797 resultados para Transdermal delivery


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Background: Obesity is epidemic worldwide, and increases in cesarean delivery rates have occurred in parallel. Objective: This study aimed to determine whether cesarean delivery is a risk factor for obesity in adulthood in a birth cohort of Brazilian subjects. Design: We initiated a birth cohort study in Ribeirao Preto, southeastern Brazil, in 1978. A randomly selected sample of 2057 subjects from the original cohort was reassessed in 2002-2004. Type of delivery, birth weight, maternal smoking, and schooling were obtained after birth. The following data from subjects were collected at 23-25 y of age: body mass index (BMI; in kg/m(2)), physical activity, smoking, and income. Obesity was defined as a BMI >= 30. A Poisson multivariable model was performed to determine the association between cesarean delivery and BMI. Results: The obesity rate in adults born by cesarean delivery was 15.2% and in those born by vaginal delivery was 10.4% (P = 0.002). Adults born by cesarean delivery had an increased risk (prevalence ratio: 1.58; 95% CI: 1.23, 2.02) of obesity at adulthood after adjustments. Conclusion: We hypothesize that increasing rates of cesarean delivery may play a role in the obesity epidemic worldwide. Am J Clin Nutr 2011;93:1344-7.

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Purpose. In the present study we examined the relationship between solvent uptake into a model membrane (silicone) with the physical properties of the solvents (e.g., solubility parameter, melting point, molecular weight) and its potential predictability. We then assessed the subsequent topical penetration and retention kinetics of hydrocortisone from various solvents to define whether modifications to either solute diffusivity or partitioning were dominant in increasing permeability through solvent-modified membranes. Methods. Membrane sorption of solvents was determined from weight differences following immersion in individual solvents, corrected for differences in density. Permeability and retention kinetics of H-3-hydrocortisone, applied as saturated solutions in the various solvents, were determined over 48 h in horizontal Franz-type glass diffusion cells. Results. Solvent sorption into the membrane could be related to differences in solubility parameters, MW and hydrogen bonding (r(2) = 0.76). The actual and predicted volume of solvent sorbed into the membrane was also found to be linearly related to Log hydrocortisone flux, with changes in both diffusivity and partitioning of hydrocortisone observed for the different solvent vehicles. Conclusions. A simple structure-based predictive model can be applied to the sorption of solvents into silicone membranes. Changes in solute diffusivity and partitioning appeared to contribute to the increased hydrocortisone flux observed with the various solvent vehicles. The application of this predictive model to the more complex skin membrane remains to be determined.

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To investigate the efficiency of encapsidation of plasmid by papillomavirus virus-like particles (PV VLPs), and the infectivity of the resultant PV pseudovirions, Cos-1 cells were transfected with an 8-kb plasmid incorporating a green fluorescent protein (GFP) reporter gene (pGSV), and infected with bovine PV (BPV-1) L1/L2 recombinant vaccinia virus to produce BPV1 pseudovirions. Approximately 1 in 1.5x10(4) of dense (1.35 g/ml) PV pseudovirions and 0.3 in 10(4) Of less-dense (1.29 g/ml) pseudovirions packaged an intact pGSV plasmid. The majority (>75%) of packaged plasmids contained deletions, and the deletions affected all tested genes. After exposure of Cos-1 cells to BPV-1 pseudovirions at an MOI of 40,000:1, 6% of cells expressed GFP giving a calculated efficiency of delivery of the pGSV plasmid, by pseudovirions which had packaged an intact plasmid, of approximately 5%. Plasmid delivery was not effected by purified pGSV plasmid, was blocked by antiserum against BPV-1, and was not blocked by DNase treatment of pseudovirions, confirming that delivery was mediated by DNA within the pseudovirion. We conclude that a major limitation to the use of PV pseudovirions as a gene delivery system is that intact plasmid DNA is not efficiently selected for packaging by VLPs in cell-based pseudovirions production systems.

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Although there are formidable barriers to the oral delivery of biologically active drugs, considerable progress in the field has been made, using both physical and chemical strategies of absorption enhancement. A possible method to enhance oral absorption is to exploit the phenomenon of lipophilic modification and mono and oligosaccharide conjugation. Depending on the uptake mechanism targeted, different modifications can be employed. To target passive diffusion, lipid modification has been used, whereas the targeting of sugar transport systems has been achieved through drugs conjugated with sugars. These drug delivery units can be specifically tailored to transport a wide variety of poorly absorbed drugs through the skin, and across the barriers that normally inhibit absorption from the gut or into the brain. The delivery system can be conjugated to the drug in such a way as to release the active compound after it has been absorbed (i.e. the drug becomes a prodrug), or to form a biologically stable and active molecule (i.e. the conjugate becomes a new drug moiety). Examples where lipid, sugar and lipid-sugar conjugates have resulted in enhanced drug delivery will be highlighted in this review.

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Methyl tetra-O-allyl, and tetra-O-[2-(tetrahydro-2H-pyranyl)oxy.-3-oxapentyl glucosides, and tetra-O-(cyanoethyl)galactosyl azide were converted into derivatives containing linkers with terminal carboxylic acid functionalities at the anomeric position and bearing four arms with phthaloyl- or BOC-protected terminal amino groups. These molecules were suitable for use in solid-phase peptide synthesis and for the preparation of dendrimers, containing multiple copies of peptides. (C) 2001 Elsevier Science Ltd. All rights reserved.

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Primary vaccine strategies against group A streptococci (GAS) have focused on the M protein-the target of opsonic antibodies important for protective immunity. We have previously reported protection of mice against GAS infection following parenteral delivery of a multi-epitope vaccine construct, referred to as a heteropolymer. This current report has assessed mucosal (intranasal (i.n.) and oral) delivery of the heteropolymer in mice with regard to the induction and specificity of mucosal and systemic antibody responses, and compared this to parenteral delivery. GAS-specific IgA responses were detected in saliva and gut upon i.n. and oral delivery of the heteropolymer co-administered with cholera toxin B subunit, respectively. High titre serum IgG responses were elicited to the heteropolymer following all routes of delivery when administered with adjuvant. Moreover, as with parenteral delivery, serum IgG antibodies were detected to the individual heteropolymer peptides following i.n. but not oral delivery. These data support the potential of the i.n. route in the mucosal delivery of a GAS vaccine. (C) 2002 Elsevier Science Ltd. All rights reserved.

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Free independent travelers require flexible, reactive service delivery due to their regularly changing location and activities and the lack of a wired Internet connection. A ubiquitous travel service delivery system that is able to dynamically deliver services in response to relevant events, such as changing location, availability of new last-minute specials, work opportunities, and safety issues can provide added value while retaining the flexibility that is so important to independent travelers. This article describes such a system. An engineering design research approach has been adopted to design the system. Issues addressed include traveler and service states and events, contexts, situations, and situation-action rules. An architecture is proposed that is based on distributed, cooperating software agents and mobile data technologies. The role of these agents is to continuously monitor situations that are occurring in the physical and virtual service spaces and to take the required action for any situations that are relevant to the traveler.

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The Crim1 gene is predicted to encode a transmembrane protein containing six von Willebrand-like cysteine-rich repeats (CRRs) similar to those in the BMP-binding antagonist Chordin (Chrd). In this study, we verify that CRIM1 is a glycosylated, Type I transmembrane protein and demonstrate that the extracellular CRR-containing domain can also be secreted, presumably via processing at the membrane. We have previously demonstrated Crim1 expression at sites consistent with an interaction with bone morphogenetic proteins (BMPs). Here we show that CRIM1 can interact with both BMP4 and BMP7 via the CRR-containing portion of the protein and in so doing acts as an antagonist in three ways. CRIM1 binding of BMP4 and -7 occurs when these proteins are co-expressed within the Golgi compartment of the cell and leads to (i) a reduction in the production and processing of preprotein to mature BMP, (ii) tethering of pre-BMP to the cell surface, and (iii) an effective reduction in the secretion of mature BMP. Functional antagonism was verified by examining the effect of coexpression of CRIM1 and BMP4 on metanephric explant culture. The presence of CRIM1 reduced the effective BMP4 concentration of the media, thereby acting as a BMP4 antagonist. Hence, CRIM1 modulates BMP activity by affecting its processing and delivery to the cell surface