Therapeutic Effects of hiPSC-Derived Glial and Neuronal Progenitor Cells-Conditioned Medium in Experimental Ischemic Stroke in Rats

Transplantation of various types of stem cells as a possible therapy for stroke has been tested for years, and the results are promising. Recent investigations have shown that the administration of the conditioned media obtained after stem cell cultivation can also be effective in the therapy of the central nervous system pathology (hypothesis of their paracrine action). The aim of this study was to evaluate the therapeutic effects of the conditioned medium of hiPSC-derived glial and neuronal progenitor cells in the rat middle cerebral artery occlusion model of the ischemic stroke. Secretory activity of the cultured neuronal and glial progenitor cells was evaluated by proteomic and immunosorbent-based approaches. Therapeutic effects were assessed by overall survival, neurologic deficit and infarct volume dynamics, as well as by the end-point values of the apoptosis- and inflammation-related gene expression levels, the extent of microglia/macrophage infiltration and the numbers of formed blood vessels in the affected area of the brain. As a result, 31% of the protein species discovered in glial progenitor cells-conditioned medium and 45% in neuronal progenitor cells-conditioned medium were cell type specific. The glial progenitor cell-conditioned media showed a higher content of neurotrophins (BDNF, GDNF, CNTF and NGF). We showed that intra-arterial administration of glial progenitor cells-conditioned medium promoted a faster decrease in neurological deficit compared to the control group, reduced microglia/macrophage infiltration, reduced expression of pro-apoptotic gene Bax and pro-inflammatory cytokine gene Tnf, increased expression of anti-inflammatory cytokine genes (Il4, Il10, Il13) and promoted the formation of blood vessels within the damaged area. None of these effects were exerted by the neuronal progenitor cell-conditioned media. The results indicate pronounced cytoprotective, anti-inflammatory and angiogenic properties of soluble factors secreted by glial progenitor cells.     

Corrosion-electrochemical behavior of nickel in an alkali metal carbonate melt under a chlorine-containing atmosphere

The corrosion-electrochemical behavior of a nickel electrode is studied in the melt of lithium, sodium, and potassium (40: 30: 30 mol %) carbonates in the temperature range 500–600°C under an oxidizing atmosphere CO₂ + 0.5O₂ (2: 1), which is partly replaced by gaseous chlorine (30, 50, 70%) in some experiments. In other experiments, up to 5 wt % chloride of sodium peroxide is introduced in a salt melt. A change in the gas-phase composition is shown to affect the mechanism of nickel corrosion.     

A Study of the Radiolysis Products of the Tri-n-Butyl-Phosphate–Isopar-M–HNO3 System before and after Regeneration with Carbonates of Organic Bases

Protection of Metals and Physical Chemistry of Surfaces - By measuring the hydrodynamic characteristics (viscosity, density of extraction mixture, and interfacial tension) and determining the...     

Precision Spectrometric Determination of Th and Pu in Solutions with Arsenazo III Using Internal Standardization

A spectrophotometric procedure with internal standardization was suggested for precision determination of the concentrations of Th and Pu in the form of colored complexes with arsenazo III in nitric acid solutions. The sensitivity of the method was significantly improved owing to the use of colored complexes. The optical density optimum (0.3-0.5) of the solutions for spectrophotometric measurements can be achieved at concentrations in solution of the element analyzed as low as (2-3) ×10^-6 M, at the arsenazo and HNO₃ concentrations of 1 ×10^-4 and 6 M, respectively. With this composition of the solution, the relative rms deviation of the results for a single run is no greater than 0.15 and 0.3% for thorium and plutonium, respectively.     

GaN grown by hydride vapor phase epitaxy on p-type 6H-SiC layers

6H-SiC/GaN pn-heterostructures were grown by subsequent epitaxial growth of p-SiC by low temperature liquid phase epitaxy (LTLPE) and n-GaN by hydride vapor phase epitaxy (HVPE). For the first time, p-type epitaxial layers grown on 6H-SiC wafers were used as substrates for GaN HVPE growth. The GaN layers exhibit high crystal quality which was determined by x-ray diffraction. The full width at a half maximum (FWHM) for the ω-scan rocking curve for (0002) GaN reflection was ∼120 arcsec. The photoluminescence spectra for these films were dominated by band-edge emission. The FWHM of the edge PL peak at 361 nm was about 5 nm (80K).     

Electrical characteristics and structural properties of ohmic contacts to p-type 4H-SiC epitaxial layers

Epitaxial films grown by low-temperature liquid phase epitaxy on p-type 4H-SiC were used as strongly doped subcontact layers for making low-resistance contacts to the p-type material. The layers had a bulk resistivity of ∼0.02 Ω · cm and an aluminum atom concentration of ∼1.5×10²⁰ cm⁻³. The absence of polytype inclusions and the distinct crystalline quality of the strongly doped subcontact layers was confirmed by x-ray diffraction methods. Ohmic contacts with resistivities less than 10⁻⁴ Ω · cm² were prepared by depositing and then annealing multilayer metal mixtures containing Al and Ti. The structural properties and energy characteristics of the resulting ohmic contacts are discussed. Fiz. Tekh. Poluprovodn. 33, 1334–1339 (November 1999)