Average Diameter Of Spheres Research Articles

Pathogenic Pathways in Early-Onset Autosomal Recessive Parkinson's Disease Discovered Using Isogenic Human Dopaminergic Neurons.

SummaryParkinson's disease (PD) is a complex and highly variable neurodegenerative disease. Familial PD is caused by mutations in several genes with diverse and mostly unknown functions. It is unclear how dysregulation of these genes results in the relatively selective death of nigral dopaminergic neurons (DNs). To address this question, we modeled PD by knocking out the PD genes PARKIN (PRKN), DJ-1 (PARK7), and ATP13A2 (PARK9) in independent isogenic human pluripotent stem cell (hPSC) lines. We found increased levels of oxidative stress in all PD lines. Increased death of DNs upon differentiation was found only in the PARKIN knockout line. Using quantitative proteomics, we observed dysregulation of mitochondrial and lysosomal function in all of the lines, as well as common and distinct molecular defects caused by the different PD genes. Our results suggest that precise delineation of PD subtypes will require evaluation of molecular and clinical data.

MP44-11 GROWTH HORMONE-RELEASING HORMONE (GHRH) ANTAGONISTS REDUCE INFLAMMATION- AND TRANSFORMING GROWTH FACTOR (TGF)-?2-INDUCED PROLIFERATION OF HUMAN BPH-1 PROSTATE EPITHELIAL CELLS GROWN IN 3D CULTURE

You have accessJournal of UrologyBenign Prostatic Hyperplasia: Basic Research & Pathophysiology1 Apr 2016MP44-11 GROWTH HORMONE-RELEASING HORMONE (GHRH) ANTAGONISTS REDUCE INFLAMMATION- AND TRANSFORMING GROWTH FACTOR (TGF)-?2-INDUCED PROLIFERATION OF HUMAN BPH-1 PROSTATE EPITHELIAL CELLS GROWN IN 3D CULTURE Petra Popovics, Andrew V. Schally, Roberto Perez, Rhenzi Cai, and Ferenc G. Rick Petra PopovicsPetra Popovics More articles by this author , Andrew V. SchallyAndrew V. Schally More articles by this author , Roberto PerezRoberto Perez More articles by this author , Rhenzi CaiRhenzi Cai More articles by this author , and Ferenc G. RickFerenc G. Rick More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.267AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Benign prostatic hyperplasia (BPH) is frequently associated with chronic inflammation. Epithelial-to-mesenchymal transition (EMT) has been recently indicated as a major factor in the pathogenesis of BPH. Evidence also suggests that inflammatory cytokines may induce BPH. Hypothalamic neuropeptides, GHRH, luteinizing hormone-releasing hormone (LHRH) and their receptors are expressed in experimental models of BPH in which antagonists of GHRH and LHRH have been shown to suppress the levels of proinflammatory cytokines and alter the expression of genes related to EMT. These findings imply a role of GHRH/LHRH in the development of prostatitis, however, this has not been investigated to date. METHODS Human BPH-1 prostatic cell line was used to generate matrigel-embedded 3D cultures in which average sphere diameters were evaluated. Chronic inflammation was induced by treating cells with THP-1 macrophage-conditioned medium whereas EMT was triggered with TGF-ß1 or TGF-ß2 peptides. The role of secreted LHRH and GHRH in inflammation-induced proliferation was determined by using the LHRH antagonist, degarelix, and a specific GHRH antagonist developed in our lab. The presence of receptors for GHRH and LHRH was confirmed in 3D cultures by immunocytochemistry and quantitative RT-PCR. RESULTS BPH-1-derived spherical structures expressed cell membrane receptors for LHRH and GHRH. Macrophage-conditioned medium induced a 26% increase (P<0.001) in the average diameter of cells and a 2-fold elevation in the expression of the EMT markers N-cadherin (p<0.01) and Snail (p<0.001) as detected by qPCR. The expression of GHRH was also increased 2.7-fold (p<0.001), whereas mRNA levels of LHRH were slightly reduced (ns). GHRH antagonist reduced inflammation-induced increase in diameter by 64% (P<0.01), while no significant change was observed after degarelix treatment. TGF-ß2 increased average sphere diameter by 32%, but this effect was reduced by 67% by the GHRH antagonist (P<0.001). In contrast, TGF-ß1 did not significantly affect sphere diameter. CONCLUSIONS This study identifies GHRH as an important factor in inflammation-induced proliferation and TGF-ß2-triggered EMT of prostate epithelial cells and suggests the merit of further investigation to elucidate the effects of GHRH antagonists in the reduction of inflammation-induced BPH. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e602-e603 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Petra Popovics More articles by this author Andrew V. Schally More articles by this author Roberto Perez More articles by this author Rhenzi Cai More articles by this author Ferenc G. Rick More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Characterization and synthesis of ZTA nanopowders and ceramics by rotating packed bed (RPB)

Uniform ZTA composites containing 25.5wt% ZrO2 were firstly prepared with rotating packed bed (RPB) reactor by coprecipitation method. The effects of RPB reactor on ZTA nanopowders were also investigated and compared with conventional reactor. The nanopowders in those reactors were characterized by XRD, SEM, TEM, EDS, and XPS. The results showed that ZTA nanopowders prepared by RPB had the lowest extent of agglomeration, the most homogeneous microstructure and the narrowest particle size distribution concentrating on 28–53nm with an average sphere diameter of 41nm. RPB could also dramatically decrease the reaction time and then decrease the energy consumption and production costs in preparation process. A further study on the microstructures of the ceramics by SEM revealed that ceramics sintered by those nanopowders also showed the smaller ZrO2 and Al2O3 grains and the more homogeneous distribution. All the results indicated that the presented novel reactor (RPB) may provide a new way to the production of nanopowders and ceramics in the industrial application.

Co-precipitated synthesis of Al2O3–ZrO2 composite ceramic nanopowders by precipitant and drying method regulation: A systematic study

Uniform Al2O3–ZrO2 composite ceramic nanopowders containing 13.1–25.5wt% ZrO2 were prepared by coprecipitation method using various precipitans (NH4HCO3, NH3·H2O, and (NH3)2CO3) and drying methods (vacuum drying, spray drying, and freeze drying). The effects of precipitants and drying methods on Al2O3–ZrO2 nanopowderswere were explored systematically by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray energy dispersive analysis (EDS), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The results showed that it is proper to use NH4HCO3 as precipitant and freeze drying as drying method when taking into account extent of agglomeration, degree of crystallinity, and elements distribution of Al2O3–ZrO2 ceramic nanopowders, which had a narrow particle size distribution concentrating on 30–60nm with an average sphere diameter of 47nm. Those findings are also elucidated at micro level to give insight into the underlying mechanism under various precipitants and dry methods. In addition, the moisture of the preparation of Al2O3–ZrO2 nanopowders was first used to predict the extent of aggregation in the subsequent calcination process. In summary, these systematic works study the influence of two key factors on properties of Al2O3–ZrO2 ceramic nanopowders and guide for the further research of high performance ceramics.

Composition and Morphology of Fly Ash Cenospheres Produced from the Combustion of Kuznetsk Coal

The chemical and phase composition, morphology, and shell structure of narrow fractions of nonmagnetic and magnetic low-density nonperforated cenospheres separated from fly ash concentrates produced via the pulverized combustion of coal from the Kuznetsk Basin (Russia) have been studied. Narrow fractions of nonmagnetic cenospheres contain 2.6–3.5 wt % Fe2O3 and include globules with a uniform smooth or relief surface and shells with different degrees of porosity. For nonmagnetic cenospheres, the aluminum concentration increase leads to an increase in the mullite phase content and a decrease in the average sphere diameter, glass-crystalline shell thickness and porosity, and the crystalline quartz content. The quartz phase comprises two modifications with different lattice parameters. The narrow fractions of magnetic cenospheres contain 3–21 wt % Fe2O3 and include globules with thick porous shells covered by heterogeneous regions of ferrospinel on their outer surface. In magnetic cenospheres, an increase in the iron concentration leads to an increase in the ferrospinel phase content and crystallite size, accompanied by a decrease in the degree of substitution of magnesium and aluminum for iron.

Room temperature deposition of nanostructured Bi2Se3 thin films for photoelectrochemical application: effect of chelating agents

Nanostructured bismuth selenide (Bi2Se3) thin films have been deposited by chemical bath deposition method at room temperature using three different chelating agents, trisodium citrate, triethanolamine and ethylenedimminetetraacetic acid. The structural, morphological, optical and photoelectrochemical properties of Bi2Se3 thin films have been investigated as a function of different chelating agents. X-Ray diffraction studies revealed that the films were nanocrystalline in nature with a rhombohedral crystal structure. Trisodium citrate chelate resulted in Bi2Se3 thin films with poor crystallinity; further improvement in the crystallinity of the films was observed with triethanolamine and ethylenedimminetetraacetic acid chelates. From scanning electron microscopy, a uniform sphere-like morphology having an average sphere diameter of 90 nm was observed with trisodium citrate chelate. In the case of triethanolamine, a fibrous morphology with an average fiber thickness of 60 nm was observed, whereas for ethylenedimminetetraacetic acid chelate, a vertically arrayed petal-like morphology having petal thickness of 50–70 nm was observed. The UV-Vis absorption studies revealed that the band gap energy of the Bi2Se3 thin films with trisodium citrate, triethanolamine and ethylenedimminetetraacetic acid chelates was 1.55, 1.48 and 1.40 eV, respectively. The maximum short circuit current densities (Jsc) of 0.158, 0.214 and 0.284 mA cm−2 and the corresponding open circuit voltages (Voc) of 196, 206 and 217 mV were obtained with trisodium citrate, triethanolamine and ethylenedimminetetraacetic acid chelates, respectively. The Bi2Se3 thin films deposited using triethanolamine and ethylenedimminetetraacetic acid chelates show better photoelectrochemical performance as compared with trisodium citrate chelate.

Hypoxia Increases the Expression of Stem-Cell Markers and Promotes Clonogenicity in Glioblastoma Neurospheres

Hypoxia promotes the expansion of non-neoplastic stem and precursor cell populations in the normal brain, and is common in malignant brain tumors. We examined the effects of hypoxia on stem-like cells in glioblastoma (GBM). When GBM-derived neurosphere cultures are grown in 1% oxygen, hypoxia-inducible factor 1alpha (HIF1alpha) protein levels increase dramatically, and mRNA encoding other hypoxic response genes, such as those encoding hypoxia-inducible gene-2, lysyl oxidase, and vascular endothelial growth factor, are induced over 10-fold. Hypoxia increases the stem-like side population over fivefold, and the percentage of cells expressing CD133 threefold or more. Notch pathway ligands and targets are also induced. The rise in the stem-like fraction in GBM following hypoxia is paralleled by a twofold increase in clonogenicity. We believe HIF1alpha plays a causal role in these changes, as when oxygen-stable HIF1alpha is expressed in normoxic glioma cells CD133 is induced. We used digoxin, which has been shown to lower HIF protein levels in vitro and in vivo, to inhibit the hypoxic response. Digoxin suppressed HIF1alpha protein expression, HIF1alpha downstream targets, and slowed tumor growth in vivo. In addition, pretreatment with digoxin reduced GBM flank xenograft engraftment of hypoxic GBM cells, and daily intraperitoneal injections of digoxin were able to significantly inhibit the growth of established subcutaneous glioblastoma xenografts, and suppressed expression of vascular endothelial growth factor.

Evaluation of new high-density ion exchange adsorbents for expanded bed adsorption chromatography

New adsorbents Q HyperZ and CM HyperZ composed of hydrogel-filled porous zirconium oxide particles were evaluated for expanded bed adsorption applications in the present work. The HyperZ adsorbents have wet density of 3.16 g ml −1, particle size of 44.5–100.8 μm and average sphere diameter of 67 μm. The bed expansion as the function of flow velocity and fluid viscosity was measured and correlated with Richardson–Zaki equation. The suitable expansion factor was considered less than 2.5, while the corresponding flow velocity was about 450 cm h −1. Liquid mixing in the bed was determined to evaluate the stability of expanded bed. The Bodenstein numbers tested were higher than 40 and the axial mixing coefficients ( D ax) were between 0.5 and 9.7 × 10 −6 m 2 s −1, which demonstrated that a stable expanded bed could be formed under suitable operation conditions. Bovine serum albumin (BSA) and lysozyme were used as model proteins to estimate the adsorption capacities of Q and CM HyperZ, respectively. The maximum equilibrium adsorption of Q and CM HyperZ could reach 45.7 and 27.2 mg g −1 drained adsorbents, respectively. It was found that yeast cells had little influence on the adsorption capacities of the two adsorbents tested. The dynamic adsorption capacity of BSA at 10% breakthrough with Q HyperZ was 35.9 mg g −1 drained adsorbent at flow velocity of 100 cm h −1 for packed bed adsorption. The values for expanded bed adsorption were 34.4 mg g −1 drained adsorbent at flow velocity of 200 cm h −1, 33.6 mg g −1 drained adsorbent at 300 cm h −1 and 31.7 mg g −1 drained adsorbent 400 cm h −1. The results demonstrated that Q HyperZ and CM HyperZ are suitable for expanded bed adsorption of biomolecules.

Morphological evolution of Au nanowires controlled by Rayleigh instability

A sound knowledge and understanding of the thermal stability of nanowires is aprerequisite for the reliable implementation of nanowire-based devices. We investigate themorphology of Au nanowires annealed isothermally at different temperatures. Duringthe processes, triggered by heating, the wires undergo various configurationalchanges to finally break up into chains of nanospheres at much lower than bulkmelting temperatures due to capillary or so-called Rayleigh instability. The role ofthree parameters, namely, wire diameter, temperature, and annealing time, onthe final morphology is investigated. Both the average sphere diameter and themean spacing between adjacent spheres are larger than the values predicted formaterials with isotropic surface energy. Possible reasons are discussed in the paper.

Overexpression of a truncated TrkB isoform increases the proliferation of neural progenitors

The truncated isoform of TrkB, TrkB.T1, has been shown to be expressed in the neurogenic region of rodent brain. TrkB.T1 lacks tyrosine kinase activity and it may modify the action of the full-length TrkB. We show here that the full-length TrkB and TrkB.T1 are expressed at the same relative expression levels in mouse neural progenitor cell cultures. The number of neurosphere-forming progenitors was reduced and apoptosis increased in neurospheres generated from mice overexpressing TrkB.T1 when compared with wild-type neurospheres. The proliferation of the transgenic neural progenitors was increased, as indicated by the larger average diameter of spheres (140% of control), the increased cell growth in an MTT assay (137% of control) and the faster rate of 3H-thymidine incorporation (128% of control) in the transgenic cell cultures than in controls. The proliferation of neural progenitors was also increased after lentivirus-mediated TrkB.T1 overexpression. A significant increase in 3H-thymidine incorporation (119% of control) and the average diameter of spheres (112% of control) in the TrkB.T1-transduced neurospheres compared with neurospheres transduced with the control vectors confirmed the role of TrkB.T1 in proliferation of neural progenitor. When induced to differentiate, progenitors overexpressing TrkB.T1 generated two to three times more neurons than did wild-type cells. The increase in the number of neurons correlated with an increase in the number of apoptotic cells (two-fold) at these time points. The data indicate that changes in the relative expression levels of different TrkB isoforms influence the replicative capacity of neural progenitors.

In Vitro Stability of Tris-acryl Gelatin Microspheres in a Multipharmaceutical Chemoembolization Solution

To evaluate the in vitro stability of tris-acryl gelatin microspheres (TAGMs) in a multipharmaceutical solution as a preliminary step before planned hepatic chemoembolization with TAGMs. Half-cm(3) aliquots of 100-300- micro m and 300-500- micro m TAGMs were suspended in 1 mL of normal saline solution (NSS), 1 mL of ethiodized oil, or 1 mL of a standard chemoembolization solution (cisplatin 100 mg, doxorubicin 50 mg, mitomycin 10 mg, ethiodized oil 3 mL, and iodixanol 5 mL). Mixtures were incubated at 37 degrees C for 24 hours and were then examined visually and with use of light microscopy. Solutions containing ethiodized oil required centrifugation for separation. Determination of average sphere diameter after 24-hour chemoembolization incubation was performed after washing in ethanol, washing in acetone, and rinsing in 0.9% aqueous sodium chloride solution. TAGMs in NSS had no gross degradation, were intact on light microscopy, and had no visually perceptible change in average diameter. TAGMs in ethiodized oil alone appeared to dissolve into a cloudy solution; however, centrifugation separated spheres from ethiodized oil as a layer, which was intact on light microscopy. Spheres incubated in the chemoembolization solution were not grossly visible as a result of the deep red color of doxorubicin (which stained the spheres), but were easily seen after centrifugation. There were similar numbers of spheres per field on microscopy with a minimal (but significant) increase in analyzed diameter. TAGMs are stable in a standard chemoembolization solution and may be suitable as a substitute for PVA particles in hepatic chemoembolization.

Preparation of a Hollow Microsphere Composed of Porous Organic-Inorganic Hybrid Wall in a W/O Microemulsion System

Abstract Hollow microspheres composed of organic-inorganic hybrid wall (polyorganosiloxane) have been synthesized as a new material in a W/O emulsion system from organosilanes. The average diameter of spheres for a typical run is 1.8 μm (standard deviation = 0.84) with a large spherical cavity in them and thermally stable at least up to 400 °C in air. The polyorganosiloxane wall is amorphous and becomes porous by treating at around 400 °C in air.

Rotational dynamics of rodlike polymers in a rod/sphere mixture

Transient electric birefringence decay studies of the rotation of rodlike polymers in solutions with spherical particles have been performed as a function of the sphere volume fraction. The rodlike polymers are helical poly-γ-benzyl, α-L-glutamates of several lengths. The spheres are coated silica particles and the solvent is a mixture of dimethyl formamide and pyridine that matches the refractive index of the spheres. The rotation of the relatively dilute rods is systematically studied as a function of the sphere concentration. In the suspension where the rods are shorter than the average sphere diameter, the rotational relaxation rate changes only slightly from the relaxation rate of pure rods in the same solvent. In the suspensions of longer rods, the rotation rate decreases rapidly as the sphere concentration increases and scales with the rod length and sphere concentration. We develop a scaling model by combining our results on rod rotation in a rod/solvent dispersion [J. K. Phalakornkul et al., Macromolecules 32, 3122 (1999)] and our experimental results on mutual diffusion of the spheres [J. K. Phalakornkul et al., Phys. Rev. E 54, 1(1996)], to determine the dependence of the rod rotation rate on the sphere concentration. The scaling exponent of the rod rotational time with rod length shows a weaker dependence on length than the scaling model prediction. We measured the viscosities of the sphere dispersions. The rotational relaxation time is not simply related to the background sphere suspension viscosity.

Freezing of polydisperse hard spheres

Freezing of polydisperse hard spheres is studied by Monte Carlo simulation and the results are interpreted with a cell model of the solid. The results supplement an earlier study of freezing of nearly monodisperse hard spheres and, within the assumption of a substitutionally disordered solid, a complete description of the freezing behavior is obtained. The density and polydispersity of the precipitate are characterized by a single curve, regardless of the composition of the fluid from which it is formed. Fractionation enables a fluid of arbitrary polydispersity to precipitate a solid of small polydispersity, dispeling the long-held notion of a fluid-phase ``critical'' polydispersity, beyond which it cannot form a solid. Nevertheless, a primary conclusion from the previous study is confirmed: a solid crystalline phase of polydispersity exceeding 5.7% of the average sphere diameter cannot be precipitated from a fluid phase.

Multiple scattering effects in water saturated beads

Ultrasonic measurements have been used to study the propagation of longitudinal waves in systems comprised of unconsolidated glass and Plexiglas spherical beads saturated with water. In each sample there is roughly a 20% spread in the sphere diameters. The mean diameters vary between 100 and 500 μm. In every sample the porosity is about 38%. We find that the measured velocity dispersion and attenuation are in generally good agreement with the results of multiple scattering calculations based on the quasicrystalline approximation. In these calculations, the average sphere diameter and porosity of the samples are modeled in terms of the radial (i.e., two site) distribution function, and the scattering properties of the individual spheres are treated exactly. Surprisingly, we find that the properties of the glass and Plexiglas bead samples are remarkably similar. This is true in spite of the fact that the elastic properties of the two materials are quite different. At the lowest frequencies, we show that essentially equal sound speeds for the glass and Plexiglas systems can be understood on the basis of the Biot theory.

Determination of spherical grain size from the average area of intersection in Ostwald ripening

When the size distribution of spherical grains is a one-parameter function, the average of the spatial diameter D can be calculated either from the average of the circular intersect area A or from the average of the linear intersect length l . The conversion factors from A to D are here calculated for the diffusion- and reaction-controlled grain size distributions in the theory of Ostwald ripening developed by Lifshitz, Slyozov, and Wagner (LSW). In the alloy of spherical Co grains dispersed in liquid Cu, the value D converted from the measured A agrees well with that obtained from l . It is therefore possible to determine the average sphere diameter simply by counting the total number of grains on intersect planes if the size distribution agrees with the LSW theory.