119 research outputs found

    Transduction of rat pancreatic islets with pseudotyped adeno-associated virus vectors

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Pancreatic islet transplantation is a promising treatment for type I diabetes mellitus, but current immunosuppressive strategies do not consistently provide long-term survival of transplanted islets. We are therefore investigating the use of adeno-associated viruses (AAVs) as gene therapy vectors to transduce rat islets with immunosuppressive genes prior to transplantation into diabetic mice.</p> <p>Results</p> <p>We compared the transduction efficiency of AAV2 vectors with an AAV2 capsid (AAV2/2) to AAV2 vectors pseudotyped with AAV5 (AAV2/5), AAV8 (AAV2/8) or bovine adeno-associated virus (BAAV) capsids, or an AAV2 capsid with an insertion of the low density lipoprotein receptor ligand from apolipoprotein E (AAV2apoE), on cultured islets, in the presence of helper adenovirus infection to speed expression of a GFP transgene. Confocal microscopy and flow cytometry were used. The AAV2/5 vector was superior to AAV2/2 and AAV2/8 in rat islets. Flow cytometry indicated AAV2/5-mediated gene expression in approximately 9% of rat islet cells and almost 12% of insulin-positive cells. The AAV2/8 vector had a higher dependence on the helper virus multiplicity of infection than the AAV 2/5 vector. In addition, the BAAV and AAV2apoE vectors were superior to AAV2/2 for transducing rat islets. Rat islets (300 per mouse) transduced with an AAV2/5 vector harboring the immunosuppressive transgene, <it>tgfÎČ1</it>, retain the ability to correct hyperglycemia when transplanted into immune-deficient diabetic mice.</p> <p>Conclusion</p> <p>AAV2/5 vectors may therefore be useful for pre-treating donor islets prior to transplantation.</p

    MC1R genotype may modify the effect of sun exposure on melanoma risk in the GEM study

    Get PDF
    We investigated whether MC1R genotype modifies the effect of sun exposure on melanoma risk in 1,018 cases with multiple melanomas (MPM) and 1,875 controls with one melanoma (SPM). There was some suggestion that MC1R genotype modified the effect of beach and water activities on MPM risk: ORs were 1.94 (95% CI 1.40–2.70) for any activities for no R variants and 1.39 (95% CI 1.05–1.84) with R variants (R151C, R160W, D294H, D84E) (p for interaction 0.08). MC1R modification of sun exposure effects appeared most evident for MPM of the head and neck: for early life ambient UV the OR was 4.23 (95% CI 1.76–10.20) with no R and 1.04 (95% CI 0.40–2.68) with R (p for interaction=0.01; p for three-way interaction=0.01). Phenotype modified the effect of sun exposure and MPM in a similar manner. We conclude that MC1R and pigmentary phenotype may modify the effects of sun exposure on melanoma risk on more continuously sun-exposed skin. Possible explanations include that risk may saturate with higher sun sensitivity for melanomas on continuously sun-exposed sites but continue to increase as sun exposure increases with lower sun sensitivity, or that sun sensitive people adapt their behaviour by increasing sun protection when exposed

    Vitamin D receptor polymorphisms and survival in patients with cutaneous melanoma: a population-based study

    Get PDF
    Factors known to affect melanoma survival include age at presentation, sex and tumor characteristics. Polymorphisms also appear to modulate survival following diagnosis. Result from other studies suggest that vitamin D receptor (VDR) polymorphisms (SNPs) impact survival in patients with glioma, renal cell carcinoma, lung, breast, prostate and other cancers; however, a comprehensive study of VDR polymorphisms and melanoma-specific survival is lacking. We aimed to investigate whether VDR genetic variation influences survival in patients with cutaneous melanoma. The analysis involved 3566 incident single and multiple primary melanoma cases enrolled in the international population-based Genes, Environment, and Melanoma Study. Melanoma-specific survival outcomes were calculated for each of 38 VDR SNPs using a competing risk analysis after adjustment for covariates. There were 254 (7.1%) deaths due to melanoma during the median 7.6 years follow-up period. VDR SNPs rs7299460, rs3782905, rs2239182, rs12370156, rs2238140, rs7305032, rs1544410 (BsmI) and rs731236 (TaqI) each had a statistically significant (trend P values < 0.05) association with melanoma-specific survival in multivariate analysis. One functional SNP (rs2239182) remained significant after adjustment for multiple testing using the Monte Carlo method. None of the SNPs associated with survival were significantly associated with Breslow thickness, ulceration or mitosis. These results suggest that the VDR gene may influence survival from melanoma, although the mechanism by which VDR exerts its effect does not seem driven by tumor aggressiveness. Further investigations are needed to confirm our results and to understand the relationship between VDR and survival in the combined context of tumor and host characteristics

    Clinicopathologic Features of Incident and Subsequent Tumors in Patients with Multiple Primary Cutaneous Melanomas

    Get PDF
    0.6–12.7% of patients with primary cutaneous melanoma will develop additional melanomas. Pathologic features of tumors in patients with multiple primary cutaneous melanomas have not been well described. In this large international multi-center case-control study, we compared the clinicopathologic features of a subsequent melanoma with the preceding (usually the first) melanoma in patients with multiple primary cutaneous melanomas, and with those of melanomas in patients with single primary cutaneous melanomas

    Effects of a partially supervised conditioning programme in cystic fibrosis: an international multi-centre randomised controlled trial (ACTIVATE-CF): study protocol

    Get PDF
    Physical activity (PA) and exercise have become an accepted and valued component of cystic fibrosis (CF) care. Regular PA and exercise can positively impact pulmonary function, improve physical fitness, and enhance health-related quality of life (HRQoL). However, motivating people to be more active is challenging. Supervised exercise programs are expensive and labour intensive, and adherence falls off significantly once supervision ends. Unsupervised or partially supervised programs are less costly and more flexible, but compliance can be more problematic. The primary objective of this study is to evaluate the effects of a partially supervised exercise intervention along with regular motivation on forced expiratory volume in 1 s (FEV1) at 6 months in a large international group of CF patients. Secondary endpoints include patient reported HRQoL, as well as levels of anxiety and depression, and control of blood sugar.; It is planned that a total of 292 patients with CF 12 years and older with a FEV1 ≄ 35% predicted shall be randomised. Following baseline assessments (2 visits) patients are randomised into an intervention and a control group. Thereafter, they will be seen every 3 months for assessments in their centre for one year (4 follow-up visits). Along with individual counselling to increase vigorous PA by at least 3 h per week on each clinic visit, the intervention group documents daily PA and inactivity time and receives a step counter to record their progress within a web-based diary. They also receive monthly phone calls from the study staff during the first 6 months of the study. After 6 months, they continue with the step counter and web-based programme for a further 6 months. The control group receives standard care and keeps their PA level constant during the study period. Thereafter, they receive the intervention as well.; This is the first large, international multi-centre study to investigate the effects of a PA intervention in CF with motivational feedback on several health outcomes using modern technology. Should this relatively simple programme prove successful, it will be made available on a wider scale internationally.; ClinicalTrials.gov Identifier: NCT01744561 ; Registration date: December 6, 2012

    Perspective:Dietary Biomarkers of Intake and Exposure - Exploration with Omics Approaches

    Get PDF
    While conventional nutrition research has yielded biomarkers such as doubly labeled water for energy metabolism and 24-h urinary nitrogen for protein intake, a critical need exists for additional, equally robust biomarkers that allow for objective assessment of specific food intake and dietary exposure. Recent advances in high-throughput MS combined with improved metabolomics techniques and bioinformatic tools provide new opportunities for dietary biomarker development. In September 2018, the NIH organized a 2-d workshop to engage nutrition and omics researchers and explore the potential of multiomics approaches in nutritional biomarker research. The current Perspective summarizes key gaps and challenges identified, as well as the recommendations from the workshop that could serve as a guide for scientists interested in dietary biomarkers research. Topics addressed included study designs for biomarker development, analytical and bioinformatic considerations, and integration of dietary biomarkers with other omics techniques. Several clear needs were identified, including larger controlled feeding studies, testing a variety of foods and dietary patterns across diverse populations, improved reporting standards to support study replication, more chemical standards covering a broader range of food constituents and human metabolites, standardized approaches for biomarker validation, comprehensive and accessible food composition databases, a common ontology for dietary biomarker literature, and methodologic work on statistical procedures for intake biomarker discovery. Multidisciplinary research teams with appropriate expertise are critical to moving forward the field of dietary biomarkers and producing robust, reproducible biomarkers that can be used in public health and clinical research

    Ambient UV, personal sun exposure and risk of multiple primary melanomas

    Get PDF
    Sun exposure is the main cause of melanoma in populations of European origin. No previous study has examined the effect of sun exposure on risk of multiple primary melanomas compared with people who have one melanoma

    Scientific Council June Meeting 2014

    Get PDF

    MITF E318K's effect on melanoma risk independent of, but modified by, other risk factors

    Get PDF
    A rare germline variant in the MITF (microphthalmia-associated transcription factor) gene, E318K, has been reported as associated with melanoma. We confirmed its independent association with melanoma (odds ratio (OR) 1.7, 95% Confidence Interval (CI) = 1.1, 2.7, p = 0.03); adjusted for age, sex, center, age*sex interaction, pigmentation characteristics, family history of melanoma and nevus density). In stratified analyses, carriage of MITF E318K was associated with melanoma more strongly in people with dark hair than fair hair (p for interaction, 0.03) and in those with no moles than some or many moles (p for interaction, <0.01). There was no evidence of interaction between MC1R “red hair variants” and MITF E318K. Moreover, risk of melanoma among carriers with “low risk” phenotypes was as great or greater than among those with “at risk” phenotypes with few exceptions
    • 

    corecore