| a novel method for measuring protein expression at the cell surface. | all methods described in the literature that allow quantitative measurements of protein expression at the cell surface are applicable to subsets of surface-exposed proteins only. we developed a new method, involving 3,3'-diaminobenzidine (dab) cytochemistry, which allowed determination of cell-surface expression of all plasma membrane proteins measured, in at least three different cell lines. adherent cells were first brought into suspension by proteinase k and edta treatment at 0 degrees c remo ... | 1993 | 8126101 |
| secondary olfactory projections and pallial topography in the pacific hagfish, eptatretus stouti. | the extent of the secondary olfactory projections shows great variation among different groups of craniates. gnathostomes typically display restricted secondary olfactory projections, whereas lampreys have more extensive projections. any attempt to determine the phylogenetic polarity of these characters, that is, to decide which is primitive and which is derived, requires an investigation of the secondary olfactory system in the sister group of lampreys and gnathostomes, the hagfishes. therefore ... | 1993 | 8288769 |
| use of a regenerable immobilized second antibody to determine azidothymidine in a flow system. | a regenerable immobilized second-antibody reactor was used to measure azidothymidine (azt) by competitive enzyme immunoassay in a flow system. the immobilized antibody was regenerated 4 times with little loss of immunospecificity. a residual enzymatic activity of about 7% of the total response was obtained with horseradish peroxidase as label. azt was measured below the nanomolar level by allowing competition to proceed for about 2 min. a limit of detection of 6.57 x 10(-11) +/- 1.56 x 10(-11) m ... | 1993 | 8291680 |
| distribution of gabaergic synaptic terminals on the dendrites of locust spiking local interneurones. | double-labelling and electron microscopy were used to assess the distribution of gabaergic synapses made onto the neurites of spiking local interneurones in the locust. the aims were to determine the sites of inputs mediating inhibition of the spiking local interneurones and to ascertain the relative abundance of such inputs. this information should allow us to understand better the integrative properties of these spiking local interneurones and the role of inhibition in shaping their receptive ... | 1993 | 8282852 |
| diencephalic gustatory connections in the channel catfish. | vertebrate gustatory systems include a tertiary ascending pathway from a secondary gustatory nucleus in the hindbrain to several forebrain nuclei. this connection is prominent in catfish, corresponding to their highly developed sense of taste. iontophoretic injections of horseradish peroxidase were used to identify the specific target nuclei of the tertiary gustatory pathway in channel catfish and to characterize those nuclei by their respective connections. efferents from the secondary gustator ... | 1993 | 7506715 |
| dynamics of protoporphyrin ix in the heme pocket of horseradish peroxidase. | the local motion of protoporphyrin ix in the heme pocket of horseradish peroxidase has been studied using fluorescence methods. the temperature dependence of the anisotropy and lifetime of a protoporphyrin ix-apo-horseradish peroxidase complex, dissolved in a solution of 80% glycerol and 20% buffer (0.1 m phosphate, ph 7.4), was determined. anisotropy data were analyzed in terms of the thermal coefficient of the frictional resistance to fluorophore movement. the resultant 'y' plot was characteri ... | 1993 | 8218388 |
| enzymatic oxidation of the bifunctional wheat inhibitor of subtilisin and endogenous alpha-amylase. | oxidation of the bifunctional wheat inhibitor of subtilisin and endogenous alpha-amylase catalyzed by horseradish peroxidase results in the loss of the inhibitory activity against both enzymes. the enzymatic oxidation is accompanied by modification of one methionine and two tryptophan residues in the protein. the results obtained, together with data on chemical modification and limited proteolysis, allow us to conclude that met34-ala35 is the reactive site of the inhibitor responsible for the in ... | 1993 | 8224231 |
| subcellular localization of alpha-tubulin and opsin mrna in the goldfish retina using digoxigenin-labeled crna probes detected by alkaline phosphatase and hrp histochemistry. | this paper describes a method for non-radioactive in situ hybridization providing subcellular localization of mrna in 3 microns cryosections. we used two alternative colorimetric reactions to detect digoxigenin-labeled crna probes: alkaline phosphatase and hrp (horseradish peroxidase). with some probes the signal with the alkaline phosphatase reaction was intense, and diffusion of the reaction product was noticeable. using hrp-conjugated antibodies improved the resolution but decreased the sensi ... | 1993 | 8107495 |
| chemical and kinetic evidence for an essential histidine residue in the electron transfer from aromatic donor to horseradish peroxidase compound i. | horseradish peroxidase, when incubated with diethyl pyrocarbonate (depc), a histidine-specific reagent, shows time-dependent inactivation to oxidize aromatic electron donor, guaiacol. the inactivation follows pseudo-first order kinetics with a second order rate constant of 0.67 min-1 m-1. the ph dependence of inactivation shows an inflection point at 6.02, indicating histidine derivatization by depc. a difference spectrum of modified versus native enzyme shows a peak at 244 nm for n-carbethoxyhi ... | 1993 | 8226738 |
| monoclonal antibody 2b5 defines a truncated o-glycan, glcnac beta 1-3gal beta 1-4glcnac beta 1-6 (galnac), on mucins from deep gastric and duodenal glands as well as metaplasia and neoplasia of gastric differentiation. | monoclonal antibody (mab) 2b5 previously generated in balb/c mice using gastric mucosa of the corpus as immunogen was characterized with regard to its binding epitope. binding assays on structurally defined neoglycolipids from mucin glycans revealed that mab 2b5 recognizes a carbohydrate epitope on a neutral o-glycan sequence from gastric mucins. this oligosaccharide chain has been characterized by mass spectrometry and methylation analysis and sequential exoglycosidase treatment of the derived ... | 1993 | 8402663 |
| cytoarchitecture, fiber connections, and ultrastructure of the nucleus pretectalis superficialis pars magnocellularis (psm) in carp. | the cytoarchitecture, fiber connections, and ultrastructure of the nucleus pretectalis superficialis pars magnocellularis (psm) were studied in cypriniform teleosts (cyprinus carpio). the psm is an oval nucleus in the pretectum. medium-sized cells and synaptic glomeruli are the main components of the nucleus. a lesser number of small cells are also present. most of the medium-sized cells form one or two cell layers on the periphery of the nucleus, and some cells are scattered among synaptic glom ... | 1993 | 8263230 |
| cytoarchitecture of spinal-projecting neurons in the brain of the larval sea lamprey. | the descending spinal projecting system of the lamprey is of interest because it includes axons that activate swimming pattern generators and because regeneration of this system is involved in the behavioral recovery of lampreys following spinal transection. however, little is known about the true size of this projection and of the distribution of its terminations along the spinal cord. brain neurons with spinal projections were studied in larval sea lampreys by using wholemount preparations lab ... | 1993 | 8245215 |
| hla class ii typing in a microtitre plate format using digoxigenin-labelled amplified dna and biotin-labelled oligonucleotide probes. | we describe a new, non-radioactive microtitre plate assay for the analysis of genetic variations at the dna level. the new method combines hybridization of oligonucleotides with pcr amplified dna in liquid phase with detection in solid phase using an elisa-reader. genomic dna is labelled with digoxigenin during pcr using a nucleotide mix containing dig-11-2'-deoxy-uridine-5'-triphosphate (dig-11-dutp). the dig labelled, amplified genomic dna is hybridized in solution with an oligonucleotide whic ... | 1993 | 9098410 |
| tanycytes in the sunfish brain: nadph-diaphorase histochemistry and regional distribution. | nadph-diaphorase histochemistry has been shown to be a useful method for identifying cells that synthesize and release nitric oxide, which is implicated in the modulation of a variety of neural functions, including synaptic transmission, cerebral blood flow, and excitotoxicity. in the sunfish brain, nadph-diaphorase histochemistry stains tanycytes specifically and almost exclusively, allowing for a thorough examination of the morphology and distribution of this type of cell. tanycytes are noncil ... | 1993 | 8254115 |
| phototaxic behavior and the retinotectal transport of horseradish peroxidase (hrp) in surgically created cyclopean salamander larvae (ambystoma). | negative phototaxis (np) was used to evaluate the recovery of vision in albino axolotl larvae with one eye discarded and the other transplanted either to the orbit (orthoclops) or to the top of the head (cyclops). np was assessed at approximately 1, 2 and 3 months postoperatively, using an automated, infrared monitor. some 88% of the orthoclopes and 64% of the cyclopes recovered np. however, among the cyclopes that did recover, the quantitative aspects of np were virtually the same as those of t ... | 1993 | 8134018 |
| connections of the olfactory bulb in the gymnotiform fish, apteronotus leptorhynchus. | this work examines the connectivity of the olfactory bulb in the gynmotiform fish apteronotus leptorhynchus. wheat germ agglutinin conjugated horseradish peroxidase was iontophoresed in different areas and depths of the bulb in order to define its efferent and afferent connections. the olfactory bulb projects bilaterally via the medial (medial and centromedial fascicles) and lateral olfactory (lateral and centrolateral fascicles) tracts. the nervus terminalis courses through the ventromedial asp ... | 1993 | 8227532 |
| numerical and monte carlo simulations of phenolic polymerizations catalyzed by peroxidase. | numerical and monte carlo simulations of horseradish peroxidase-catalyzed phenolic polymerizations have been performed. kinetic constants for the simulations were fit to data from the oxidation and polymerization of bisphenol a. simulations of peroxidase-catalyzed phenolic polymerization were run as a function of enzyme concentration and radical transfer and radical coupling rate constants. predictions were performed with respect to conversion vs. time and number average molecular weight and pol ... | 1993 | 18613127 |
| the early development of major projections from caudal levels of the spinal cord to the brainstem and cerebellum in the gray short-tailed brazilian opossum, monodelphis domestica. | the brazilian short-tailed opossum, monodelphis domestica, is born 14-15 days after copulation and is available for experimentation at stages of development corresponding to those which occur in utero in placental mammals. in the present study, we took advantage of the opossum's embryology to study the development of projections from caudal levels of the spinal cord to the brainstem and cerebellum using axonal tracing methods. in all cases, a 2-3 day survival time was used for axonal transport. ... | 1993 | 7693371 |
| giant terminals in the dorsal octavolateralis nucleus of lampreys. | the dorsal octavolateralis nucleus of lampreys is a primary nucleus for electroreceptive stimuli in the medulla. in lampetra japonica, the rostral and caudal thirds of this nucleus are exclusively occupied by giant terminals, which become evident when the primary fibers of an electrosensory nerve (recurrent branch of the anterior lateral line nerve) are labeled with horseradish peroxidase. we studied the ultrastructure of these terminals. they contain neurofilaments, mitochondria, microtubules, ... | 1993 | 8227516 |
| acidosomes: recipients of multiple sources of membrane and cargo during development and maturation. | acidosomes are organelles that in paramecium are responsible for the acidification of phagosomes before phagosomes fuse with lysosomes. using a combination of (a) the quick-freeze deep-etch (qf-de) technique, (b) monoclonal antibodies (mabs) that label specific membrane pools including those of the acidosomes, and (c) horseradish peroxidase (hrp)-uptake studies, we followed the development of acidosomes from the golgi complex as well as the rapid transfer of hrp into the acidosomes. we also stud ... | 1993 | 8270639 |
| light emission accompanies oxygen uptake during the peroxidative metabolism of tetracyclines. | tetracycline molecules offer several sites for peroxidative metabolism of the type known to lead to oxygen consumption and electronic excitation. accordingly, when tetracycline and chlortetracycline were exposed to horseradish peroxidase in the presence of hydrogen peroxide, oxygen was taken up and light emission was observed. the overall quantum yield of chemiluminescence is on the order of 10(-6), but that of chemiexcitation may be orders of magnitude higher as suggested by studies of sensitiz ... | 1993 | 8234480 |
| commissural neurons of the electrosensory lateral line lobe of apteronotus leptorhynchus: morphological and physiological characteristics. | extracellular injections of horseradish peroxidase were used to label commissural cells connecting the electrosensory lateral line lobes of the weakly electric fish apteronotus leptorhynchus. multiple commissural pathways exist; a caudal commissure is made up of ovoid cell axons, and polymorphic cells' axons project via a rostral commissure. intracellular recording and labeling showed that ovoid cells discharge spontaneously at high rates, fire at preferred phases to the electric organ discharge ... | 1993 | 8229894 |
| [the interaction of bifunctional monoclonal antibodies with antigens studied by a radioimmunological method]. | the quadroma produced bifunctional antibodies (babs) with double specificity to alpha-endorphin (alpha-end) and horseradish peroxidase (hrp) were compared with the parental anti-alpha-end monoclonal antibodies (mabs) in respect to their binding to alpha-end. babs were purified from quadroma culture medium by sequential hrp-sepharose and alpha-end-sepharose affinity chromatography. using radioimmunological method the affinity of the individual anti-alpha-end combining sites of babs was shown to b ... | 1993 | 7906961 |
| model systems for oxidative drug metabolism studies. catalytic behavior of water-soluble metalloporphyrins depends on both the intrinsic robustness of the catalyst and the nature of substrates. | sulfonated manganese and iron porphyrins have been used as catalysts in attempts to mimick the oxidation of acetaminophen and two ellipticine derivatives by horseradish peroxidase. cofactors were potassium monopersulfate for the synthetic catalyst and hydrogen peroxide for the natural enzyme. hindered metalloporphyrins, i.e. with ortho positions of the meso-phenyl rings substituted with methyl groups [iron(iii) and manganese(iii) derivatives of octasodium mesotetrakis(3,5-disulfonatomesityl)porp ... | 2013 | 7902241 |
| high-performance liquid chromatography of amino acids, peptides and proteins. cxxx. modified porous zirconia as sorbents in affinity chromatography. | the utilisation of organosilanes to introduce active chemical groups onto zirconia surfaces, suitable for the subsequent immobilisation of proteins or other biomimetic ligands, is described. two different types of porous zirconia-based particles with nominal pore diameters of 160 and 1000 a pore size were modified with two different affinity ligands. in the first case, methods to immobilise iminodiacetic acid-cu(ii) and its application in cu(ii) immobilised metal ion affinity chromatography (ima ... | 1993 | 8408422 |
| topographic organization of descending projection neurons to the spinal cord of the goldfish, carassius auratus. | several neurons from different nuclei give rise to descending spinal tracts and project to various levels in the spinal cord of goldfish, carassius auratus. these were visualized by retrograde transport of horseradish peroxidase (hrp) administered to the bilaterally transected spinal cord at 6 levels, corresponding to 1st, 5th, 10th, 15th, 20th and 25th segments of the vertebral column. as many as 16 brain nuclei or neuronal aggregations and the mauthner cells project posteriorly up to the 20th ... | 1993 | 7690299 |
| chemiluminescence from bamboo shoot cut. | bamboo shoot cut emitted weak light, which could be visualized with a two dimensional imaging system. a water extract of bamboo shoot contained tyrosine (a major component of total amino acids), bityrosine and peroxidase. bamboo shoot peroxidase-h2o2-tyrosine system also emitted weak light with maxima at 490nm, 530nm and longer wavelength, identical to that in horseradish peroxidase-h2o2 system. judging from these results, chemiluminescence from bamboo shoot cut might be originated from excited ... | 1993 | 8394697 |
| increased serotoninergic innervation of the hamster's superior colliculus alters retinotectal projections. | anterograde tracing with horseradish peroxidase (hrp) was used to compare the organization of retinotectal projections in normal adult hamsters and in animals that sustained subcutaneous injections of the neurotoxin 5,7-dihydroxytryptamine (5,7-dht) on the day of birth. neonatal injection of this neurotoxin decreases the density of the serotoninergic (5-ht) innervation of the cerebral and cerebellar cortices, but increases the density of these fibers in the brainstem including the superior colli ... | 1993 | 8376625 |
| a quantitative determination of singlet oxygen with horseradish peroxidase. | a singlet oxygen determination method based on the formation of dimethyl-(2,5)-2-methoxy-5-hydroperoxydihydrofuran (dmfo2) followed by acid hydrolysis with 0.1 n h2so4 is described. hydrogen peroxide is formed thereby as a product of hydrolysis which is then determined by the horseradish peroxidase-catalyzed formation of the homovanillic acid dimer. since dmfo2 is a crystalline compound with sufficient stability it can be used as a primary standard for the determination. the peroxidase-catalyzed ... | 1993 | 8238883 |
| in vitro slow fluctuation in horseradish peroxidase activity. | in vitro slow fluctuations in the level of horseradish peroxidase activity were observed in long-range experiments (72-144 h). besides random fluctuations, regular slow oscillatory patterns with period lengths ranging from 10.0 to 39.0 h were detected by statistical analysis. the possibility that these oscillations in enzyme activity could have reflected changes in the physical environment of the experimental setup has been thoroughly examined and ruled out. periodic exposition of the enzyme sol ... | 1993 | 8403067 |
| interaction of myeloperoxidase with peroxynitrite. a comparison with lactoperoxidase, horseradish peroxidase and catalase. | polymorphonuclear neutrophils generate both nitric oxide and superoxide and these molecules can combine to form peroxynitrite. neutrophils also contain myeloperoxidase which reacts with peroxynitrous acid (hoono). on mixing myeloperoxidase with hoono compound ii was formed. compound i could not be detected as an intermediate. the apparent second-order rate constant of formation of compound ii was strongly ph-dependent (2.5 x 10(5) m-1 x s-1 at ph 8.9 and 6.2 x 10(6) m-1 x s-1 at ph 7.2). the pka ... | 1993 | 8394811 |
| instability of the abts/peroxidase reaction product in biological buffers. | the commonly used horseradish peroxidase dye substrate, 2,2'-azino-bis(3-ethyl-benzthiazoline-6-sulphonic acid) (abts), was found to be unstable under certain conditions after reaction with the peroxidase. a survey of several buffers and ph values showed that the oxidized dye was destabilized by raising the ph or by the use of "good" buffers. it is recommended that use of this dye in a peroxidase-based detection system be confined to acetate buffer at low ph, if possible, and that phosphate or t ... | 1993 | 8373594 |
| trigeminal primary afferent projections to the spinal cord of the frog, rana ridibunda. | the distribution in the spinal cord of the trigeminal primary projections in the frog rana ridibunda was studied by means of the anterograde transport of horseradish peroxidase (hrp). upon entering the medulla via the single trigeminal root, a conspicuous descending tract that reaches the cervical spinal cord segments is established. this projection arises in the ophthalmic (v1), maxillary (v2), and mandibular (v3) trigeminal nerve subdivisions. in the spinal cord, only a minor somatotopic arran ... | 1993 | 8371275 |
| navigational errors made by growth cones without filopodia in the embryonic xenopus brain. | we have developed an exposed brain preparation for observing growth cone pathfinding behavior while performing in vivo pharmacological manipulations, and we used it to test whether xenopus retinal growth cones need filopodia to navigate. time-lapse video observation showed that cytochalasin b acted quickly and reversibly when applied; cytochalasin b-treated growth cones lacked filopodia, but had active lamellipodia and continued to advance slowly. whereas normal retinotectal axons visualized wit ... | 1993 | 8352941 |
| multivesicular bodies in hep-2 cells are maturing endosomes. | conventional fluorescence microscopy of fixed hep-2 cells as well as video microscopy of living cells incubated with transferrin-texas red (tf-txr) for < 60 min revealed distinct punctuate endosomal structures. quantitative ultrastructural analysis using horseradish peroxidase (hrp) and cationized gold as tracers showed that spherical multivesicular bodies (mvbs) were the predominant endocytic compartments in hep-2 cells and that mvbs within 60 to 90 min matured into lysosomes still containing i ... | 1993 | 8223712 |
| detection of ascorbate peroxidase activity in native gels by inhibition of the ascorbate-dependent reduction of nitroblue tetrazolium. | a method for the detection of ascorbate peroxidase activity in native electrophoretic gels is described. the assay is based on the ability of ascorbate peroxidase to prevent the ascorbate-dependent reduction of nitroblue tetrazolium in the presence of h2o2. the method was found to be both sensitive (detection of less than 0.01 units of ascorbate peroxidase activity) and specific for ascorbate peroxidase activity. the application of the method for the detection of ascorbate peroxidase activity in ... | 1993 | 8214598 |
| a study of hydrogen peroxide generation by, and antioxidant activity of, granuflex (duoderm) hydrocolloid granules and some other hydrogel/hydrocolloid wound management materials. | the effect of granuflex hydrocolloid granules (0.01-0.50% w/v) on the rate of proliferation of murine (l929) fibroblasts was examined. the dose-response curve showed a significant (p < 0.02) pro-proliferant effect at 0.05%, and a significant (p < 0.02) antiproliferant effect at 0.50%, mirroring the dose-response curve produced by hydrogen peroxide in the concentration range 10(-9) - 10(-4) mol/l. the antiproliferant effect at 0.20% w/v was abolished by catalase, suggesting that the biological ac ... | 1993 | 7654573 |
| collateral sprouting in the electrosensory lateral line lobe of weakly electric teleosts (gymnotiformes) following ricin ablation. | sprouted collateral axons were observed in the electrosensory lateral line lobe (ell) of gymnotiform teleosts (apteronotus leptorhynchus) following the ablation of the supraorbital branch of the anterior lateral line nerve. ablation was accomplished by using microinjections of the toxic lectin ricin. sprouted axons were followed for up to 26 weeks postablation. ricin exposure severely reduced axonal numbers and the peripheral electroreceptors in the region innervated by these fibers. to visualiz ... | 1993 | 8345105 |
| hybrid hybridomas producing bispecific antibodies to cea and peroxidase isolated by a combination of hat medium selection and fluorescence activated cell sorting. | a combination of fluorescence-activated cell sorting and hat medium selection has been used to establish bispecific antibody (biabs)-producing hybrid hybridomas. for this purpose hypoxanthine-guanine phosphoribosyl transferase (hgprt)-deficient mutants were isolated from a hybridoma line (d11-dg2) producing anti-cea antibodies by 8-azaguanine treatment. the resulting hat-sensitive hybrid cells were stained with the fluorescence marker tetramethyl rhodamine isothiocyanate (tritc) and fused by pol ... | 1993 | 8335963 |
| survival of ganglion cells which form the retino-retinal projection during optic nerve regeneration in the frog. | during optic nerve regeneration in the frog, axons transiently grow along the opposite optic nerve forming a retino-retinal projection. in the present study, we crushed the left optic nerve in the frog litoria (hyla) moorei and later applied horseradish peroxidase (hrp) or diamidino yellow (dy) to the right optic nerve. in one series, retinae were examined 3 days after application of the tracer. the retino-retinal projection was found to be maximal at 5 weeks, fell significantly by 7 weeks, and ... | 2006 | 8338804 |
| phenylbutazone peroxidatic metabolism and conjugation. | phenylbutazone, a nonsteroidal anti-inflammatory drug, elicits therapeutic as well as toxic effects by unknown pathways. phenylbutazone was shown to form a conjugate with the heterocyclic amine bladder carcinogen 2-amino-4-(5-nitro-2-furyl)-thiazole (anft). to understand further the reactivity of these compounds, this study was conducted to identify the conjugate formed and determine the mechanism of conjugate formation. both prostaglandin h synthase and horseradish peroxidase catalyzed conjugat ... | 1993 | 8331577 |
| peroxidase-dependent metal-independent oxidation of low density lipoprotein in vitro: a model for in vivo oxidation? | oxidative modification of low density lipoprotein is believed to be an important pathway by which the lipoprotein becomes atherogenic. the in vitro systems for oxidative modification of low density lipoprotein thus far described all appear to depend upon the presence in the medium of free transition metal ions (copper or iron). in vivo, on the other hand, these metals are present almost exclusively in tightly complexed forms that do not catalyze oxidative modification. the present studies descri ... | 1993 | 8327462 |
| perivascular astrocytes and endothelium in the development of the blood-brain barrier in the optic tectum of the chick embryo. | the role played by perivascular astrocytes in neural vessel maturation was investigated in microvessels of the chick embryo optic tectum. three-dimensional reconstructions and quantitative analyses were made, and permeability was studied. on embryonic days 14-16, 12.5% of the microvessel wall is surrounded by astrocyte endfeet which, in most cases (82%), are located under endothelium junctions; the latter, at this stage, partly prevent the extravascular escape of the marker horseradish peroxidas ... | 1993 | 8214622 |
| an enzyme immunoassay for carcinoembryonic antigen (cea) with homogeneous reactivity to different cea preparations and low cross-reactivity with cea-related normal antigens. | a new sandwich-type solid-phase enzyme immunoassay (eia) for carcinoembryonic antigen (cea) was established by using two selected monoclonal antibodies (mabs). one mab, f82-61, which is immobilized on polystyrene beads, reacts with an epitope present on the n-terminal domain (n) of the cea molecule and the other, f11-39, which is conjugated to horseradish peroxidase (hrp), recognizes an epitope present on the c-terminal domain (b3) of the cea molecule. the assay consists of incubating 0.05 ml of ... | 1993 | 7686200 |
| distribution of synapses on identified cell types in a gustatory subdivision of the nucleus of the solitary tract. | two morphological types of neurons in the rostral nucleus of the solitary tract (nst) in the hamster send axons to the parabrachial nucleus (pbn). elongate cells have oval cell bodies and 2 mediolaterally oriented primary dendrites. large stellate cells have polygonal cell bodies and 3-5 radiating primary dendrites. both cell types are located in the rostral central subdivision of the nst, surrounded by primary afferent axons from the oral cavity. this study uses electron microscopy to evaluate ... | 1993 | 8331219 |
| binding of horseradish, lignin, and manganese peroxidases to their respective substrates. | the present study utilizes 1h nmr spectroscopy to characterize the binding of substrate to heme active site of three different peroxidases, horseradish peroxidase, lignin peroxidase, and manganese peroxidase. information has been obtained on the site of p-cresol binding to the active-site cavity of the cyanide derivative of horseradish peroxidase. this information was obtained by relaxation enhancements of the substrate protons and connectivities between the latter and heme 8-ch3 and a phe resid ... | 1993 | 8504102 |
| peroxidase-catalyzed co-oxidation of indole-3-acetic acid and xanthene dyes in the absence of hydrogen peroxide. | the effect of xanthene dyes on the chemiluminescence from the aerobic indole-3-acetic acid (iaa) oxidation, catalyzed by horseradish peroxidase (hrp), was studied. the rate of iaa oxidation and dye destruction were controlled. it was found that the addition of dyes to the iaa/hrp/o2 system resulted in: (i) the appearance of emission in the region of dye fluorescence, (ii) an increase of the total chemiluminescence intensity, (iii) a decrease of the emission duration, (iv) the acceleration of iaa ... | 1993 | 8504861 |
| the octavolateral systems in the stingray, dasyatis sabina. i. primary projections of the octaval and lateral line nerves. | the central projections of the electrosensory, mechanosensory, and octaval nerves of the atlantic stingray were examined by transganglionic transport of horseradish peroxidase. particular attention was paid to the relation of the projections to cell plates c1 and c2, and to a newly described cell plate, c3. the electroreceptors in the stingray are found in three groups on the dorsal and ventral sides of the body. the electroreceptors are represented topographically on the ipsilateral dorsal nucl ... | 1993 | 8514920 |
| aging, cytochrome oxidase activity, and hydrogen peroxide release by mitochondria. | the objective of this study was to explore the possible cause(s) underlying the previously observed, age-related increase in the rate of mitochondrial h2o2 release in the housefly. the hypothesis that an imbalance between different respiratory complexes may be a causal factor was tested. cytochrome c oxidase activity was found to sharply decline in the latter part of the life span of the flies. effects of different substrates and respiratory inhibitors were determined in order to ascertain if a ... | 1993 | 8392019 |
| clinical evaluation of new cancer-associated antigen ca125 ii in epithelial ovarian cancers: comparison with ca125. | with use of monoclonal antibodies (moabs) m 11 and oc125, a sensitive sandwich immunoradiometric assay (irma) for ca125 ii was developed. ca125 antigen was adsorbed by moab oc125 and m 11, but horseradish peroxidase-labelled oc125 did not compete with m 11, indicating that although these two moabs recognized ca125 antigen, they reacted with separate antigenic determinants. we also demonstrate that the dual capture technique with oc125 and m 11 antibodies has a larger dynamic range than oc125 alo ... | 1993 | 8330391 |
| detection system for membrane immunoassay based on the trapping of a highly colored intermediate of the peroxidase reaction. | the oxidation of ortho-dianisidine by membrane bound horseradish peroxidase in the presence of sodium dextran sulfate affords a dark-green insoluble product, identified as an unstable meriquinone intermediate previously reported in literature. cationic and unsubstituted dextrans do not stabilize the intermediate. the highest yield of the intermediate is observed at ph 4.0-5.0 and concentration of dextran sulfate ca. 0.5%. new highly sensitive detection system for peroxidase has been developed on ... | 1993 | 8317703 |
| differential responses of single reticulospinal cells to spatially localized stimulation of the optic tectum in a teleost fish, salmo trutta. | to determine whether the topographically organized retinal input to the optic tectum is subsequently mapped onto the reticular formation, the responses of antidromically identified reticulospinal cells to tectal surface stimulation were investigated in 45 decerebrated, paralysed trout. the tectum was stimulated through a silver ball surface electrode at 24 different locations, and extracellular recordings were made from the rhombencephalic brainstem with glass microelectrodes filled with a 10% s ... | 1993 | 8261144 |
| evidence of early topographic organization in the embryonic olivocerebellar projection: a model system for the study of pattern formation processes in the central nervous system. | many projection systems within the peripheral and central nervous system are topographically organized, and it has become increasingly clear that interactions which occur during development determine the projection patterns these systems exhibit in the adult. the olivocerebellar system was chosen as a model system for this study of afferent pattern formation because it has several characteristics which lend themselves to a study of this type. applications of horseradish peroxidase were made to b ... | 1993 | 8219355 |
| is horseradish peroxidase a ligninolytic enzyme? | structural modifications of spruce liginins catalyzed by plant horseradish peroxidase (hrp) were studied. changes in lignin structure were characterized by monomeric composition determination and hydrodynamic property analysis. results show that hrp modifies lignin monomeric composition without alteration of polymer gel permeation pattern. this indicates that hrp and lip have similar but different biodegradative effects. | 1993 | 8019876 |
| localization of free and bound biotin in cells from green pea leaves. | cytosol and vacuoles from protoplasts, chloroplasts, and mitochondria from green pea (pisum sativum) leaves were purified and examined for their biotin content. the bulk of free biotin was shown to be exclusively associated with the cytosolic fraction at a concentration of about 4 pmol/mg protein and no bound biotin was detected. the bulk of bound biotin (biotin-containing carboxylases) was associated with the soluble fraction of chloroplasts and mitochondria at a concentration of about 1.2 and ... | 1993 | 8489267 |
| mathematical model for the luminol chemiluminescence reaction catalyzed by peroxidase. | a kinetic model that accurately describes intensity vs. time reaction profiles for the chemiluminescence reaction between luminol and hydrogen peroxide, as catalyzed by horseradish peroxidase, is derived and evaluated. a set of three differential equations is derived and solved to provide intensity time information for the first 200 seconds of the reaction. the model accurately predicts intensity-time profiles when literature values are used for all but one of the reaction rate constants. furthe ... | 1993 | 18601298 |
| nucleus isthmi in goldfish: in vitro recordings and fiber connections revealed by hrp injections. | recordings of field potentials in nucleus isthmi (ni) were obtained in an in vitro preparation of goldfish brain using a lateral approach. horseradish peroxidase (hrp) was injected from recording electrodes to verify recordings within the nucleus and to label axonal pathways and cell bodies. activity in ni was repetitive and could be elicited by stimulation of the optic nerve, tectum, pretectum, or tectobulbar tract. spontaneous activity was present in some preparations and consisted of bursts w ... | 2007 | 8494796 |
| analysis of hla class ii polymorphism using polymerase chain reaction. | a simple, rapid, and precise method of typing hla class ii polymorphism would be valuable in the areas of disease susceptibility, tissue transplantation, individual identification, and anthropological genetics. herein, we describe a method of analyzing class ii sequence polymorphism based on polymerase chain reaction (pcr) amplification and hybridization with oligonucleotide probes. many more dna-defined alleles at the class ii loci have been identified than can be distinguished by conventional ... | 1993 | 8489336 |
| chick embryo metanephros: the glycosylation pattern as revealed with lectin conjugates. | fragments of metanephros were taken from chick embryos and studied from the 7th to the 21st d of incubation. a battery of 7 different horseradish peroxidase-labelled lectins (pna, cona, dba, sba, lta, wga and uea i) was used to analyse the distribution and changes of carbohydrate moieties in glycoconjugates along the metanephric nephron from the s-shaped body stage onwards. dba and sba reacted for a short time at some sites during the considered period of incubation. provided wga and cona reacte ... | 1993 | 8351973 |
| flask cells and flask-shaped glandular cells of amphibian skin specifically produce fucose-rich glycoproteins. | a battery of horseradish peroxidase-conjugated lectins has been employed as a cytochemical tool for the labelling of specific cell types in amphibian epidermis. among the lectins used, only ulex europaeus i (uea i) showed specific reaction with the cytoplasm of flask cells. in addition, uea i stained flask-shaped secretory cells in dermal glands and a reaction on glandular ductal cells was also observed. at the electron microscopic level, lectin binding was found in granules distributed among mi ... | 1993 | 8335482 |
| retinal projections to the pretectum, accessory optic system and superior colliculus in pigmented and albino ferrets. | retinal projections to the pretectal nuclei, accessory optic system and superior colliculus in pigmented and albino ferrets were studied using anterograde tracing techniques. both nissl- and myelin-stained material was used to identify the pretectal nuclei, nuclei of the accessory optic system and the layers of the superior colliculus. following monocular injection of either horseradish peroxidase or rhodamine-b-isothiocyanate, four pretectal nuclei, including the nucleus of the optic tract, pos ... | 1993 | 8261124 |
| preparation and characterization of bifunctional unilamellar vesicles for enhanced immunosorbent assays. | small unilamellar phospholipid vesicles with covalently attached biotin and horseradish peroxidase (hrp) were prepared and characterized in terms of hydrodynamic diameter, amount and activity of immobilized enzyme, and number of biotin molecules on the outer vesicle surface. in addition, the specific adsorption of these bifunctional vesicles and commercially available biotin-labeled horseradish peroxidase (b-hrp) to antibiotin antibody (aba) coated polystyrene microtiter plate wells was examined ... | 2013 | 7763694 |
| location of retinal ganglion cells contributing to the early imprecision in the retinotopic order of the developing projection to the superior colliculus of the wallaby (macropus eugenii). | the position of ganglion cells contributing to the early imprecision in retinotopic order in the developing retinocollicular projection in the wallaby (macropus eugenii) has been determined. deposits of horseradish peroxidase conjugated to wheat germ agglutinin (wga-hrp) were made in the caudal pole of the superior colliculus (sc) at ages ranging from 22 days after birth, when sparse retinal axons have only just reached the caudal pole of the sc and are yet to cover its surface completely, to 96 ... | 1993 | 7686568 |
| spinal cord neuron classes in embryos of the smooth newt triturus vulgaris: a horseradish peroxidase and immunocytochemical study. | spinal cord neurons were investigated in embryos of triturus vulgaris, the smooth newt, just prior to hatching. these embryos can swim if freed from their egg membranes. horseradish peroxidase (hrp) labelling, together with gaba and glycine immunocytochemistry (icc), revealed nine distinct anatomical classes of neuron. 1. ventrolateral motoneurons with mainly dorsal dendrites, sometimes a descending central axon and peripheral axon innervating the trunk muscles. 2. dorsal primary sensory rohon-b ... | 1993 | 8099742 |
| miniaturized flexible amperometric lactate probe. | a flexible lactate electrode was made of 400 +/- 100 7-micron-diameter carbon fibers, epoxy embedded in a 0.3-mm-diameter polyimide tubing. the electrode was modified by precipitating on it the relatively insoluble complex formed between 1100 kda partially n-ethylamine quaternized poly[(vinylpyridine)-os(bipyridine)2cl]cl (pos-ea) and lactate oxidase. the steady-state lactate electrooxidation current, at 2 mm lactate concentration and at 22 degrees c, was 400 na. the 50 +/- 10 microac cm-2 curre ... | 1993 | 8494172 |
| catalytic properties of horseradish peroxidase reconstituted with the 8-(hydroxymethyl)- and 8-formylheme derivatives. | recent studies suggest that 8-(thiomethyl)- and 8-formylheme modifications may be present in, respectively, lactoperoxidase and myeloperoxidase. to examine whether these heme modifications contribute to the unusual catalytic properties of the mammalian peroxidases, we have reconstituted apo-horseradish peroxidase (hrp) with 8-(hydroxymethyl)heme (8hm-hrp) and 8-formylheme (8f-hrp) and have characterized the reconstituted enzymes. native hrp and 8hm-hrp have identical spectra in the ferric, compo ... | 1993 | 8385486 |
| defined analyte-enzyme conjugates as signal generators in immunoassays. | we investigated the synthesis of progesterone-horseradish peroxidase (p-hrp) conjugates and products purified by affinity chromatography. the obtained preparations were characterized with an immobilized monoclonal antibody in solid-phase immunoassays. three homogeneous p-hrp conjugates were isolated. two preparations were identified to contain a single progesterone ligand on the enzyme molecule. a third preparation contained two progesterone ligands. we postulate that conjugation can occur at tw ... | 1993 | 8489010 |
| cytostatic effects of horseradish and thyroid peroxidase derived free radicals. | an otherwise noncytostatic flux of h2o2 from glucose and glucose oxidase became cytostatic to cultured chinese hamster ovary (cho) cells when horseradish or thyroid peroxidase was added to the culture medium. electron spin resonance (esr) measurements showed that one or more factors present in the culture medium promote the one-electron oxidation of a reduced nitroxide or glutathione in an h2o2/peroxidase-dependent process. moreover, a reduced nitroxide conferred significant protection against t ... | 1993 | 8468022 |
| effects of age, sex, and menopausal status on plasma lipoprotein(a) levels. the framingham offspring study. | lipoprotein(a) [lp(a)] is an atherogenic particle that structurally resembles a low density lipoprotein (ldl) particle but contains a molecule of apolipoprotein(a) attached to apolipoprotein b-100 by a disulfide bond. because elevated plasma levels of lp(a) have been shown to be an independent risk factor for coronary artery disease, it is important to define normal ranges for this lipoprotein. | 1993 | 8462142 |
| induction of functional follicular dendritic cell development in severe combined immunodeficiency mice. influence of b and t cells. | ag injected into immune mice immediately complexes with specific antibody. immune complexes not phagocytosed by macrophages are transported by ag transport cells to lymph node follicles for trapping by follicular dendritic cells (fdc). these fdc serve as a long term repository of unprocessed ag that is believed to maintain both b cell memory and the secondary antibody response. severe combined immunodeficiency mice lack functional b cells and t cells. consequently, this mutation also appears to ... | 1993 | 8454847 |
| the pyramidal tract of the hedgehog (erinaceus europaeus) and its relationship with the olfactory bulb. | the pyramidal tract of the hedgehog has been investigated. the motor cerebral cortex was first located electrophysiologically and subsequently ablated. ablation of the motor cortex did not apparently cause motor deficits. the cerebral hemisphere of the operated side, brain stem and spinal cord were removed for histological examination. the nauta-gygax and the horseradish peroxidase methods were employed to study the course and origin of the above mentioned tract. the pyramidal tract runs ipsilat ... | 1993 | 8338386 |
| a chemiluminescent immunoassay for the diagnosis of grapevine closteroviruses on nitrocellulose membrane. | a dot-immunobinding assay was adapted on enhanced chemiluminescence (diba-ecl), which employs luminol, a cyclic diacylhydrazide, as substrate for horseradish peroxidase conjugated with a secondary antibody, for the diagnosis of grapevine closteroviruses i and iii. the sensitivity of diba-ecl was also compared to other immunoenzymatic methods. diba-ecl proved to be at least 16 times more sensitive than the dot-immunobinding assay using chloronaphthol/diaminobenzidine mixture as a substrate, which ... | 1993 | 8320305 |
| stimulation of p(i) transport in opossum kidney cells by hyposmotic media. | exposure of various cells to hyposmotic media (hypo) results in a rapid inhibition of both receptor-mediated and fluid-phase endocytosis. we used this maneuver to investigate the role of endocytosis in regulation of pi transport in opossum kidney (ok) cells. following exposure to hypo, na(+)-dependent pi uptake increased rapidly, reaching a maximum within 5 min, and remained elevated up to 30 min. this was associated with a simultaneous reduction of horseradish peroxidase uptake. kinetic studies ... | 1993 | 7682788 |
| segmental arrangement of reticulospinal neurons in the goldfish hindbrain. | the hindbrain is evolutionarily conserved among diverse vertebrate phyla. in vertebrate embryos, the hindbrain is segmentally organized as a series of overt swellings known as rhombomeres. in the larval zebrafish brachydanio rerio, conspicuous and identifiable reticulospinal neurons are positioned in the center of rhombomeres. segmentally homologous reticulospinal neurons that share a range of morphological, developmental, and biochemical features occupy adjacent rhombomeres. we have recently sh ... | 1993 | 8454739 |
| ifn-gamma modulation of epithelial barrier function. time course, reversibility, and site of cytokine binding. | the single cell-thick intestinal epithelium forms a crucial barrier between the host and environment, and is modeled in vitro by a monolayer of polarized, highly differentiated t84 epithelial cells impermeable to most macromolecules because of functional intercellular tight junctions. absence of a permeability defect across the monolayer, either transcellular or paracellular, is indicated by development of a transepithelial electrical resistance of > or = 1000 ohm-cm2, reported to be markedly di ... | 1993 | 8450217 |
| catalytic and interfacial aspects of enzymatic polymer synthesis in reversed micellar systems. | the enzyme horseradish peroxidase, when encapsulated in reversed micelles, is capable of catalyzing the synthesis of phenolic and aromatic amine polymers. the synthesis of polyethylphenol is specifically considered in this article and is found to be extremely feasible in the micellar system. polymer chain growth can be controlled to some degree by manipulating the ability of the solvent to sustain chain solubility; this is effectively done by adjusting the surfactant concentration. this results ... | 1993 | 18609584 |
| interaction of edta with horseradish peroxidase: 1h-nmr study. | interaction of edta with horseradish peroxidase (hrp) was investigated by nmr relaxation-rate measurements. at ph 4.0, the apparent dissociation constant (kd) for the edta binding to hrp was deduced to be 78 mm from the relaxation measurements. from ph-dependence of 1h-nmr line width of edta, it was observed that edta binds to hrp only under acidic conditions (ph < 5). the binding of edta to hrp was facilitated by protonation of an acid group on the enzyme with pka 4.0. the kd for edta binding t ... | 1993 | 8448175 |
| analysis of binding of biotinylated protoplast-release-inducing protein that induces release of gametic protoplasts in the closterium peracerosum-strigosum-littorale complex. | a protoplast-release-inducing protein (pr-ip) which is released from mating-type plus (mt(+)) cells and induces the release of gametic protoplasts from matingtype minus (mt(-)) cells of closterium was biotinylated and then used to examine the interaction of this protein with mt(-) cells. the protoplast-release-inducing activity of pr-ip was not altered after the biotinylation. when mt(-) cells that had been pre-cultured for 24 h were incubated with biotinylated pr-ip for 6 h in nitrogen-deficien ... | 1993 | 24178507 |
| direct and indirect competitive monoclonal antibody-based elisa of aflatoxin b1 in groundnut. | direct and indirect competitive enzyme-linked immunosorbent assays were optimized for the determination of aflatoxin b1 in groundnut utilizing a specific monoclonal antibody developed at the university of strathclyde, uk. the monoclonal antibody was conjugated to horseradish peroxidase (hrp) for direct competitive assay, while a commercially available goat-antimouse igg-hrp conjugate was employed for indirect competitive elisa. both elisas detected aflatoxin b1 as low as 20 pg/well. methanol-wat ... | 1993 | 23606068 |
| mature, growing ganglion cells acquire new synapses in the retina of the goldfish. | the goldfish retina grows throughout the animal's life, primarily by a balloon-like expansion. with this expansion, dendritic arbors of ganglion cells show scaled growth; arbors increase in size from small to large with no change in their architecture (hitchcock & easter, 1986; bloomfield & hitchcock, 1991). the study reported here showed that ganglion cell arbors acquire new synapses with this growth. arbors from a single type of ganglion cell in retinas of small, young and large, old fish were ... | 2007 | 8485086 |
| detection and quantitation of heme-containing proteins by chemiluminescence. | a commercial assay for chemiluminescence (cl) has recently been developed for visualizing horseradish peroxidase-conjugated probes for antibodies and nucleic acids. to assess the utility of cl for detecting the peroxidase activity of other heme-containing proteins, the sensitivity of cl and a standard chromogenic stain for visualizing heme-proteins in sds-polyacrylamide electrophoretic gels were compared. the ability of these systems to visualize heme-proteins on electroblots and dot blots was a ... | 1993 | 8470793 |
| monitoring coupling of peptides to carrier proteins using biotinylated peptide. | the amount of synthetic peptide coupled to a carrier protein is a critical parameter in production of antipeptide antibodies. in the method described, biotinylated peptide was included as a tracer to monitor the coupling of peptide to keyhole limpet hemocyanin or bsa. the extent of coupling was assessed by first fractionating free and coupled peptide by gel filtration, then slot blotting an aliquot of each fraction onto nitrocellulose. the biotinylated peptide was detected using an avidin-horser ... | 1993 | 8457355 |
| amperometric sensors for peroxide, choline, and acetylcholine based on electron transfer between horseradish peroxidase and a redox polymer. | amperometric sensors have been developed for hydrogen peroxide, choline, and acetylcholine by immobilization of horseradish peroxidase, (hrp), choline oxidase, and acetylcholinesterase in a cross-linked redox polymer deposited on glassy carbon electrodes. peroxide sensors, prepared by immobilization of hrp alone, gave detection limits of 10 nm and a linear response up to ca. 1 mm. coimmobilization of hrp and glucose oxidase was used to establish the feasibility of highly efficient bienzyme senso ... | 1993 | 8452244 |
| peroxidase-linked anti-basic fibroblast growth factor monoclonal antibody fab' conjugates: application for two-site enzyme immunoassay and immunohistochemical detection. | after conjugating thiol groups in the hinge region of monoclonal antibody (mab) fab' fragments specific for basic fibroblast growth factor (bfgf) with maleimido-horseradish peroxidase hrp) complexes synthesized by incubation of hrp with the heterobifunctional reagent n-succinimidyl-4-(maleimidomethyl)cyclohexane-1-carboxylate, we developed a fluorometric enzyme immunoassay method based on the sandwiching of the factor between anti-bfgf igg-coated polystyrene beads and the conjugates, and also an ... | 2005 | 7873645 |
| activity-driven sharpening of the retinotectal projection in goldfish: development under stroboscopic illumination prevents sharpening. | blocking or synchronizing activity during regeneration of the retinotectal projection prevents both the sharpening of the retinotopic map recorded on tectum and the refinement of the structure of individual arbors within the plane of the map, and this refinement is triggered by n-methyl-d-aspartate (nmda) receptors. we tested whether activity-driven refinement also occurs during development of the projection in larval and young adult goldfish. shortly after hatching, larval goldfish were placed ... | 1993 | 7684064 |
| structure of recurrent axon collaterals of frog lumbar motoneurons as revealed by intracellular hrp labelling. | iontophoretical injection of horseradish peroxidase (hrp) into lumbar motoneurons of the isolated and perfused frog spinal cord allowed to reveal recurrent axon collaterals of motoneurons and to study their structural organization. the axons of about 50% of stained motoneurons gave rise to recurrent collaterals. motoneurons emitted usually one and in a few cases two recurrent axon collaterals. recurrent collaterals exhibited a complex ramification pattern with numerous swellings presumably corre ... | 1993 | 7681718 |
| enzyme complex amplification--a signal amplification method for use in enzyme immunoassays. | an amplification system for enzyme immunoassays, in which complexes of streptavidin, biotinylated horseradish peroxidase, antibody are used to detect biotinylated target molecules was developed. in enzyme-linked immunosorbent assay (elisa) experiments this enzyme complex enhancement (eca) system gave up to a better than two orders of magnitude increase in sensitivity, compared to a horseradish peroxidase-conjugated streptavidin detection system. the eca system was shown to be applicable to direc ... | 1993 | 8465954 |
| a step towards understanding the folding mechanism of horseradish peroxidase. tryptophan fluorescence and circular dichroism equilibrium studies. | the guanidinium chloride denaturation/renaturation of the holo- and apo-horseradish peroxidase isoenzyme c (hrp) has been studied by fluorescence and circular dichroism spectroscopies. a distinct equilibrium intermediate of the apoprotein could be detected at low concentrations of guanidinium chloride (0.5 m). this intermediate has a secondary structure content like that of the native protein but a poorly defined tertiary structure. renaturation of the apo-hrp is reversible and 100% activity cou ... | 1993 | 8444158 |
| kinetics and mechanism of the peroxidase-catalyzed iodination of tyrosine. | the kinetics of iodination of tyrosine by hydrogen peroxide and iodide, catalyzed by both horseradish peroxidase (hrp) and lactoperoxidase (lpo), were studied. the initial rates of formation of both molecular i2 and monoiodotyrosine (mit) were measured with stopped flow techniques. the following reactions occur in both systems. enzymatic: feiii + h2o2-->fev = o + h2o; fev = o + i(-)-->feiii-o-i-; feiii-o-i- + h(+)-->feiii + hoi; feiii-o-i- + i- + h(+)-->feiii + i2 + ho-. iodine equilibria: i2 + ... | 1993 | 8448141 |
| early pattern of neuronal differentiation in the xenopus embryonic brainstem and spinal cord. | wholemount antibody labeling techniques and horseradish peroxidase backfilling were used to analyze the pattern of neuronal differentiation in the embryonic xenopus central nervous system between stages 22 and 35/36. in the spinal cord, the first neurons to differentiate are the rohon-beard neurons; they are followed by ventral neurons with descending axons (descending interneurons, motoneurons) and lateral interneurons with commissural axons. the somata and axons of these primary neurons form d ... | 1993 | 8423241 |
| differential effects of brefeldin a on transport of secretory and lysosomal proteins. | brefeldin a (bfa) rapidly blocks anterograde exocytotic transport through the golgi complex. sustained retrograde traffic induced by brefeldin a causes redistribution of constituents of the golgi, but not the trans-golgi network (tgn), to the endoplasmic reticulum (er). in the present study on hepg2 cells, we have observed a differential effect of bfa on transport from the tgn of two soluble proteins: alpha 1-antitrypsin as a representative of secretory proteins and cathepsin d as a prototype of ... | 1993 | 8428908 |
| functional participation of the valvula cerebelli on the goldfish dorsal light response. | most fish swim freely in three dimensions. the vestibular organs of fish are well developed and play an important role in maintaining postural equilibrium. postural equilibrium in teleost fish also depend on visual information. dorsal light response (dlr) of fish has been well-known as representative visually guided behavioral response since von holst's description in 1935. the dlr, an innate behavior of teleost fish, whereby the back is oriented toward a given light source, represents a simple ... | 1993 | 11538539 |
| synaptophysin has a selective distribution in early endosomes of pc12 cells. | we have studied the endocytic pathway in pc12 cells and localized synaptophysin to a subpopulation of early endosomes. endocytosis was examined by electron microscopy using horseradish peroxidase as an endocytic tracer. immediately following brief incubations with horseradish peroxidase, label was seen in small vesicles and tubules which appeared to be part of the tubular early endosomal network. a large vacuolar structure, containing a rim of horseradish peroxidase reaction product and an elect ... | 1993 | 8445410 |
| immunohistochemical study of nerves in lumbar spine ligaments. | an indirect horseradish peroxidase immunohistochemical technique was used to identify neurofilaments protein-immunoreactive fibers in lumbar spine ligaments, from patients who underwent spinal surgery for disc herniation. histologically, neural elements were abundant in all ligaments examined. in the ligamentum flavum the neurofilaments protein-immunoreactive nerve fibers were located especially close to blood vessels and fat globules. bundles of nerve fibers were seen in all ligaments specimens ... | 1993 | 8441943 |
| modifying an enzyme immunoassay of immunoreactive trypsinogen to use time-resolved fluorescence. | a coated microtiter-well, enzyme-linked immunometric assay for quantifying immunoreactive trypsinogen in dried blood spots was modified to use time-resolved fluorescence of europium in place of end-point enzymatic color development as the quantification step. the streptavidin-horseradish peroxidase and color development solutions supplied as packaged reagents were replaced by europium-labeled avidin, and the signal was developed with commercially available enhancement solution and read by time-r ... | 1993 | 8432010 |
| thiols as peroxidase substrates. | the abilities of haem peroxidases to catalyse the oxidation of various thiols were studied using the spin-trapping electron spin resonance (esr) technique. myeloperoxidase, a neutrophil and monocyte enzyme, catalysed the oxidation of cysteamine, cysteine methyl, and ethyl ester and to some extent 2-mercaptoethanol and thioglycollic acid. this peroxidase poorly catalysed the oxidation of cysteine, n-acetylcysteine, penicillamine, and glutathione under the same conditions. the dependence on ph of ... | 1993 | 8381104 |
| [measurement of serum pa values by a newly developed enzyme immunoassay]. | serum prostate-specific antigen (pa) values detected by a newly developed enzyme immunoassay (eia, markit-m pa) as a successor of markit-f pa, which has been a leading kit in japan, were evaluated for its role in the diagnosis of cancer of the prostate and follow-up of the patients afflicted with the disease. the system is one-step sandwich type eia using horseradish peroxidase as a tracer and has 0.50-100 ng/ml of detectable range with small amount of sample volume (25 microliters) and reliable ... | 1993 | 7681886 |
| ph dependence of the active site of horseradish peroxidase compound ii. | using x-ray absorption spectroscopy, we investigated the active site of horseradish peroxidase (hrp) compound ii at two different ph values. the results indicate that the bond length of the sixth coordinated ligand of the active site was 1.90 +/- 0.02 a at ph 7, decreasing to 1.72 +/- 0.02 a at ph 10. the average iron-to-pyrrole nitrogen and the proximal ligand bond lengths showed no significant changes. the position of higher coordination shells around the iron center changed, implying that som ... | 1993 | 8422396 |
| horseradish peroxidase-catalyzed two-electron oxidations. oxidation of iodide, thioanisoles, and phenols at distinct sites. | the atypical two-electron oxidation of thioanisole and its p-methyl, p-methoxy, and p-nitro analogues by horseradish peroxidase, contrary to earlier reports, stereoselectively produces the (s) sulfoxides in 60-70% enantiomeric excess. horseradish peroxidase reconstituted with delta-meso-ethylheme has little peroxidase (guaiacol oxidizing) activity, as previously reported, but exhibits increased sulfoxidation activity. difference spectroscopy shows that guaiacol binds to delta-meso-ethylheme-reco ... | 1993 | 8420938 |
| iodide modulation of the edta-induced iodine reductase activity of horseradish peroxidase by interaction at or near the edta-binding site. | horseradish peroxidase (hrp) catalyses the reduction of iodinium ion (i+) to iodide by h2o2 in the presence of edta. i+ reduction occurs optimally at ph 6 whereas the enzyme catalyses iodide oxidation optimally at ph 3.5. thus the two activities reside on the same enzyme with two characteristic ph optima. iodide modulates the expression of the reductase activity by edta. higher concentrations of iodide inhibit the reductase activity by edta. nitrite, an electron donor, acts similarly to iodide. ... | 1993 | 8424798 |