Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Acrylamides”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,009 records · Page 56Linked to original sources
PubMed1995

Effects of nine active ingredients in Chinese herbal medicine sho-saiko-to on 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide mutagenicity.

The antimutagenic effects of nine active compounds in the Chinese herbal medicine "sho-saiko-to" on mutagenesis induced by a direct-acting mutagen, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (AF-2) were investigated in Salmonella typhimurium, strain TA100. The active compounds examined were classified into two major groups, saponins and flavonoids, the former comprising glycyrrhizin, saikosaponins a, c, and d, and ginsenosides Rb1 and Rg1, and the latter, baicalin, baicalein and wogonin. Saikosaponin a and ginsenoside Rb1 were found to reduce the mutagenicity of AF-2 significantly when applied post-AF-2-treatment in the Salmonella mutagenicity assay. Ginsenoside Rb1 also decreased the mutagenic activity of AF-2 in a simultaneous treatment protocol. The results indicate that saikosaponin a and ginsenoside Rb1 may enhance DNA repair, and ginsenoside Rb1 may also have the ability to inactivate the mutagenic activity of AF-2 directly. On the other hand, saikosaponin d and baicalin showed a slight enhancing effect. None of the compounds, except baicalein, showed any toxic effect on the test strain. These findings may be useful for the development of chemopreventive agents.

Animals↗
PubMed1966

Lipoprotein patterns in acrylamide gel electrophoresis.

Lipoproteins of serum stained before electrophoresis gave distinct patterns in acrylamide gel of 3-percent concentration. Samples compared in parallel on gel slabs showed qualitative differences in migration rates of beta-lipoprotein bands.

Blood Protein Electrophoresis↗
PubMed1996

Three-dimensional imaging of single molecules solvated in pores of poly(acrylamide) gels.

Individual fluorescent molecules and individual singly labeled proteins were observed in the water-filled pores of poly(acrylamide) gels by far-field microscopy. Brownian motion was markedly reduced by the gel framework, thus enabling extended study of single fluorophores in aqueous environments. A highly axially dependent laser field was used both to excite the fluorophores and to image the molecules in three dimensions. Single molecules were followed as they moved within and through the porous gel structure. In contrast to dry polymeric hosts, these water-based gels may form a useful medium for single-molecule studies of biological systems in vitro.

Acrylic Resins↗
PubMed1969

Acrylamide gel electrophoresis of group A streptococcal cell walls.

Patterns obtained by acrylamide gel electrophoresis of group A streptococcal cell walls were characteristic for M types 1, 2, 3, 4, and 5, respectively. Best results were obtained with cell walls which had been solubilized with a phenol-acetic acid-water mixture. The method will make it possible to compare group A streptococci of epidemiological and clinical significance and to separate components for more critical analysis.

Bacterial Proteins↗
PubMed1971

Acrylamide gel electrophoresis of intracellular proteins during early stages of sporulation in Bacillus subtilis.

Acrylamide gel electrophoresis of unfractionated cellular extracts of Bacillus subtilis is shown to be an effective method for characterizing many of the changes in protein composition, when coupled with specific histological-type staining reactions. The results obtained here by using extracts from cells at different stages of growth and sporulation are consistent with observations from other laboratories where extensively purified and highly characterized enzymes have been studied. In several instances, the histochemical reactions can be associated with a specific enzymatic function and appear to indicate the presence of multiple molecular forms. In other instances, the data cannot be evaluated in terms of known enzyme function because the specificity of the histochemical analysis is not certain. However, the assays described permit monitoring of electrophoretic changes at the level of individual proteins within sporulating cultures. The results suggest that B. subtilis may contain two "hexokinase-like" enzymes which cease to function before sporulation is initiated. Aldolase and alanine dehydrogenase are detectable as single bands of enzyme activity during vegetative growth but as multiple molecular forms once sporulation has been initiated. Reduced nicotinamide adenine dinucleotide dehydrogenase activity is represented by an entire family of reactive species in these crude extracts, which undergo multiple changes during the early stages of sporulation. Tricarboxylic acid cycle dehydrogenase enzymes and those bands having esterase activity on alpha-naphthyl acetate show detectable changes in specific activity after cessation of exponential growth. Glucose dehydrogenase is not detectable until the sequence of changes leading to spore formation has progressed for 4 or 5 hr.

Alanine↗
PubMed1970

Thin-layer acrylamide gel electrophoresis.

A thin-layer acrylamide gel electrophoresis technique suitable for analysis of serum or urine proteins is described in detail. The method gives sharp differentiation of protein fractions and is particularly suitable for the analysis of biological solutions containing proteins in low concentration.

Acrylic Resins↗
PubMed1970

The effect of acrylamide on the peripheral nervous system of the baboon.

In the baboon, acrylamide produces a clinical illness characterized by weakness and ataxia of the limbs, weakness of bulbar muscles, and finally tetraplegia. Histological examination shows extensive involvement of peripheral nerves, the main histological change being a Wallerian type of degeneration affecting the distal ends of the largest diameter nerve fibres. The phenomenon of `dying back' has been demonstrated in single teased fibres. Changes also occur in the paranodal myelin; these are not necessarily associated with degeneration of the axon, since intercalated segments and extension of myelin from neighbouring internodes are present in recovering animals. Demyelination of whole internodes is rare. Paranodal changes may be found a few millimetres proximal to complete degeneration, but may also occur on fibres which are otherwise normal in the length examined. The mechanism of the paranodal changes is uncertain, but they may indicate a secondary response of the Schwann cell to a primary change in the axon.

Acrylic Resins↗
PubMed2002

Morphology of poly(methacrylic acid)/poly(N-isopropyl acrylamide) interpenetrating polymeric networks.

The morphology of interpenetrating polymeric networks (IPNs) composed of the temperature-sensitive poly(N-isopropyl acrylamide) (PNIPAAm) and the pH-sensitive poly(methacrylic acid) (PMAA) were investigated by scanning electron microscopy (SEM). The IPN hydrogels were prepared by a sequential UV polymerization method. SEM studies were conducted on IPN hydrogel samples dried by different methods, and the influence on the IPN structure was discussed. The environmental conditions induced morphological changes for these dual sensitive IPN hydrogels which were studied by cryogenic SEM, when the gels were analyzed in their wet state. The results showed that the porous size in the IPN was strongly influenced by the environmental pH and temperature. Decrease in pH and increase in temperature resulted in significant pore size decrease for the swollen IPNs hydrogels.

Acrylic Resins↗
PubMed1993

Mechanism of cytoplasmic calcium changes in platelets in contact with polystyrene and poly(acrylamide-co-methacrylic acid) surfaces.

Changes in cytoplasmic free calcium levels ([Ca2+]i) in platelets in contact with polystyrene (PSt) and poly(acrylamide-co-methacrylic acid) (PAAmMAc) particles were evaluated and results were compared with those from two representative biological calcium agonists; thrombin and calcium ionophore A23187. PSt particles stimulated a steep increase in cytoplasmic calcium levels in platelets as much as thrombin and A23187. Serratia protease-treated platelets showed a steep increase in [Ca2+]i by PSt particles, suggesting that PSt surfaces can initiate platelet activation independent of a glycoprotein Ib (GPIb)-mediated pathway. By contrast, dibucaine-treated platelets showed little increase in [Ca2+]i by PSt particles, indicating that microfilament assembly, including binding of GPIb with actin binding protein, should be required for platelet activation in contact with PSt surfaces. PAAmMAc particles induced little increase in cytoplasmic calcium levels in platelets. However, PAAmMAc particle-treated platelets demonstrated little response to thrombin in terms of an increase in [Ca2+]i and ATP release, suggesting the possibility that PAAmMAc surfaces may regulate [Ca2+]i by influencing platelet metabolism. Furthermore, sodium azide-treated platelets showed an increase in [Ca2+]i in platelets when contacting PAAmMAc particles, supporting the suggestion that PAAmMAc surfaces could regulate platelet functions. Fluorescence polarization measurements using 1,6-diphenyl-1,3,5-hexatriene-loaded platelets revealed that PAAmMAc particles increased membrane fluidity in platelets, which may be due to physicochemical interaction with PAAmMAc surfaces.

Acrylic Resins↗
PubMed1995

Cytoplasmic calcium level and membrane fluidity of platelets contacting poly(acrylamide-co-methacrylic acid) particles with different surface properties.

Changes in cytoplasmic free calcium levels and membrane fluidity of platelets in contact with poly(acrylamide-co-methacrylic acid) (PAAmMAc) particles were examined to analyze the mechanistic aspect of regulating platelet function. Our previous studies demonstrated interesting features of PAAmMAc particles during interaction with platelets: (1) PAAmMAc particles induce no calcium increase but enhance membrane fluidity of platelets: (2) thrombin induces no calcium increase in platelets when the platelets were mixed previously with PAAmMAc particles; and (3) PAAmMAc particles induce a calcium increase in platelets when they were treated previously with sodium azide (NaN3). These results suggest the possibility that PAAmMAc surfaces may regulate the calcium level by influencing platelet metabolism. In this study, non-cross-linked PAAmMAc solution with the same chemical composition as the particles showed a suppressive effect on thrombin-induced calcium increase, but, no influence on membrane fluidity. This result indicates that aggregated macromolecular surface assemblies of PAAmMAc may dominate the increase in membrane fluidity of platelets although the calcium change is induced by discrete molecular level interaction between the PAAmMAc and platelet membranes. It was also revealed that the suppression of thrombin-induced calcium increase and the membrane fluidity increase in platelets by PAAmMAc particles were reduced by albumin-treatment of the particles. This result suggests that such phenomena may be due to a decrease in any physicochemical interaction of PAAmMAc surfaces with albumin, rather than platelet metabolic change. PAAmMAc particle surfaces with higher carboxyl groups exhibited a more suppressive effect on thrombin-induced calcium increase, whereas those with lower carboxyl groups derived a higher calcium increase when the platelets were treated previously with NaN3. These results suggest the importance of electrostatic and any other physicochemical interaction of PAAmMAc chains on regulating cytoplasmic calcium levels.

Acrylic Resins↗
PubMed1980

In vitro and in vivo reactivity and specificity of fractions from sonicates of Mycobacterium tuberculosis separated by gradient acrylamide gel electrophoresis.

Fractions of cell sonicates from the H37Rv strain of Mycobacterium tuberculosis prepared by gradient acrylamide gel electrophoresis (GAGE) were examined by immunoelectrophoretic analysis and tested for biologic reactivity and antigenic specificity. Each was tested for the ability to elicit delayed type hypersensitivity reactions in the skin of guinea pigs sensitized with M. tuberculosis, M. kansasii, M. intracellulare (Battey), M. scrofulaceum (Gause), and M. fortuitum. Peripheral lymphocytes from persons infected with mycobacteria were also exposed to fractions, and the increase in [3H]thymidine incorporation into DNA was used as an index of stimulation (lymphocyte transformation). Only 4 fractions (6, 11, 12, and 16) were found to be significantly more specific than the unfractionated sonicate, and none was monospecific for M. tuberculosis. The results of fused rocket immunoelectrophoresis suggested that incomplete separation of antigens and/or shared group-specific multideterminant antigens may have accounted for the observed cross-reactions.

Animals↗
PubMed2003

Diffusion-based model to predict the conservation of gratings recorded in poly(vinyl alcohol)-acrylamide photopolymer.

Photopolymers are interesting materials for use in recording information in holography. We study the holographic behavior and stability of volume holograms recorded in poly(vinyl alcohol)--acrylamide photopolymers with and without a cross linker. Using a first-harmonic diffusion model, we analyze the residual monomer that remains when volume diffraction gratings are recorded in photopolymer materials. The importance of this residual monomer to the stability of the gratings is evaluated.

Journal Article↗
PubMed2004

Investigation of the diffusion processes in a self-processing acrylamide-based photopolymer system.

Results from the investigation of the diffusion processes in a dry acrylamide-based photopolymer system are presented. The investigation is carried out in the context of experimental research on optimization of the high-spatial-frequency response of the photopolymer. Tracing the transmission holographic grating dynamics at short times of exposure is utilized to measure diffusion coefficients. The results reveal that two different diffusion processes contribute with opposite sign to the refractive-index modulation responsible for the diffraction grating buildup. Monomer diffusion from dark to bright fringe areas increases the refractive-index modulation. It is characterized with diffusion constant D0 = 1.6 x 10(-7) cm2/s. A second diffusion process takes place during the recording. It decreases the refractive-index modulation and we ascribe it to diffusion of short-chain polymer molecules or radicals from bright to dark fringe areas. The estimated diffusion coefficient for this process is D0 = 6.35 x 10(-10) cm2/s. The presence of the second process could be responsible for the poor high-spatial-frequency response of the investigated photopolymer system. Comparison with the diffusion in photopolymer systems known for their good response at high spatial frequencies shows that both investigated diffusion processes occur in a much faster time scale.

Journal Article↗
PubMed2006

Optimization of a thick polyvinyl alcohol-acrylamide photopolymer for data storage using a combination of angular and peristrophic holographic multiplexing.

The capability of polyvinyl alcohol-acrylamide photopolymer materials to obtain angularly multiplexed holographic gratings has been demonstrated [Appl. Phys. B 76, 851 (2003)]. A combination of two multiplexing methods--peristrophic and angular multiplexing--is used to record 60 holograms. An exposure schedule method is used to optimize the capability of the photopolymerizable holographic material and obtain holograms with a higher, more uniform diffraction efficiency. In addition, because of this exposure schedule method, the entire dynamic range (M#) of the material will be exploited, obtaining values of approximately M# approximately 9 in layers approximately 800 microm thick.

Journal Article↗
PubMed1999

Bioconversion of acrylonitrile to acrylamide using a thermostable nitrile hydratase.

Although providing an attractive route for production of acrylamide from acrylonitrile, utilization of nitrile hydratase enzymes has been limited by the requirement for low temperature bioconversion conditions. This report summarizes a search for thermostable nitrile hydratases from aerobic moderate thermophiles screened for ability to grow on acrylonitrile at concentrations to 1% at elevated temperatures. A new isolate Bacillus sp. BR449 constitutively expresses a thermostable nitrile hydratase with properties including low substrate inhibition and broad temperature range with optimal activity at 55 degrees C. With prolonged exposure, BR449 nitrile hydratase exhibited temperature- dependent inactivation by acrylonitrile, which is attributed to alkylation of nucleophilic sites on the enzyme.

Journal Article↗