. Dermcidin could not be detected in the western blot. In addition, these antibodies have been tested on latent fingermarks left on polyvinylidene fluoride (PVDF) membrane, as well as on whitened and non-whitened paper. The detection of fingermarks was successful with all three antibodies.
Resumo:
Purpose: To assess the composition and compliance with legislation of multivitamin/multiminerals (MVM) in Switzerland. Methods: Information on the composition of vitamin/minerals supplements was obtained from the Swiss drug compendium, the Internet, pharmacies, parapharmacies and supermarkets. MVM was defined as the presence of at least 5 vitamins and/or minerals. Results: 95 MVM were considered. The most frequent vitamins were B6 (73.7%), C (71.6%), B2 (69.5%) and B1 (67.4%); the least frequent were K (17.9%), biotin (51.6%), pantothene (55.8%) and E (56.8%). Around half of MVMs provided >150% of the ADI for vitamins. The most frequent minerals were zinc (66.3%), calcium (55.8%), magnesium (54.7%) and copper (48.4%), and the least frequent were fluoride (3.2%), phosphorous (17.9%) and chrome (22.1%). Only 25% of MVMs contained iodine. More than two thirds of MVMs provided between 15 and 150% of the ADI for minerals, and few MVMs provided >150% of the ADI. While few MVMs provided <15% of the ADI for vitamins, a considerable fraction did so for minerals (32.7% for magnesium, 26.1% for copper and 22.6% for calcium). Conclusion: There is a great variability regarding the composition and amount of MVMs in Switzerland. Several MVM do not comply with the Swiss legislation.