283 research outputs found

    Scaling-Up Techniques for the Nanofabrication of Cell Culture Substrates via Two-Photo Polymerization for Industrial-Scale Expansion of Stem Cells

    Get PDF
    Stem-cell-based therapies require a high number (106–109) of cells, therefore in vitro expansion is needed because of the initially low amount of stem cells obtainable from human tissues. Standard protocols for stem cell expansion are currently based on chemically-defined culture media and animal-derived feeder-cell layers, which expose cells to additives and to xenogeneic compounds, resulting in potential issues when used in clinics. The two-photon laser polymerization technique enables three-dimensional micro-structures to be fabricated, which we named synthetic nichoids. Here we review our activity on the technological improvements in manufacturing biomimetic synthetic nichoids and, in particular on the optimization of the laser-material interaction to increase the patterned area and the percentage of cell culture surface covered by such synthetic nichoids, from a low initial value of 10% up to 88% with an optimized micromachining time. These results establish two-photon laser polymerization as a promising tool to fabricate substrates for stem cell expansion, without any chemical supplement and in feeder-free conditions for potential therapeutic uses

    A word of caution: do not wake sleeping dogs; micrometastases of melanoma suddenly grew after progesterone treatment

    Get PDF
    Background: Hormonal treatment might affect the immune response to tumor antigens induced in cancer patients who are being vaccinated. Case presentation: A 33 years-old woman was diagnosed with cutaneous melanoma in May 2009. Her melanoma was located in the intermammary sulcus, had a Breslow thickness of 4 mm, a Clark’s level IV, it was ulcerated and highly melanotic. The bilateral sentinel node biopsy was negative. She entered into a randomized Phase II/III clinical study comparing a vaccine composed of irradiated melanoma cells plus BCG plus GM-CSF versus IFN-alpha 2b and she was assigned to the vaccine arm. During the two years treatment she remained disease-free; the final CAT scan being performed in August 2011. Between November and December 2011, her gynecologist treated her with three cycles of 200 mg progesterone/day for ten days, every two weeks, for ovary dysfunction. In November 2011 the patient returned to the Hospital for clinical and imaging evaluation and no evidence of disease was found. At the next visit in March 2012 an ultrasound revealed multiple, large metastases in the liver. A CAT scan confirmed the presence of liver, adrenal glands and spleen metastases. A needle biopsy of a liver lesion revealed metastatic melanoma of similar characteristics to the original tumor. We suggest that progesterone treatment triggered proliferation of so far dormant micrometastases that were controlled during CSF470 vaccine treatment. Conclusion: The use of progesterone in patients with melanoma that are under immunological treatments should be carefully considered, since progesterone could modify the balance of pro-inflammatory and Th1 functions to a regulatory and anti-inflammatory profile of the immune system that could have an impact in tumor progression.Fil: Mordoh, Jose. Fundacion Cancer. Centro de Investigaciones Oncologicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tapia, Ivana Jaqueline. Fundacion Cancer. Centro de Investigaciones Oncologicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Barrio, Maria Marcela. Fundacion Cancer. Centro de Investigaciones Oncologicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Ablation of integrin-mediated cell-collagen communication alleviates fibrosis

    Get PDF
    Objectives Activation of fibroblasts is a hallmark of fibrotic processes. Besides cytokines and growth factors, fibroblasts are regulated by the extracellular matrix environment through receptors such as integrins, which transduce biochemical and mechanical signals enabling cells to mount appropriate responses according to biological demands. The aim of this work was to investigate the in vivo role of collagen–fibroblast interactions for regulating fibroblast functions and fibrosis. Methods Triple knockout (tKO) mice with a combined ablation of integrins α1β1, α2β1 and α11β1 were created to address the significance of integrin-mediated cell–collagen communication. Properties of primary dermal fibroblasts lacking collagen-binding integrins were delineated in vitro. Response of the tKO mice skin to bleomycin induced fibrotic challenge was assessed. Results Triple integrin-deficient mice develop normally, are transiently smaller and reveal mild alterations in mechanoresilience of the skin. Fibroblasts from these mice in culture show defects in cytoskeletal architecture, traction stress generation, matrix production and organisation. Ablation of the three integrins leads to increased levels of discoidin domain receptor 2, an alternative receptor recognising collagens in vivo and in vitro. However, this overexpression fails to compensate adhesion and spreading defects on collagen substrates in vitro. Mice lacking collagen-binding integrins show a severely attenuated fibrotic response with impaired mechanotransduction, reduced collagen production and matrix organisation. Conclusions The data provide evidence for a crucial role of collagen-binding integrins in fibroblast force generation and differentiation in vitro and for matrix deposition and tissue remodelling in vivo. Targeting fibroblast–collagen interactions might represent a promising therapeutic approach to regulate connective tissue deposition in fibrotic diseases

    Dynamic Computational Model Suggests That Cellular Citizenship Is Fundamental for Selective Tumor Apoptosis

    Get PDF
    Computational models in the field of cancer research have focused primarily on estimates of biological events based on laboratory generated data. We introduce a novel in-silico technology that takes us to the next level of prediction models and facilitates innovative solutions through the mathematical system. The model's building blocks are cells defined phenotypically as normal or tumor, with biological processes translated into equations describing the life protocols of the cells in a quantitative and stochastic manner. The essentials of communication in a society composed of normal and tumor cells are explored to reveal “protocols” for selective tumor eradication. Results consistently identify “citizenship properties” among cells that are essential for the induction of healing processes in a healthy system invaded by cancer. These properties act via inter-cellular communication protocols that can be optimized to induce tumor eradication along with system recovery. Within the computational systems, the protocols universally succeed in removing a wide variety of tumors defined by proliferation rates, initial volumes, and apoptosis resistant phenotypes; they show high adaptability for biological details and allow incorporation of population heterogeneity. These protocols work as long as at least 32% of cells obey extra-cellular commands and at least 28% of cancer cells report their deaths. This low percentage implies that the protocols are resilient to the suboptimal situations often seen in biological systems. We conclude that our in-silico model is a powerful tool to investigate, to propose, and to exercise logical anti-cancer solutions. Functional results should be confirmed in a biological system and molecular findings should be loaded into the computational model for the next level of directed experiments

    The relationship between childhood body weight and dental caries experience:an umbrella systematic review protocol

    Get PDF
    Abstract Background Obesity and dental caries are global public health problems which can impact in childhood and throughout the life course. In simple terms, childhood dental caries and body weight are linked via the common risk factor of diet. An association between dental caries and obesity has been described in a number of studies and reviews. However, similarly, a relationship has also been noted between low body weight and caries experience in children. This protocol will provide the framework for an umbrella review to address the following question: Does the available evidence support a relationship between dental caries experience and body weight in the child population? Methods This review protocol outlines the process to carry out an umbrella systematic review which will synthesise previous reviews of childhood dental caries experience and body weight. An umbrella review methodology will be used to examine the methodological and reporting quality of existing reviews. Discussion The final umbrella review aims to aggregate the available evidence in order to provide a summary for policymakers and to inform healthcare interventions. Systematic review registration PROSPERO CRD4201604730

    Investigation of the midgut structure and ultrastructure in Cimex lectularius and Cimex pipistrelli (Hemiptera, Cimicidae)

    Get PDF
    Cimicidae are temporary ectoparasites, which means that they cannot obtain food continuously. Both Cimex species examined here, Cimex lectularius (Linnaeus 1758) and Cimex pipistrelli (Jenyns 1839), can feed on a non-natal host, C. lectularius from humans on bats, C. pipistrelli on humans, but never naturally. The midgut of C. lectularius and C. pipistrelli is composed of three distinct regions—the anterior midgut (AMG), which has a sack-like shape, the long tube-shaped middle midgut (MMG), and the posterior midgut (PMG). The different ultrastructures of the AMG, MMG, and PMG in both of the species examined suggest that these regions must fulfill different functions in the digestive system. Ultrastructural analysis showed that the AMG fulfills the role of storing food and synthesizing and secreting enzymes, while the MMG is the main organ for the synthesis of enzymes, secretion, and the storage of the reserve material. Additionally, both regions, the AMG and MMG, are involved in water absorption in the digestive system of both Cimex species. The PMG is the part of the midgut in which spherites accumulate. The results of our studies confirm the suggestion of former authors that the structure of the digestive tract of insects is not attributed solely to diet but to the basic adaptation of an ancestor

    Effect of Audiovisual Training on Monaural Spatial Hearing in Horizontal Plane

    Get PDF
    The article aims to test the hypothesis that audiovisual integration can improve spatial hearing in monaural conditions when interaural difference cues are not available. We trained one group of subjects with an audiovisual task, where a flash was presented in parallel with the sound and another group in an auditory task, where only sound from different spatial locations was presented. To check whether the observed audiovisual effect was similar to feedback, the third group was trained using the visual feedback paradigm. Training sessions were administered once per day, for 5 days. The performance level in each group was compared for auditory only stimulation on the first and the last day of practice. Improvement after audiovisual training was several times higher than after auditory practice. The group trained with visual feedback demonstrated a different effect of training with the improvement smaller than the group with audiovisual training. We conclude that cross-modal facilitation is highly important to improve spatial hearing in monaural conditions and may be applied to the rehabilitation of patients with unilateral deafness and after unilateral cochlear implantation
    • …
    corecore