| wheat germ agglutinin (wga) reduces adh-induced water flow and induces cell surface changes in epithelial cells of frog urinary bladder. | the functional and structural changes induced by apical wheat germ agglutinin (wga) 100 micrograms/ml exposure on frog urinary bladder have been investigated and the possible correlations between these effects discussed. bladders, apically exposed to wga for 30 min to 3 hr exhibit a marked reduction of their response to antidiuretic hormone (adh) challenge and of their hydrosmotic reactivity. structural changes triggered by wga treatment are: 1. apical invaginations of the plasma membrane, inter ... | 1989 | 2631978 |
| addition of nerve growth factor to the interior of a tubular prosthesis increases sensory neuron regeneration in vivo. | the sciatic nerve of adult mice was transected and the proximal and distal nerve stumps were sutured into a polyethylene tube. the tubes were implanted either empty, or the lumen was filled with pure collagen or a mixture of collagen/nerve growth factor (ngf). six weeks later, cells in the l3-l5 dorsal root ganglia (drg) were retrogradely filled with horseradish peroxidase (hrp). the data demonstrate that the addition of ngf to the interior of the tubular prosthesis can significantly increase th ... | 1989 | 2620177 |
| anatomical study of the innervation pattern of the sonic muscle of the oyster toadfish. | the sonic muscle of the oyster toadfish opsanus tau contracts in almost perfect synchrony along its rostrocaudal extent. we explored some of the anatomical mechanisms underlying this synchronization. cleared and stained wholemounts demonstrate that axons innervating the rostral portion of the muscle run caudally in the main nerve trunk before branching in the rostral direction, thus increasing their path length and potentially equalizing conduction time to different parts of the muscle. differen ... | 1989 | 2611636 |
| identification of vestibular efferent neurons in the gerbil: histochemical and retrograde labelling. | the efferent neurons of the gerbil vestibular system were investigated by retrograde tracing techniques and cytochemical staining for acetylcholinesterase (ache), choline acetyltransferase (chat) and a number of peptides. the location, bilateral distribution, cell area and number of neurons in two identified groups of retrogradely labelled cells were described and quantified. the larger of the two groups was located dorsolateral to the facial nerve genu, ventral and medial to the vestibular nucl ... | 1989 | 2599041 |
| histogenetic study of the vestibular ganglion in the developing chick embryo by lectin-horseradish peroxidase methods. | hatchery eggs of white leghorn hens were incubated and the vestibular ganglion cells of 3.5- to 6-day-old chick embryos were studied by the lectin-horseradish peroxidase methods (wga, uea-1). in the 3.5-day-old chick embryos, the facial-acoustic ganglion mass was recognized close to the otic vesicle. the statoacoustic ganglion reacted to lectins on the rhombencephalic side, indicating that glycoconjugates play a role in the nerve connection between ganglion and rhombencephalon. in the 4-day-old ... | 1989 | 2594334 |
| primary vestibular projections in the chinchilla. | the central projections of fibers from the vestibular nerve were studied in 19 chinchillas after horseradish peroxidase labelling. in addition, the limits of the vestibular nuclei and the anatomical characteristics of their neurons were also studied. all five vestibular nuclei received primary afferents, but there were extensive areas of them that received very little or no projections at all, such as the rostral part of the superior vestibular nucleus, the dorsocaudal part of the lateral vestib ... | 1989 | 2590025 |
| the segmentation gene krüppel of drosophila melanogaster has homeotic properties. | in drosophila hindgut, malpighian tubules and posterior midgut develop from the most posterior region of the blastoderm. one of the genes that influences the differentiation of the malpighian tubules is krüppel (kr), a segmentation gene of the gap class. kr homozygous embryos lack thoracic and abdominal segments and, depending on the allele, develop nearly normal malpighian tubules or do not differentiate them at all. in the wild type, injection of horseradish peroxidase (hrp) into cells of the ... | 1989 | 2565277 |
| development of the nucleus isthmi in xenopus, ii: branching patterns of contralaterally projecting isthmotectal axons during maturation of binocular maps. | the tectum of xenopus frogs receives input from both eyes. the contralateral eye's projection reaches the tectum directly, via the optic nerve, and the ipsilateral eye's projection reaches the tectum indirectly, via the nucleus isthmi. under normal conditions, the topography of the ipsilateral map relayed from the nucleus isthmi is in register with the topography of the retinotectal map from the contralateral eye. during development, the process of aligning the two maps is complicated by the dra ... | 1989 | 2562146 |
| signal processing in a simple vertebrate photoreceptor system: the teleost pineal organ. | the integrating circuitry and efferent pathways for neural signals evoked in the photosensory pineal organ by changes in ambient illumination have been investigated by a multidisciplinary approach. intrapineal efferent neurons were identified by means of retrograde filling with horseradish peroxidase (hrp). in addition to several types of neurons, photoreceptor cells that emitted axons to the brain via the pineal tract were observed. the presence of several populations of local interneurons (put ... | 1989 | 2555826 |
| involvement of cysteine, serotonin and their analogues in peroxidase-oxidase reactions. | myeloperoxidase-oxidase reactions with close to physiological concentrations of thiols and phenols were studied. cysteine was shown to be a myeloperoxidase-oxidase substrate when catalytic amounts of serotonin were added as cosubstrate. penicillamine could be substituted for cysteine and acetaminophen could be substituted for serotonin. the properties of these peroxidase-oxidase reactions, e.g. the dependence on substrate and myeloperoxidase concentration, reduced oxygen species, metal ions and ... | 1989 | 2545363 |
| states of determination of single cells transplanted between 512-cell xenopus embryos. | single cells from 512-cell xenopus embryos, totally labeled with intracellular horseradish peroxidase, were transplanted orthotopically (from either dorsal or lateral marginal zone) or heterotopically (between these two marginal zones) to unlabeled host embryos at the 512-cell stage. at tailbud stage 23 the locations, numbers, and histotypes of labeled cells were recorded. the transplanted cell had divided many times, giving rise to labeled progeny that expressed a wide range of cell types and w ... | 1989 | 2535820 |
| astroglial differentiation in the opossum superior colliculus. | glial markers, namely, vimentin, glial fibrillary acidic protein (gfap), and glycogen, as well as accumulation of axon-borne horseradish peroxidase (hrp), were used to visualize radial glial cells in the developing opossum superior colliculus (sc) and to follow changes in young astrocytes of the superficial layers. vimentin, gfap, and glycogen are relatively abundant in elements of the median ventricular formation (mvf), which persists at least as late as weaning time, i.e., postconception day 1 ... | 1989 | 2524443 |
| central projections of the nervus terminalis in four species of amphibians. | the central projections of the nervus terminalis were investigated in two anuran and two urodele species by means of horseradish peroxidase injections into one nasal cavity. in anurans, the nervus terminalis projects to the medial septum, to the preoptic nucleus, to the nucleus of the anterior commissure and to the hypothalamus. in addition to these structures, the dorsal thalamus, the infundibulum and the mesencephalic tegmentum are innervated in urodeles. the structure containing the highest d ... | 1989 | 2514961 |
| clinical applications of luminescent assays for enzymes and enzyme labels. | a wide range of luminescent assays for enzyme labels has been developed. the clinical application of luminescent assays for horseradish peroxidase, alkaline phosphatase, xanthine oxidase, beta-d galactosidase, and glucose 6-phosphate dehydrogenase is discussed. the enzyme luminescent methods provide improved sensitivity compared with colorimetric and fluorimetric assays. a new reagent, dioxetane phosphate, has provided a simple and extremely sensitive assay for alkaline phosphatase. the availabl ... | 1989 | 2509654 |
| chemiluminescent oxidation of ribose catalyzed by horseradish peroxidase in presence of hydrogen peroxide. | the reaction of ribose with horseradish peroxidase in the presence of h2o2 is accompanied by light emission. the detection of horseradish peroxidase compound ii (feo2+) indicates that the enzyme participates in a normal peroxidatic cycle. hydrogen peroxide converts horseradish peroxidase into compound 1 (feo2+) which in turn is converted into compound ii by abstracting a hydrogen atom from ribose forming a ribosyl radical. in aerated solutions oxygen rapidly adds to the ribosyl radical. based on ... | 1989 | 2502483 |
| interaction of intermediate filaments with nuclear lamina and cell periphery. | ultrastructural observations of the cytoskeleton suggest that the connection of the intermediate filaments (ifs) to actin microfilaments (mfs) at the plasma membrane and the nuclear lamina inside the nuclear membrane link signals received at the cell periphery to the nucleus. when these connections are viewed in three dimensions using detergent extracted cytoskeletal preparations from tissue cultures or slices made from tissue, the ifs are seen to run without interruption from the cell periphery ... | 1989 | 2491340 |
| accessibility of colloidal gold and horseradish peroxidase to cytosolic spaces in limulus ventral photoreceptors. | physiological studies of intracellular messengers frequently employ intracellular injections of large molecules that either monitor or modulate the metabolism of the messenger cascade. injected molecules have unknown mobility in the cytosol and unknown accessibility to various cytosolic compartments, including those postuiated to be traversed by intracellular messenger molecules. in order to determine whether injected molecules have access to the confined spaces through which messenger molecules ... | 1989 | 2487647 |
| immunological changes following treatment of psoriasis with cyclosporin. | five patients treated for severe plaque psoriasis with cyclosporin were studied. cryostat sections of biopsies taken from the same lesional skin areas before and during therapy were examined for immunological surface markers, and deposits of immunoglobulins and complement using a panel of monoclonal and polyclonal antibodies. fc gamma-receptors (fcr) were detected using soluble immune complexes of horseradish peroxidase (hrp)-anti-hrp. during therapy the dermal accumulation of t-lymphocytes (cd3 ... | 1989 | 2481929 |
| the distribution of hippocampal and spinal projecting cells in the locus coeruleus of tottering mice. | wheat germ agglutinin conjugated to horseradish peroxidase and fast blue were used as retrograde tracers to examine the distribution of coeruleohippocampal and coeruleospinal somata within the locus coeruleus of normal and tottering mutant mice. the distributions of these projection neuron populations in normal mice are similar to what has been found in other species, and the distributions of these projection neurons in tottering mice are indistinguishable from those in normal mice, in spite of ... | 1989 | 2479883 |
| the penetration of exogenous tracers through the enameloid organ of developing teleost fish teeth. | in order to determine whether exogenous materials permeate to the forming tooth enameloid matrix, teleost species were injected intramuscularly with horseradish peroxidase (hrp) or myoglobin, or; intracardially with lanthanum nitrate or hrp, then killed a predetermined intervals post-injection. tooth bearing bones were processed for transmission electron microscopy. at the enameloid matrix formation stage, capillaries associated with the enameloid organ were few in number and rarely fenestrated. ... | 1989 | 2479118 |
| [use of a peroxidase marker to detect the diffusion of protein in gel]. | the method for the assessment of the protein gel diffusion rate implies the employment of protein conjugates with horseradish peroxidase; the diffusion of these conjugates can be easily visualized by covering the gel with a cellulose acetate film wetted with a solution of the substrate specific for peroxidase. the necessary concentration of the protein can be selected with this method, as well as the time of the diffusion of the proteins tested as chemoattractants in studies on cellular chemotax ... | 1989 | 2469845 |
| selective suppression of endogenous peroxidase activity: application for enhancing appearance of hrp-labeled neurons in vitro. | a simple procedure to suppress selectively the endogenous peroxidase activity of red blood cells in histological sections of the mammalian nervous system is described. pretreatment of sections with a series of ethanol solutions results in selective abolition of red blood cell staining and also leads to enhanced visualization of neurons that have been injected with horseradish peroxidase (hrp). the method is particularly useful for processing in vitro brain slices that contain hrp-labeled neurons ... | 1989 | 2465461 |
| differential projections of b and c sympathetic axons in peripheral nerves of the bullfrog. | accumulating evidence indicates that electrophysiologically distinct subsets of sympathetic neurons selectively innervate different classes of targets. the organization of this system may therefore be reflected in the sympathetic fiber contents of peripheral nerves. to test this possibility, we have mapped the pathways followed by three groups of postganglionic sympathetic axons in the bullfrog by recording compound action potentials and by retrograde tracing with horseradish peroxidase (hrp). t ... | 1988 | 3265943 |
| a horizontal cell selectively contacts blue-sensitive cones in cyprinid fish retina: intracellular staining with horseradish peroxidase. | a horizontal cell selectively contacting blue-sensitive cones has been intracellularly stained with horseradish peroxidase in the retina of a cyprinid fish, the roach. the light microscopical morphology of the cell belonged to the h3 category of horizontal cells found in cyprinid fish retinae. in response to spectral stimuli, the cell generated chromaticity-type s-potentials that were hyperpolarizing to blue and depolarizing to yellow-orange. a red-sensitive hyperpolarizing component was absent ... | 1988 | 2468167 |
| ultrastructural evidence for direct monosynaptic rubrospinal connections to motoneurons in macaca mulatta. | the magnocellularis division of the red nucleus of the macaca mulatta, a midbrain structure involved in processing motor information, is known by light microscopic analysis to project, via the rubrospinal tract, to the contralateral intermediate horn of the spinal cord. physiological studies, however, provide additional evidence for direct monosynaptic connections to motoneurons subserving distal musculature. this electron microscopic study demonstrates, by analyzing the anterograde transport of ... | 1988 | 2465507 |
| forebrain connections of the gustatory system in ictalurid catfishes. | horseradish peroxidase tracing and extracellular electrophysiological recording techniques were employed to delineate prosencephalic connections of the gustatory system in ictalurid catfishes. the isthmic secondary gustatory nucleus projects rostrally to several areas of the ventral diencephalon including the nucleus lobobulbaris and the nucleus lateralis thalami. injections of hrp in the vicinity of the nucleus lobobulbaris reveal an ascending projection to the telencephalon terminating in the ... | 1988 | 3216048 |
| abilities of peroxidases to catalyse peroxidase-oxidase oxidation of thiols. | the abilities of various peroxidases to catalyse the peroxidase-oxidase oxidation of seven aminothiols were studied. cysteamine and cysteine esters were found to be peroxidase-oxidase substrates for eosinophil peroxidase and myeloperoxidase, whereas other thiols tested were inactive or poorly active with these peroxidases. with lactoperoxidase and horseradish peroxidase, all the tested thiols were inactive or poorly active as peroxidase-oxidase substrates. these studies suggest that a main reaso ... | 1988 | 2852004 |
| plasticity in the developing chick visual system: topography and maintenance of experimentally induced ipsilateral projections. | the present work examines the topography of the contra- and ipsilateral centrifugal projections from the isthmooptic nuclei (ions) to the remaining retina in monocular chick embryos. after removal of the left eyecup at embryonic day (e)1.5, the ions were investigated at various embryonic stages by the retrograde transport of fluorescent dyes and horseradish perioxidase (hrp) injected into the remaining eye. the projection of the ipsilateral ion was consistently found at e13 and frequently disapp ... | 1988 | 3230167 |
| pioneer neurones use basal lamina as a substratum for outgrowth in the embryonic grasshopper limb. | during axonogenesis, contacts made by the growth cone with its substratum are important in guiding the direction of neurone outgrowth. this study examines the contacts made by the growth cones of pioneer neurones in the embryonic grasshopper limb. individual pioneer neurones at different stages of development were injected with horseradish peroxidase and the contacts made by the filopodia at the tip of their growth cones were examined by electron microscopy. filopodia made few contacts with meso ... | 1988 | 3268405 |
| localization of gaba and glycine in goldfish retina by electron microscopic postembedding immunocytochemistry: improved visualization of synaptic structures with lr white resin. | a post-embedding, electron microscopic immunocytochemistry technique, modified from existing protocols, was used to examine the labelling patterns of gaba immunoreactivity and glycine immunoreactivity in goldfish retina. retinae were fixed in mixed aldehyde solution, dehydrated in ethanol, stained en bloc with uranyl acetate and phosphotungstic acid and embedded in lr white resin. substances were localized in thin sections by floating grids first on a drop of primary antiserum and then on a coll ... | 1988 | 3230403 |
| transcytosis of protein through the mammalian cerebral epithelium and endothelium. i. choroid plexus and the blood-cerebrospinal fluid barrier. | the potential for transcytosis (endocytosis----intracellular transport----exocytosis) of protein and membrane events associated with fluid phase and adsorptive endocytic processes within epithelia of the choroid plexus [blood-cerebrospinal fluid (csf) barrier] were investigated in mice injected intravenously or into the lateral cerebral ventricle with native horseradish peroxidase (hrp) or the lectin wheatgerm agglutinin (wga) conjugated to hrp. wga binds to specific cell surface oligosaccharide ... | 1988 | 3230399 |
| inactivation kinetics of horseradish peroxidase microinjected into hepatocytes from mice of various ages. | we have studied degradation of proteins in liver parenchymal cells in culture obtained from mice of various ages. horseradish peroxidase (hrp) was microinjected into the cells by the hypertonic-hypotonic method of okada and rechsteiner (cell, 29 (1982) 33-41). rate of inactivation of hrp was examined biochemically. average functional half-lives of the enzyme were 50 h, 53 h and 75 h in the cells of young (3-8 months old), middle-aged (18-20 months old) and old (28-30 months old) mice, respective ... | 1988 | 3226154 |
| an improved solid-phase enzyme and luminescent immunoassay system for steroid hormones and digoxin. | a uniform solid-phase system has been developed for enzyme (elisa) or luminescent (lia) immunoassays for steroids. these assays were improved by (a) irradiating microtiter plates or polystyrene tubes before coating with antibody or protein a, (b) coating the plastic trays with nonspecific anti-gamma-globulin or protein a instead of the steroid-specific first antibody, and (c) partial denaturation of the second antibody before coating the plates or tubes with it. specific antibodies were raised a ... | 1988 | 3058365 |
| [detection of anti-dna antibody by horseradish peroxidase elisa]. | | 1988 | 2978404 |
| unitary conductance changes at teleost mauthner cell glycinergic synapses: a voltage-clamp and pharmacologic analysis. | 1. the magnitude and kinetics of inhibitory postsynaptic currents (ipscs) evoked in the goldfish mauthner (m-) cell by intracellular stimulation of identified presynaptic interneurons (unitary responses) and by activation of the recurrent collateral network were determined with single-and double electrode voltage-clamp techniques. 2. the peak magnitude of the inhibitory conductance changes were 5610 +/- 4800 ns (mean +/- sd; n = 13) for the collateral response, and 144 +/- 44 ns (n = 7) for the ... | 1988 | 2466964 |
| anatomical specificity of regenerated muscle sensory afferents in the spinal cord of the bullfrog. | the specificity of central projections made by regenerated muscle sensory fibers in the brachial spinal cord was studied with anatomical tracing methods. sensory fibers were interrupted by freezing dorsal roots in postmetamorphic bullfrogs. after several months, regenerated sensory fibers were labeled with horseradish peroxidase applied to the triceps brachii muscle nerve, and their arborizations within the spinal cord were reconstructed from serial cross sections. most of the regenerated projec ... | 1988 | 2466950 |
| role of oxygen during horseradish peroxidase turnover and inactivation. | horseradish peroxidase catalyzed oxidation of phenol has been reinvestigated to determine the requirements of facile enzyme autoinactivation. turnover of this peroxidase was monitored spectrophotometrically at 400 nm and found dependent on the concentration of phenol and hydrogen peroxide. the inactivation of the peroxidase required both substrates, phenol and h2o2, but surprisingly was also potentiated by molecular oxygen. exclusion of diffusible superoxide or hydroxyl radicals had slight effec ... | 1988 | 3196329 |
| specific staining on thin-layer chromatograms of glycosphingolipids of neolacto series and gangliosides with a terminal n-acetylneuraminyl residue by different procedures with wheat germ agglutinin. | sensitive staining methods with wheat germ agglutinin were developed for the detection of glycosphingolipids of neolacto series (a) and gangliosides with a terminal n-acetylneuraminyl residue (b) on thin-layer chromatograms. (a) neolacto series glycosphingolipids were treated by beta-galactosidase on the chromatograms in the presence of taurodeoxycholate. then the chromatograms were incubated with biotinated wheat germ agglutinin followed by incubation with a complex of avidin and biotinated hor ... | 1988 | 2461740 |
| application of the reaction of dithioesters with epsilon-amino groups in lysine to the chemical modification of proteins. | the reaction of lysine with dithioesters was applied to horseradish peroxidase donor: hydrogen-peroxide oxidoreductase, ec 1.11.1.7) using carboxymethyl dithiotridecanoate: three to four lysine residues were modified. the modified enzyme was soluble and active in diethyl ether. papain (ec 3.4.22.2) was modified with carboxymethyl dithiobenzoate: two lysine residues were modified. the modified enzyme was soluble and active in dimethylsulfoxide. from these results it is concluded that dithioesters ... | 1988 | 3142523 |
| projections of digit afferents to the cuneate nucleus in the raccoon before and after partial deafferentation. | within the cuneate nucleus of the raccoon, the representations of individual forepaw digits are anatomically separated by densely myelinated laminae. this unique arrangement was utilized to determine whether the terminations of cutaneous afferents from individual digits are precisely restricted to the appropriate region of the cuneate nucleus or overlap with afferents from adjacent digits. by using the transganglionic transport of horseradish peroxidase (hrp), it was found that, for each digit, ... | 1988 | 2463292 |
| axons added to the regenerated visual pathway of goldfish establish a normal fiber topography along the age-axis. | throughout a goldfish's life, new generations of ganglion cells are added on the retinal margin and their axons extend centrally to occupy predictable positions in the retinotectal pathway, adjacent to their predecessors and subjacent to the pia. the stacking of successive generations of axons defines the age-axis of the pathway. this study examined whether an ordered array of predecessor axons is a prerequisite for the patterned growth of new axons. one optic nerve was crushed intraorbitally an ... | 1988 | 3198799 |
| regenerated optic fibers in goldfish reestablish a crude sectoral order in the visual pathway. | the goldfish optic pathway is regenerated after an optic nerve crush. we have examined the axonal topography of the regenerated pathway by labeling, with horseradish peroxidase (hrp), axons originating from retinal sectors or annuli. the positions of the labeled axons in the cross section of the pathway were compared to the normal and related to the factors that may influence axonal pathfinding. the positions of retinal axons in the cross section of the normal pathway are predictable from the re ... | 1988 | 2461975 |
| oxygen-17 nuclear magnetic resonance spectroscopic studies of carbonmonoxyperoxidases. | we have obtained oxygen-17 (17o) nuclear magnetic resonance (nmr) spectra of c17o ligands bound to ferrous horseradish peroxidase isozyme a, isozyme c, and ferrous chloroperoxidase, as a function of ph. our results show that the peroxidases exist in two distinct states, the acidic and alkaline forms, which undergo reversible acid-base-induced transitions characterized by a single pk value. the two forms are characterized spectroscopically in much the same way in all three proteins, suggesting a ... | 1988 | 3182785 |
| [isolation and characterization of monoclonal antibodies to horseradish peroxidase]. | monoclonal antibodies to horseradish peroxidase were obtained. the interaction of two antibody clones with the enzyme was studied. antibodies of one clone were found to inhibit the enzyme activity during the oxidation of 2.2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate) diammonium salt and the cooxidation of luminol and luciferin. the latter was concomitant with a complete inhibition of the peroxidase activity. the values of binding constants as determined by the solid phase immunoenzymatic and ... | 1988 | 3251550 |
| identification of microinjected cells using biotinylated antibodies and strep-avidin-conjugated horseradish peroxidase. | results from experiments using needle microinjection of cells are often compromised by an inability to readily demonstrate which cells within a population have been injected. the technique described here allows the unambiguous identification of cells that have been successfully microinjected. sequential incubation of fixed cells with biotinylated anti-immunoglobulin antibodies, followed by horseradish peroxidase (hrp)-conjugated strep-avidin and hrp substrate, provides a sensitive assay for iden ... | 1988 | 3239762 |
| development of the optic tecta in the frog limnodynastes dorsalis. | in limnodynastes dorsalis neurogenesis of the optic tecta and the pattern of cellular lamination was determined by [3h]thymidine autoradiography. there was a rostral to caudal gradient of cell proliferation with peak neurogenesis in mid-larval life and by metamorphosis generation was complete. the cellular layers formed as each portion of tectum was generated. as evidenced by comparison of animals killed within 24 h of [3h]thymidine injection and those injected as larvae and killed at more matur ... | 1988 | 3233731 |
| afferent projections of the trigeminal nerve in the goldfish, carassius auratus. | the horseradish peroxidase (hrp) histochemical technique was used to examine the peripheral distribution and afferent projections of the trigeminal nerve in the goldfish, carassius auratus. sensory fibers of the trigeminal nerve distribute over the head via four branches. the ophthalmic branch distributes fibers to the region above the eye and naris. the maxillary and mandibular branches innervate the regions of the upper and lower lip, respectively. a fourth branch of the trigeminal nerve was d ... | 1988 | 3216394 |
| a group of genes required for pattern formation in the ventral ectoderm of the drosophila embryo. | mutations in the genes spitz (spi), star (s), single-minded (sim), pointed (pnt), rhomboid (rho) (all zygotic), and sichel (sic) (maternal), collectively called the spitz group, cause similar pattern alterations in ventral ectodermal derivatives of the drosophila embryo. the cuticle structures lacking in mutant embryos normally derive from longitudinal strips of the ventro-lateral blastoderm. defects were found in the median part of the central nervous system in whole-mount embryos stained with ... | 1988 | 3209069 |
| edge detection in images using marr-hildreth filtering techniques. | details of the morphology of light microscope images of horseradish peroxidase labeled mammalian neurons in cell culture were investigated. a modified marr-hildreth edge-detecting algorithm was used in an image processor to obtain a continuous border of the labeled neurons. the interior of the border was filled to obtain isolated binary silhouettes of the neurons. these silhouettes can be used for further quantitative studies. | 1988 | 3199849 |
| enhancement of macrophage spreading and phagocytosis by peroxidative enzymes. | macrophages stimulated by various substances exhibit altered morphology, metabolism, and enhanced phagocytosis. the present studies were done to show if peroxidative enzymes would affect macrophage spreading and phagocytosis. resident peritoneal macrophages, collected from c57bi mice were exposed to various concentrations of peroxidases and compared with appropriate controls. results indicated that 0.01 microm myeloperoxidase (mypo), 0.09 microm horseradish peroxidase (hrp), 0.16 microm lactoper ... | 1988 | 2852544 |
| anomalous retrograde labeling of brain cells from the eye in the goldfish: evidence for long distance growth of sprouted neurites. | we have used retrograde labeling with horseradish peroxidase (hrp) and a wheat germ agglutinin conjugate of hrp (wga:hrp) to investigate the projections of the nucleus postglomerulosus (npg) both in normal goldfish and in animals which had undergone retinal removal. in normal animals, our evidence indicates that npg projects only to the optic tectum. using small hrp and wga:hrp application sites in the tectum, we have shown that npg cells have broadly spread terminals in the tectal neuropil and ... | 1988 | 2846340 |
| bilateral projections from the medial superior olivary nucleus to the inferior colliculus in the mole (mogera robusta). | a retrograde tracing study in the mole using wheat germ-agglutinated horseradish peroxidase (wga-hrp) indicated that the medial superior olivary nucleus (mso) projects to the inferior colliculus (ic) bilaterally. considering the strict ipsilateral projections from the mso to the ic in all other eutherian species ever reported, the bilateral projection in the mole is quite unique. this may reflect specializations of the peripheral auditory apparatus of the underground dwellers and/or primitivenes ... | 1988 | 2461789 |
| neurons in the medial cortex give rise to timm-positive boutons in the cerebral cortex of lizards. | the origin of timm-positive presynaptic boutons in the cerebral cortex of the lizard, podarcis hispanica, was investigated by injections of horseradish peroxidase (hrp)-saponine in timm-positive areas, i.e. the dorsal and dorsomedial cortices. a broad retrograde labelling of cell somata in the medial cortex was found. injections of hrp-saponine in the medial cortex resulted in broad anterograde labelling of boutons located in the timm-positive zones. a double-labelling of the hrp labelled bouton ... | 1988 | 2461786 |
| mixed-junction axon terminals on identified principal abducens motoneurons in the monitor lizard. | motoneurons in the principal abducens nucleus of the monitor lizard varanus exanthematicus were identified by retrograde labeling following application of horseradish peroxidase to the abducens nerve. the ultrastructure and synaptology of thirty labeled neurons were studied. we observed a type of axon terminal which forms mixed junctions with the cell bodies and the initial axon segments of labeled motoneurons. the juxtaposed membranes of the terminals and the motoneurons display gap junctions a ... | 1988 | 3196908 |
| direct parasympathetic pathway to the eye: revisited. | intraocular injections of wheat germ agglutinin horseradish peroxidase appeared to confirm previous experimental and clinical data supporting the existence of a direct, non-synapsing, parasympathetic pathway from the mesencephalon to the eye. quantitative and qualitative differences between the two pathways were noted. the intraocular injection of the fluorescent dyes fast blue and nuclear yellow failed to provide mesencephalic labeling. the implications of these findings are discussed. | 1988 | 2461785 |
| brainstem origin of serotonin- and enkephalin-immunoreactive afferents to the opossum's cerebellum. | previous studies have described the distribution of serotonin- and enkephalin-immunoreactive elements in the posterior lobe vermis of the opossum's cerebellum. in the present study we have used a double labeling paradigm which combines the retrograde transport of horseradish peroxidase (hrp) with serotonin and enkephalin immunohistochemistry to determine the brainstem origin of serotoninergic and enkephalinergic neurons that project to the opossum's cerebellar cortex. subsequent to hrp injection ... | 1988 | 3198786 |
| projections from the medial cortex in the brain of lizards: correlation of anterograde and retrograde transport of horseradish peroxidase with timm staining. | efferent projections of the medial cortex of the lizards podarcis hispanica and gallotia stehlinii were studied by examining the transport of horseradish peroxidase; results were correlated with those from timm-stained sections. two efferent systems were found. the first reaches the distal part of the outer plexiform layer in the medial, dorsomedial, and dorsal cortices, i.e., zones that are negative to timm staining, and possibly originates from horizontal fusiform neurons. the second reaches t ... | 1988 | 2461968 |
| solvent isotope effects on nmr spectral parameters in high-spin ferric hemoproteins: an indirect probe for distal hydrogen bonding. | the influence of solvent isotope composition on 1h-nmr resonance position and linewidth of heme methyls has been investigated for a variety of high-spin ferric hemoproteins for the purpose of detecting hydrogen-bonding interactions in the heme cavity. consistently larger hyperfine shifts and paramagnetic linewidths in 2h2o than 1h2o are observed for metmyoglobins and methemoglobin possessing a coordinated water molecule. the analysis of the dynamics of labile proton exchange in sperm whale metmy ... | 1988 | 2844271 |
| singlet oxygen production from the peroxidase-catalyzed oxidation of indole-3-acetic acid. | the aerobic oxidation of indole-3-acetic acid catalyzed by horseradish peroxidase produces 1268 nm emission characteristic of singlet oxygen. lactoperoxidase also oxidizes indole-3-acetic acid to produce singlet oxygen, but in contrast to horseradish peroxidase, this enzyme system requires hydrogen peroxide. in both of these systems, the intensity of the 1268 nm emission is small due to quenching of the singlet oxygen by indole-3-acetic acid and by reaction products derived from indole-3-acetic ... | 1988 | 3170541 |
| identification of a monoclonal antibody to abscission tissue that recognises xylose/fucose-containing n-linked oligosaccharides from higher plants. | monoclonal antibodies raised against extracts of the rachis abscission zone of sambucus nigra l. were selected for high reactivity towards abscission-zone proteins. one antibody (yz1/2.23) has been shown to cross-react, by both indirect and competition enzyme-linked immunosorbent assay and by western blotting, with a number of plant enzymes including horseradish peroxidase, rice α-glucosidase, almond β-glucosidase and the lectins from phaseolus vulgaris and erythrina cristagalli.the major n-link ... | 1988 | 24221933 |
| interactions of unconjugated bilirubin with bile salts. | the rate of peroxidation of unbound, unconjugated bilirubin (ucb) was used to assess the interactions of ucb with four taurine-conjugated bile salts at ph 8.2, 37 degrees c, and an ionic strength of 0.15. each of the four structurally different bile salts markedly decreased the rate of peroxidation of ucb in the presence of horseradish peroxidase (hrp); 30% of ucb was bound even at low, premicellar bile salt concentrations (1 mm). at high bile salt concentrations (75 mm), taurocholate (tc) and t ... | 1988 | 3235915 |
| projection-neurons that send axons through the lumbar spinal cord of the chick embryo are not obviously distributed in a segmentally repetitive pattern. | earlier studies have shown that the formation of the segmentally repetitive pattern of spinal nerves in avian embryos depends upon the segmental arrangement of the somites and does not reflect an intrinsic pattern of the spinal cord. these studies could not, however, rule out the possibility that some elements of the central nervous system are intrinsically segmented. the question remained, for instance, whether projection-neurons are distributed in a segmentally repetitive pattern within the sp ... | 2004 | 3216431 |
| pancreatic heterotopia: a reappraisal and clinicopathologic analysis of 32 cases. | a total of 32 histologically documented cases of heterotopic pancreas was found in a review of the records of the department of pathology at the chang gung memorial hospital between 1977 and 1987. this review was done to ascertain the clinical significance of this uncommon entity. in 14 patients (44%), the aberrant pancreatic tissue was symptomatic; in the other 18 (56%), it was found incidentally. in the symptomatic group, the heterotopic pancreatic tissue was found in a duplication cyst of the ... | 1988 | 3051429 |
| reaction between ortho-semiquinones and oxygen: pulse radiolysis, electron spin resonance, and oxygen uptake studies. | the cytotoxicity to tumor cells or cardiotoxic side effects of certain para-quinone antitumor drugs have been attributed to the corresponding semiquinones and derived superoxide and hydroxyl radicals. it has also been suggested that ortho-semiquinones, including those that arise during melanogenesis, produced via either the one-electron oxidation of catechol(amine)s or the one-electron reduction of the corresponding quinones, react with molecular oxygen to give superoxide and hydrogen peroxide. ... | 1988 | 2845864 |
| distribution of morphologically different retinal axon terminals in the hamster dorsal lateral geniculate nucleus. | afferent terminal arbors in the hamster lgbd were labelled with horseradish peroxidase (hrp) implanted into the optic tract. three morphologically distinct terminal types, each with a different regional distribution, were observed. type r1 terminals are large, ovoid swellings and are predominantly distributed medially within the nucleus. type r2 terminals are very small, clustered varicosities and are distributed laterally and ventrally. type r3 terminals are medium in size and their distributio ... | 1988 | 2465068 |
| aberrant growth of regenerating retinotectal axons subsequent to optic tract ablation in goldfish. | this study examined the effect of optic tract ablation on retinotectal fiber regeneration in goldfish. approximately two-thirds of the left optic tract was removed, and, at various times post lesion (10-75 days), the course of regenerating retinotectal fibers was traced using horseradish peroxidase. in all experimental animals, axons were observed regenerating through the visual pathway but at the brachia most of the fibers were channeled through the ventral brachium. we present evidence that fi ... | 1988 | 2465065 |
| resonance raman spectroscopic evidence for heme iron-hydroxide ligation in peroxidase alkaline forms. | horseradish peroxidase will convert from a five-coordinate high-spin heme at neutral ph to a six-coordinate low-spin heme at alkaline ph. though alkaline forms of other heme proteins such as hemoglobin and myoglobin are known to contain a heme-ligated hydroxide, alkaline horseradish peroxidase has been considered not to contain a ligated hydroxide. several alternatives have been proposed which would be stronger field ligands than a hydroxide ion. in this report we provide resonance raman evidenc ... | 1988 | 3417650 |
| synaptic analysis of amacrine cells with neuropeptide y-like immunoreactivity in turtle retina. | neuropeptide y-like immunoreactivity has been localized previously within three classes of amacrine cells in the turtle retina. we have used the avidin-biotin with horseradish peroxidase technique to label these neurons for examination at the ultrastructural level to answer the following questions. where are the synaptic contacts of these neurons made? what types of neurons are involved pre- and postsynaptically? what is the intracellular distribution of the immunoreactivity? processes with neur ... | 1988 | 3225348 |
| an anomaly in the auditory brain stem projections of hypopigmented ferrets. | the number of cochlear nucleus (cn) neurones projecting to the ipsi- and contralateral inferior colliculus (ic) was studied in darkly pigmented and hypopigmented ferrets by the retrograde transport of wheat germ agglutinin-horseradish peroxidase. the contralateral projection in all divisions of the cn of both albino and 'red eyed' ferrets was normal. however, the ipsilateral projection from the anteroventral cn was significantly smaller in albino than in pigmented ferrets. the volume of each div ... | 1988 | 3198516 |
| onset and development of intersegmental projections in the chick embryo spinal cord. | the ontogeny of intersegmental (propriospinal) projections was studied in the chick embryo spinal cord between embryonic day 2.5 and day 6. our goals were 1) to determine the earliest projections of intersegmental interneurons between specific spinal regions and to establish the cell types involved; and 2) to follow the ontogeny of these projections during the early formative stages of spinal cord development. studies were carried out in vitro by using an isolated spinal cord/brainstem preparati ... | 1988 | 2464626 |
| a monoclonal antibody-based enzyme-linked immunosorbent assay of aflatoxin b1 in peanut products. | an improved enzyme-linked immunosorbent assay (elisa) combined with monoclonal antibody (mab) and one-step extraction method was established for the estimation of aflatoxin b1 (afb1) in a peanut product. afb1 was converted to afb1-oxime, and then conjugated with bovine serum albumin (bsa). spleen cells from mice immunized with afb1-bsa conjugates were fused with myeloma cells. after double selection with afb1-ovalbumin (ova) and carbodiimide-modified ova, five stable hybridoma cells secreting an ... | 1988 | 23605161 |
| cyclic modulation of sertoli cell junctional complexes in a seasonal breeder: the mink (mustela vison). | the development and modulation of sertoli cell junctions was studied in newborn and adult mink during the active and inactive spermatogenic phases. the techniques used were electron microscopy of freeze-fractured replicas and thin sections of tissues infused with horseradish peroxidase as a junction permeability tracer. in the newborn, freeze-fractured developing junctions had either spherical or fibrillar particles. in addition, junctional domains where particles were associated preferentially ... | 1988 | 3189199 |
| ultrastructural characterization of gerbil olivocochlear neurons based on differential uptake of 3h-d-aspartic acid and a wheatgerm agglutinin-horseradish peroxidase conjugate from the cochlea. | two populations of olivocochlear (oc) neurons have been identified in the gerbil brain stem on the basis of differential labeling patterns of 3h-d-aspartic acid (d-asp) and wheatgerm agglutinin-horseradish peroxidase conjugate (wga/hrp) from the cochlear perilymph. while both populations are capable of uptake and retrograde uptake of wga/hrp, one population accumulates and retrogradely transports d-asp (d-asp oc neurons) and the other does not (non-d-asp oc neurons). d-asp oc neurons are found i ... | 1988 | 3171669 |
| bipolar origin of synaptic inputs to sustained off-ganglion cells in the mudpuppy retina. | 1. the synaptic inputs to sustained off-center ganglion cells of the mudpuppy retina were studied using a superfused retina-eye-cup preparation. intra- and extracellular electrophysiological recording techniques were carried out during bath application of 2-amino-4-phosphonobutyrate (apb), a glutamate analog that selectively blocks the light responses of on-bipolars but has minor effects on off-bipolar or horizontal cells. 2. the use of apb reduced ganglion cell inputs to those arising from the ... | 1988 | 3171660 |
| mechanism of formation and structural characterization of dna adducts derived from peroxidative activation of benzidine. | although the peroxidative metabolism of benzidine and other carcinogenic arylamines has been regarded as a significant pathway in extrahepatic tissues, the mechanism of peroxidase-mediated covalent binding to dna has remained unclear. in this study, we have compared the metabolic activation of benzidine by prostaglandin h synthase, horseradish peroxidase, chloroperoxidase, and lactoperoxidase. all four peroxidases mediated the binding of benzidine to dna and equimolar amounts of hydrogen peroxid ... | 1988 | 3136947 |
| foundations of immunohistochemistry. a practical review. | in this review of immunohistochemical methods, an emphasis is placed on the historic development of enzyme-linked procedures that are applicable to antigen localization in routinely processed tissues. as the technology of immunohistochemistry has improved, a bewildering montage of antibodies, bridges, labels, and chromogens has evolved. each has its apparent advantages, yet each also has certain limitations. admittedly, a comprehensive review of these different methods is beyond the scope of thi ... | 1988 | 3046324 |
| oxidation of cyanide to the cyanyl radical by peroxidase/h2o2 systems as determined by spin trapping. | the cyanyl radical was formed during the oxidation of potassium or sodium cyanide by horseradish peroxidase, lactoperoxidase, chloroperoxidase, nadh peroxidase, or methemoglobin in the presence of hydrogen peroxide. the spin adducts of the cyanyl radical with 5,5-dimethyl-1-pyrroline-n-oxide and n-tert-butyl-alpha-phenylnitrone were quite stable at neutral ph. the identity of these spin adducts could be demonstrated using 13c-labeled cyanide and by comparison with the spin adducts of the formami ... | 1988 | 2844117 |
| control of cell number in the developing neocortex. i. effects of early tectal ablation. | target availability is an important factor in the early control of neuron number in many structures in the developing vertebrate nervous system. in early neocortical development, the role of target availability in the survival of subcortically projecting neurons is not yet understood, particularly because these cells' axons are widely distributed and highly branched. in this study, we have looked for alterations in the pattern of early cell death, adult cell density and adult morphology of pyram ... | 1988 | 2464411 |
| mechanism of azide binding to chloroperoxidase and horseradish peroxidase: use of an iodine laser temperature-jump apparatus. | the kinetics of azide binding to chloroperoxidase have been studied at eight ph values ranging from 3.0 to 6.6 at 9.5 +/- 0.2 degrees c and ionic strength of 0.4 m in h2o. the same reaction was studied in d2o at pd 4.36. in addition, results were obtained on azide binding to horseradish peroxidase at pd 4.36 and ph 4.56. typical relaxation times were in the range 10-40 microseconds. the value of kh/kd(on) for chloroperoxidase is 1.16, and kh/kd(off) is 1.7; corresponding values for horseradish p ... | 1988 | 3219358 |
| surface view patterns of intrinsic and extrinsic cortical connections of area 17 in a prosimian primate. | patterns of cortical connections were studied in brain sections cut parallel to the surface of mechanically flattened cortex after single, double, or multiple injections of wheatgerm agglutinin conjugated to horseradish peroxidase (wga-hrp) in area 17 of galagos (galago crassicaudatus). intrinsic connections of area 17 included a systematic pattern of patches of labeled cells and terminations associated with blobs of high cytochrome oxidase activity. the patches of connections extended with decr ... | 1988 | 2463054 |
| projections of nucleus angularis and nucleus laminaris to the lateral lemniscal nuclear complex of the barn owl. | interaural phase and intensity are cues by which the barn owl determines, respectively, the azimuth and elevation of a sound source. physiological studies indicate that phase and intensity are processed independently in the auditory brainstem of the barn owl. the phases of spectral components of a sound are encoded in nucleus magnocellularis (nm), one of the two cochlear nuclei. nm projects solely and bilaterally to nucleus laminaris (nl), wherein interaural phase difference is computed. the oth ... | 1988 | 2463287 |
| persistence of the pars externa system of the anterior olfactory nucleus in a microsmatic primate, callithrix jacchus. | the pars externa (pe) system of the anterior olfactory nucleus (aon) in a primate, callithrix jacchus, was defined by its architecture and by its connection patterns with the main olfactory bulb (mob) as revealed by tracing techniques. focal, unilateral injections of wheat germ agglutinin-conjugated horseradish peroxidase into the mob yielded ipsilaterally labelled afferent neurons in all subdivisions of the aon, with the exception of a clearly circumscribed area in the ventrolateral retrobulbar ... | 1988 | 2458800 |
| heme-linked ionization and ligand binding produce identical changes of proximal heme stereochemistry in reduced horseradish peroxidase. evidence for existence of two protein conformations. | the visible and near infrared magnetic circular dichroism spectra of chemically reduced horseradish peroxidase at neutral and alkaline ph values and 5-coordinate protoheme-(2-methylimidazole) at ph 9.1 were compared at 4.2 k with those of photolysis products of their carbon monoxide complexes. from the results obtained we concluded that: (i) there are two protein conformations of hrp which determine the geometry of the fe-n(his) bond; (ii) the transition from one conformation (heme stereochemist ... | 1988 | 3402602 |
| effect of alpha-latrotoxin on the frog neuromuscular junction at low temperature. | 1. alpha-latrotoxin (alpha-ltx) was applied to frog cutaneous pectoris muscles bathed at 1-3 degrees c in either ringer solution, ca2+-free ringer solution with 1 mm-egta and 4 mm-mg2+ or ringer solution plus 4 mm-mg2+, and its effects on miniature end-plate potential (mepp) frequency, nerve terminal ultrastructure and uptake of horseradish peroxidase (hrp) were studied. 2. large concentrations (2 micrograms/ml) of alpha-ltx increased mepp rates to levels above 100/s at all junctions, but the ti ... | 1988 | 3266245 |
| metabolism of 3,3'-dichlorobenzidine by horseradish peroxidase. | 1. the peroxidatic oxidation of 3,3'-dichlorobenzidine by horseradish peroxidase in the presence of h2o2 was examined spectrophotometrically and the reactivity of the spectral species were compared to those formed from the peroxidative oxidation of benzidine. 2. the horseradish peroxidase-catalyzed oxidation of 3,3'-dichlorobenzidine yielded two transient and one stable spectral species with absorption maxima at 630 nm, 370 nm and 410 nm, respectively, whereas that of benzidine yielded three sta ... | 1988 | 3188570 |
| antigen absorption by the jejunal epithelium of children with cow's milk allergy. | to establish if intestinal permeability to exogenous antigens is involved in cow's milk allergy (cma) in infants, 33 children 1 to 24 months old (18 controls and 15 with cma) were tested for intestinal permeability to the protein marker horseradish peroxidase (hrp). jejunal biopsies were performed either during the initial period of diagnosis, at the mean (and se) age of 3 +/- 1 months, and/or 1 yr later, at the age of 13 +/- 2 months, just before and after a milk challenge. a small fragment of ... | 1988 | 3186332 |
| gaba-activated whole-cell currents in isolated retinal ganglion cells. | 1. we have begun to analyze neurotransmitter-activated conductances in retinal ganglion cells by measuring the response of single voltage-clamped adult goldfish ganglion cells to gamma-aminobutyric acid (gaba). here we describe 1) our method of identifying ganglion cells in vitro after their dissociation from papain-treated retinas, and 2) the response of these cells to gaba in the tight-seal whole cell configuration of the patch-clamp method (cf. 41) after 1-4 days of primary cell culture. 2. g ... | 1988 | 3171634 |
| concanavalin a binding sites on the surface of drosophila melanogaster sperm: a fluorescence and ultrastructural study. | the distribution of alpha-d-mannose/alpha-d-glucose terminal residues in the plasma membrane of drosophila melanogaster spermatozoon has been investigated by fluorescence and electron microscopy using concanavalin a (con a) labeling. the results indicate the presence of distinct domains on the sperm surface. intense binding of con a to the plasma membrane is highly restricted to the acrosomal region and to the endpiece of the tail. in the former, con a receptors are not homogeneously distributed ... | 1988 | 3147297 |
| changes in binomial parameters of quantal release at crustacean motor axon terminals during presynaptic inhibition. | 1. the effects of presynaptic inhibition on quantal release of transmitter were investigated at neuromuscular junctions of the motor axon supplying one of the limb muscles of a crab (pachygrapsus crassipes). 2. binomial analysis of transmitter release recorded at selected neuromuscular junctions with an extracellular 'macro-patch' electrode indicated high probability of release (p) from a limited number of available sites (n). during presynaptic inhibition, both n and p were reduced. 3. the bino ... | 1988 | 2907048 |
| primary olfactory projections and the nervus terminalis in the african lungfish: implications for the phylogeny of cranial nerves. | primary olfactory and central projections of the nervus terminalis were investigated by injections of horseradish peroxidase into the olfactory epithelium in the african lungfish. in addition, gonadotropin-releasing hormone (gnrh) immunoreactivity of the nervus terminalis system was investigated. the primary olfactory projections are restricted to the olfactory bulb located at the rostral pole of the telencephalon; they do not extend into caudal parts of the telencephalon. a vomeronasal nerve an ... | 1988 | 2847523 |
| prostaglandin hydroperoxidase-dependent oxidation of phenylbutazone: relationship to inhibition of prostaglandin cyclooxygenase. | prostaglandin h synthase (phs) hydroperoxidase-mediated metabolism of phenylbutazone and the relationship of this metabolism to the inhibition of phs cyclooxygenase by phenylbutazone was investigated. phenylbutazone was metabolized to several intermediates and metabolites. a phenylbutazone carbon-centered radical (an = 14.6 g) formed by phs hydroperoxidase was trapped by 2-methyl-2-nitrosopropane and detected by esr in incubations with ram seminal vesicle microsomes. 4-hydroperoxy- and 4-hydroxy ... | 1988 | 2842654 |
| mechanism-based inactivation of horseradish peroxidase by sodium azide. formation of meso-azidoprotoporphyrin ix. | catalytic turnover of sodium azide by horseradish peroxidase, which produces the azidyl radical, results in inactivation of the enzyme with ki = 1.47 mm and kinact = 0.69 min-1. inactivation of 80% of the enzyme requires approximately 60 equiv each of nan3 and h2o2. the enzyme is completely inactivated by higher concentrations of these two agents. meso-azidoheme as well as some residual heme are obtained when the prosthetic group of the partially inactivated enzyme is isolated and characterized. ... | 1988 | 3179265 |
| a nuclear overhauser effect study of the heme crevice in the resting state and compound i of horseradish peroxidase: evidence for cation radical delocalization to the proximal histidine. | the assignment of resolved hyperfine-shifted resonances in high-spin resting state horseradish peroxidase (hrp) and its double-oxidized reactive form, compound i (hrp-i), has been carried out by using the nuclear overhauser effect (noe) starting with the known heme methyl assignments in each species. in spite of the efficient spin-lattice relaxation and very broad resonances, significant noes were observed for all neighboring pyrrole substituents, which allowed the assignment of the elusive prop ... | 1988 | 3179262 |
| identification and properties of an oxoferryl structure in myeloperoxidase compound ii. | myeloperoxidase compound ii has been characterized by using optical absorption and resonance raman spectroscopies. compared to compounds ii in other peroxidases, the electronic and vibrational properties of this intermediate are strongly perturbed due to the unusual active-site iron chromophore that occurs in myeloperoxidase. despite this difference in prosthetic group, however, other properties of myeloperoxidase compound ii are similar to those observed for this intermediate in the more common ... | 1988 | 2846034 |
| comparison of conjugation procedures for the preparation of monoclonal antibody-enzyme conjugates. | four monoclonal antibodies belonging to different subclasses and with differing isoelectric points were coupled to horseradish peroxidase (hrp) and alkaline phosphatase (ap) using various conjugation procedures. the conjugates were tested by enzyme immunoassay and their efficiency was characterized by the antibody and enzyme concentrations needed to obtain an arbitrary od value. the suitability of antibody for conjugation through nh2 groups was tested by fluorodinitrobenzene (fdnb). hrp conjugat ... | 1988 | 3135335 |
| photobiochemistry without light. | efficient excited state formation - much higher than that hitherto expected - may occur in organelles and in intact cells. excited triplet states can be enzymatically generated in high yields by different routes. an example is the oxidation of isobutanal to acetone and formic acid, catalyzed by horseradish peroxidase. other enzymatic systems that generate triplet carbonyls are linear aliphatic aldehydes when oxidized by peroxidase/o2, or the indole-3-acetic acid/peroxidase/o2-reaction. the latte ... | 1988 | 3294032 |
| morphological identification of the motor neurons innervating the dorsal longitudinal flight muscle of drosophila melanogaster. | the dorsal longitudinal flight muscle (dlm) of drosophila is composed of six muscle fibers (dlm1-6 from ventral to dorsal) and innervated by five motor neurons (mns), dlm1-4 being innervated singly by mn1-4, and dlm5 and 6 being jointly innervated by mn5. this study identifies and describes the five motor neurons that innervate these six muscle fibers. horseradish peroxidase (hrp) applied intracellularly to single identified dlm fibers resulted in the labeling of the single motor neuron innervat ... | 1988 | 3145293 |
| direct esr detection of a free radical intermediate during the peroxidase-catalyzed oxidation of the antimalarial drug primaquine. | oxidation of the antimalarial primaquine by horseradish peroxidase and h2o2 was demonstrated by visible light absorption and esr spectroscopy. initial product analysis indicated a 15% yield of o-demethoxylation products, methanol and the quinone-imine derivative, and organic extractable polymeric material. horseradish peroxidase was substituted by methemoglobin, and both enzymes showed greater activity at acidic ph values. during the enzymatic oxidation of primaquine, a drug-derived free radical ... | 1988 | 2840077 |
| putative cholinergic projections from the nucleus isthmi and the nucleus reticularis mesencephali to the optic tectum in the goldfish (carassius auratus). | the nucleus isthmi of fish and amphibians has reciprocal connections with the optic tectum, and biochemical studies suggested that it may provide a major cholinergic input to the tectum. in goldfish, we have combined immunohistochemical staining for choline acetyltransferase with retrograde labeling of nucleus isthmi neurons after tectal injections of horseradish peroxidase. seven fish received tectal horseradish peroxidase injections, and brain tissue from these animals was subsequently process ... | 1988 | 2463280 |
| origins of descending projections to the medulla oblongata and rostral medulla spinalis in the urodele salamandra salamandra (amphibia). | descending projections to the medulla oblongata and rostral medulla spinalis have been examined in the urodele salamandra salamandra with retrograde horseradish peroxidase tracing. ipsilateral projections originate from the striatum and the nucleus ventrolateralis thalami and reach the medulla oblongata. the ipsilateral nucleus praeopticus magnocellularis reaches the medulla spinalis. the rostral part of the nucleus tuberculi posterioris projects to the ipsilateral medulla oblongata; its caudal ... | 1988 | 2458392 |