479 research outputs found

    Mucoadhesive microspheres of chitosan and polyvinyl alcohol as a carrier for intranasal delivery of insulin: in vitro and in vivo studies

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    The aim of this study was to investigate the capabilities of chitosan microspheres as drug carrier system in co-formulation with polyvinyl alcohol (PVA), to improve the systemic absorption of intranasal insulin delivery. Insulin loaded microspheres was developed from varying ratio of chitosan solutions along with polyvinyl alcohol (PVA) as additive polymer using spray drying method. Different formulations were developed and morphological studies of the optimized formulas showed that the size range of spherical shaped particulate matters existed from 200 nm to 2 mm. It was clearly observed that physicochemical properties of the microspheres were extensively affected by changing the concentration ratio of the two polymeric materials. In vitro studies of insulin release pattern was performed in various time intervals up to 24 h. It was evident that microspheres made up of chitosan showed initial burst release but slower release as the experiment continued. Microspheres made up of combination of the aforementioned two polymers had instant, sharp and burst drug release. Surprisingly there was no absorption after intranasal delivery of chitosan-PVA microspheres in groups of rats comparing to formulated chitosan microspheres having profound absorption due to their smaller particle size, slower drug release rate and better mucoadhesive properties. Therefore, significant reduction in the plasma blood glucose level for chitosan based optimized formulation was seen right after 4.5 hours compared with control group. The aim of the present study was to fabricate an appropriate application of polymeric microspheres for intranasal delivery of insulin using a novel optimized formulation based on industrial level spray drying technique and to realize the possible barriers in scale up process of its large scale production, considering the effectiveness of polyvinyl alcohol (PVA) and chitosan to increase mucoadhesivness, gelling ability and ultimately effective release behavior pattern of insulin. According to this study, the combination of the polymers used and the mean particle size of formulated microspheres were found to be key factors in insulin drug release resulting for further enhancement of insulin absorption via intranasal route of delivery

    Comparative analyses of time-course gene expression profiles of the long-lived sch9Δ mutant

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    In an attempt to elucidate the underlying longevity-promoting mechanisms of mutants lacking SCH9, which live three times as long as wild type chronologically, we measured their time-course gene expression profiles. We interpreted their expression time differences by statistical inferences based on prior biological knowledge, and identified the following significant changes: (i) between 12 and 24 h, stress response genes were up-regulated by larger fold changes and ribosomal RNA (rRNA) processing genes were down-regulated more dramatically; (ii) mitochondrial ribosomal protein genes were not up-regulated between 12 and 60 h as wild type were; (iii) electron transport, oxidative phosphorylation and TCA genes were down-regulated early; (iv) the up-regulation of TCA and electron transport was accompanied by deep down-regulation of rRNA processing over time; and (v) rRNA processing genes were more volatile over time, and three associated cis-regulatory elements [rRNA processing element (rRPE), polymerase A and C (PAC) and glucose response element (GRE)] were identified. Deletion of AZF1, which encodes the transcriptional factor that binds to the GRE element, reversed the lifespan extension of sch9Δ. The significant alterations in these time-dependent expression profiles imply that the lack of SCH9 turns on the longevity programme that extends the lifespan through changes in metabolic pathways and protection mechanisms, particularly, the regulation of aerobic respiration and rRNA processing

    Factors Influencing the Severity of Menopause Symptoms in Korean Post-menopausal Women

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    We have relatively limited knowledge of symptomatic aspects of the postmenopause, rather than perimenopause. We tried to determine the factors associated with experiencing menopausal symptoms by Korean postmenopausal women. A total of 657 Korean women who underwent a natural menopause completed multiple questionnaires, which included questions regarding their attitudes to menopause, depressive symptoms, state anxiety, self-esteem, dyadic relationships, sociodemographic variables, and 11-item Menopause Rating Scale (MRS). Multiple regression analyses were performed to collectively examine the relative impact of each independent variable on the quality of life, as determined by the MRS. Decreased severity of menopausal symptoms was associated with more time spent in education, an employed status, a history of pregnancy, longer postmenopausal duration, positive attitudes to menopause, higher state anxiety, heightened self-esteem, and higher dyadic consensus. Increased severity of menopausal symptoms was also associated with absence of a partner, alcohol consumption, a history of hormone replacement therapy, a history of probable premenstrual dysphoric disorder, and increased severity of depressive symptoms. Sociodemographic characteristics, lifestyle factors, premenstrual dysphoric disorder, attitudes to menopause, a dyadic relationship with a partner, and the inner psychological status can be associated with the severity of menopause symptoms specifically in Korean postmenopausal women

    CaSNP: a database for interrogating copy number alterations of cancer genome from SNP array data

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    Cancer is known to have abundant copy number alterations (CNAs) that greatly contribute to its pathogenesis and progression. Investigation of CNA regions could potentially help identify oncogenes and tumor suppressor genes and infer cancer mechanisms. Although single-nucleotide polymorphism (SNP) arrays have strengthened our ability to identify CNAs with unprecedented resolution, a comprehensive collection of CNA information from SNP array data is still lacking. We developed a web-based CaSNP (http://cistrome.dfci.harvard.edu/CaSNP/) database for storing and interrogating quantitative CNA data, which curated ∼11 500 SNP arrays on 34 different cancer types in 104 studies. With a user input of region or gene of interest, CaSNP will return the CNA information summarizing the frequencies of gain/loss and averaged copy number for each study, and provide links to download the data or visualize it in UCSC Genome Browser. CaSNP also displays the heatmap showing copy numbers estimated at each SNP marker around the query region across all studies for a more comprehensive visualization. Finally, we used CaSNP to study the CNA of protein-coding genes as well as LincRNA genes across all cancer SNP arrays, and found putative regions harboring novel oncogenes and tumor suppressors. In summary, CaSNP is a useful tool for cancer CNA association studies, with the potential to facilitate both basic science and translational research on cancer

    Identification of microbial DNA in human cancer

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    <p>Abstract</p> <p>Background</p> <p>Microorganisms have been associated with many types of human diseases; however, a significant number of clinically important microbial pathogens remain to be discovered.</p> <p>Methods</p> <p>We have developed a genome-wide approach, called Digital Karyotyping Microbe Identification (DK-MICROBE), to identify genomic DNA of bacteria and viruses in human disease tissues. This method involves the generation of an experimental DNA tag library through Digital Karyotyping (DK) followed by analysis of the tag sequences for the presence of microbial DNA content using a compiled microbial DNA virtual tag library.</p> <p>Results</p> <p>To validate this technology and to identify pathogens that may be associated with human cancer pathogenesis, we used DK-MICROBE to determine the presence of microbial DNA in 58 human tumor samples, including brain, ovarian, and colorectal cancers. We detected DNA from Human herpesvirus 6 (HHV-6) in a DK library of a colorectal cancer liver metastasis and in normal tissue from the same patient.</p> <p>Conclusion</p> <p>DK-MICROBE can identify previously unknown infectious agents in human tumors, and is now available for further applications for the identification of pathogen DNA in human cancer and other diseases.</p

    Current challenges in glioblastoma : intratumour heterogeneity, residual disease and models to predict disease recurrence

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    Glioblastoma (GB) is the most common malignant primary brain tumour, and despite the availability of chemotherapy and radiotherapy to combat the disease, overall survival remains low with a high incidence of tumour recurrence. Technological advances are continually improving our understanding of the disease and in particular our knowledge of clonal evolution, intratumour heterogeneity and possible reservoirs of residual disease. These may inform how we approach clinical treatment and recurrence in GB. Mathematical modelling (including neural networks), and strategies such as multiple-sampling during tumour resection and genetic analysis of circulating cancer cells, may be of great future benefit to help predict the nature of residual disease and resistance to standard and molecular therapies in GB

    Identification of GBV-D, a Novel GB-like Flavivirus from Old World Frugivorous Bats (Pteropus giganteus) in Bangladesh

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    Bats are reservoirs for a wide range of zoonotic agents including lyssa-, henipah-, SARS-like corona-, Marburg-, Ebola-, and astroviruses. In an effort to survey for the presence of other infectious agents, known and unknown, we screened sera from 16 Pteropus giganteus bats from Faridpur, Bangladesh, using high-throughput pyrosequencing. Sequence analyses indicated the presence of a previously undescribed virus that has approximately 50% identity at the amino acid level to GB virus A and C (GBV-A and -C). Viral nucleic acid was present in 5 of 98 sera (5%) from a single colony of free-ranging bats. Infection was not associated with evidence of hepatitis or hepatic dysfunction. Phylogenetic analysis indicates that this first GBV-like flavivirus reported in bats constitutes a distinct species within the Flaviviridae family and is ancestral to the GBV-A and -C virus clades

    Integrated Analyses of Copy Number Variations and Gene Expression in Lung Adenocarcinoma

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    Numerous efforts have been made to elucidate the etiology and improve the treatment of lung cancer, but the overall five-year survival rate is still only 15%. Identification of prognostic biomarkers for lung cancer using gene expression microarrays poses a major challenge in that very few overlapping genes have been reported among different studies. To address this issue, we have performed concurrent genome-wide analyses of copy number variation and gene expression to identify genes reproducibly associated with tumorigenesis and survival in non-smoking female lung adenocarcinoma. The genomic landscape of frequent copy number variable regions (CNVRs) in at least 30% of samples was revealed, and their aberration patterns were highly similar to several studies reported previously. Further statistical analysis for genes located in the CNVRs identified 475 genes differentially expressed between tumor and normal tissues (p<10−5). We demonstrated the reproducibility of these genes in another lung cancer study (p = 0.0034, Fisher's exact test), and showed the concordance between copy number variations and gene expression changes by elevated Pearson correlation coefficients. Pathway analysis revealed two major dysregulated functions in lung tumorigenesis: survival regulation via AKT signaling and cytoskeleton reorganization. Further validation of these enriched pathways using three independent cohorts demonstrated effective prediction of survival. In conclusion, by integrating gene expression profiles and copy number variations, we identified genes/pathways that may serve as prognostic biomarkers for lung tumorigenesis

    Therapeutic and Prognostic Implications of BRAF V600E in Pediatric Low-Grade Gliomas.

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    Purpose BRAF V600E is a potentially highly targetable mutation detected in a subset of pediatric low-grade gliomas (PLGGs). Its biologic and clinical effect within this diverse group of tumors remains unknown. Patients and Methods A combined clinical and genetic institutional study of patients with PLGGs with long-term follow-up was performed (N = 510). Clinical and treatment data of patients with BRAF V600E mutated PLGG (n = 99) were compared with a large international independent cohort of patients with BRAF V600E mutated-PLGG (n = 180). Results BRAF V600E mutation was detected in 69 of 405 patients (17%) with PLGG across a broad spectrum of histologies and sites, including midline locations, which are not often routinely biopsied in clinical practice. Patients with BRAF V600E PLGG exhibited poor outcomes after chemotherapy and radiation therapies that resulted in a 10-year progression-free survival of 27% (95% CI, 12.1% to 41.9%) and 60.2% (95% CI, 53.3% to 67.1%) for BRAF V600E and wild-type PLGG, respectively ( P \u3c .001). Additional multivariable clinical and molecular stratification revealed that the extent of resection and CDKN2A deletion contributed independently to poor outcome in BRAF V600E PLGG. A similar independent role for CDKN2A and resection on outcome were observed in the independent cohort. Quantitative imaging analysis revealed progressive disease and a lack of response to conventional chemotherapy in most patients with BRAF V600E PLGG. Conclusion BRAF V600E PLGG constitutes a distinct entity with poor prognosis when treated with current adjuvant therapy

    Therapeutic and Prognostic Implications of BRAF V600E in Pediatric Low-Grade Gliomas

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    Purpose BRAF V600E is a potentially highly targetable mutation detected in a subset of pediatric low-grade gliomas (PLGGs). Its biologic and clinical effect within this diverse group of tumors remains unknown. Patients and Methods A combined clinical and genetic institutional study of patients with PLGGs with long-term follow-up was performed (N = 510). Clinical and treatment data of patients with BRAF V600E mutated PLGG (n = 99) were compared with a large international independent cohort of patients with BRAF V600E mutated-PLGG (n = 180). Results BRAF V600E mutation was detected in 69 of 405 patients (17%) with PLGG across a broad spectrum of histologies and sites, including midline locations, which are not often routinely biopsied in clinical practice. Patients with BRAF V600E PLGG exhibited poor outcomes after chemotherapy and radiation therapies that resulted in a 10-year progression-free survival of 27% (95% CI, 12.1% to 41.9%) and 60.2% (95% CI, 53.3% to 67.1%) for BRAF V600E and wild-type PLGG, respectively (P < .001). Additional multivariable clinical and molecular stratification revealed that the extent of resection and CDKN2A deletion contributed independently to poor outcome in BRAF V600E PLGG. A similar independent role for CDKN2A and resection on outcome were observed in the independent cohort. Quantitative imaging analysis revealed progressive disease and a lack of response to conventional chemotherapy in most patients with BRAF V600E PLGG. Conclusion BRAF V600E PLGG constitutes a distinct entity with poor prognosis when treated with current adjuvant therapy. (C) 2017 by American Society of Clinical Oncolog
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