Search results for "Sphere"
showing 10 items of 2121 documents
Cyclin-Dependent Kinase 4 Regulates Adult Neural Stem Cell Proliferation and Differentiation in Response to Insulin
2017
Abstract Insulin is one of the standard components used to culture primary neurospheres. Although it stimulates growth of different types of cells, the effects of insulin on adult neural stem cells (NSCs) have not been well characterized. Here, we reveal that insulin stimulates proliferation, but not survival or self-renewal, of adult NSCs. This effect is mediated by insulin receptor substrate 2 (IRS2) and subsequent activation of the protein kinase B (or Akt), leading to increased activity of the G1-phase cyclin-dependent kinase 4 (Cdk4) and cell cycle progression. Neurospheres isolated from Irs2-deficient mice are reduced in size and fail to expand in culture and this impaired proliferati…
Conformational dynamics of a single protein monitored for 24 hours at video rate
2018
We use plasmon rulers to follow the conformational dynamics of a single protein for up to 24 h at a video rate. The plasmon ruler consists of two gold nanospheres connected by a single protein linker. In our experiment, we follow the dynamics of the molecular chaperone heat shock protein 90 (Hsp90), which is known to show “open” and “closed” conformations. Our measurements confirm the previously known conformational dynamics with transition times in the second to minute time scale and reveals new dynamics on the time scale of minutes to hours. Plasmon rulers thus extend the observation bandwidth 3–4 orders of magnitude with respect to single-molecule fluorescence resonance energy transfer a…
Pharmacokinetics of a sustained release formulation of PDGFβ-receptor directed carrier proteins to target the fibrotic liver
2018
Liver fibrogenesis is associated with excessive production of extracellular matrix by myofibroblasts that often leads to cirrhosis and consequently liver dysfunction and death. Novel protein-based antifibrotic drugs show high specificity and efficacy, but their use in the treatment of fibrosis causes a high burden for patients, since repetitive and long-term parenteral administration is required as most proteins and peptides are rapidly cleared from the circulation. Therefore, we developed biodegradable polymeric microspheres for the sustained release of proteinaceous drugs. We encapsulated the drug carrier pPB-HSA, which specifically binds to the PDGF beta R that is highly upregulated on a…
Characterization of the canine rostral ventricular-subventricular zone: Morphological, immunohistochemical, ultrastructural, and neurosphere assay st…
2017
The mammalian ventricular-subventricular zone (V-SVZ) presents the highest neurogenic potential in the brain of the adult individual. In rodents, it is mainly composed of chains of neuroblasts. In humans, it is organized in layers where neuroblasts do not form chains. The aim of this study is to describe the cytoarchitecture of canine V-SVZ (cV-SVZ), to assess its neurogenic potential, and to compare our results with those previously described in other species. We have studied by histology, immunohistochemistry (IHC), electron microscopy and neurosphere assay the morphology, cytoarchitecture and neurogenic potential of cV-SVZ. Age groups of animals were performed. Histological and ultrastru…
Fabrication of amorphous strontium polyphosphate microparticles that induce mineralization of bone cells in vitro and in vivo.
2017
Abstract Here we describe the fabrication process of amorphous strontium-polyphosphate microparticles (“Sr-a-polyP-MP”). The effects of these particles on growth and gene expression were investigated with SaOS-2 cells as well as with human mesenchymal stem cells (MSC) and compared with those particles prepared of amorphous calcium-polyphosphate (“Ca-a-polyP-MP”) and of strontium salt. The results revealed a markedly higher stimulation of growth of MSC by “Sr-a-polyP-MP” compared to “Ca-a-polyP-MP” and a significant increase in mineralization of SaOS-2 cells, as well as an enhanced upregulation of the expression of the genes encoding for alkaline phosphatase and the bone morphogenetic protei…
Mucoadhesive solid lipid microparticles for controlled release of a corticosteroid in the chronic obstructive pulmonary disease treatment.
2017
Therapeutic efficacy of inhaled drugs is limited by rapid clearance from the site of action due to absorption into systemic circulation or metabolic degradation by alveolar macrophages. Drug delivery systems offer new solutions to clinical problems especially in the treatment of pulmonary diseases. In particular, Solid Lipid Microparticles (SLM) in the range of 3-5 µm are suggested as systems for delivery of therapeutics to the lung as, because of their size, they are able to deposit into secondary bronchi, avoiding systemic absorption typical of alveolar regions. Here, we describe two novel different SLMs prepared with chitosan and alginate for sustained release of fluticasone propionate (…
Taeniasis vs cysticercosis infection routes
2016
Although cysticercosis caused by Taenia solium ( T. soliu ) is considered a neglected disease, its life cycle has been well known for more than two centuries. T. solium not only causes cysticercosis but also taeniasis in humans. These two diseases have totally different infection routes. To acquire taeniasis (the presence of the adult stage of T. solium in the intestine), humans have to ingest the larval stage (cysticercus) that infects a variety of organs and viscera in pigs, its intermediate hosts. Therefore, taeniasis is acquired when eating raw or undercooked infected pork. The adult stage in the human intestine release eggs that contain a hexacanth embryo, the oncosphere. If humans acc…
Photoferrotrophy: Remains of an Ancient Photosynthesis in Modern Environments
2017
Photoferrotrophy, the process by which inorganic carbon is fixed into organic matter using light as an energy source and reduced iron [Fe(II)] as an electron donor, has been proposed as one of the oldest photoautotrophic metabolisms on Earth. Under the iron-rich (ferruginous) but sulfide poor conditions dominating the Archean ocean, this type of metabolism could have accounted for most of the primary production in the photic zone. Here we review the current knowledge of biogeochemical, microbial and phylogenetic aspects of photoferrotrophy, and evaluate the ecological significance of this process in ancient and modern environments. From the ferruginous conditions that prevailed during most …
Plants assemble species specific bacterial communities from common core taxa in three arcto-alpine climate zones
2017
Evidence for the pivotal role of plant-associated bacteria to plant health and productivity has accumulated rapidly in the last years. However, key questions related to what drives plant bacteriomes remain unanswered, among which is the impact of climate zones on plant-associated microbiota. This is particularly true for wild plants in arcto-alpine biomes. Here, we hypothesized that the bacterial communities associated with pioneer plants in these regions have major roles in plant health support, and this is reflected in the formation of climate and host plant specific endophytic communities. We thus compared the bacteriomes associated with the native perennial plants Oxyria digyna and Saxi…
Impact of packaging on the microbiological, physicochemical and sensory characteristics of a “pasta filata” cheese
2018
Abstract The present study evaluated the effects of four packaging technologies (vacuum, 2 types of modified atmosphere packaging [MAP1 = 70% N2/30% CO2; MAP2 = 100% N2] and paraffin) on the microbiological, chemical, physical and volatile organic composition, and the sensory characteristics of typical Sicilian stretched raw milk PDO (Protected Destination of Origin) Vastedda della Valle del Belice (VdB) cheese. The packaging applied did not affect the microbiological profiles of the cheeses. Of the chemical and physical parameters, only pH and water activity (aw) were statistically different among the trials. In particular, the cheeses wrapped in paraffin showed the highest pH value while …