200 research outputs found

    Gastroretentive drug delivery system of captopril and hydrochlorothiazide bilayer tablet: formulation, optimization and in vivo evaluation

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    The purpose of the present study was to develop and optimize floating-bioadhesive bilayer gastroretentive drug delivery system (GRDDS) exhibiting a unique combination of floatation and bioadhesion to prolong residence in the stomach using captopril (CP) and hydrochlorothiazide (HCTZ) as a model drug. Captopril being unstable in intestinal pH and HCTZ has specific absorption from duodenum and the first part of the jejunum and to a small extent in the stomach are suitable candidate for GRDDS. 32 factorial design was employed in formulating and optimizing the GRDDS for bilayer tablet of CP and HCTZ matrix tablet. The main effect and interaction terms were quantitatively evaluated using a mathematical model. The gastroretentive ability of the tablets was evaluated by X-radiographic studies in healthy human volunteer. The tablet releases CP and HCTZ for extended period up to 24 h in controlled manner. The predicted values agreed well with the experimental values and the results demonstrate the feasibility of the optimization methodology in the development of GRDDS. The tablet was buoyant for up to 16 h in human stomach. Development of once a day gastroretentive formulation of CP and HCTZ improves the patience compliance and bioavailability of drugs.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Gastroretentive drug delivery system of captopril and hydrochlorothiazide bilayer tablet: formulation, optimization and in vivo evaluation

    Get PDF
    The purpose of the present study was to develop and optimize floating-bioadhesive bilayer gastroretentive drug delivery system (GRDDS) exhibiting a unique combination of floatation and bioadhesion to prolong residence in the stomach using captopril (CP) and hydrochlorothiazide (HCTZ) as a model drug. Captopril being unstable in intestinal pH and HCTZ has specific absorption from duodenum and the first part of the jejunum and to a small extent in the stomach are suitable candidate for GRDDS. 32 factorial design was employed in formulating and optimizing the GRDDS for bilayer tablet of CP and HCTZ matrix tablet. The main effect and interaction terms were quantitatively evaluated using a mathematical model. The gastroretentive ability of the tablets was evaluated by X-radiographic studies in healthy human volunteer. The tablet releases CP and HCTZ for extended period up to 24 h in controlled manner. The predicted values agreed well with the experimental values and the results demonstrate the feasibility of the optimization methodology in the development of GRDDS. The tablet was buoyant for up to 16 h in human stomach. Development of once a day gastroretentive formulation of CP and HCTZ improves the patience compliance and bioavailability of drugs.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Participatory women’s groups and counseling through home visits to improve child growth in rural eastern India: protocol for a cluster randomised controlled trial

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    Background: Childhood stunting (low height-for-age) is a marker of chronic undernutrition and predicts children’s subsequent physical and cognitive development. An estimated 52 million children in India are stunted. There is a broad consensus on determinants of child undernutrition and interventions to address it, but a lack of operational research testing strategies to increase the coverage of these interventions in high burden areas. Our study aims to assess the impact, costeffectiveness, and scalability of a community intervention involving a government-proposed community-based worker to improve growth in children under two

    Multiplex polymerase chain reaction for simultaneous quantitation of human nuclear, mitochondrial, and male Y-chromosome DNA: Application in human identification

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    Human forensic casework requires sensitive quantitation of human nuclear (nDNA), mitochondrial (mtDNA), and male Y-chromosome DNA from complex biomaterials. Although many such systems are commercially available, no system is capable of simultaneously quantifying all three targets in a single reaction. Most available methods either are not multiplex compatible or lack human specificity. Here, we report the development of a comprehensive set of human-specific, target-specific multiplex polymerase chain reaction (PCR) assays for DNA quantitation. Using TaqMan-MGB probes, our duplex qPCR for nDNA/mtDNA had a linear quantitation range of 100 ng to 1 pg, and our triplex qPCR assay for nDNA/mtDNA/male Y DNA had a linear range of 100-0.1 ng. Human specificity was demonstrated by the accurate detection of 0.05 and 5% human DNA from a complex source of starting templates. Target specificity was confirmed by the lack of cross-amplification among targets. A high-throughput alternative for human gender determination was also developed by multiplexing the male Y primer/probe set with an X-chromosome-based system. Background cross-amplification with DNA templates derived from 14 other species was negligible aside from the male Y assay which produced spurious amplifications from other nonhuman primate templates. Mainstream application of these assays will undoubtedly benefit forensic genomics. © 2004 Elsevier Inc. All rights reserved

    Gastroretentive drug delivery system of captopril and hydrochlorothiazide bilayer tablet: formulation, optimization and in vivo evaluation

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    The purpose of the present study was to develop and optimize floating-bioadhesive bilayer gastroretentive drug delivery system (GRDDS) exhibiting a unique combination of floatation and bioadhesion to prolong residence in the stomach using captopril (CP) and hydrochlorothiazide (HCTZ) as a model drug. Captopril being unstable in intestinal pH and HCTZ has specific absorption from duodenum and the first part of the jejunum and to a small extent in the stomach are suitable candidate for GRDDS. 32 factorial design was employed in formulating and optimizing the GRDDS for bilayer tablet of CP and HCTZ matrix tablet. The main effect and interaction terms were quantitatively evaluated using a mathematical model. The gastroretentive ability of the tablets was evaluated by X-radiographic studies in healthy human volunteer. The tablet releases CP and HCTZ for extended period up to 24 h in controlled manner. The predicted values agreed well with the experimental values and the results demonstrate the feasibility of the optimization methodology in the development of GRDDS. The tablet was buoyant for up to 16 h in human stomach. Development of once a day gastroretentive formulation of CP and HCTZ improves the patience compliance and bioavailability of drugs.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Ketone Ester Treatment Improves Cardiac Function and Reduces Pathologic Remodeling in Preclinical Models of Heart Failure

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    BACKGROUND: Accumulating evidence suggests that the failing heart reprograms fuel metabolism toward increased utilization of ketone bodies and that increasing cardiac ketone delivery ameliorates cardiac dysfunction. As an initial step toward development of ketone therapies, we investigated the effect of chronic oral ketone ester (KE) supplementation as a prevention or treatment strategy in rodent heart failure models. METHODS: Two independent rodent heart failure models were used for the studies: transverse aortic constriction/myocardial infarction (MI) in mice and post-MI remodeling in rats. Seventy-five mice underwent a prevention treatment strategy with a KE comprised of hexanoyl-hexyl-3-hydroxybutyrate KE (KE-1) diet, and 77 rats were treated in either a prevention or treatment regimen using a commercially available β-hydroxybutyrate-(R)-1,3-butanediol monoester (DeltaG; KE-2) diet. RESULTS: The KE-1 diet in mice elevated β-hydroxybutyrate levels during nocturnal feeding, whereas the KE-2 diet in rats induced ketonemia throughout a 24-hour period. The KE-1 diet preventive strategy attenuated development of left ventricular dysfunction and remodeling post-transverse aortic constriction/MI (left ventricular ejection fraction±SD, 36±8 in vehicle versus 45±11 in KE-1; P=0.016). The KE-2 diet therapeutic approach also attenuated left ventricular dysfunction and remodeling post-MI (left ventricular ejection fraction, 41±11 in MI-vehicle versus 61±7 in MI-KE-2; P<0.001). In addition, ventricular weight, cardiomyocyte cross-sectional area, and the expression of ANP (atrial natriuretic peptide) were significantly attenuated in the KE-2-treated MI group. However, treatment with KE-2 did not influence cardiac fibrosis post-MI. The myocardial expression of the ketone transporter and 2 ketolytic enzymes was significantly increased in rats fed KE-2 diet along with normalization of myocardial ATP levels to sham values. CONCLUSIONS: Chronic oral supplementation with KE was effective in both prevention and treatment of heart failure in 2 preclinical animal models. In addition, our results indicate that treatment with KE reprogrammed the expression of genes involved in ketone body utilization and normalized myocardial ATP production following MI, consistent with provision of an auxiliary fuel. These findings provide rationale for the assessment of KEs as a treatment for patients with heart failure

    Recommendation of short tandem repeat profiling for authenticating human cell lines, stem cells, and tissues

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    Cell misidentification and cross-contamination have plagued biomedical research for as long as cells have been employed as research tools. Examples of misidentified cell lines continue to surface to this day. Efforts to eradicate the problem by raising awareness of the issue and by asking scientists voluntarily to take appropriate actions have not been successful. Unambiguous cell authentication is an essential step in the scientific process and should be an inherent consideration during peer review of papers submitted for publication or during review of grants submitted for funding. In order to facilitate proper identity testing, accurate, reliable, inexpensive, and standardized methods for authentication of cells and cell lines must be made available. To this end, an international team of scientists is, at this time, preparing a consensus standard on the authentication of human cells using short tandem repeat (STR) profiling. This standard, which will be submitted for review and approval as an American National Standard by the American National Standards Institute, will provide investigators guidance on the use of STR profiling for authenticating human cell lines. Such guidance will include methodological detail on the preparation of the DNA sample, the appropriate numbers and types of loci to be evaluated, and the interpretation and quality control of the results. Associated with the standard itself will be the establishment and maintenance of a public STR profile database under the auspices of the National Center for Biotechnology Information. The consensus standard is anticipated to be adopted by granting agencies and scientific journals as appropriate methodology for authenticating human cell lines, stem cells, and tissues

    Can Genetic Analysis of Putative Blood Alzheimer’s Disease Biomarkers Lead to Identification of Susceptibility Loci?

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    Although 24 Alzheimer’s disease (AD) risk loci have been reliably identified, a large portion of the predicted heritability for AD remains unexplained. It is expected that additional loci of small effect will be identified with an increased sample size. However, the cost of a significant increase in Case-Control sample size is prohibitive. The current study tests whether exploring the genetic basis of endophenotypes, in this case based on putative blood biomarkers for AD, can accelerate the identification of susceptibility loci using modest sample sizes. Each endophenotype was used as the outcome variable in an independent GWAS. Endophenotypes were based on circulating concentrations of proteins that contributed significantly to a published blood-based predictive algorithm for AD. Endophenotypes included Monocyte Chemoattractant Protein 1 (MCP1), Vascular Cell Adhesion Molecule 1 (VCAM1), Pancreatic Polypeptide (PP), Beta2 Microglobulin (B2M), Factor VII (F7), Adiponectin (ADN) and Tenascin C (TN-C). Across the seven endophenotypes, 47 SNPs were associated with outcome with a p-value ≤1x10-7. Each signal was further characterized with respect to known genetic loci associated with AD. Signals for several endophenotypes were observed in the vicinity of CR1, MS4A6A/MS4A4E, PICALM, CLU, and PTK2B. The strongest signal was observed in association with Factor VII levels and was located within the F7 gene. Additional signals were observed in MAP3K13, ZNF320, ATP9B and TREM1. Conditional regression analyses suggested that the SNPs contributed to variation in protein concentration independent of AD status. The identification of two putatively novel AD loci (in the Factor VII and ATP9B genes), which have not been located in previous studies despite massive sample sizes, highlights the benefits of an endophenotypic approach for resolving the genetic basis for complex diseases. The coincidence of several of the endophenotypic signals with known AD loci may point to novel genetic interactions and should be further investigated
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