24 research outputs found

    A High Cell-Bearing Capacity Multibore Hollow Fiber Device for Macroencapsulation of Islets of Langerhans

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    Macroencapsulation of islets of Langerhans is a promising strategy for transplantation of insulin-producing cells in the absence of immunosuppression to treat type 1 diabetes. Hollow fiber membranes are of interest there because they offer a large surface-to-volume ratio and can potentially be retrieved or refilled. However, current available fibers have limitations in exchange of nutrients, oxygen, and delivery of insulin potentially impacting graft survival. Here, multibore hollow fibers for islets encapsulation are designed and tested. They consist of seven bores and are prepared using nondegradable polymers with high mechanical stability and low cell adhesion properties. Human islets encapsulated there have a glucose induced insulin response (GIIS) similar to nonencapsulated islets. During 7 d of cell culture in vitro, the GIIS increases with graded doses of islets demonstrating the suitability of the microenvironment for islet survival. Moreover, first implantation studies in mice demonstrate device material biocompatibility with minimal tissue responses. Besides, formation of new blood vessels close to the implanted device is observed, an important requirement for maintaining islet viability and fast exchange of glucose and insulin. The results indicate that the developed fibers have high islet bearing capacity and can potentially be applied for a clinically applicable bioartificial pancreas

    Vaginal dryness in primary Sjögren's syndrome:a histopathological case control study

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    The aim was to study clinical, histopathological and immunological changes in the vagina and cervix of women with primary SS, which might explain vaginal dryness. Methods: We included 10 pre-menopausal female primary SS patients with vaginal dryness and 10 pre-menopausal controls undergoing a laparoscopic procedure. The vaginal health index was recorded. Multiplex immunoassays and flow cytometry were performed on endocervical swab and cervicovaginal lavage samples to evaluate cellular and soluble immune markers. Mid-vaginal and endocervical biopsies were taken and stained for various leucocyte markers, caldesmon (smooth muscle cells), avian V-ets erythroblastosis virus E26 oncogene homologue (ERG; endothelial cells) and anti-podoplanin (lymphatic endothelium). The number of positive pixels per square micrometre was calculated. Results: One patient was excluded because of Clamydia trachomatis, and two controls were excluded because of endometriosis observed during their laparoscopy. Vaginal health was impaired in primary SS. CD45+ cells were increased in vaginal biopsies of women with primary SS compared with controls. Infiltrates were predominantly located in the peri-epithelial region, and mostly consisted of CD3+ lymphocytes. In the endocervix, CD45+ infiltrates were present in patients and in controls, but a higher number of B lymphocytes was seen in primary SS. Vascular smooth muscle cells were decreased in the vagina of primary SS patients. No differences were found in leucocyte subsets in the vaginal and endocervical lumen. CXCL10 was increased in endocervical swab samples of primary SS patients. Conclusion: Women with primary SS show impaired vaginal health and increased lymphocytic infiltration in the vagina compared with controls. Vaginal dryness in primary SS might be caused by vascular dysfunction, possibly induced by IFN-mediated pathways

    IGF system targeted therapy:Therapeutic opportunities for ovarian cancer

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    The insulin-like growth factor (IGF) system comprises multiple growth factor receptors, including insulin-like growth factor 1 receptor (IGF-1R), insulin receptor (IR)-A and-B. These receptors are activated upon binding to their respective growth factor ligands, IGF-I, IGF-II and insulin, and play an important role in development, maintenance, progression, survival and chemotherapeutic response of ovarian cancer. In many pre-clinical studies anti-IGF-1R/IR targeted strategies proved effective in reducing growth of ovarian cancer models. In addition, anti-IGF-1R targeted strategies potentiated the efficacy of platinum based chemotherapy. Despite the vast amount of encouraging and promising pre-clinical data, anti-IGF-1R/IR targeted strategies lacked efficacy in the clinic. The question is whether targeting the IGF-1R/IR signaling pathway still holds therapeutic potential. In this review we address the complexity of the IGF-1R/IR signaling pathway, including receptor heterodimerization within and outside the IGF system and downstream signaling. Further, we discuss the implications of this complexity on current targeted strategies and indicate therapeutic opportunities for successful targeting of the IGF-1R/IR signaling pathway in ovarian cancer. Multiple-targeted approaches circumventing bidirectional receptor tyrosine kinase (RTK) compensation and prevention of system rewiring are expected to have more therapeutic potential

    Restoration of impaired intestinal barrier function by the hydrolysed casein diet contributes to the prevention of type 1 diabetes in the diabetes-prone BioBreeding rat

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    Aims/hypothesis Impaired intestinal barrier function is observed in type I diabetes patients and animal models of the disease. Exposure to diabetogenic antigens from the intestinal milieu due to a compromised intestinal barrier is considered essential for induction of the autoimmune process leading to type I diabetes. Since a hydrolysed casein (HC) diet prevents autoimmune diabetes onset in diabetes-prone (DP)-BioBreeding (BB) rats, we studied the role of the HC diet on intestinal barrier function and, therefore, prevention of autoimmune diabetes onset in this animal model. Methods DP-BB rats were fed the HC diet from weaning onwards and monitored for autoimmune diabetes development. Intestinal permeability was assessed in vivo by lactulose mannitol test and ex vivo by measuring trans-epithelial electrical resistance (TEER). Levels of serum zonulin, a physiological tight junction modulator, were measured by ELISA. heal mRNA expression of Myo9b, Cldn1, Cldn2 and Ocln (which encode the tight junction-related proteins myosin IXb, claudin-1, claudin-2 and occludin) and Il-10, Tgf-beta (also known as Il10 and Tgfb, respectively, which encode regulatory cytokines) was analysed by quantitative PCR. Results The HC diet reduced autoimmune diabetes by 50% in DP-BB rats. In DP-BB rats, prediabetic gut permeability negatively correlated with the moment of autoimmune diabetes onset. The improved intestinal barrier function that was induced by HC diet in DP-BB rats was visualised by decreasing lactulose:mannitol ratio, decreasing serum zonulin levels and increasing ileal TEER. The HC diet modified ileal mRNA expression of Myo9b, and Cldn1 and Cldn2, but left Ocln expression unaltered. Conclusions/interpretation Improved intestinal barrier function might be an important intermediate in the prevention of autoimmune diabetes by the HC diet in DP-BB rats. Effects on tight junctions, ileal cytokines and zonulin production might be important mechanisms for this effect

    Patienten met hypertensie en hogere body mass index hebben lagere vitamine D-spiegels na suppletie

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    OBJECTIVE To investigate the relation between body mass index (BMI) and Vitamin D level after supplementation with colecalciferol 2000 IE/day for one year. DESIGN Double-blind randomized controlled trial. METHODS Patients with hypertension and low 25(OH)D levels were approached if they met inclusion and not exclusion criteria and had signed informed consent. They were assigned to take either colecalciferol 2000 IE/day or placebo tablets for one year. Participants were checked at baseline, 6 and 12 months. As part of this study we looked at the relation between BMI and 25(OH)D level at 6 and 12 months using a mixed model regression analysis. RESULTS Compared to participants with a normal BMI (18.6-25.0 kg/m2) mean Vitamin D levels were 10 nmol/L lower in participants with a high BMI (25.1-30.0 kg/m2) and 28 nmol/L lower in participants with a very high BMI (> 30.0 kg/m2) after 12 months of supplementation. In participants that took > 80% of the tablets, 94% reached a level > 75 nmol/L after 12 months of supplementation with colecalciferol (n = 35). A BMI rise of 1 kg/m2 correlated with a 1.6 nmol/L lower Vitamin D level after correction for other factors (P = 0.0012). CONCLUSION BMI has a significant influence on the Vitamin D level after supplementation of 2000 IE/day colecalciferol for one year

    Patients with hypertension and higher body mass index have tower Vitamin D levels after supplementation

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    OBJECTIVE To investigate the relation between body mass index (BMI) and Vitamin D level after supplementation with colecalciferol 2000 IE/day for one year. DESIGN Double-blind randomized controlled trial. METHODS Patients with hypertension and low 25(OH)D levels were approached if they met inclusion and not exclusion criteria and had signed informed consent. They were assigned to take either colecalciferol 2000 IE/day or placebo tablets for one year. Participants were checked at baseline, 6 and 12 months. As part of this study we looked at the relation between BMI and 25(OH)D level at 6 and 12 months using a mixed model regression analysis. RESULTS Compared to participants with a normal BMI (18.6-25.0 kg/m2) mean Vitamin D levels were 10 nmol/L lower in participants with a high BMI (25.1-30.0 kg/m2) and 28 nmol/L lower in participants with a very high BMI (&gt; 30.0 kg/m2) after 12 months of supplementation. In participants that took &gt; 80% of the tablets, 94% reached a level &gt; 75 nmol/L after 12 months of supplementation with colecalciferol (n = 35). A BMI rise of 1 kg/m2 correlated with a 1.6 nmol/L lower Vitamin D level after correction for other factors (P = 0.0012). CONCLUSION BMI has a significant influence on the Vitamin D level after supplementation of 2000 IE/day colecalciferol for one year.</p

    Potential mechanisms explaining why hydrolyzed casein-based diets outclass single amino acid-based diets in the prevention of autoimmune diabetes in diabetes-prone BB rats

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    Background It remains controversial whether avoidance of dietary diabetogenic triggers, such as cow's milk proteins, can prevent type 1 diabetes in genetically susceptible individuals. Here, different extensive casein hydrolysates (HC) and single amino acid (AA) formulations were tested for their effect on mechanisms underlying autoimmune diabetes pathogenesis in diabetes-prone BioBreeding rats. Intestinal integrity, gut microbiota composition and mucosal immune reactivity were studies to assess whether these formulations have differential effects in autoimmune diabetes prevention. Methods Diabetes-prone BioBreeding rats received diets in which the protein fraction was exchanged for the different hydrolysates or AA compositions, starting from weaning until the end of the experiment (d150). Diabetes development was monitored, and faecal and ileal samples were collected. Gut microbiota composition and cytokine/tight junction mRNA expression were measured by quantitative polymerase chain reaction. Cytokine levels of ileum explant cultures were measured by ELISA, and intestinal permeability was measured in vivo by lactulose-mannitol assay. Results Both HC-diet fed groups revealed remarkable reduction of diabetes incidence with the most pronounced effect in Nutramigen (R)-fed animals. Interestingly, AA-fed rats only showed delayed autoimmune diabetes development. Furthermore, both HC-fed groups had improved intestinal barrier function when compared with control chow or AA-fed animals. Interestingly, higher IL-10 levels were measured in ileum tissue explants from Nutramigen (R)-fed rats. Beneficial gut microbiota changes (increased Lactobacilli and reduced Bacteroides spp. levels) were found associated especially with HC-diet interventions. Conclusions Casein hydrolysates were found superior to AA-mix in autoimmune diabetes prevention. This suggests the presence of specific peptides that beneficially affect mechanisms that may play a critical role in autoimmune diabetes pathogenesis. Copyright (c) 2012 John Wiley & Sons, Ltd

    Phase I/II study protocol to assess safety and efficacy of adoptive cell therapy with anti-PD-1 plus low-dose pegylated-interferon-alpha in patients with metastatic melanoma refractory to standard of care treatments: the ACTME trial

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    IntroductionTreatment with anti-PD-1 immunotherapy does not lead to long-lasting clinical responses in approximately 60% of patients with metastatic melanoma. These refractory patients, however, can still respond to treatment with tumour infiltrating lymphocytes (TIL) and interferon-alpha (IFNa). A combination of TIL, pegylated-interferon-alpha (PEG-IFNa) and anti-PD-1 is expected to provide a safe, feasible and effective therapy for patients with metastatic melanoma, who are refractory to standard of care treatment options.Methods and analysisPatients are treated in two phases. In phase I, the safety of the combination TIL and anti-PD-1 is assessed (cohort 1) according to CTCAE 4.03 criteria. Subsequently, the safety of cotreatment with PEG-IFNa is tested in cohort 2. The efficacy will be evaluated in the second phase of the trial. Efficacy is evaluated according to RECIST 1.1 and immune-related response criteria. Clinical and immunological parameters will be evaluated for their relation with clinical responsiveness.Ethics and disseminationEthical approval of the trial was obtained from the Central Committee on Research Involving Human Subjects in the Netherlands. The trial results will be shared with the scientific community at (inter)national conferences and by publication in a peer-reviewed journal.Trial registration numberNCT03638375; Pre-results.Experimental cancer immunology and therapyPersonalised TherapeuticsSurgical oncolog

    Low-dose interferon-alpha preconditioning and adoptive cell therapy in patients with metastatic melanoma refractory to standard (immune) therapies: a phase I/II study

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    Background Adoptive cell therapy (ACT) with tumor-reactive T cells has shown consistent clinical efficacy. We evaluated the response to ACT in combination with interferon alpha (IFNa) preconditioning in patients with stage IV metastatic melanoma, most of which were progressive on cytotoxic T-lymphocyte-associated protein 4 and/or programmed cell death protein 1 checkpoint blockade therapy. Methods Thirty-four patients were treated with ex vivo expanded tumor reactive T cells, derived from mixed lymphocyte autologous tumor cultures, or with autologous tumor-infiltrating lymphocytes and evaluated for clinical response. Clinical and immunological parameters associated with response were also evaluated. Results Best overall response defined as clinical benefit, comprising either complete response, partial response or stable disease >6 months, was observed in 29% of the patients. Forty-three per cent of the 14 immunotherapy-naive patients and 20% of the 20 patients progressive on prior immunotherapy benefited from ACT. The overall survival (OS) was 90% versus 28.6% at 1 year and 46.7% versus 0% at 3 years follow-up, of responder and non-responder patients, respectively. Median OS was 36 versus 7 months, respectively. IFNa pretreatment resulted in leukopenia, neutropenia and lymphopenia, which was sustained during the treatment in clinical responders and associated with response. Differences in antigen specificity, but not in phenotype, cytokine profile or CD8+ T cell number of the ACT products correlated with clinical response. Cross-reactivity of the ACT products to one or more allogeneic human leukocyte antigen-matched melanoma cell lines was associated with short OS after treatment while the ACT products of very long-term survivors showed no cross-reactivity but recognized patient-specific neoantigens. Conclusion This study demonstrates that ACT in combination with a mild IFNa preconditioning regimen can induce clinical benefit even in immunotherapy pretreated patients, although with lower success than in immunotherapy-naive patients. ACT products comprising neoantigen reactivity may be more effective.Surgical oncolog
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