| a proposed mechanism for p-aminoclonidine allergenicity based on its relative oxidative lability. | p-aminoclonidine (apraclonidine) is a selective alpha 2 adrenergic agonist used to reduce intraocular pressure in the treatment of glaucoma. use of apraclonidine is frequently associated with severe local allergic effects which warrant discontinuation of the drug in affected patients. we have assessed the oxidative lability of apraclonidine relative to a panel of adrenergic agonists and/or known allergens; amodiaquine, epinephrine, clonidine, and brimonidine. these compounds were compared by the ... | 1997 | 9305586 |
| lc-biosensor system for the determination of the neurotoxin β-n-oxalyl-l-α,β-diaminopropionic acid. | an analysis system is described for the determination of the neurotoxin β-n-oxalyl-l-α,β-diaminopropionic acid (β-odap). the system is based on liquid chromatographic separation of β-odap from interfering amino acids on an anion exchange column coupled with an amperometric enzyme electrode for the registration of β-odap. the electrode is based on a graphite rod modified with an os(2+/3+) redox polymer cross-linked with l-glutamate oxidase and horseradish peroxidase. this lc-bienzyme electrode an ... | 1997 | 21639270 |
| hydrogen bond network in the distal site of peroxidases: spectroscopic properties of asn70 --> asp horseradish peroxidase mutant. | the distal his in peroxidases forms a hydrogen bond with the adjacent asn, which is highly conserved among many plant and fungal peroxidases. our previous work [nagano, s., tanaka, m., ishimori, k., watanabe, y., & morishima, i. (1996) biochemistry 35, 14251-14258] has revealed that the replacement of asn70 in horseradish peroxidase c (hrp) by val (n70v) and asp (n70d) discourages the oxidation activity for guaiacol, and the elementary reaction rate constants for the mutants was decreased by 10- ... | 1997 | 9245411 |
| amygdalo-hypothalamic projections in the lizard podarcis hispanica: a combined anterograde and retrograde tracing study. | the cells of origin and terminal fields of the amygdalo-hypothalamic projections in the lizard podarcis hispanica were determined by using the anterograde and retrograde transport of the tracers, biotinylated dextran amine and horseradish peroxidase. the resulting labeling indicated that there was a small projection to the preoptic hypothalamus, that arose from the vomeronasal amygdaloid nuclei (nucleus sphericus and nucleus of the accessory olfactory tract), and an important projection to the r ... | 1997 | 9259488 |
| octavolateral neurons projecting to the middle and posterior rhombencephalic reticular nuclei of larval lamprey: a retrograde horseradish peroxidase labeling study. | the octavolateral area of lampreys, which receives primary fibers from the octaval and lateral line nerves, is involved in the premotor organization of body movements through secondary projections to the reticular formation. here, the typology of neurons of the three octavolateral nuclei (ventral, medial, and dorsal) that putatively project to the middle and posterior rhombencephalic reticular nuclei were studied by retrograde transport of horseradish peroxidase (hrp) applied to these reticular ... | 1997 | 9254035 |
| thermal stabilization of enzymes immobilized within carbon paste electrodes. | in this note we report on the remarkable thermal stabilization of enzymes immobilized in carbon paste electrodes. amperometric biosensors are shown for the first time to withstand a prolonged high-temperature (>50 °c) stress. nearly full activity of glucose oxidase is retained over periods of up to 4 months of thermal stress at 60-80 °c. dramatic improvements in the thermostability are observed for polyphenol oxidase, lactate oxidase, alcohol oxidase, horseradish peroxidase, and amino acid oxida ... | 1997 | 21639334 |
| a new sensitive, whole-cell hybridization technique for detection of bacteria involving a biotinylated oligonucleotide probe targeting rrna and tyramide signal amplification. | a tyramide signal amplification system with biotinylated oligonucleotide probes and streptavidin-horseradish peroxidase was used to increase the sensitivity of fluorescent in situ hybridization techniques. when applied to both gram-negative and -positive bacteria immobilized on glass slides, a 7- to 12-fold amplification of the fluorescence signal was observed relative to that of cells hybridized with fluorescently monolabeled probes. a large proportion (62 to 78%) of bacteria could be detected ... | 1997 | 16535676 |
| tract-tracing in the nervous system of vertebrates using horseradish peroxidase and its conjugates: tracers, chromogens and stabilization for light and electron microscopy. | surprisingly the first generation of tract-tracing techniques based on intra-axonal transport, that is the methods utilizing the uptake and transport of horseradish peroxidase (hrp), still rank among the most widely used neuroanatomical tracing techniques. the success of these methods can be ascribed to several characteristics. they are fast and easy to implement. complicated injection apparatus is unnecessary. the reaction products are visualized through simple histochemical reactions, and they ... | 1997 | 9385065 |
| primary aromatic amines: their n-oxidative bioactivation. | there exists a diversity of pathways in mammalian cells serving to activate primary aromatic amines. 1 n-oxidative mixed-function turnover usually involves participation of the cytochrome p450 superfamily, while catalysis by the flavin-containing monooxygenases is restricted to a few amines capable of forming imine tautomers. surprisingly, haemoglobin metabolizes cytotoxic and carcinogenic arylamines via a monooxygenase-like mechanism, but peroxygenase activity is also operative. 2 in extrahepat ... | 1997 | 9292284 |
| organization and connections of octaval and lateral line centers in the medulla of a clupeid, dorosoma cepedianum. | in the clupeid fishes, the functionally specialized utricle and cephalic lateral line respond to sound pressure by virtue of their mechanical coupling to the auditory bullae. the cytoarchitecture of, and primary inputs to, the octavolateralis area were studied in the gizzard shad, dorosoma cepedianum, in order to determine whether first-order acoustic and lateral line areas of the medulla are likewise specialized. the octavolateralis area of dorosoma is composed of the nuclei that have been obse ... | 1997 | 9282888 |
| evaluation of cathepsin d immunostaining in colorectal adenocarcinoma. | cathepsin d (cd), an estrogen-regulated lysosomal protease, has been detected in a variety of tissues. cd expression has been correlated with the invasive potential of breast cancer, acting as an autocrine mitogen or as a protease that degrades the extracellular matrix. the role of cd expression in predicting prognosis or invasive potential in colorectal carcinomas is mostly unknown. | 1997 | 9274788 |
| nonisotopic quantitative analysis of protein-dna interactions at equilibrium. | two versions of an enzyme-linked immunosorbent assay-type method to quantify protein-dna interactions at equilibrium were developed. the first variant comprised immobilization of dna-binding protein on microtiter plates, incubation with biotinylated dna, and tagging of bound dna with streptavidin- and biotin-substituted horseradish peroxidase. in the second version, biotinylated dna was immobilized on streptavidin-substituted microtiter plates, incubated with dna-binding protein, and bound prote ... | 1997 | 9245437 |
| interpretation of the reactivity of peroxidase compounds i and ii with phenols by the marcus equation. | the catalytic cycle of heme peroxidases involves two reactive states, compound i and compound ii. although their reduction potentials at ph 7 are similar, compound i is in general more reactive towards organic substrates than compound ii. the different reactivities have until now remained unexplained. in this study, the reactions of compounds i and ii of peroxidase from horseradish with phenols were analyzed using the marcus equation of electron-transfer. both reactions exhibit similar reorganiz ... | 1997 | 9256240 |
| horseradish peroxidase oxidation of tyrosine-containing peptides and their subsequent polymerization: a kinetic study. | tyrosine-containing model peptides were oxidized by horseradish peroxidase (hrp). this led to a peptide polymerization via condensation of the aromatic rings. dimers, trimers, and tetramers (depending on the peptide length and on the position of the tyrosine in the sequence) were identified by electron spray mass spectroscopy. the second-order rate constants of the second step of the hrp reduction (cii --> e) was decreased by the presence of a positively charged amino group in the vicinity of th ... | 1997 | 9214295 |
| transient-state and steady-state kinetics of the oxidation of aliphatic and aromatic thiols by horseradish peroxidase. | in the course of oxidation of thiols by peroxidases thiyl radicals are formed which are known to undergo several free-radical conjugative reactions, among others leading to hydrogen peroxide formation. the present paper for the first time presents a comparative transient-state and steady-state investigation of the reaction of 15 aliphatic and aromatic mono- and dithiols with horseradish peroxidase (hrp). both sequential-stopped-flow spectrophotometric investigations of the reaction of hrp interm ... | 1997 | 9271219 |
| synaptic connections between identified neuron types in the antennal lobe glomeruli of the cockroach, periplaneta americana: ii. local multiglomerular interneurons. | synapses between three types of antennal lobe neurons, namely, local multiglomerular interneurons, antennal receptor neurons, and gamma-aminobutyric acid (gaba)-immunoreactive neurons, were studied by means of a combination of three different markers. the interneurons were labeled by intracellular injection of horseradish peroxidase (hrp) into a single soma or a small group of neurons. antennal receptor cells were marked by experimentally induced anterograde degeneration, and gaba-containing neu ... | 1997 | 9208997 |
| a compartment-based, asymmetric representation of the retina in an induced projection to the olfactory cortex. | displacing the optic nerve into the telencephalon in adult rana pipiens induces a projection to olfactory cortex. we have examined the topographic organization of this projection anatomically by injecting a mixture of biotin dextran (bda) with 3h-amino acids into the affected eye immediately after making cuts across defined sectors of the nerve fiber layer to trace the complementary patterns of anterograde migration of bda and 3h label in the cut and intact retinal axons, respectively. fibers fr ... | 1997 | 9208990 |
| protoporphyrin ix potentiates horseradish peroxidase-catalyzed oxidation of nadh:involvement of enzyme-porphyrin interaction. | protoporphyrin ix potentiates horseradish peroxidase-catalyzed hydrogen peroxide-mediated nadh oxidation, but the porphyrin cannot change the enzyme-catalyzed o-dianisidine oxidation. spectrofluorimetric studies reveal that an interaction occurs between horseradish peroxidase and protoporphyrin ix. the interaction is predominantly hydrophobic and entropy-driven endothermic process. this interaction may influence the potentiation effect of the protoporphyrin ix on horseradish peroxidase-catalyzed ... | 1997 | 19856293 |
| enhancer effect of fluorescein on the luminol-h2o2-horseradish peroxidase chemiluminescence: energy transfer process. | the chemiluminescence of the luminol-h2o2-horseradish peroxidase system is increased by fluorescein. fluorescein produces an enhancement of the luminol chemiluminescence similar to that of phenolphthalein, by an energy transfer process from luminol to fluorescein. the maximum intensity and the total chemiluminescence emission (between 380 and 580 nm) of luminol with fluorescein was more than three times greater than without fluorescein; however, the emission duration was shorter. the emission sp ... | 2015 | 9481607 |
| direct colorimetric monoclonal antibody enzyme immunoassay for estradiol-17 beta in saliva. | we developed a direct microtiter plate enzyme immunoassay to measure estradiol-17 beta in saliva. the assay has a commercially available monoclonal antibody, raised against estradiol-17 beta-6-carboxymethyloximebovine serum albumin, and a homologous horseradish peroxidase conjugate measured colorimetrically. the detection limit (equivalent to b0-3 sd) is 365 amol/well or 7.3 pmol/l when 50-microl samples are assayed. cross-reactivity with estrone and estriol, testosterone, or progesterone is < 0 ... | 1997 | 9216451 |
| interpretation of multiple q(0,0) bands in the absorption spectrum of mg-mesoporphyrin embedded in horseradish peroxidase. | mg-mesoporphyrin horseradish peroxidase (mgmp-hrp) and mgmp-hrp complexed with naphtohydroxamic acid (nha) have been studied by fluorescence line narrowing (fln) and pressure tuning spectral hole burning (shb) techniques. in each sample, the low temperature absorption spectra show more than one transition in the origin range of the q band. comparisons with broad-band fluorescence spectra and fln studies suggest that the multiple band feature originates from the presence of different configuratio ... | 1997 | 9199803 |
| a specific and sensitive elisa for measuring s-100b in cerebrospinal fluid. | a sensitive, simple and specific sandwich elisa for s-100b is described. this method involves the binding of a monoclonal anti-s-100b antibody to the wall of a microtitre plate. this capture antibody is subsequently incubated with s-100b standard, control or patient sample in the form of cerebrospinal fluid (csf). after incubation, the microtitre plate is washed and horseradish peroxidase-labelled polyclonal anti-s-100b is added (detector antibody). the amount of detector antibody bound to the m ... | 1997 | 9236913 |
| differences of the primate flocculus and ventral paraflocculus in the mossy and climbing fiber input organization. | potential sources of cerebellar cortical afferent fibers were identified in the vestibular ganglion, medulla oblongata, pons, and cerebellar nucleus of seven anesthetized macaca fuscata after local injections of wheat germ agglutinin-conjugated horseradish peroxidase or fast blue into the flocculus (fl) or ventral paraflocculus (vp). there were differences in the sources of mossy fibers to the fl and vp. labeled neurons, after injections into the fl, were located mainly in the ipsilateral vestib ... | 1997 | 9184995 |
| fos expression in catecholaminergic medullary neurons induced by chemical stimulation of stomach projecting to the paraventricular nucleus of the hypothalamus in rats. | to determine whether medullary catecholaminergic neurons expressing fos induced by chemical stimulation of the stomach project to the paraventricular nucleus of hypothalamus (pvh) in rats. | 1997 | 27041943 |
| parallel medullary gustatospinal pathways in a catfish: possible neural substrates for taste-mediated food search. | taste and tactile fibers in the facial nerve of catfish innervate extraoral taste buds and terminate somatotopically in the facial lobe (fl)-a medullary structure crucial for gustatory-mediated food search. the present study was performed to determine the neural linkages between the gustatory input and the spinal motor output. spinal injections of horseradish peroxidase (hrp) label spinopetal cells in the octaval nuclei, the nucleus of the medial longitudinal fasciculus, and reticulospinal neuro ... | 1997 | 9169545 |
| factors controlling the substrate specificity of peroxidases: kinetics and thermodynamics of the reaction of horseradish peroxidase compound i with phenols and indole-3-acetic acids. | the rates of oxidation of reducing substrates by heme peroxidases have previously been thought to be controlled only by their ease of oxidation. in the present study, we have compared the kinetics and thermodynamics of the oxidation of indole-3-acetic acid and derivatives and of phenols by horseradish peroxidase. different dependencies of the reaction rates on the thermodynamic driving force reveal substrate specificity controlled by the enzyme-substrate complexes dissociation constants (michael ... | 1997 | 9188707 |
| axonal connections of the medial magnocellular nucleus of the anterior neostriatum in zebra finches. | the medial magnocellular nucleus of the anterior neostriatum (mman) is a small cortical nucleus which was previously identified as a component of the neural circuitry controlling vocal behavior in songbirds based on its efferent connection to the high vocal center (hvc), a major song control nucleus (nottebohm et al. [1982] j. comp. neurol. 207:344-357; bottjer et al. [1989] j. comp. neurol. 279:312-326). we have conducted tract tracing experiments (using wheat-germ agglutinin-horseradish peroxi ... | 1997 | 9183699 |
| synergistic enhancement of the horseradish peroxidase-catalyzed oxidation of luminol by 4-substituted phenylboronic acids. | combinations of 4-substituted phenylboronic acids [phenyl, iodo, bromo, and trans-4-(3-propenoic acid) substituents] have been discovered to have synergistic effects in the horseradish peroxidase (hrp) catalyzed chemiluminescent oxidation of luminol. three types of effect have been observed: 1. synergistic reduction in the background light emission of a luminol-peroxide assay reagent to a value lower than the background obtained with either enhancer individually; 2. increase in signal to backgro ... | 1997 | 18966838 |
| novel chemiluminescent substrate and probe systems for the identification of cfdeltaf508 genotypes. | background: chemiluminescence detection systems are rapidly gaining popularity as safer alternatives to isotopic methods in molecular diagnostics with equal sensitivity and specificity. in addition, they offer versatility of detection because of the availability of different haptens for labeling the probes, the antihapten antibodies conjugated with either alkaline phosphatase (ap) or horseradish peroxidase (hrp), and their respective chemiluminescent substrates. a novel dual chemiluminescent sub ... | 1997 | 10462598 |
| determination of sugar specificity of jackfruit lectin by a simple sugar-lectin binding assay using microtiter plate. | sugar-lectin binding assay was developed as a simple method which employed direct coating of microtiter plate with galactose-binding lectins. biotin-galactose conjugate was used to bind to the immobilized lectins. the bound conjugate was then detected using streptavidin-horseradish peroxidase. using the assay in conjunction with various competing carbohydrates, jackfruit lectin from artocarpus heterophyllus was found to be specific for alpha-anomer of galactoside with an aromatic residue. | 1997 | 9238539 |
| distribution of motoneurons innervating tail muscles in the pigeon. | the distribution of motoneurons innervating the tail muscles, m. levator caudae, m. depressor caudae, m. pubocaudalis externus, m. pubocaudalis internus, m. lateralis caudae and m. flexor cruris, in the adult pigeon was examined by retrograde transport of horseradish peroxides. labeled motoneurons innervating tail muscles were distributed in the longitudinal column of the spinal cord below the sacral spinal segment 5. the average diameter of cell bodies ranged from 23.7 to 62.5 microns. each mot ... | 1997 | 9234225 |
| model development for horseradish peroxidase catalyzed removal of aqueous phenol. | once activated by hydrogen peroxide, horseradish peroxidase (hrp) catalyzes the oxidation of aqueous aromatic compounds to produce high molecular weight polymers of low solubility. a pseudo steady-state kinetic model of the hrp-hydrogen peroxide-aromatic compound system was modified to incorporate enzyme inactivation mechanisms in order to improve its predictive ability. the kinetic constants of the model were calibrated using a series of experimental data sets. the model's ability to predict th ... | 1997 | 18634091 |
| enzyme immunoaffinity chromatography--a rapid semi-quantitative immunoassay technique for screening the presence of isoproturon in water samples. | immunochromatography devices based on the principles of affinity chromatography and enzyme immunoassay have been developed to illustrate the possibility of providing extra-laboratory 'in the field' tests for pesticide monitoring. isoproturon was chosen in this study as an example though other pesticides could have been used provided a suitable antiserum existed. the test system was prepared by immobilising isoproturon antibodies to porous silica which were then packed into disposable columns (im ... | 1997 | 9246817 |
| enrichment of glutamate-like immunoreactivity in the retinotectal terminals of the viper vipera aspis: an electron microscope quantitative immunogold study. | a post-embedding immunogold study was carried out to estimate the immunoreactivity to glutamate in retinal terminals, p axon terminals and dendrites containing synaptic vesicles in the superficial layers of the optic tectum of vipera. retinal terminals, identified following either intraocular injection of tritiated proline, horseradish peroxidase (hrp) or short-term survivals after retinal ablation, were observed to be highly glutamate-immunoreactive. a detailed quantitative analysis showed that ... | 1997 | 9243346 |
| an enhanced immunocytochemical method for staining bone marrow trephine sections. | the detection of cellular antigens in fixed decalcified bone marrow trephine (bmt) sections depends on the method of processing, the nature of the antigen and antibody, antigen retrieval techniques, and the sensitivity of the immunocytochemical method. this study evaluated a tyramide enhanced avidin-biotin immunostaining method on formalin fixed decalcified bmt sections to determine whether the method could detect previously undetectable antigens. | 1997 | 9215121 |
| glycoconjugate saccharidic moieties of the exocrine and endocrine pancreas in the chick embryo, newborn and adult. | a battery of horseradish peroxidase-conjugated lectins (pna, sba, dba, wga, cona, lta and ueai) was used to study the distribution of glycoconjugate sugar residues in the exocrine and endocrine pancreas of chick embryos, 1-day-old chicks and adult animals. during the period of incubation considered here, the time of appearance and changes in the oligosaccharides were noted in the acinar cells, in the endocrine cells of the "light islets" and in the capillary endothelial cells. in the developing ... | 1997 | 9187740 |
| generation of free radicals during anoxia and reoxygenation in perfused osteoblastlike cells. | sensitivity to ischemia and reperfusion injury is a main problem afflicting tissues exposed to a prolonged period of oxygen deprivation. the generation of oxygen free radicals, in particular, is considered a major cause of postischemic reperfusion injury. however, studies on the mechanisms of production of free radicals are limited by the difficulty to measure in real time their formation and to discriminate between the different oxyradical species. the aim of this study was to determine whether ... | 1997 | 9170387 |
| excitatory and inhibitory vestibular pathways to the extraocular motor nuclei in goldfish. | electrophysiological, ultrastructural, and immunohistochemical techniques were utilized to describe the excitatory and inhibitory vestibular innervation of extraocular motor nuclei in the goldfish. in antidromically activated oculomotor motoneurons, electrical stimulation of the intact contralateral vestibular nerve produced short-latency, variable amplitude electrotonic excitatory postsynaptic potentials (epsps) at 0.5-0.7 ms followed by chemical epsps at 1.0-1.3 ms. stimulation of the ipsilate ... | 1997 | 9163391 |
| poisonous plants: when they are a threat to children. | plant toxic to humans abound in home and yard as well as open fields and woods. only experienced botanists and serious students of edible vegetation can distinguish safely what is edible, inedible, or simply toxic. parents should be instructed to protect their children from truly toxic household plants and train their children never to eat a plant not provided to them by someone trustworthy as edible. if a child or an adult consumes a possibly toxic plant, the regional poison center should be co ... | 1997 | 9114716 |
| kinetic studies on the oxidation of phenols by the horseradish peroxidase compound ii. | oxidation of substituted phenols by horseradish peroxidase compound ii were studied using stopped-flow technique. dissociation constants (k(d)) of hrp-ii-phenol complexes were deduced from the kinetic data. magnitudes of k(d) fall in a relatively narrow range of 3-11 mm. these are comparable to 3-10 mm reported for the binding of substituted phenols to native hrp, suggesting that the mode of binding of phenols to native hrp and hrp compound ii may be similar. ph dependence of the apparent second ... | 1997 | 9165102 |
| low catalytic turnover of horseradish peroxidase in thiocyanate oxidation. evidence for concurrent inactivation by cyanide generated through one-electron oxidation of thiocyanate. | the catalytic turnover of horseradish peroxidase (hrp) to oxidize scn- is a hundredfold lower than that of lactoperoxidase (lpo) at optimum ph. while studying the mechanism, hrp was found to be reversibly inactivated following pseudo-first order kinetics with a second order rate constant of 400 m-1 min-1 when incubated with scn- and h2o2. the slow rate of scn- oxidation is increased severalfold in the presence of free radical traps, 5-5-dimethyl-1-pyrroline n-oxide or alpha-phenyl-tert-butylnitr ... | 1997 | 9110998 |
| stereochemistry of the fe(ii)- and fe(iii)-cyanide complexes of the homodimeric scapharca inaequivalvis hemoglobin. a resonance raman and ftir study. | resonance raman measurements carried out in parallel on ferrous and ferric scapharca inaequivalvis dimeric hemoglobin cyanide derivatives allowed the identification of the electron density marker bands and heme core size marker bands in both derivatives in comparison with those obtained for the carbonmonoxy and deoxy adducts. the iron cyanide stretching mode, measured for the first time in a ferrous hemoprotein, has been detected at 455 cm(-1), only 6 cm(-1) lower than in the corresponding ferri ... | 1997 | 9109658 |
| dichlorodihydrofluorescein and dihydrorhodamine 123 are sensitive indicators of peroxynitrite in vitro: implications for intracellular measurement of reactive nitrogen and oxygen species. | 2,7-dichlorodihydrofluorescein (dcdhf), commonly known as dichlorofluorescin, and dihydrorhodamine 123 (dhr) are often used to detect the production of reactive nitrogen and oxygen species in cells via oxidation to their respective fluorescent products. to determine which biological oxidants might be involved, dcdhf and dhr were exposed to a number of oxidants in vitro to determine which are capable of oxidizing these compounds. formation of dichlorofluorescein (dcf) and rhodamine is typically m ... | 1997 | 9701053 |
| epitope mapping of horseradish peroxidase (isoenzyme c). | peptide scanning (pepscan) was used to determine linear antigenic determinants of horseradish peroxidase isoenzyme c (hrpc). for this purpose, we synthesized 303 overlapping hexapeptide fragments (with a step of one amino acid residue) of the protein primary structure and studied their interactions with anti-hrpc polyclonal antisera by elisa. experiments with various titers of antisera allowed us to determine linear antigenic determinants of hrpc; several such determinants were spatially located ... | 1997 | 9275282 |
| evidence for fusion between multilamellar endosomes and autophagosomes in hela cells. | the organelles of the endocytic and autophagic pathways were studied in hela cells using immunoelectron microscopy and stereological techniques. in the absence of autophagic stimulation, characteristic particulate structures containing closely packed layers of membrane received the fluid-phase marker horseradish peroxidase after 25 min uptake. these multilamellar endosomes contained the majority of the cellular immunogold labeling obtained by using a monoclonal antibody (1b5) directed against a ... | 1997 | 9127730 |
| histological distribution of fr-1, a cyclic rgds-peptide, binding sites during early embryogenesis, and isolation and initial characterization of fr-1 receptor in the sand dollar embryo. | a fibronectin-related synthetic cyclic h-cys-arg-gly-asp-ser-pro-ala-ser-ser-cys-oh (rgdspass) peptide (fr-1) binding site in the embryo of the sand dollar clypeaster japonicus was specified using dansyl-labeled fr-1 (dns-fr-1) and horseradish peroxidase-labeled fr-1, and an fr-1 receptor was isolated using fr-1-affinity column chromatography. the fr-1 introduced to the blastocoel of blastulae inhibited primary mesenchyme cell (pmc) migration in mesenchyme blastulae, and complete gastrulation an ... | 1997 | 9108334 |
| in vitro free radical metabolism of phenolphthalein by peroxidases. | phenolphthalein, a widely used laxative, is the active ingredient in more than a dozen commercial nonprescription formulations. fast-flow epr studies of the reaction of phenolphthalein with horseradish peroxidase (hrp) and hydrogen peroxide permit the direct detection of two free radicals. one has epr parameters characteristic of phenoxyl radicals. the other has a broad unresolved spectrum, possibly arising from free radical polymeric products of the initial phenoxyl radical. epr spin-trapping s ... | 1997 | 9107547 |
| formation of reactive nitrogen species during peroxidase-catalyzed oxidation of nitrite. a potential additional mechanism of nitric oxide-dependent toxicity. | involvement of peroxynitrite (onoo-) in inflammatory diseases has been implicated by detection of 3-nitrotyrosine, an allegedly characteristic protein oxidation product, in various inflamed tissues. we show here that nitrite (no2-), the primary metabolic end product of nitric oxide (no.), can be oxidized by the heme peroxidases horseradish peroxidase, myeloperoxidase (mpo), and lactoperoxidase (lpo), in the presence of hydrogen peroxide (h2o2), to most likely form no.2, which can also contribute ... | 1997 | 9065416 |
| mechanisms of active oxygen species reduction by non-steroidal anti-inflammatory drugs. | many forms of active oxygen have been suggested to participate in the course of inflammation. anti-inflammatory drugs have been considered to function as active oxygen inhibitors. however, detailed mechanisms for such inhibitory activity remain unclear because of little well established methods to study inhibitory effect of anti-inflammatory drugs on active oxygen species. in this report, the author investigated four non-steroidal anti-inflammatory drugs, including acetaminophen, sodium salicyla ... | 1997 | 9202422 |
| a 4-term energy level scheme for the high-spin ferrous hemoproteins: evidence for the 5e eta, and 5b2 terms as the ground multiplets in hemoproteins with a histidine and a cysteine protein-derived heme ligand, respectively. | we have carried out analysis of the electronic level scheme of the high-spin ferrous hemoproteins by simultaneous fit of the adjustable parameters of a 4-term theoretical model to low-temperature magnetic circular dichroism (mcd), room temperature absorption spectra and available magnetic susceptibility and or mössbauer data of myoglobin, horseradish peroxidase and cytochrome p450. the high reliability of the ligand field parameter values obtained for deoxymyoglobin is confirmed by good agreemen ... | 1997 | 9177039 |
| [amplification of immunologic reactions using catalytic deposition at the reaction sites of tyramine derivatives. a decisive gain in sensitivity in immunohistochemistry and in situ hybridization]. | in the catalyzed reporter deposition technique, horseradish peroxidase catalyzes the activation of conjugated phenolic compounds resulting in the covalent binding of the radicalized intermediates to electron rich moieties in the protein molecules present at the site of reaction. comparing the biotinyl-, digoxigeninyl-, and fluoresceinyl-derivatives of tyramine and four immunohistochemical formats, we showed that the most sensitive detection system was that using biotinyl-tyramide and an immunohi ... | 1997 | 9162152 |
| [equilibrium and kinetic parameters of interaction between peroxidase conjugates of strophanthin and anti-peroxidase antibodies]. | interactions of three horseradish peroxidase (hrp)-strophanthin conjugates containing one, two, or three glycoside molecules (hrp-str1, 2, or 3, respectively) with polyclonal anti-hrp antibodies were studied by homogeneous enzyme immunoassay. the total peroxidase activity of free conjugates and their immune complexes was estimated from the oxidation of o-phenylenediamine. the dissociation constants of the immune complexes and the rate constants of their dissociation and formation were determined ... | 2006 | 9157414 |
| apical effect of diosmectite on damage to the intestinal barrier induced by basal tumour necrosis factor-alpha. | in many digestive diseases the intestinal barrier is weakened by the release of proinflammatory cytokines, including tumour necrosis factor-alpha (tnf alpha). | 1997 | 9135522 |
| location of efferent terminals of the primate flocculus and ventral paraflocculus revealed by anterograde axonal transport methods. | efferents of the flocculus (fl) and ventral paraflocculus (vp) were examined in seven anesthetized macaca fuscata by anterograde axonal transport method using wheat germ agglutinin-conjugated horseradish peroxidase or phaseolus vulgaris leucoagglutinin. several major foci of axon terminals were found in the vestibular nuclear complex and cerebellar nuclei. a difference was seen in the location of efferent terminals between the fl and vp. when the tracer covered the fl, labeled axon terminals wer ... | 1997 | 9129184 |
| bacterial evolution and silicon. | this review examines the possible role of silicon in molecular evolution. it is possible silicon participated in early molecular evolution by providing a stable mineral surface or gel structure where the assembly and replication of primitive genetic information occurred. however, as molecular evolution proceeded, silicon was not required in the evolution of c-based organisms. silicon can be accumulated by diatoms and other living organisms such as silicoflagellates, some xanthophytes, radiolaria ... | 1997 | 9111922 |
| localization of nadph-diaphorase containing neurons in the spinal dorsal horn and spinal sensory ganglia of the turtle chrysemys d'orbigny. | nadph-diaphorase positive (ndp) neurons and nerve fibers were found in the spinal dorsal horn (dh) and sensory ganglia of the turtle chrysemys d'orbigny. three well-defined types of ndp neurons were found in the dh: (a) elongated nerve cells with two radially arranged dendritic branches, (b) neurons with rostrocaudal dendritic branches, (c) bitufted neurons with two, practically symmetric branches that project to the ipsilateral and contralateral dorsal horns. a combination of the techniques tha ... | 1997 | 9108212 |
| peroxidase substrates stimulate the oxidation of hydralazine to metabolites which cause single-strand breaks in dna. | hydrazines are believed to be oxidized by peroxidases to reactive intermediates responsible for a variety of adverse side effects including cancer and drug-induced lupus. however, hydrazines are regarded as a poor peroxidase substrates because inactivation of the peroxidase occurs during oxidation of these compounds. we have investigated the hypothesis that efficient peroxidase substrates, termed mediators, may stimulate peroxidase-catalyzed oxidation of hydrazines to intermediates capable of ca ... | 1997 | 9084913 |
| a model for interpreting the tracer labeling of interendothelial clefts. | we extended the model describing the low molecular weight electron dense tracer wake in the interendothelial cleft and surrounding tissue to describe the time-dependent transport of intermediate size solutes of 1.0-3.5 nm radius by convection and diffusion in an interendothelial cleft containing a fiber matrix. this model provides a quantitative basis on which to reinterpret electron microscopic studies of the distribution of tracers such as horseradish peroxidase (hrp; molecular weight = 40,000 ... | 2007 | 9084841 |
| binding of iodide to arthromyces ramosus peroxidase investigated with x-ray crystallographic analysis, 1h and 127i nmr spectroscopy, and steady-state kinetics. | the site and characteristics of iodide binding to arthromyces ramosus peroxidase were examined by x-ray crystallographic analysis, 1h and 127i nmr, and kinetic studies. x-ray analysis of an a. ramosus peroxidase crystal soaked in a ki solution at ph 5.5 showed that a single iodide ion is located at the entrance of the access channel to the distal side of the heme and lies between the two peptide segments, phe90-pro91-ala92 and ser151-leu152-ile153, 12.8 a from the heme iron. the distances betwee ... | 1997 | 9038188 |
| the inactivation and catalytic pathways of horseradish peroxidase with m-chloroperoxybenzoic acid. a spectrophotometric and transient kinetic study. | the kinetics of the catalytic cycle and irreversible inactivation of horseradish peroxidase c (hrp-c) reacting with m-chloroperoxybenzoic acid (mcpba) have been studied by conventional and stopped-flow spectrophotometry. mcpba oxidized hrp-c to compound i with a second order-rate constant k1 = 3.6 x 10(7) m-1 s-1 at ph 7.0, 25 degrees c. excess mcpba subsequently acted as a one-electron reducing substrate, converting compound i to compound ii and compound ii to resting, ferric enzyme. in both of ... | 1997 | 9038149 |
| early development and developmental plasticity of the fasciculus gracilis in the north american opossum (didelphis virginiana). | the first objective of the present study was to ask when axons of the fasciculus gracilis reach the nucleus gracilis in the north american opossum (didelphis virginiana). when fast blue (fb) was injected into the lumbar cord on postnatal day (pd) 1 and the pups were killed 2 days later, labeled axons were present within a distinct fasciculus gracilis at thoracic and cervical levels of the cord. when comparable injections were made at pd3 or 5 and the pups were allowed to survive for the same tim ... | 1997 | 9051256 |
| terminal morphology of two branches arising from a single stem-axon of pretectal (psm) neurons in the common carp. | the induction of postsynaptic structures by presynaptic terminals is suggested in a teleost brain. neurons in the nucleus pretectalis superficialis pars magnocellularis (psm) in the common carp are known to send fibers to the corpus mamillare (cm) and the nucleus lateralis valvulae (nlv). individual axons of psm neurons bifurcate (or give off an axon collateral), both of which reach the target areas in the cm and nlv. the morphology of horseradish peroxidase-labeled terminals in the cm and nlv a ... | 1997 | 9034898 |
| evidence of spinocerebellar mossy fiber segregation in the juvenile staggerer cerebellum. | developmental and experimental studies of climbing fiber and mossy fiber connectivity in the cerebellum have suggested that purkinje cells are the critical organizing elements for connectivity patterns. this hypothesis is supported by evidence that spinocerebellar mossy fiber projections are abnormally diffuse in p25 sg/sg mutant mice in which the differentiation of a reduced number of sg/sg purkinje cells is blocked due to a cell autonomous defect. however, mossy fiber distribution may be disru ... | 1997 | 9034896 |
| organization of somatosensory cortex and distribution of corticospinal neurons in the eastern mole (scalopus aquaticus). | the somatotopic organization of somatosensory cortex of the eastern mole (scalopus aquaticus) was explored with multiunit microelectrode recordings from middle layers of cortex. the recordings revealed the presence of at least parts of two systematic representations of the body surface in the lateral cortex. one of the representations appears to be primary somatosensory cortex (s1), and it contained cytochrome oxidase dark regions, separated by light septa that formed isomorphs with some body pa ... | 1997 | 9034895 |
| synaptic connections between identified neuron types in the antennal lobe glomeruli of the cockroach, periplaneta americana: i. uniglomerular projection neurons. | a combination of three different labels was used to demonstrate synapses between three types of neurons within the glomeruli: 1) antennal receptor cells, 2) gamma-aminobutyric acid (gaba)-immunoreactive neurons, and 3) uniglomerular projection neurons. receptor cell axons were experimentally severed and caused to degenerate; uniglomerular projection neurons, a subgroup of glomerular output neurons, were labeled by intracellular horseradish peroxidase (hrp) injection and gaba-containing neurons b ... | 1997 | 9034893 |
| a chemiluminescent flow sensing device for determination of choline and phospholipase d activity in biological samples. | a chemiluminescent flow-sensing device for the determination of phospholipase d (pld) activity and/or choline (ch) in biological samples using choline oxidase (cho) and horseradish peroxidase (hrp) immobilized on eupergit c (polymer beads of methacrylamide, n-methylene-bis-methacrylamide, and allyl-glycidyl-ether) was developed. the best results were obtained with immobilized cho and hrp at a polymer beads wet weight ratio of 16:1. the optimized parameters of the developed sensing device were 56 ... | 1997 | 9056196 |
| mutation of distal residues of horseradish peroxidase: influence on substrate binding and cavity properties. | the manner in which the distal heme pocket residues of peroxidases control the reaction mechanism and ligand binding has been investigated further by analysis of the electronic absorption and resonance raman (rr) spectra of distal site mutants of recombinant horseradish peroxidase (hrp-c*). the roles of the conserved distal histidine and arginine residues, particularly in the context of the catalytic mechanism originally proposed for cytochrome c peroxidase (ccp), have been evaluated by studying ... | 1997 | 9063902 |
| amperometric sensors for simultaneous superoxide and hydrogen peroxide detection. | a two-channel sensor capable of almost instantaneous simultaneous detection of superoxide radical and hydrogen peroxide in the concentration range 10(-)(7)-10(-)(4) m is very important for understanding of a number of rapid kinetics processes. a glassy carbon working microelectrode covered by an electrodeposited polypyrrole/horseradish peroxidase (ppy/hrp) membrane was employed as a h(2)o(2) sensor. another glassy carbon microelectrode covered by a composite membrane of an inside layer of ppy/hr ... | 1997 | 21639197 |
| development of a monoclonal antibody to urinary degradation products from the c-terminal telopeptide alpha 1 chain of type i collagen. application in an enzyme immunoassay and comparison to crosslaps elisa. | a monoclonal antibody maba7 was raised against a synthetic peptide having a sequence (ekahdggr) specific for a part of the c-telopeptide alpha 1 chain of type i collagen. maba7 was labelled with horseradish peroxide and used in a competitive one-step enzyme-linked immunosorbent assay (elisa) for measurement of urinary type i collagen degradation products. the assay was technically evaluated and preliminary clinical data are presented. the measuring range was 200-7000 micrograms l-1 with a detect ... | 1997 | 9127460 |
| peroxidase-catalyzed oxidation of beta-carotene in hl-60 cells and in model systems: involvement of phenoxyl radicals. | recent studies provide extensive evidence for the importance of carotenoids in protecting against oxidative stress associated with a number of diseases. in particular, reactions of carotenoids with phenoxyl radicals generated by peroxidase-catalyzed one-electron metabolism of phenolic compounds may represent an important antioxidant function of carotenoids. to further our understanding of the antioxidant mechanisms of carotenoids, we used in the present work two different phenolic compounds, phe ... | 1997 | 9075202 |
| spectroscopic evidence for a conformational transition in horseradish peroxidase at very low ph. | resonance raman (rr), electronic absorption, and circular dichroism (cd) spectroscopies of the ferric, ferrous, and ferrous-co forms of horseradish peroxidase (hrp-c) at ph 3.1 are reported. the cd spectra in the uv region show only a small decrease in the alpha-helical content upon ph lowering, whereas dramatic changes are observed in the soret region. the final form of ferric hrp-c is 5-coordinate high-spin heme whose histidine ligand is replaced by a water ligand with a polar character. the e ... | 1997 | 9012679 |
| roles of efficient substrates in enhancement of peroxidase-catalyzed oxidations. | efficient peroxidase substrates may have a critical role in the oxidation of secondary compounds by peroxidases. hydrazines are often oxidized slowly by peroxidases due, in part, to hydrazine-dependent inactivation of these enzymes. peroxidase-catalyzed oxidation of hydrazines may be dramatically affected by an efficient peroxidase substrate. we investigated this hypothesis in a model system using the well-known peroxidase substrate chlorpromazine (cpz) and the hydrazine derivative isoniazid. cp ... | 1997 | 8993327 |
| effect of distal cavity mutations on the binding and activation of oxygen by ferrous horseradish peroxidase. | mutations have been introduced at residues arg-38 or his-42 in horseradish peroxidase isoenzyme c (hrpc) in order to probe the role of these key distal residues in the reaction of ferrous hrpc with dioxygen. the association and dissociation rate constants for dioxygen binding to his-42 --> leu, his-42 --> arg, arg-38 --> leu, arg-38 --> lys, arg-38 --> ser, and arg-38 --> gly variants have been measured using stopped-flow spectrophotometry. replacement of his-42 by leu or arg increases the oxyge ... | 1997 | 8995273 |
| new physiological effects of 5-aminolevulinic acid in plants: the increase of photosynthesis, chlorophyll content, and plant growth. | 5-aminolevulinic acid (ala) promoted the growth and yield of several crops and vegetables at concentrations lower than those eliciting herbicidal responses, i.e., less than 1.8 mm by foliar spray and 60 μm by root soaking. to evaluate the physiological action of ala, the effects of ala on plants were examined by several bioassay systems at 0.0006-600 μm. ala at 0.06-6 μm by root soaking increased the growth of rice seedlings in light, but did not affect this in darkness. in horseradish shoot pri ... | 1997 | 27396878 |
| kinetics of tert-butyl hydroperoxide decomposition in erythrocyte suspension. | the kinetics of tert-butyl hydroperoxide (t-bhp) decomposition was examined in erythrocyte suspension from c57b1/6 mice by the chemiluminescence method. the reaction with horseradish peroxidase, t-bhp (20 nmol/ml), and luminol was accompanied by a rapid chemiluminescence increase. the integral value of the chemiluminescence signal correlated with the t-bhp concentration at every moment of time. in the erythrocyte suspension, the half-life of t-bhp decomposition was 23.8 s. the decomposition rate ... | 1997 | 9553936 |
| the retinopetal visual system in the chameleon (chameleo chameleon). | intraocular injections of rhodamine and horseradish peroxidase in chameleon, labelled retrogradely neurons in the ventromedial tegmental region of the mesencephalon and the ventrolateral thalamus of the diencephalon. in both areas, staining was observed contralaterally to the injected eye. labelling was occasionally observed in some rhombencephalic motor nuclei. these results indicate that chameleons, unlike other reptilian species, have two retinopetal nuclei. | 1997 | 9476209 |
| effects of acetonitrile on horseradish peroxidase (hrp)-anti hrp antibody interaction. | the effects of the water-miscible organic solvent acetonitrile on the enzymatic activity of horseradish peroxidase (hrp) and on hrp-anti-hrp binding have been investigated. results showed that both the catalytic activity of hrp and the binding ability of the antibody were affected on increasing the concentration of the organic solvent. the activity of hrp varied with the organic composition of the solvent, indicating that the conformation of the enzyme was affected. the binding ability of the an ... | 1997 | 9366020 |
| quantitative and topographical study of retinal ganglion cells in the chameleon (chameleo chameleon). | chameleons display a number of well-described physiological peculiarities of their visual system, but there is no information on the topography of the retinal ganglion cell layer. in the present study, ganglion cell density of the chameleon retina was constructed from whole mounts of the retina stained with cresyl violet. for the identification of ganglion cells, these latter cells were labelled retrogradely with horseradish peroxidase applied to the optic nerve. using this criterion, the propor ... | 1997 | 9365807 |
| correlation of lectin binding with lymph node metastasis in oral cancers. | lymph node metastasis is an important factor that influences the treatment policy and prognosis of oral cancers. the cell membrane is known to play a role in the metastatic process. the aim of the present study was to evaluate the relationship of lectin binding frequency of oral cancer cells to their capacity to metastasize to the lymph node. smears collected from tumours of 66 untreated patients were stained with jackfruit lectin (jfl) conjugated with horseradish peroxidase (hrp), with diaminob ... | 1997 | 9192548 |
| use of methyl methacrylate resin for embedding bone marrow trephine biopsy specimens. | to evaluate the use of methyl methacrylate resin as an embedding medium for undecalcified bone marrow trephine biopsy specimens. | 1997 | 9059356 |
| promotion of glutathione-gamma-glutamyl transpeptidase-dependent lipid peroxidation by copper and ceruloplasmin: the requirement for iron and the effects of antioxidants and antioxidant enzymes. | oxidative damage (lipid peroxidation, lpo) induced in a completely defined system containing glutathione (gsh), purified gamma-glutamyl transpeptidase (ggt), and edta- and adp-chelated ferric iron was enhanced by catalytic amounts of cupric ions and by ceruloplasmin (cp). the enhancement depended on gsh concentration, ggt activity, the presence of iron, and the chelation of copper by o-phenanthroline. high concentrations of cp inhibited lpo. cu- and cp-enhanced, gsh-ggt-driven lpo was inhibited ... | 1997 | 9020310 |
| possible involvement of free radical scavenging properties in the action of tumor necrosis factor-alpha. | constitutive production of hydroxyl radicals from four established cancer cell lines was detected as spin adducts of 5,5-dimethyl-l-pyroline-n-oxide (dmpo), using an electron spin resonance spectrometer. the generated hydroxyl radicals was decreased in three out of four cancer cell lines when incubated in vitro for 3 h with tnf-alpha no direct scavenging effect of tnf-alpha on hydroxyl radicals or superoxide anions was observed in the in vitro radical generation system. the modulation of intrace ... | 1997 | 9013130 |
| circulating autoantibodies recognizing peroxidase-oxidized low density lipoprotein. evidence for new antigenic epitopes formed in vivo independently from lipid peroxidation. | oxidatively modified ldls are antigenic and elicit the generation of autoantibodies often detected in plasma and within plaques of atherosclerotic patients. although cu(2+)-oxidized ldl and malondialdehyde (mda)-modified ldl are usually used as antigens in immunoassays, other, still unrecognized epitopes may be formed in vivo during ldl oxidation and may induce antibody production. antibodies recognizing ldl oxidatively modified by cu2+, 2,2'-azobis-(2-amidino propane) hydrochloride (aaph), and ... | 1997 | 9012648 |
| peroxidase activation of 4-hydroxytamoxifen to free radicals detected by epr spectroscopy. | 4-hydroxytamoxifen is a major metabolite of the antiestrogenic drug tamoxifen used in the treatment of women with breast cancer. 4-hydroxytamoxifen is broken down by a horseradish peroxidase/h2o2 system very much more rapidly than tamoxifen and causes much greater dna damage determined by 32p-postlabelling. epr spin trapping of 4-hydroxytamoxifen reaction products in the presence of the free radical trap 5,5-dimethyl-1-pyrroline n-oxide, together with glutathione as a hydrogen donor, resulted in ... | 1997 | 8981033 |
| the forebrain of the blind cave fish astyanax hubbsi (characidae). ii. projections of the olfactory bulb. | the primary subdivisions of the telencephalon of a characidian, astyanax hubbsi, were extensively described and this subsequent study elucidates the organization of the secondary olfactory system based on horseradish peroxidase (hrp) and carbocyanine dye (dii) tracing techniques. both methods yielded similar results. two fiber bundles project from the olfactory bulbs into the ventral rostral telencephalon: the medial olfactory tract (tom), embedded in the white matter of the ventral telencephalo ... | 1997 | 8980851 |
| a tract-tracing study of the central projections of the mesencephalic nucleus of the trigeminus in the guppy (lebistes reticulatus, teleostei), with some observations on the descending trigeminal tract. | we studied the central projections of the mesencephalic nucleus of the trigeminal nerve (mesv) in the guppy (lebistes reticulatus), after application of horseradish peroxidase or fluorescein dextran amine into the eye orbit. a small number (1 to 13) of large mesencephalic trigeminal neurons were solid labeled in the ipsilateral rostral mesencephalon. at the level of the trigeminal nerve entrance, the united process of each mesencephalic trigeminal cell bifurcates, giving rise to a peripheral bra ... | 1997 | 8971415 |
| scanning force microscopy of dna deposited onto mica: equilibration versus kinetic trapping studied by statistical polymer chain analysis. | this paper reports a study of the deposition process of dna molecules onto a mica surface for imaging under the scanning force microscope (sfm). kinetic experiments indicate that the transport of dna molecules from the solution drop onto the surface is governed solely by diffusion, and that the molecules are irreversibly adsorbed onto the substrate. a statistical polymer chain analysis has been applied to dna molecules to determine the deposition conditions that lead to equilibrium and those tha ... | 1996 | 9000621 |
| applying hollow fibres for separating free and bound label in continuous-flow immunochemical detection. | on-line liquid chromatography-immunochemical detection (lc-icd) provides the possibility to individually monitor cross-reactive compounds overcoming the need of tedious fraction collection. icd is performed as a post-column reaction detection system and is based on a two-step immunoreaction. in the first step unlabelled antibodies are added to the lc effluent and allowed to react with antigens (analytes) eluting from the lc column. the amount of analytes bound to the antibodies is measured by ad ... | 1996 | 8997748 |
| quantitative analysis of triphasic (h3) horizontal cell-cone connectivity in the cyprinid fish (roach) retina. | although horizontal cells encode chromatic information by means of a variety of spectrally opponent light-evoked response patterns, their synaptic connections with the different spectral classes of cone are not completely understood. in the cyprinid fish retina, where a hierarchical set of interactions between horizontal cells and cone types has been proposed, a particular type of horizontal cell generates light-evoked triphasic (red-hyperpolarizing/green depolarizing/blue-hyperpolarizing) respo ... | 1996 | 9068853 |
| isolation and characterization of early endosomes, late endosomes and terminal lysosomes: their role in protein degradation. | although endosomal proteolysis has been reported (e.g. for peptide hormones and lysosomal enzymes), lysosomes are believed to be the main site of degradation in the endocytic pathway. we have studied the separate roles of lysosomes and prelysosomal endocytic organelles in the degradation of ovalbumin in j774 cells. the ovalbumin was labelled with 125i-tyramine cellobiose (125i-tc-ova). the labelled degradation products formed from this probe are trapped at the site of formation. to separate lyso ... | 1996 | 9013338 |
| rantes chemokine expression in transplant-associated accelerated atherosclerosis. | the pathogenesis of transplantation-associated accelerated atherosclerosis is poorly understood, but it is likely to be an alloimmune response involving infiltration of the vessel wall by t lymphocytes and monocytes leading to smooth muscle cell proliferation and extracellular matrix deposition. rantes is a chemokine that selectively chemoattracts t lymphocytes, nk cells, monocytes, and eosinophils. the expression of rantes in accelerated atherosclerosis was investigated by in situ hybridization ... | 1996 | 8981204 |
| acid-catalyzed oxidation of the anticancer agent mitoxantrone by nitrite ions. | mitoxantrone (1,4-dihydroxy-5,8-bis[2-[(2-hydroxyethyl)amino]ethyl]amino-9,10-anth rac enedione; mxh2) is a novel anticancer agent that is useful in the treatment of leukemia and breast cancer. in contrast to other anthracenedione-based agents, this drug causes fewer side effects, mainly because it is resistant to metabolic reduction. we investigated the interaction between mxh2 and inorganic nitrite (no2-) in aqueous solutions and found that this drug undergoes acid-catalyzed oxidation by nitri ... | 1996 | 8967984 |
| differential back-invasion of a single complex dendrite of an abducens motoneuron by n-methyl-d-aspartate-induced oscillations: a simulation study. | intracellular recording of abducens motoneurons in vivo has shown that ionophoretic applications of n-methyl-d-aspartate produced long-lasting membrane potential oscillations including a slow depolarization plateau with a burst of fast action potentials. this complex n-methyl-d-aspartate pattern was reproduced in the model of abducens motoneuron in vivo identified, intracellularly stained with horseradish peroxidase and reconstructed at high spatial resolution. the excitable soma of the simulate ... | 1996 | 8938748 |
| differential sprouting responses in axonal fiber systems in the dentate gyrus following lesions of the perforant path in wlds mutant mice. | axons in both peripheral nerves and central fiber pathways undergo very slow wallerian degeneration in wlds mutant mice. it has recently been shown that in wlds mutant mice there is a delay in the intensification of acetylcholinesterase histochemical staining in the molecular layer of the dentate gyrus following lesions of the entorhinal cortex. thus, it appears that delayed post-lesion reactive sprouting is associated with the delayed degeneration of cut central axons in this mutant. we have st ... | 1996 | 8973802 |
| resonance raman spectra of native and mesoheme-reconstituted horseradish peroxidase and their catalytic intermediates. | resonance raman studies of native and mesoheme-reconstituted horseradish peroxidase and their catalytic intermediates, known as compounds i and ii, have been conducted using both near uv ( approximately 350 nm) and visible (406.7 nm) excitation. careful power studies indicate that the authentic compound i spectra are obtainable using near uv excitation, but that use of visible excitation results in contamination of the compound i spectrum with the spectrum of a compound ii-like photoproduct. usi ... | 1996 | 8910524 |
| catalytic roles of the distal site asparagine-histidine couple in peroxidases. | there are highly conserved hydrogen bonds between the distal his and the adjacent asn in many peroxidases. although the crystal structure of horseradish peroxidase c (hrp) is not available, comparison of the amino acid sequence with cytochrome c peroxidase indicates that asn70 is making the hydrogen bond with the distal his in the active site of hrp. to investigate the catalytic roles of the hydrogen bond, asn70 in hrp was replaced with val (n70v) or asp (n70d). though uv-vis, cd, and 1h-nmr spe ... | 1996 | 8916910 |
| effect of polymers on enhanced chemiluminescent assays for peroxidase and peroxidase labels. | hydroxypropyl methylcellulose, hydroxyethyl cellulose, and hydroxybutyl methylcellulose stabilized light emission in a boronic acid-enhanced chemiluminescent assay for horseradish peroxidase. the stabilization of light emission was concentration-dependent and more effective with substituted boronic acid enhancers (e.g. 4-iodophenylboronic acid) than with substituted phenol enhancers (e.g. 4-iodophenol). hydroxybutyl methylcellulose improved the linearity of the dose-response curve in a peroxidas ... | 2015 | 9343314 |
| cytogenetic, developmental, and biochemical effects of aluminum, iron, and their mixture in sea urchins and mussels. | the present study was undertaken to evaluate the toxicity of aluminum sulfate, ferric chloride and their 1:1 mixture (mix) on early development, fertilization and offspring quality in three sea urchins species (sphaerechinus granularis, paracentrotus lividus, psammechinus microtuberculatus) and in mussels (mytilus galloprovincialis). the endpoints were the following: a) larval malformations; b) developmental arrest; c) embryonic mortality; d) fertilization success; e) cytogenetic effects, and f) ... | 1996 | 8975818 |
| anatomical and physiological investigation of auditory input to the superior colliculus of the echolocating megachiropteran bat rousettus aegyptiacus. | the objective of this study was to investigate whether a representation of auditory space in the superior colliculus (sc) of the echolocating megachiropteran bat (rousettus aegyptiacus) exists. additionally the subcortical auditory connectivity of the sc was investigated. a total of 207 units were recorded in five awake animals while presenting acoustic stimuli (white noise, clicks, and pure tones) at different positions in space. six units responded to acoustic stimulation. three of these locat ... | 1996 | 8951391 |
| thapsigargin-induced transport of cholera toxin to the endoplasmic reticulum. | cholera toxin is normally observed only in the golgi apparatus and not in the endoplasmic reticulum (er) although the enzymatically active a subunit of cholera toxin has a kdel sequence. here we demonstrate transport of horseradish peroxidase-labeled cholera toxin to the er by electron microscopy in thapsigargin-treated a431 cells. thapsigargin treatment strongly increased cholera toxin-induced camp production, and the formation of the catalytically active a1 fragment was somewhat increased. bin ... | 1996 | 8901582 |