| increases in peroxide formation by the photosystem ii oxygen evolving reactions upon removal of the extrinsic 16, 22 and 33 kda proteins are reversed by cacl2 addition. | this communication introduces a new spectrophotometric assay for the detection of peroxide generated by photosystem ii (ps ii) under steady state illumination in the presence of an electron acceptor. the assay is based on the formation of an indamine dye in a horseradish peroxidase coupled reaction between 3-(dimethylamino)benzoic acid and 3-methyl-2-benzothiazolinone hydrazone. using this assay, we found that as the o2 evolution activity of ps ii-enriched membrane fragments is decreased by trea ... | 1993 | 24317998 |
| vitronectin: possible contribution to the closed-eye external host-defense mechanism. | eye closure causes a shift in the preocular tear film, from a reflex tear-rich layer which is in dynamic equilibrium to a secretory iga-rich layer which is stagnant in nature. this is accompanied by complement conversion and plasminogen activation, followed by polymorphonuclear (pmn) cell recruitment. it is suggested that this shift to a secretory iga and pmn cell-rich layer serves to protect the ocular surfaces from trapped microorganisms. the mechanisms whereby autologous damage is avoided are ... | 1993 | 22822923 |
| immunohistochemical analysis of transgene expression. | immunohistochemistry can be used to localize the peptide or protein product of the transgene, or to identify particular cell types within tissue sections by labeling a specific protein. there are many ways to do this. today many involve a primary antibody to the protein of interest, and a secondary antibody plus a fluorescent or enzyme tag to visualize the reaction. the fluorescent tag is observed by viewing it through a microscope equipped with a light source of the correct wavelength to excite ... | 1993 | 21390686 |
| tetrodotoxin-sensitive dendritic spiking and control of axonal firing in a lobster mechanoreceptor neurone. | 1. a primary mechanosensory neurone, the anterior gastric receptor (agr) associated with gastric mill muscle in the lobster foregut was examined in vitro with extra- and intra-cellular recording techniques to understand processes of dendritic integration and dendro-axonal communication. 2. agr has a 't'-shaped geometry; its two long (> 3 mm) primary dendrites project distally to spatially separate, stretch sensitive terminals and converge centrally onto a common apical neurite that leads to a bi ... | 1993 | 8487209 |
| developmental regulation of regenerative specificity in the bullfrog. | the accuracy with which motor axons reinnervate the hindlimb following ventral rhizotomy was studied in the bullfrog (rana catesbeiana) by mapping the locations within the lumbar lateral motor column of motoneurons retrogradely labeled with horseradish peroxidase. at early stages of development, axons regenerate to the correct hindlimb region. in older tadpoles and frogs, axons appear to regenerate to targets determined by basal lamina tubes, which persist in the distal nerve stump after the sev ... | 1993 | 8457898 |
| projection patterns of primary sensory neurons studied by transganglionic methods: somatotopy and target-related organization. | the anatomical organization of the centrally projecting branches of different peripheral sensory nerves was not possible to investigate efficiently until the development of the axonal tracing methods. horseradish peroxidase applied peripherally could be visualized in central projection areas provided a sensitive histochemical method was used; this created the basis for transganglionic tracing from the periphery. this has permitted the investigation of large-scale projections from peripheral sens ... | 1993 | 8457868 |
| enzymatic formation and electrochemical characterization of multiply substituted glutathione conjugates of hydroquinone. | 1,4-benzoquinone can undergo redox cycling in the presence of glutathione to produce multiply substituted products. it has previously been shown that the nephrotoxicity of the hydroquinone-glutathione conjugates increases with increasing substitution. however, based on chromatographically-assisted hydrodynamic voltammetry (ca-hdv), the oxidation potential was shown to apparently increase which, should lead to decreased toxicity. from the chemical formation of multiply substituted hydroquinone-gl ... | 1993 | 8450717 |
| a morphological study of the principal and accessory abducens nuclei in the caspian terrapin (mauremys caspica). | the location of principal and accessory motoneurons and principal interneurons of the nucleus abducens was determined in the caspian terrapin (mauremys caspica) by means of horseradish peroxidase histochemical tracing. enzyme injections were made into the ipsilateral lateral rectus and retractor bulbi muscles and into the contralateral oculomotor nucleus. labeled principal abducens motoneurons formed a cluster of cells in the rhombencephalon, under the ivth ventricle and adjacent to the medial l ... | 1993 | 8431756 |
| optic synapses are found in diencephalic neuropils before development of the tectum in xenopus. | the position of the earliest optic synapses in xenopus and the stage at which they developed were studied with the electron microscope after labelling of optic axons with horseradish peroxidase. in addition, tritiated thymidine autoradiography and bromodeoxyuridine immunohistology were used to identify the birth dates of cells in the regions where the synapses had been found. the earliest mature optic synapses were found in the mid-diencephalic region, where the major diencephalic optic neuropil ... | 1993 | 8430898 |
| distribution, morphology, and central projections of mesencephalic trigeminal neurons in the frog rana ridibunda. | the distribution, morphology, and central projections of the mesencephalic trigeminal neurons in the frog rana ridibunda were studied with tracing techniques. retrograde tracing with horseradish peroxidase (hrp) or the fluorescent tracer fluorogold, and anterograde tracing by means of phaseolus vulgaris leucoagglutinin, the fluorescent dye dii, and hrp were used. the mesencephalic trigeminal nucleus (mesv) of rana ridibunda is formed by a population of 100 to 125 unipolar or multipolar cells tha ... | 1993 | 8417625 |
| neuroanatomical substrate for the dorsal light response. i. differential afferent connections of the lateral lobe of the valvula cerebelli in goldfish (carassius auratus). | the afferent connections of the lateral lobe of the valvula cerebelli in goldfish were investigated by retrograde labeling with horseradish peroxidase (hrp). retrogradely labeled neurons were observed ipsilaterally in the lateral nucleus of the valvula and contralaterally in the inferior olivary nucleus after hrp injection into all parts of the lateral valvula. the valvulopetal projections from these nuclei were topographically arranged. after hrp injection confined to the rostral half of the la ... | 1993 | 8387162 |
| heat stress affects blood-brain barrier permeability to horseradish peroxidase in mice. | the blood-brain barrier of mice subjected to hyperthermia for 0-135 min was examined using horseradish peroxidase (hrp) and evans blue dye tracers by light, fluorescence and electron microscopy. neither control nor heat-stressed mice exhibited extravasation of the evans blue dye-albumin complex from the brain microvasculature. gross examination of vibratome sections processed to reveal hrp reaction product exhibited multiple microfoci of hrp extravasation. electron microscopic observations of th ... | 1993 | 8372642 |
| the primary octaval nuclei and inner ear afferent projections in the otophysan ictalurus punctatus. | physical coupling between the swimbladder and the inner ear is believed to contribute to the enhanced hearing abilities of otophysans relative to those of teleosts lacking comparable otic specializations. we hypothesized that the auditory circuitry of otophysans might also exhibit derived features [mccormick and braford, 1988]. as a first test of this hypothesis, we examined the normal anatomy and inner ear inputs of the primary octaval nuclei in the catfish ictalurus punctatus. from nissl-stain ... | 1993 | 8324624 |
| hypophysiotropic neurons in the hypothalamus of the catfish clarias batrachus: a cobaltous lysine and hrp study. | seven hypothalamic nuclei and several isolated perikarya that send projections to the pituitary gland were identified following administration of cobaltous lysine or horseradish peroxidase (hrp) to severed hypophysial stalks of previously hypophysectomized catfish, clarias batrachus. retrogradely labelled neurons were identified in the nucleus preopticus periventricularis, suprachiasmatic nucleus, paraventricular and supraoptic divisions of the magnocellular nucleus preopticus (npo) and nucleus ... | 1993 | 8324622 |
| activity of horseradish peroxide adsorbed on radio frequency glow discharge-treated polymers. | horseradish peroxidase (hrp) has been used as a model enzyme in this study of its physical adsorption and residual enzyme activity on radio frequency glow discharge (rfgd)-treated polymers. the specific enzymatic activity of hrp adsorbed on different surfaces was assumed to be an indication of the extent of its conformational alterations on the surfaces. the surfaces studied were poly (ethylene terephthalate) (pet), polytetrafluoroethylene (ptfe), and tetrachloroethylene and tetrafluoroethylene ... | 1993 | 8297829 |
| areal, modular, and connectional organization of visual cortex in a prosimian primate, the slow loris (nycticebus coucang). | slow lorises (nycticebus coucang) are nocturnal prosimian (i.e. strepsirhine) primates, closely related to bushbabies (galago spp.). we examined the organization of visual cortex in four hemispheres from two slow lorises, using connectional and architectonic techniques. all hemispheres were flattened and sections stained for myelin and cytochrome oxidase (co). our results indicate, first, that the primary visual area (v1) in slow lorises has a system of small co-dense blobs, as has been describe ... | 1993 | 8275299 |
| the visual system of the florida garfish, lepisosteus platyrhincus (ginglymodi). iii. retinal ganglion cells. | the vitreal vascularization, optic nerve fiber layer and the retinal ganglion cells are examined in the florida garfish, one of the two surviving genera of the ginglymode group of actinopterygian fishes. in the absence of a choroidal gland, a well developed system of hyaloid blood vessels overlie the inner retina. the optic nerve fiber and ganglion cell layers are integrated to form a series of alternating columns or fascicles emanating from an elongated optic nerve head. horseradish peroxidase ... | 1993 | 8275298 |
| fate of severed cortical projection axons. | corticospinal neurons show a primarily degenerative response to axotomy in adult mammals. the long remaining proximal axon with its extensive synaptic contacts may contribute to the lack of initial regenerative response in this cell type. we examined a related group of cortical axons after lesions in the subcortical white matter close to their cell bodies of origin. with cholera b chain conjugated to horseradish peroxidase (ctb-hrp), transcallosal axons projecting into areas of a lesion were lab ... | 1993 | 8145268 |
| evidence for peroxidase-mediated metabolism of cyclophosphamide. | lung and bladder injury are side-effects of chemotherapy with cyclophosphamide (cp). although the mixed-function oxidases are known to metabolize cp to reactive species, inhibitors of these enzymes have no significant effect on therapeutic activity or lung toxicity in vivo. in contrast, inhibitors of prostaglandin h synthase (phs) can significantly decrease cp-induced lung injury. the current studies examined whether peroxidases can bioactivate cp in vitro. a mixture of 14c (ring) and 3h (side c ... | 2013 | 8095224 |
| quantitative analysis of gaba-immunoreactive synapses in the inner plexiform layer of the bufo marinus retina: identification of direct output to ganglion cells and contacts with dopaminergic amacrine cells. | we have recently reported that about 50% of amacrine cells and some of the bipolar and ganglion cells are gaba-immunoreactive in the retina of bufo marinus. synapses formed by these elements in the inner plexiform layer were studied. gaba-immunoreactive amacrine cell processes were found most frequently in synaptic contact with non-immunoreactive amacrine cells. double-label experiments showed that some of these non-gaba-immunoreactive elements contain tyrosine hydroxylase immunoreactivity. anot ... | 1993 | 8093900 |
| optic terminals form axosomatic synapses with deep tectal neurons in bufo marinus. | previous studies have shown that a small proportion of the retinal fibres to the optic tectum terminates in the deep tectal cellular layers (layers 6 and 4) in anura. horseradish peroxidase was applied to the cut central end of the optic nerve of bufo marinus to study the synaptic connections of these retinotectal afferents. some of the retinotectal afferents arrive at the deep tectal layers and form synapses with dendrites (7% of all tectal inputs) and on the somata of the deep tectal cells (0. ... | 1993 | 8069289 |
| olfactory and nonolfactory projections in the river lamprey (lampetra fluviatilis) telencephalon. | the projections of the olfactory bulb, the primordial dorsal, piriform and hippocampal pallia, and of the dorsal thalamus were studied in the lamprey lampetra fluviatilis using horseradish peroxidase (hrp) and hrp coupled to the wheat germ agglutinin (wga-hrp). there was obtained an experimental morphological evidence of the presence of the direct thalamo-telencephalic projections in this vertebrate species. the anterior and posterior parts of the dorsal thalamic nucleus, the nucleus of bellonci ... | 1993 | 7693801 |
| the olivocerebellar projection in normal (+/+), heterozygous weaver (wv/+), and homozygous weaver (wv/wv) mutant mice: comparison of terminal pattern and topographic organization. | olivocerebellar organization and topography were analyzed in adult normal (+/+), heterozygous weaver (wv/+), and homozygous weaver (wv/wv) mutant mice. the two genotypes (wv/+ and wv/wv) of the weaver mutant present a gradation of abnormal cerebellar morphology. purkinje cell (pc) ectopia ranges from mild (wv/+) to moderate (wv/wv), and regional pc loss is also graded in the two types. to determine olivocerebellar organization and topography, tritiated amino acids were placed into different regi ... | 1993 | 7693502 |
| retinal input to the suprachiasmatic nucleus before and after puberty in djungarian hamsters. | retinal projections to the suprachiasmatic nucleus (scn) mediate the effect of photoperiod to entrain circadian rhythms and to control reproductive maturation in the djungarian hamster. to determine whether the retinal innervation of the scn had fully developed by the onset of puberty in this hamster species, prepubertal and postpubertal hamsters received an intraocular unilateral injection of horseradish peroxidase (hrp), and after 24 h, the anterograde transport of hrp to the scn was studied. ... | 1993 | 7686436 |
| direct and indirect "cortico"-rubral and rubro-cerebellar cortical projections in the pigeon. | in birds the red nucleus is the most rostral cell group in the brain having projections to all levels of the spinal cord (cabot et al., prog. brain res., 57:79-108, 1982), but its sources of afferents are incompletely known. in order to determine these, a series retrograde and anterograde tracing experiments was carried out, largely with cholera toxin b-chain conjugated to horseradish peroxidase. the results show that a sparse and diffuse projection to the red nucleus arises from deep regions of ... | 1992 | 1282921 |
| slow potentials activated by afferent and direct stimulation in spinal interneurons of laminae iii-v. | stimulation of hairy skin afferent fibers and/or direct depolarizing current injection initiates persistent changes in membrane potential (slow potentials), lasting up to 1 min or longer, in some deep dorsal horn neurons. intracellular staining with horseradish peroxidase shows that these cells are interneurons, suggesting that slow potentials modulate moment-to-moment impulse transmission in local spinal circuits. | 1992 | 1283555 |
| visual and infrared input to the same dendrite in the tectum opticum of the python, python regius: electron-microscopic evidence. | in snakes with infrared receptors, the optic tectum receives input from both the visual and the infrared senses. we investigated the infrared and optic fiber terminations in the tectum with a combination of horseradish peroxidase and degeneration labeling. in addition to synapses by visual and infrared fibers onto individual neurons, we were able to observe for the first time visual and infrared synapses on one and the same dendrite. | 1992 | 1473007 |
| afferent innervation of the vestibular nuclei in the chinchilla. ii. description of the vestibular nerve and nuclei. | the morphological characteristics of the vestibular nuclei of the chinchilla were studied in horizontally cut serial sections of the brain stem. horseradish peroxidase labeling allowed unambiguous delineation of the vestibular nuclei and areas of innervation by the vestibular afferent fibers. the cytoarchitecture of the vestibular nuclei was documented with the aid of camera lucida drawings and quantitatively evaluated with computerized methodology. the cellular groups identified in other specie ... | 1992 | 1472999 |
| afferent innervation of the vestibular nuclei in the chinchilla. i. a method for labeling individual vestibular receptors with horseradish peroxidase. | a new method was developed for specific labeling of primary vestibular afferent fibers from selected end-organs with horseradish peroxidase (hrp) applied extracellularly in the inner ear space. in 48 chinchillas, labeling was performed successfully in all animals by scratching the surface of the sensory end-organ of interest with an electrolytically sharpened needle and replacing the fluid in the vestibule with 30% hrp solution. merely replacing the vestibular fluid (endo- and perilymph) with hr ... | 1992 | 1335348 |
| softening of the packing density of horseradish peroxidase by a h-donor bound near the heme pocket. | we use pressure tuning of spectral holes to estimate the compressibility of protein molecules by optical means. we found that the compressibility of mesoporphyrin-substituted horseradish peroxidase increases by a factor of three when it incorporates small aromatic h-donor molecules that bind in the vicinity of its heme pocket. such a dramatic softening of its packing density corresponds to a jump from a compressibility range characteristic for the solid state into that characteristic for liquids ... | 1992 | 19431865 |
| lectin-binding profiles for normal skin appendages and their tumors. | a histochemical investigation of lectin-binding sites was carried out on formalin-fixed paraffin-embedded sections of 60 skin appendage tumors and adjacent normal skin appendages, using four different biotinylated lectins, peanut agglutinin (pna), dolichos biflorus agglutinin (dba), soybean agglutinin (sba), and ulex europaeus agglutinin-1 (uea-1), and avidin-biotin-horseradish peroxidase labeling. in the secretory segments of eccrine sweat glands, the superficial dark cells showed strong cytopl ... | 1992 | 1487569 |
| one-step molecular hla-dr prescreening employing a set of 14 sequence specific oligonucleotides in a non-radioactive tetramethylammonium chloride hybridization protocol. | a novel non-radioactive protocol for molecular generic hla-dr typing is introduced, employing sequence specific oligonucleotides (ssos) enzymatically 3'-labelled with biotin-14-datp via terminal deoxynucleotidyltransferase in a tetramethylammonium chloride hybridization procedure. the detection reaction is carried out, using streptavidin conjugated horseradish peroxidase which is bound to the ssos, in combination with a light emitting detection system. fourteen ssos and one control sso are emplo ... | 1992 | 1477091 |
| elimination of electrooxidizable interferant-produced currents in amperometric biosensors. | electrooxidizable ascorbate, urate, and acetaminophen that interfere with amperometric glucose assays are completely and rapidly oxidized by hydrogen peroxide in a multilayer electrode. the multilayer electrode is composed of an immobilized, but not electrically "wired", horseradish peroxidase (hrp) film coated onto a film of electrically "wired" glucose oxidase (go). the "wired" enzyme is connected by a redox epoxy network to a vitreous carbon electrode. the current from the electrooxidizable i ... | 1992 | 1463213 |
| morphogenesis of retinal ganglion cells during formation of the fovea in the rhesus macaque. | the morphology of retinal ganglion cells within the central retina during formation of the fovea was examined in retinal explants with horseradish-peroxidase histochemistry. a foveal depression was first apparent in retinal wholemounts at embryonic day 112 (e112; gestational term is approximately 165 days). at earlier fetal ages, the site of the future fovea was identified by several criteria that included peak density of ganglion cells, lack of blood vessels in the inner retinal layers, arcuate ... | 1992 | 1450112 |
| oxidation mechanism of vitamin e analogue (trolox c, 6-hydroxy-2,2,5,7,8-pentamethylchroman) and vitamin e by horseradish peroxidase and myoglobin. | the oxidation of 6-hydroxy-2,2,5,7,8-pentamethylchroman, trolox c, and alpha-tocopherol by horseradish peroxidase was examined by stopped-flow and esr experiments. the catalytic intermediate of horseradish peroxidase during the oxidation of vitamin e analogues and vitamin e was invariably compound ii, and rate constants for the rate-determining step decreased in the order 6-hydroxy-2,2,5,7,8-pentamethylchroman > trolox c > alpha-tocopherol. the formation of phenoxyl radicals from substrates was ... | 1992 | 1332620 |
| lectin histochemistry in psoriasis, lichen planus and seborrheic keratosis. | lectin binding patterns in psoriasis, lichen planus and seborrheic keratosis lesions were studied using 14 different biotinyl lectins and avidin-horseradish peroxidase. compared with normal epidermis, there were significant quantitative and qualitative differences, some of which were characteristic. | 1992 | 1299550 |
| inactivation and reactivation of horseradish peroxidase immobilized by various procedures. | horseradish peroxidase (hrp) immobilized by coupling the amino acid side chain amino groups or carbohydrate spikes to the matrix has been studied for its resistance to heat, urea-induced inactivation and ability to regain activity after denaturation in order to understand the influence of the nature of immobilization procedure on these processes. the various immobilized preparations were obtained and their properties studied: sp-hrp was obtained by direct coupling of hrp to cyanogen bromide-acti ... | 1992 | 1294465 |
| evidence for free radical formation during horseradish peroxidase-catalyzed n-demethylation of crystal violet. | crystal violet (gentian violet) can undergo an oxidative metabolism, catalyzed by horseradish peroxidase, resulting in formaldehyde formation. the n-demethylation reaction was strongly inhibited by reduced glutathione. evidence for the formation of a crystal violet radical during the horseradish peroxidase catalyzed reaction was the detection of thiyl and ascorbate radicals from glutathione and ascorbate, respectively. the concentration of radicals from both compounds was significantly increased ... | 1992 | 1333891 |
| central projections and motor nuclei of the facial, glossopharyngeal, and vagus nerves in the mormyrid fish gnathonemus petersii. | most of the information about the anatomy of the fish's cranial nerves was collected in the first two decades of this century. experimental analysis of the viith, ixth, and xth cranial nerves by modern tract tracing techniques started about 20 years ago. several species have been investigated to date, including one species of agnatha (myxinoidea), two species of elasmobranchs, and species of some orders of teleostei like cyprinidae, siluriformes, perciformes, and gadidae. the sensory and motor n ... | 1992 | 1447406 |
| the effect of extracts from garden radish (raphanus sativus) and horseradish (amoracia rusticana) on platelet functional activity in vitro. | | 1992 | 1492118 |
| mechanism of formation of the thioether conjugate of the bladder carcinogen 2-amino-4-(5-nitro-2-furyl)-thiazole (anft). | the formation of thioether conjugates is an important pathway for inactivation of certain carcinogens. this study assessed the mechanism by which the bladder carcinogen 2-amino-4-(5-nitro-2-furyl)-thiazole (anft) forms a glutathione conjugate (anft-sg). peroxidatic metabolism of anft, in the presence of glutathione, results in anft-sg formation. both prostaglandin h synthase and horseradish peroxidase can catalyze this reaction. metabolism of the reducing co-substrates anft, phenol, and aminopyr ... | 1992 | 1423880 |
| metabolism of 3-tert-butyl-4-hydroxyanisole by horseradish peroxidase and hydrogen peroxide. | 3-tert-butyl-4-hydroxyanisole (3-bha) was metabolized in the presence of horseradish peroxidase and hydrogen peroxide to 2-tert-butyl-p-benzoquinone (tbq), 2,3-epoxy-5-tert-butyl-1,4-benzoquinone (tbq-epoxide), and two known dimers. the formation of tbq from 3-bha required both horseradish peroxidase and hydrogen peroxide. when 2.5 mm 3-bha was incubated with horseradish peroxidase and hydrogen peroxide, the formation of tbq increased with hydrogen peroxide concentration up to 5 mm and decreased ... | 2013 | 1362932 |
| synthesis and characterization of estrogen 2,3- and 3,4-quinones. comparison of dna adducts formed by the quinones versus horseradish peroxidase-activated catechol estrogens. | catechol estrogens (ce) are among the major metabolites of estrone (e1) and 17 beta-estradiol (e2). oxidation of these metabolites to semiquinones and quinones could generate ultimate carcinogenic forms of e1 and e2. the 2,3- and 3,4-quinones of e1 and e2 were synthesized by mno2 oxidation of the corresponding ce, following the method for synthesizing e1-3,4-quinone [abul-hajj (1984) j. steroid biochem. 21, 621-622]. characterization of these compounds was accomplished by uv, nuclear magnetic re ... | 2013 | 1336990 |
| novel method for isolating mammalian cells defective in fluid-phase endocytosis. | a new method for isolating mutants defective in fluid-phase endocytosis has been developed based on the observation that endocytosed horseradish peroxidase can be made lethal to cells. the method was used to isolate a mutant from chinese hamster ovary cells, termed hrp-1, that was temperature-sensitive for viability and had a 70% reduction in the rate of horseradish peroxidase endocytosis at the restrictive temperature. at high temperature, hrp-1 cells were also defective in the secretory path a ... | 1992 | 1287852 |
| [the structural organization of the snail sensory systems]. | in the paper are reviewed the author's data on the structure of peripheral nervous system of the body wall, gravitational organs--statocysts, eyes, and organs of distant chemoreception--ommatophors, or posterior head tentacles, of the snails helix vulgaris and helix pomatia. localization in the cns of central parts of the main sensory systems is shown and some structural characteristics of them are described. the data on the organization of the procerebrum which takes part in processing of infor ... | 2008 | 1284183 |
| functional properties and axon terminations of interneurons in laminae iii-v of the mammalian spinal dorsal horn in vitro. | 1. the functional organization of interneurons in spinal laminae iii-v was studied in an isolated preparation of hamster dorsal horn with sensory innervation from an excised skin patch. morphological details of 40 neurons were visualized by intracellular injection of horseradish peroxidase. active and passive membrane properties, synaptic responses to cutaneous nerve volleys, and responses to innocuous mechanical stimuli were determined for 25 cells with identified axons. 2. neurons were classif ... | 1992 | 1282540 |
| immunocytochemical identification of primary olfactory afferents in rainbow trout. | we have used a combination of techniques to analyze the primary olfactory projection in trout: anterograde tract tracing with horseradish peroxidase (hrp) and immunocytochemistry with antisera to olfactory marker protein (omp) and to keyhole limpet hemocyanin (klh). hrp labeling and the omp antiserum revealed a subset of ciliated receptor neurons with a wide dendrite that lacked the protruding knob found on other receptor neurons. the organization of the primary olfactory axons was clearly revea ... | 1992 | 1430339 |
| afferents to the oculomotor nucleus in the goldfish (carassius auratus) as revealed by retrograde labeling with horseradish peroxidase. | the goal of this work was to compare the distribution and morphology of neurons projecting to the oculomotor nucleus in goldfish with those previously described in other vertebrate groups. afferent neurons were revealed by retrograde labeling with horseradish peroxidase. the tracer was electrophoretically injected into the oculomotor nucleus. the location of the injection site was determined by the antidromic field potential elicited in the oculomotor nucleus by electrical stimulation of the ocu ... | 1992 | 1401270 |
| further study of the aberrant optic nerve projection to olfactory cortex. | when implanted into the cerebral hemisphere, the regenerating optic nerve of the adult frog (rana pipiens) forms a well-defined terminal field in the pars ventralis of the lateral (olfactory) cortex, and sometimes expands medially into the postolfactory eminence. these adjacent areas receive their normal input from the main olfactory bulb. the aberrant projection extends caudally toward the core neuropil of the medial amygdaloid nucleus, which receives its normal input from the accessory olfacto ... | 1992 | 1401269 |
| embryonic development of synapses on spiking local interneurones in locust. | the development of synapses on an identified population of spiking local interneurones in the thoracic ganglia of embryonic locusts was examined by means of intracellular horseradish peroxidase injection and electron microscopy. in adult locusts, spiking local interneurones of the midline group receive direct inputs onto a ventral field of branches from leg mechanosensory afferents and in turn make output synapses, mainly from a dorsal field of branches, directly upon leg motor neurones, nonspik ... | 1992 | 1430330 |
| mechanism of enantioselective oxygenation of sulfides catalyzed by chloroperoxidase and horseradish peroxidase. spectral studies and characterization of enzyme-substrate complexes. | the binding of a series of alkyl aryl sulfides to chloroperoxidase (cpo) and horseradish peroxidase (hrp) has been investigated by optical difference spectroscopy, circular dichroism, paramagnetic nmr spectroscopy, and nmr relaxation measurements. the data are consistent with binding of the sulfides in the distal side of the heme pocket with cpo and near the heme edge with hrp. a linear correlation between the binding constants of para-substituted sulfides to cpo and the taft sigma i parameter s ... | 1992 | 1390727 |
| biotin amplification of biotin and horseradish peroxidase signals in histochemical stains. | a procedure is described for intensifying histochemical reactions by amplification of biotinylated sites. this is achieved by deposition of biotinylated tyramine on the tissue through the enzymatic action of horseradish peroxidase (hrp). the amplified biotin sites are subsequently visualized by binding them to avidin, to which a marker is attached. this amplification greatly increases the sensitivity of staining procedures that employ hrp (and/or biotin) in tissue. for neuroanatomical pathway tr ... | 1992 | 1527370 |
| allatostatin-immunoreactive neurons projecting to the corpora allata of adult diploptera punctata. | a monoclonal antibody against allatostatin i was used to demonstrate the allatostatin-immunoreactive pathways between the brain and the corpus cardiacum-corpus allatum complex in the adult cockroach diploptera punctata. the antibody was two to three orders of magnitude more sensitive to allatostatin i than to the other four known members of the allatostatin family. whole and sectioned brains in which immunoreactivity was localized with horseradish peroxidase-h2o2-diaminobenzidine reaction showed ... | 1992 | 1423517 |
| axoplasmic transport of horseradish peroxidase in single neurons of the dorsal root ganglion studied in vitro by microinjection. | the dependence of anterograde axoplasmic transport on cytoskeletal components was investigated using microinjection of horseradish peroxidase (hrp) into the somata of chick dorsal root ganglion cells in vitro. microinjected hrp was transported anterogradely in the neurites and their branches; this transport was disturbed by colchicine in a drug-dependent and time-dependent manner. cytochalasin b, a drug that depolymerizes actin, did not inhibit the transport of hrp, despite the formation of loca ... | 1992 | 1384982 |
| amplified assay of alkaline phosphatase using flavin-adenine dinucleotide phosphate as substrate. | a simple to use, robust, quantitative, and extremely sensitive colorimetric assay for alkaline phosphatase (ec 3.1.3.1), designed to be used as a detection system in diagnostic assays employing antibodies or gene probes, is described. this technology is based on the novel principle of prosthetogenesis, according to which a purpose-designed substrate (a prosthetogen) for a primary analyte-linked enzyme label is hydrolyzed to produce a prosthetic group for a detector enzyme system. the prosthetoge ... | 1992 | 1360771 |
| h nmr investigation of the influence of interacting sites on the dynamics and thermodynamics of substrate and ligand binding to horseradish peroxidase. | the influence of substrate benzhydroxamic acid (bha) and iron ligand (cyanide) on the thermodynamics and dynamics of each of the two binding sites of horseradish peroxidase (hrp) isozyme c has been investigated by 1h nmr spectroscopy. a combination of line-width analysis and saturation transfer spectroscopy has allowed the direct determination of the off-rate of substrate and ligand in the absence or presence of the other. these off-rates, together with available dissociation constants obtained ... | 1992 | 1390702 |
| the structure of the diencephalic prepacemaker nucleus revisited: light microscopic and ultrastructural studies. | the prepacemaker nucleus (ppn), a bilateral cluster of neurons at the boundary of diencephalon and mesencephalon, controls frequency modulations of the electric organ discharge in weakly electric knifefish (eigenmannia sp.). previous light microscopic studies employing retrograde labelling with horseradish peroxidase suggested that the ppn is restricted to a small area, located approximately 400 microns laterally from the third ventricle and fusing at its medial edge with the thalamic central po ... | 1992 | 1385493 |
| study of yolk precursor transport in the avian ovary with the use of horseradish peroxidase. | ovaries of adult japanese quails were exposed in vivo to the exogenous protein horseradish peroxidase (hrp) for varying lengths of time to investigate ultrastructurally the permeability of the wall of these follicles, the protein uptake capacity of granulosa and oocyte and the kinetics of protein uptake in different stages. there is a sudden increase in permeability of the follicle wall from previtellogenesis to vitellogenesis. this is not due to a loss of sealing (tight) junctions in the granul ... | 1992 | 1445788 |
| interconnections between the pretectum and visual thalamus in reptiles, caiman crocodilus. | interconnections between the visual thalamus and the pretectum were investigated in one species of reptiles, caiman crocodilus, by injections of horseradish peroxidase into nucleus rotundus. nucleus pretectalis was identified as a major target of rotundal efferents as well as a significant input to nucleus rotundus. the presence of a pretectal nucleus with neural connections and topographic location similar to nucleus pretectalis of caiman has been described in lizards and pigeons. taken togethe ... | 1992 | 1436668 |
| the use of streptavidin-biotinylglycans as a tool for characterization of oligosaccharide-binding specificity of lectin. | a new rapid and sensitive method for characterizing lectin specificity using streptavidin-biotinylglycans as a tool is presented. this assay is analogous to enzyme immunoassay and takes advantage of the strong, irreversible adsorption of streptavidin to the wells of the chambers of titer plates. a series of streptavidin-biotinylglycans was first coated on a microtiter plate, and then one of six lectins, concanavalin a, wheat germ agglutinin, phaseolus vulgaris (red kidney bean) erythro-agglutini ... | 1992 | 1443561 |
| antibody-antigen complex formation with immobilized immunoglobulins. | we have investigated the complex formation between an immobilized monoclonal antibody and antigens that differ in size about 50-fold. as a model system, we used an iodinated progesterone derivative and a progesterone-horseradish peroxidase conjugate as tracer and a monoclonal antibody as binding protein. the antibody was immobilized by four different methods: physical adsorption, chemical binding, and binding via protein g in the absence or presence of a protective protein (gelatin). these inves ... | 1992 | 1280003 |
| innervation of the amphibian and basilar papillae in the leopard frog: reconstructions of single labeled fibers. | amphibians have two auditory organs specialized for reception of airborne sounds: the amphibian papilla and the basilar papilla. in this report we examine the morphology of the ganglion cells and the afferent innervation of the sensory epithelium in both auditory organs of the leopard frog, rana pipiens pipiens. extracellular injections of either biocytin or horseradish peroxidase (hrp) were made into the viii nerve; they labeled ganglion cells, their axons, and their terminal fibers within the ... | 1992 | 1522248 |
| colloidal gold as a biocompatible immobilization matrix suitable for the fabrication of enzyme electrodes by electrodeposition. | glucose oxidase, horseradish peroxidase, xanthine oxidase, and carbonic anhydrase have been adsorbed to colloidal gold sols with good retention of enzymatic activity. adsorption of xanthine oxidase on colloidal gold did not result in a change in enzymatic activity as determined by active site titration with the stoichiometric inhibitor pterin aldehyde and by measurement of the apparent michaelis constant (k'(m)). gold sols with adsorbed glucose oxidase, horseradish peroxidase, and xanthine oxida ... | 1992 | 18601142 |
| identification of subcellular compartments involved in biosynthetic processing of cathepsin d. | we have assigned the biosynthetic processing steps of cathepsin d to intracellular compartments which are involved in its transport to lysosomes in hepg2 cells. cathepsin d was synthesized as a 51-kda proenzyme. after formation of 51-55-kda intermediates due to processing of n-linked oligosaccharides, procathepsin d was proteolytically processed to an intermediate 44-kda and the mature 31-kda enzyme. the intersection of the biosynthetic pathway of cathepsin d with the endocytic pathway was label ... | 1992 | 1322403 |
| direct enzyme immunoassay of estradiol in serum of women enrolled in an in vitro fertilization and embryo transfer program. | we present a fast and simple direct enzyme immunoassay for the sexual steroid hormone estradiol-17 beta in serum of women enrolled in an in vitro fertilization and embryo transfer program. we added 25 microl of standards or samples and 125 microl of a mixture of monoclonal antibody and displacing agents to the wells of a microtiter plate previously coated with a second antibody. after 30 min 50 microl estradiol-horseradish peroxidase conjugate is added. total incubation time is 75 min. the immun ... | 1992 | 1643707 |
| improved accuracy in diagnostic immunohistochemistry, lectin histochemistry and in situ hybridization using a gold-labeled horseradish peroxidase antibody and silver intensification. | improvements in the use of the avidin-biotin peroxidase complex technique and direct as well as indirect labeled avidin-biotin methods for application in diagnostic immunohistochemistry, lectin histochemistry and in situ hybridization are reported. the new technology combines the advantages of immunoenzyme and immunogold silver staining techniques and can be performed on routinely fixed and paraffin-embedded tissues. | 1992 | 1501450 |
| effect of monensin on the neuronal ultrastructure and endocytic pathway of macromolecules in cultured brain neurons. | 1. the endocytic pathway of horseradish peroxidase (hrp) was investigated in the perikarya of cultured neurons by electron microscopy and enzyme cytochemistry. the tracer was observed in endocytic pits and vesicles, endosomes, multivesicular bodies, and lysosomes. it took approximate 15 min for the transfer of hrp from the exterior of the cell to the lysosomes. 2. monensin induced distension of the golgi apparatus and formation of intracellular vacuoles. when neurons were incubated with both mon ... | 1992 | 1394368 |
| follicular dendritic cell and iccosomes in germinal center reactions. | the development and destination of immune complex coated bodies (iccosomes) was investigated at the ultrastructural level in the germinal centers (gc) of murine lymph nodes after secondary-immunization with horseradish peroxidase. immediately after a booster injection, large amounts of immune complex (ic) were trapped on the surface of the cytoplasmic extensions of follicular dendritic cells (fdc). cytoplasmic extensions, consisting mainly of fdc processes with associated ic, formed complex lame ... | 1992 | 1391799 |
| characterisation of a haem active-site mutant of horseradish peroxidase, phe41----val, with altered reactivity towards hydrogen peroxide and reducing substrates. | a horseradish peroxidase variant ([f41v] hrp-c*), in which val replaces the conserved phe at position 41 adjacent to the distal his, has been constructed. its composition and spectroscopic, catalytic and substrate-binding properties were compared with those of the wild-type recombinant (hrp-c*) and plant (hrp-c) enzymes. presteady-state kinetic measurements of the rate constant for compound i formation (k1) revealed an eightfold decrease in the reactivity of the phe41----val variant towards h2o2 ... | 1992 | 1633806 |
| developmental segregation in the afferent projections to mammalian auditory hair cells. | the mammalian ear contains two types of auditory receptors, inner and outer hair cells, that lie in close proximity to each other within the sensory epithelium of the cochlea. in adult mammals, these two classes of auditory hair cells are innervated by separate populations of afferent neurons that differ strikingly in their cellular morphology and their pattern of arborization within the cochlea. at present, it is unclear when or how these distinctive patterns of cochlear innervation emerge and ... | 1992 | 1631126 |
| activation of the carcinogen n-hydroxy-n-(2-fluorenyl)benzamide via chemical and enzymatic oxidations. comparison to oxidations of the structural analogue n-hydroxy-n-(2-fluorenyl)acetamide. | chemical or enzymatic oxidations of the carcinogen n-hydroxy-n-(2- fluorenyl)benzamide (n-oh-2-fba) were investigated under the conditions facilitating one-electron oxidation or oxidative cleavage of n-hydroxy-n-(2-fluorenyl)acetamide (n-oh-2-faa). hplc methods were developed for separation and quantitation of the above hydroxamic acids and their respective oxidation products. to identify the products of oxidation of n-oh-2-fba, n-(benzoyloxy)-2-fba (n-bzo-2-fba) was synthesized and shown to und ... | 2007 | 1327249 |
| horseradish peroxidase-catalyzed aerobic oxidation of indole-3-acetic acid. ii. oxygen uptake and chemiexcitation. | light emission from the horseradish peroxidase-catalyzed aerobic or anaerobic oxidation of indole-3-acetic acid has been investigated under opposite extreme conditions of enzyme/substrate ratio. the o2-dependent chemiluminescent processes represent a minor part of the total oxygen consumption. superoxide is involved in chemiexcitation as is evident from the observed inhibitory effect of superoxide dismutase. at high enzyme/substrate ratio, only a part of the emission is dependent on superoxide i ... | 1992 | 1318695 |
| enzyme immunoassay techniques. an overview. | in spite of the great variety of enzyme immunoassays (eia) they can be classified into two groups 'analyte-observed' and 'reagent-observed' assays, depending on their reaction principle. the latter are favored by use of monoclonal antibodies and are characterized by a greater sensitivity, a larger measuring range, a lower susceptibility to disturbing influences. they can be used only for detection of macromolecules. for heterogeneous eias to be used on laboratory scale, simple adsorption of anti ... | 1992 | 1613258 |
| ascending general visceral pathways within the brainstems of two teleost fishes: ictalurus punctatus and carassius auratus. | the primary general visceral nucleus in goldfish (carassius auratus) and catfish (ictalurus punctatus) is located at the ventroposterior boundary of the vagal gustatory lobe and receives coelomic visceral, but not gustatory inputs. the neuronal tracer horseradish peroxidase (hrp) was employed to visualize sources of input to and ascending projections from the primary general visceral nucleus in these species. in addition, immunocytochemical techniques were utilized to define the cytological divi ... | 1992 | 1629401 |
| central location of the motoneurons that supply the cucullaris (trapezius) of the clearnose skate, raja eglanteria. | a complex of three muscles (one lateral, one intermediate and one medial in position) in the clearnose skate, raja eglanteria, is believed to be wholly, or in part, homologous to the cucullaris (trapezius). the retrograde transport of horseradish peroxidase was used to discover the central location of the motoneurons that supply each of these muscles. motoneurons that project to the lateral muscle occupy the caudal part of the ventral nucleus of x. this nucleus is situated ventrolateral to the d ... | 1992 | 1393552 |
| kinetic studies on the formation and decomposition of compounds ii and iii. reactions of lignin peroxidase with h2o2. | the present study characterizes the serial reactions of h2o2 with compounds i and ii of lignin peroxidase isozyme h1. these two reactions constitute part of the pathway leading to formation of the oxy complex (compound iii) from the ferric enzyme. compounds ii and iii are the only complexes observed; no compound iii* is observed. compound iii* is proposed to be an adduct of compound iii with h2o2, formed from the complexation of compound iii with h2o2 (wariishi, h., and gold, m. h. (1990) j. bio ... | 1992 | 1317857 |
| characterization of biotin and 3-methylcrotonyl-coenzyme a carboxylase in higher plant mitochondria. | mitochondria from green pea (pisum sativum) leaves were purified free of peroxisomes and chlorophyll contamination and examined for their biotin content. the bulk of the bound biotin detected in plant mitochondria was shown to be associated with the matrix space to a concentration of about 13 micromolar, and no free biotin was detected. western blot analysis of mitochondrial polypeptides using horseradish peroxidase-labeled streptavidin revealed a unique biotin-containing polypeptide with a mole ... | 1992 | 16668906 |
| morphology of hrp-labelled cochlear nerve axons in the dorsal cochlear nucleus of the developing hamster. | to study the development of the central terminal arbors of the cochlear nerve fibers in the dorsal cochlear nucleus, horseradish peroxidase-labelled axons in young and adult hamsters were analyzed morphometrically. brainstem slices with whole cochlear nuclei were maintained in a slice chamber and the cochlear nerve root was injected with a mixture of wheat germ agglutinin-horseradish peroxidase, horseradish peroxidase and poly-l-ornithine. the poly-l-ornithine was added to keep the injection sit ... | 1992 | 1500375 |
| monoclonal antibodies specific to sailfish serum albumin: development of an assay for the identification of fish species in the field. | balb/c mice were immunized with albumin purified from sailfish (istiophorus albicans) serum. hybridomas were produced and screened by elisa for reactivity with the purified albumins of sailfish, blue marlin (makaira nigricans) and white marlin (tetrapturus albidus). monoclonal antibodies (mabs) from 16 different clones exhibited activity against sailfish albumin. thirteen of the mabs showed cross-reactivity with the marlin species. three mabs exhibited distinct specificity for sailfish albumin. ... | 1992 | 1500069 |
| inhibitory synaptic input to identified rubrospinal neurons in macaca fascicularis: an electron microscopic study using a combined immuno-gaba-gold technique and the retrograde transport of wga-hrp. | rubrospinal neurons of the magnocellular division of the red nucleus of macaca fascicularis were retrogradely labeled following spinal cord microinjections of wheat germ agglutinin-horseradish peroxidase, as demonstrated by the chromagen tetramethylbenzidine, identifying the mesencephalic cells of origin of this descending motor pathway. the tissue was processed for electron microscopy and subsequently tested on the electron microscope grid for immunoreactivity of gamma aminobutyric acid (gaba) ... | 1992 | 1383282 |
| role of nonacidic endosomes in recycling of adh-sensitive water channel structures. | toad urinary bladder epithelial cells respond to the hormone adh by increasing the water permeability of their luminal membrane. this action is mediated by insertion into the apical membrane of specific water channels. in the absence of adh these channels appear to be present in tubular cytoplasmic vesicles as morphologically distinctive intramembrane structures called particle aggregates. adh induces these vesicles to fuse with the apical membrane, transferring their aggregate-water channels in ... | 1992 | 1379533 |
| anatomical organization of the brainstem octavolateralis area of the oyster toadfish, opsanus tau. | anatomical studies were undertaken to analyze the brainstem organization of the auditory, vestibular, and lateral line nuclei in a teleost, the oyster toadfish, opsanus tau. neuronal cytoarchitectonics and horseradish peroxidase label of cranial nerves were utilized to delineate the borders of the five octavus and two lateralis brainstem nuclei. each of the eight octavolateralis nerves were labeled individually to compare and contrast their central projections. projections of the three semicircu ... | 1992 | 1619042 |
| functional organization of vagal reflex systems in the brain stem of the goldfish, carassius auratus. | the coordination of secretory and motor responses to food within the alimentary canal requires well organized brain stem reflex systems. in the goldfish, carassius auratus, three vagal reflex systems control three phases of ingestion and digestion. the orobranchial system sorts food from substrate, the pharyngeal chewing organ prepares items deemed to be food for digestion and absorption, and the abdominal system regulates the digestion of food. each system is represented in the central nervous ... | 1992 | 1619041 |
| application of phase partitioning and thiophilic adsorption chromatography to the purification of monoclonal antibodies from cell culture fluid. | a two-step method for the isolation of an igg1 monoclonal antibody against horseradish peroxidase from hybridoma cell culture supernatant is described. purification was achieved using an aqueous two-phase extraction procedure in conjunction with thiophilic adsorption chromatography. in an aqueous two-phase system composed of 5% peg 1540 and 22% phosphate the monoclonal antibody preferentially associates with the peg-rich top phase whereas proteins such as albumin and transferrin partition into t ... | 1992 | 1593132 |
| chemical and kinetic evidence for an essential histidine in horseradish peroxidase for iodide oxidation. | horseradish peroxidase (hrp), when incubated with diethylpyrocarbonate (depc), shows a time-dependent loss of iodide oxidation activity. the inactivation follows pseudo-first order kinetics with a second order rate constant of 0.43 min-1 m-1 at 30 degrees c and is reversed by neutralized hydroxylamine. the difference absorption spectrum of the modified versus native enzyme shows a peak at 244 nm, characteristic of n-carbethoxyhistidine, which is diminished by treatment with hydroxylamine. correl ... | 1992 | 1577815 |
| endocytosis is regulated by protein kinase a, but not protein kinase c in a secretory epithelial cell line. | endocytosis in the chloride secreting epithelial cell line t84 was monitored by uptake of the fluid-phase markers fitc-dextran and horseradish peroxidase (hrp). uptake of marker was inhibited by incubation of cells at 4 degrees c, consistent with an endocytic uptake. although activation of the camp-dependent second messenger pathway has been shown to stimulate exocytosis in this cell line, it caused a 63% reduction in endocytosis as measured by uptake of fluid-phase markers. in contrast, the pre ... | 1992 | 1375455 |
| vanadium effect on the activity of horseradish peroxidase, catalase, glutathione peroxidase, and superoxide dismutase in vitro. | the effect of vanadium (v) on the activity of horseradish peroxidase, catalase, glutathione peroxidase, and superoxide dismutase has been studied. a competitive inhibition pattern was evident for vanadate ions on the activity of horseradish peroxidase (ki = 41.2 microm). no significant inhibitory effects were found when v(v) was tested with catalase and when either v(iv) or v(v) were assayed with glutathione peroxidase. for the latter, the effect of v on the different components of the reaction ... | 1992 | 1325536 |
| neuromuscular specificity following cross-stage hindlimb transplantation. | in order to determine whether spinal motoneurons can regenerate to their proper targets at stages beyond those when such specificity is typically expressed, autologous and homologous (same- and cross-stage) hindlimb transplantations were performed using bullfrog tadpoles (rana catesbeiana). neuromuscular specificity was assessed by applying horseradish peroxidase to the ventral thigh of the transplanted hindlimb and mapping the locations of retrogradely labeled motoneurons. previously, we found ... | 1992 | 1577125 |
| the oxidation of 4-aminobiphenyl by horseradish peroxidase. | the oxidation of the carcinogen 4-aminobiphenyl (4-abp) catalyzed by the model peroxidase enzyme horseradish peroxidase (hrp) was investigated. 4-abp served as a reducing cosubstrate for hrp during the enzyme-catalyzed reduction of the synthetic hydroperoxide, 5-phenyl-4-penten-1-yl hydroperoxide, to its corresponding alcohol. spectral analysis during the incubation of hrp, 4-abp, and h2o2 showed an increase in absorbance at 230 and 325 nm and decrease at 270 nm, suggesting metabolite formation. ... | 2013 | 1504256 |
| probing the mechanism of horseradish peroxidase by site-directed mutagenesis. | | 1992 | 1397626 |
| n-glycosylation of horseradish peroxidase from cell culture. | | 1992 | 1397521 |
| direct w-like geniculate projections to the cytochrome oxidase (co) blobs in primate visual cortex: axon morphology. | the primate lateral geniculate nucleus (lgn) is composed of large, medium, and small cells located, respectively, in magnocellular (m), parvocellular (p), and specialized layers (intercalated and s-layers in simians, koniocellular (k) layers in prosimians). several studies have examined the physiology and connections of m and p lgn cells and have concluded that they provide separate contributions to visual perception via separate pathways. less is known about the structure and contributions of t ... | 1992 | 1375606 |
| ultrastructural, biochemical and electrophysiological changes induced by 5,6-dihydroxytryptamine in the cns of the snail helix pomatia l. | the serotonin neurotoxin, 5,6-dihydroxytryptamine (5,6-dht), was injected into the body cavity of snails. changes induced in the central nervous system (cns) by the neurotoxin were studied by morphological, electrophysiological and biochemical techniques for up to 90 days following injection. the neurotoxin induced a variety of ultrastructural alterations during the early phase (1st to 6th days) following treatment. on day 6 after treatment, membranous structures first appeared in the synaptic-l ... | 1992 | 1324760 |
| independent mosaics of large inner- and outer-stratified ganglion cells in the goldfish retina. | goldfish retinal ganglion cells were filled with horseradish peroxidase and studied in flatmounts. two regular mosaics of large neurons with many of the properties of mammalian alpha ganglion cells were found, differing from each other in spacing, size, and dendritic stratification. the existence of biplexiform ganglion cells with additional dendrites in the outer plexiform layer was also confirmed. one of the two alpha-like mosaics consisted of giant ganglion cells with thick primary dendrites ... | 1992 | 1578007 |
| secondary mesenchyme of the sea urchin embryo: ontogeny of blastocoelar cells. | secondary mesenchyme in sea urchin embryos is released into the blastocoel after primary mesenchyme, and although these cells have been recognized for some time, we lack knowledge about many fundamental aspects of their origin and fate. here we documented the ontogeny of one of the principal, and least well-known, types of cells derived from secondary mesenchyme. the blastocoelar cells arise from mesenchyme released from the tip of the archenteron following the initial phase of gastrulation. the ... | 1992 | 1583452 |
| immunohistochemical organization of the ventral lateral geniculate nucleus in the tree shrew. | the ventral lateral geniculate nucleus (vlgn) of the tree shrew (tupaia belangeri) was differentiated into multiple subdivisions (dorsal cap, intergeniculate leaflet, parvicellular segment, and internal and external magnocellular laminae, the latter being further divisible into a lateral and medial division) on the basis of retinal projections, immunochemistry, and histochemistry. retinal projections traced with intravitreal injections of wheat germ agglutinin conjugated horseradish peroxidase r ... | 1992 | 1316386 |
| physiological and morphological correlations of horizontal cells in the mudpuppy retina. | 1. horizontal cells (hcs) of the mudpuppy (necturus maculosus) retina were physiologically characterized with the use of intracellular recordings in a superfused, dark-adapted, retina-eyecup preparation. 2. physiological analysis included an evaluation of rod versus cone input and a determination of the receptive field size with the use of a displaced slit of light. 3. the morphology of hcs was established through intracellular staining with horseradish peroxidase (hrp) and lucifer yellow mixed ... | 1992 | 1588385 |
| a fibre matrix model for the restricting junction of the blood-brain barrier in a cephalopod mollusc: implications for capillary and epithelial permeability. | a model is proposed for the novel restricting junction forming the blood-brain barrier in a cephalopod mollusc, the cuttlefish sepia officinalis. the model is based on electron-microscopic findings, from both thin-section and freeze-fracture material, the distribution of electron-dense tracers, and radioisotopic measurements of permeability using small non-electrolytes. biochemical properties of sepia plasma proteins are also considered. it is proposed that an effective blood-brain barrier is ac ... | 1992 | 1588349 |
| electron-dense tracer evidence for a blood-brain barrier in the cuttlefish sepia officinalis. | electron-dense tracers were used to study the permeability of the blood-brain interface in a cephalopod mollusc, the cuttlefish sepia officinalis. gel filtration established that horseradish peroxidase is a suitable tracer for in vivo injection, but microperoxidase is not, being subject to binding by plasma proteins. perfusion-fixed brain vertical and optic lobes showed no endogenous peroxidatic activity. horseradish peroxidase was injected intravenously, and allowed to circulate for 10-35 min b ... | 1992 | 1588347 |
| peroxidase-mediated glutathione conjugation of benzo[a]pyrene-7,8-dihydrodiol is enhanced by benzo[a]pyrene phenols in vitro. | we reported previously that glutathione (gsh) is oxidized by peroxidases to a thiyl radical that can react with a number of chemicals, including the penultimate carcinogenic metabolite benzo[a]pyrene-7,8-dihydrodiol (7,8-b[a]pd), to give gsh conjugates. here, we report that phenolic metabolites of benzo[a]pyrene (b[a]p) enhance the peroxidase-mediated formation of glutathione conjugates of 7,8-b[a]pd. the gsh conjugation of 7,8-b[a]pd in a horseradish peroxidase/peroxide system was increased ove ... | 1992 | 1576701 |