Conjugation of PolyPEG to Interferon Alpha Extends Serum Half-Life while Maintaining Low Viscosity of the Conjugate

2015 ◽  
Vol 26 (3) ◽  
pp. 452-459 ◽  
Author(s):  
B. Podobnik ◽  
B. Helk ◽  
V. Smilović ◽  
Š. Škrajnar ◽  
K. Fidler ◽  
...  
Keyword(s):  
Interferon Alpha ◽  
Half Life ◽  
Low Viscosity

scholarly journals Effects of interferon alpha on autocrine growth factor loops in B lymphoproliferative disorders.

1990 ◽  
Vol 172 (6) ◽  
pp. 1729-1734 ◽  
Author(s):  
H E Heslop ◽  
A C Bianchi ◽  
F T Cordingley ◽  
M Turner ◽  
W Chandima ◽  
...  
Keyword(s):  
Growth Factor ◽  
Interferon Alpha ◽  
Half Life ◽  
Lymphoproliferative Disorders ◽  
Therapeutic Effects ◽  
Mrna Levels ◽  
Autocrine Growth ◽  
Cytokine Mrna ◽  
Autocrine Growth Factor ◽  
Ifn Alpha

The B lymphoproliferative disorders B chronic lymphocytic leukemia (B-CLL) and hairy cell leukemia (HCL) produce a number of autocrine growth factors, including tumor necrosis factor (TNF), interleukin 6 (IL-6), and IL-1, all of which may induce positive feedback growth loops. If such malignancies depend on these autocrine growth loops for survival, their interruption may be therapeutically valuable. Interferon alpha (IFN-alpha) abrogates TNF- or IL-6-induced proliferation of HCL and B-CLL cells in vitro and has therapeutic activity in these diseases. We have investigated the possibility that IFN-alpha may act by interrupting autocrine growth factor loops. If purified B-CLL or HCL cells are cultured in the presence of TNF, there is induction of mRNA for TNF, IL-1 alpha, IL-1 beta, and IL-6. However, culture in the presence of IFN-alpha in addition to TNF reduced the level of mRNA for all these cytokines, compared with cells cultured in TNF alone. While cytokine mRNA levels were diminished, levels of mRNA for the ribonuclease activator 2-5A synthetase were increased. Analysis of the kinetics of cytokine mRNA production showed that levels fall shortly after the rise of 2-5A synthetase mRNA. IFN-alpha may produce these effects by shortening the half-life of cytokine mRNA, since TNF mRNA half-life in B-CLL and HCL cells is substantially reduced when the cells are cultured with IFN-alpha. These data suggest that IFN-alpha may mediate its therapeutic effects in these malignancies by blocking autocrine growth factor loops.

scholarly journals Interferon to PEG-Interferon: A Review

1970 ◽  
Vol 17 (2) ◽  
pp. 113-116 ◽  
Author(s):  
MA Ahad ◽  
MA Alim ◽  
ARM Saifuddin Ekram
Keyword(s):  
Immune System ◽  
Polyethylene Glycol ◽  
Interferon Alpha ◽  
Half Life ◽  
Pegylated Interferon ◽  
Therapeutic Benefits ◽  
Naturally Occurring ◽  
Recombinant Technology ◽  
Mammalian Immune System

The interferons (IFNs) are group of naturally occurring cytokines that are secreted by cells of mammalian immune system when they are stimulated by viral, bacterial and other antigens. There are number of alpha IFNs available for treatment purposes. The two most commonly used α-2a and α-2b are made by recombinant technology. When interferon Alpha-2a is combined with polyethylene glycol (PEG), it is known as pegylated interferon or PEG interferon. Polyethylene glycol (PEG) is a safe, inert and nontoxic molecule. Therapeutic benefits of altering proteins with PEG include an improvement in half-life due to reduced renal and cellular clearance, enhanced protection from proteolysis and a reduction in toxicity.   doi: 10.3329/taj.v17i2.3460   TAJ 2004; 17(2): 113-116

scholarly journals Enhancing the antivirus activity of chimeric canine interferon with ricin subunit B by using nanoparticle formulations

RSC Advances ◽  
2020 ◽  
Vol 10 (21) ◽  
pp. 12671-12679
Author(s):  
Chengbiao Sun ◽  
Mingxin Dong ◽  
Yucong Song ◽  
Jianxu Zhang ◽  
Yan Wang ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Interferon Alpha ◽  
Broad Spectrum ◽  
Antiproliferative Activity ◽  
Half Life ◽  
Intrinsic Properties ◽  
Antivirus Activity ◽  
Subunit B ◽  
Poor Stability

Despite interferon alpha having a broad spectrum of antiviral activity and strong antiproliferative activity, its applications are severely limited due to the intrinsic properties of proteins, such as poor stability and short serum half-life.

Assessment of Foamed Fluids Based on Surfactants and Nanoparticles for Fracturing and Acidizing Applications

2021 ◽  
Author(s):  
Abeer Alarawi ◽  
Abdullah Al Moajil ◽  
Abdullah Alrustum ◽  
Waddah AlMahri
Keyword(s):  
Half Life ◽  
Foam Stability ◽  
Foam Height ◽  
Spherical Shape ◽  
Stability Index ◽  
Life Time ◽  
High Viscosity ◽  
Optical Microscope ◽  
Low Viscosity ◽  
Average Size

Abstract Foamed fluids are commonly used in acidizing and fracturing applications to minimize formation damage, improve fluid recovery, and as diverting-agents. However, significant concerns with foamed fluids are poor stability and low viscosity. The study objectives include evaluating the commercially available surfactants’ foamability and stability when mixed with and without nanoparticles. The prepared foamed fluid characteristics such as rheology, morphology, stability, and proppant suspension were evaluated. Foam loop rheometer experiments were conducted at 1500 psi and 70% N2 quality to assess foam-stability and rheological properties. Foam decaying time was detected by half-life-time measurements (measuring foam-height as a function of time). Turbiscan was used to study the proppant settling using backscattering light. A high-resolution optical microscope was used to observe foam morphology and stability. The surfactant C-nanoparticles-based foamed fluid demonstrated stable foam with a high viscosity value that reached >110 cP at 100 S-1 77 °F and 70% N2 quality. Compared to the surfactant-based foamed fluid, combining the surfactant with nanoparticles as a foam-stabilizer increased the foam-half-life-time by nearly 35-75%. Foam bubbles size of surfactants A and B (with/without NPs) were large with an irregular shape and tended to rupture intermittently within 50 and 8 minutes, respectively. Bubbles average size of surfactant C (with/without NPs) based foams was small, and the count was higher than the foams of surfactants A and B. surfactant C (with/without NPs) based foams demonstrated bubbles with a spherical shape. Turbiscan stability index values of several surfactants-nanoparticles-based foamed fluids were almost comparable at 77 and 122 °F. Lastly, the foam fluids’ proppant settling velocity prepared with nanoparticles was lower than pure surfactant-based foams.

The Use of Styrenes as Embedding Media for Electron Microscopy

1971 ◽  
Vol 29 ◽  
pp. 488-489
Author(s):  
Edward D. De-Lamater ◽  
Eric Johnson ◽  
Thad Schoen ◽  
Cecil Whitaker
Keyword(s):  
Electron Microscopy ◽  
Surface Tension ◽  
Ultraviolet Light ◽  
Methyl Ethyl Ketone Peroxide ◽  
Methyl Ethyl ◽  
Styrene Polymerization ◽  
Radical Initiation ◽  
Tertiary Butyl ◽  
Low Viscosity ◽  
Free Radical Initiation

Monomeric styrenes are demonstrated as excellent embedding media for electron microscopy. Monomeric styrene has extremely low viscosity and low surface tension (less than 1) affording extremely rapid penetration into the specimen. Spurr's Medium based on ERL-4206 (J.Ultra. Research 26, 31-43, 1969) is viscous, requiring gradual infiltration with increasing concentrations. Styrenes are soluble in alcohol and acetone thus fitting well into the usual dehydration procedures. Infiltration with styrene may be done directly following complete dehydration without dilution.Monomeric styrenes are usually inhibited from polymerization by a catechol, in this case, tertiary butyl catechol. Styrene polymerization is activated by Methyl Ethyl Ketone peroxide, a liquid, and probably acts by overcoming the inhibition of the catechol, acting as a source of free radical initiation.Polymerization is carried out either by a temperature of 60°C. or under ultraviolet light with wave lengths of 3400-4000 Engstroms; polymerization stops on removal from the ultraviolet light or heat and is therefore controlled by the length of exposure.

Some quantitative applications of vascular corrosion casting

1992 ◽  
Vol 50 (1) ◽  
pp. 738-739
Author(s):  
Fred E. Hossler
Keyword(s):  
Blood Vessels ◽  
Nuclear Orientation ◽  
Three Dimensional ◽  
Surrounding Tissue ◽  
Confocal Laser ◽  
Corrosion Casting ◽  
Venous Valve ◽  
Casting Technique ◽  
Low Viscosity ◽  
Quantitative Measurements

Preparation of replicas of the complex arrangement of blood vessels in various organs and tissues has been accomplished by infusing low viscosity resins into the vasculature. Subsequent removal of the surrounding tissue by maceration leaves a model of the intricate three-dimensional anatomy of the blood vessels of the tissue not obtainable by any other procedure. When applied with care, the vascular corrosion casting technique can reveal fine details of the microvasculature including endothelial nuclear orientation and distribution (Fig. 1), locations of arteriolar sphincters (Fig. 2), venous valve anatomy (Fig. 3), and vessel size, density, and branching patterns. Because casts faithfully replicate tissue vasculature, they can be used for quantitative measurements of that vasculature. The purpose of this report is to summarize and highlight some quantitative applications of vascular corrosion casting. In each example, casts were prepared by infusing Mercox, a methyl-methacrylate resin, and macerating the tissue with 20% KOH. Casts were either mounted for conventional scanning electron microscopy, or sliced for viewing with a confocal laser microscope.

Investigation of thin sections of biological standards by EDX, EELS, and Auger electron spectroscopy

1990 ◽  
Vol 48 (2) ◽  
pp. 184-185
Author(s):  
S. Lehner ◽  
H.E. Bauer ◽  
R. Wurster ◽  
H. Seiler
Keyword(s):  
Processing System ◽  
Beam Current ◽  
Beam Diameter ◽  
Thin Sections ◽  
Biologically Relevant ◽  
Energy Filtering ◽  
Low Viscosity ◽  
Carbon Foils ◽  
Electron Microscopical ◽  
Exchange Membrane

In order to compare different microanalytical techniques commercially available cation exchange membrane SC-1 (Stantech Inc, Palo Alto), was loaded with biologically relevant elements as Na, Mg, K, and Ca, respectively, each to its highest possible concentration, given by the number concentration of exchangeable binding sites (4 % wt. for Ca). Washing in distilled water, dehydration through a graded series of ethanol, infiltration and embedding in Spurr’s low viscosity epoxy resin was followed by thin sectioning. The thin sections (thickness of about 50 nm) were prepared on carbon foils and mounted on electron microscopical finder grids.The samples were analyzed with electron microprobe JXA 50A with transmitted electron device, EDX system TN 5400, and on line operating image processing system SEM-IPS, energy filtering electron microscope CEM 902 with EELS/ESI and Auger spectrometer 545 Perkin Elmer.With EDX, a beam current of some 10-10 A and a beam diameter of about 10 nm, a minimum-detectable mass of 10-20 g Ca seems within reach.

Ultrastructural autoradiography of L6 skeletal-muscle cells exposed to a tritiated macrolide antibiotic (LY237216) in vitro

1992 ◽  
Vol 50 (1) ◽  
pp. 612-613
Author(s):  
S.L. White ◽  
C.B. Jensen ◽  
D.D. Giera ◽  
D.A. Laska ◽  
M.N. Novilla ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Quantitative Analysis ◽  
Macrolide Antibiotic ◽  
Circle Method ◽  
Apical Surface ◽  
Polycarbonate Membrane ◽  
L6 Cells ◽  
Low Viscosity ◽  
Erythromycin A

In vitro exposure to LY237216 (9-Deoxo-11-deoxy-9,11-{imino[2-(2-methoxyethoxy)ethylidene]-oxy}-(9S)-erythromycin), a macrolide antibiotic, was found to induce cytoplasmic vacuolation in L6 skeletal muscle myoblast cultures (White, S.L., unpubl). The present study was done to determine, by autoradiographic quantitative analysis, the subcellular distribution of 3H-LY237216 in L6 cells.L6 cells (ATCC, CRL 1458) were cultured to confluency on polycarbonate membrane filters (Millipore Corp., Bedford, MA) in M-199 medium (GIBCO® Labs) with 10% fetal bovine serum. The cells were exposed from the apical surface for 1-hour to unlabelled-compound (0 μCi/ml) or 50 (μCi/ml of 3H-LY237216 at a compound concentration of 0.25 mg/ml. Following a rapid rinse in compound-free growth medium, the cells were slam-frozen against a liquid nitrogen cooled, polished copper block in a CF-100 cryofixation unit (LifeCell Corp., The Woodlands, TX). Specimens were dried in the MDD-C Molecular Distillation Drier (LifeCell Corp.), vapor osmicated and embedded in Spurrs low viscosity resin. Ultrathin sections collected on formvar coated stainless steel grids were counter-stained, then individually mounted on corks. A monolayer of Ilford L4 nuclear emulsion (Polysciences, Inc., Warrington, PA) was placed on the sections, utilizing a modified “loop method”. The emulsions were exposed for 7-weeks in a light-tight box at 4°C. Autoradiographs were developed in Microdol-X developer and examined on a Philips EM410LS transmission electron microscope. Quantitative analysis of compound localization employed the point and circle approach of Williams; incorporating the probability circle method of Salpeter and McHenry.

The concerted use of SEM, TEM, and SCM for examination of resin-dentin interfaces

1994 ◽  
Vol 52 ◽  
pp. 476-477
Author(s):  
B. Van Meerbeek ◽  
L. J. Conn ◽  
E. S. Duke
Keyword(s):  
Surface Layer ◽  
Stress Distribution ◽  
Phosphoric Acid ◽  
Bonding Mechanism ◽  
Restorative Dentistry ◽  
Dental Adhesive ◽  
Low Viscosity ◽  
Dentin Adhesives ◽  
Acid Etch ◽  
Tooth Tissue

Restoration of decayed teeth with tooth-colored materials that can be bonded to tooth tissue has been a highly desirable property in restorative dentistry for many years. Advantages of such an adhesive restorative technique over conventional techniques using non-adhesive metal-based restoratives include improved restoration retention with minimal sacrifice of sound tooth tissue for retention purposes, superior adaptation and sealing of the restoration margins in prevention of caries recurrence, improved stress distribution across the tooth-restoration interface throughout the whole tooth, and even reinforcement of weakened tooth structures. The dental adhesive technology is rapidly changing. An efficient resin bond to enamel has already long been achieved. Its bonding mechanism has been fully elucidated and has proven to be a durable and reliable clinical treatment. However, bonding to dentin represents a greater challenge. After the failures of a dentin acid-etch technique in imitation of the enamel phosphoric-acid-etch technique and a bonding procedure based on chemical adhesion, modern dentin adhesives are currently believed to bond to dentin by a micromechanical hybridization process. This process is developed by an initial demineralization of the dentin surface layer with acid etchants exposing a collagen fibril arrangement with interfibrillar microporosities that subsequently become impregnated by low-viscosity monomers. Although the development of such a hybridization process has well been documented in the literature, questions remain with respect to parameters of-primary importance to adhesive efficacy.

The microstructure of functionalized poLyacrylonitrile beads for bioseparations

1990 ◽  
Vol 48 (4) ◽  
pp. 1094-1095
Author(s):  
Eduardo A. Kamenetzky ◽  
David A. Ley
Keyword(s):  
Aqueous Solution ◽  
Affinity Chromatography ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Surface Coverage ◽  
Vacuum Impregnation ◽  
Thin Sections ◽  
Selective Staining ◽  
Low Viscosity ◽  
Diamond Knife

The microstructure of polyacrylonitrile (PAN) beads for affinity chromatography bioseparations was studied by TEM of stained ultramicrotomed thin-sections. Microstructural aspects such as overall pore size distribution, the distribution of pores within the beads, and surface coverage of functionalized beads affect performance properties. Stereological methods are used to quantify the internal structure of these chromatographic supports. Details of the process for making the PAN beads are given elsewhere. TEM specimens were obtained by vacuum impregnation with a low-viscosity epoxy and sectioning with a diamond knife. The beads can be observed unstained. However, different surface functionalities can be made evident by selective staining. Amide surface coverage was studied by staining in vapor of a 0.5.% RuO4 aqueous solution for 1 h. RuO4 does not stain PAN but stains, amongst many others, polymers containing an amide moiety.

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