Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.11.1.7 (peroxidase)
65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Carboxypeptidase P has been purified by immunoaffinity chromatography from pig kidneys. A single-step assay with Z-Pro-Met (where Z represents benzyloxycarbonyl) as substrate was used, methionine being determined by using L-amino acid oxidase and horseradish peroxidase. The enzyme constitutes about 1.5% of the kidney microvillar proteins. Triton X-100-solubilized and papain-released forms of the enzyme were isolated. The former had an apparent subunit Mr of 135 000, and the latter form contained two polypeptide chains of Mr 128 000 and 95 000. The undenatured forms were dimeric proteins. In common with other microvillar hydrolases, carboxypeptidase P was a glycoprotein and each subunit contained one Zn atom. MnCl2 (1 mM) in the assay was necessary for maximum activity; in its absence, 0.5 mM-ZnSO4 produced a limited activation, but was inhibitory at higher concentrations. The Km for Z-Pro-Met, in the presence of MnCl2, was 4.1 mM, and the kcat. for freshly prepared enzyme was 1230 min-1. The enzyme lost activity during storage at -20 degrees C. In a limited survey of peptides, hydrolysis was observed only with substrates containing a proline, alanine or glycine residue in the P1 position, and these included angiotensins II and III. The best substrate in this series was Val-Ala-Ala-Phe.
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PMID:Proteins of the kidney microvillar membrane. Purification and properties of carboxypeptidase P from pig kidneys. 403 59

A system for studying growth and development of transplanted subpopulations of postmitotic cerebral cortical neurons is described. The cytotoxic drug methylazoxymethanol (MAM) was given to pregnant rats on the fourteenth day of gestation to destroy precursor cells of layers II-IV of the fetal cerebral cortex. Layer V and VI precursor cells which had completed their final division before MAM treatment and were unaffected by it, were labeled by a prior injection of [3H]thymidine. This strategy provides a donor cerebral cortex containing mainly neurons destined to form layers V and VI of the adult cerebral cortex; these cells are postmitotic. Pieces of donor cerebral cortex were transplanted to the cerebral hemispheres of normal newborn hosts at one day, two days, or 6 days after MAM treatment; survival was assessed 1-12 weeks after transplantation by autoradiography of histological sections. Radiolabeled graft cells survived in 89% of recipients and many of these grew axons into the host, as indicated by retrograde labeling with horseradish peroxidase. Significant numbers of graft cells could also be stained immunocytochemically for glutamic acid decarboxylase or for the peptides, somatostatin, vasoactive intestinal polypeptide or cholecystokinin. A second group of experiments examined the routes of early axon outgrowth from normal and postmitotic fetal grafts. When the donor cortex had been incubated in a mixture of [3H]proline and [3H]leucine for 20 min prior to transplantation, the earliest axons growing out of the graft into normal newborn hosts could be assessed by autoradiography of axoplasmic transport after survivals in the host of 7 days. Normal and postmitotic grafts taken at E15 or E20 were capable of outgrowth, though the axons of E20 postmitotic cells did not grow far. The location of the transplant was the major determinant of where graft cells' axons grew and growth was mainly into existing axonal pathways of the host. In a third group of experiments, long term axonal projections from normal and postmitotic fetal transplants to 4 regions of the host brain--thalamus, contralateral cortex, striatum, and hippocampus--were examined with retrograde tracers 2-4 months after transplantation. Projections from grafts to the 4 host sites were highly dependent on the presence of nearby host axons connecting with those sites. Neurons in all types of graft projected to one or other of the 4 sites, but generally in small numbers. Higher proportions of cells in grafts from E15 MAM-treated donors projected to the host thalamus.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Transplantation of fetal postmitotic neurons to rat cortex: survival, early pathway choices and long-term projections of outgrowing axons. 404 17

The transient occipital cortical component of the pyramidal tract which we previously had identified during the postnatal development of the rat (Stanfield et al., '82) has been studied with anterograde as well as retrograde techniques. A continuous band of retrogradely labeled layer V neurons which spans the entire cortex including the occipital cortex is seen following injections of the fluorescent marker Fast Blue into the pyramidal decussation during the first postnatal week. No labeled cells are found in the occipital cortex following similar injections made on postnatal day 20 (P20), although such injections label many neurons in the more rostral cortical fields. However, if the Fast Blue injection is made on P2 and the animal is allowed to survive until P25 a large number of Fast Blue-labeled layer V neurons is found in the occipital cortex, even though an acute, second injection of the retrograde tracer Nuclear Yellow made into the pyramidal decussation shortly before the animal is killed results in no occipital cortical labeling. When Fast Blue injections confined to the mid- or upper-cervical spinal cord are made on P4 and the animals are killed on P9, again many retrogradely labeled neurons are found in the occipital cortex. Further, when injections of 3H-proline or wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) confined to the occipital cortex are made during the first 2 postnatal weeks, anterogradely transported label is seen within the pyramidal tract. At all stages examined the amount of such label and its caudal extent are less than that seen following similar injections into the parietal or frontal cortex. The greatest extent of the labeled occipital cortical fibers is reached at about the end of the first postnatal week and the number of these fibers seems to peak at about this same time. At this stage many of these labeled axons extend for a considerable distance down the spinal cord with some reaching as far caudal as lower lumbar levels, and at this stage some of these labeled occipital corticospinal fibers enter into the spinal gray. Over the next week the number of occipital cortical fibers in the pyramidal tract rapidly decreases and by P17 occipital cortical injections of 3H-proline or WGA-HRP result in virtually no transported label caudal to the pons.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The transient corticospinal projection from the occipital cortex during the postnatal development of the rat. 404 13

The distribution of callosal cells and terminals was studied in the posterior neocortex of pups whose ages ranged from 3 to 16 days and in adult rats 2 months of age or older. Callosal cells and terminations were revealed using retrograde (horseradish peroxidase) and anterograde (horseradish peroxidase; tritiated proline) tracing techniques, respectively, and the distribution of callosal connections was analyzed in tangential or coronal histological sections. In agreement with previous studies, we observed that the pattern of callosal connections in areas 17 and 18 of adult rats contains the following features: (1) a dense band of callosal cells and terminations separating the interiors of areas 17 and 18a, (2) a ringlike configuration anterolateral to area 17, (3) a region of dense labeling lateral to area 18a, (4) several narrow bands of labeling that bridge area 18a at different anteroposterior levels, and (5) one or more labeled regions in area 18b. In all these callosal regions, labeled cells and terminations are densely aggregated in layers II-III, Va, and Vc-VIa, and less densely in layer IV and the remaining portions of layers V and VI. High densities of isotope-labeled fibers are also observed in the lower half of layer I. Throughout the interiors of areas 17 and 18a, a significant number of labeled cells are observed in layers Vc-VIa. In contrast to adult rats, in neonates no distinct tangential pattern of callosal connections is apparent. Instead, labeled cells are densely aggregated in two continuous horizontal bands located in cortical layers Va and Vc-VIa, and callosal axons are largely restricted to white matter. During the first 2 postnatal weeks there is a progressive loss of callosal cells in regions that normally have few callosal cells in the adult (e.g., interiors of areas 17 and 18a) and an increase in the number of cells in layers II-IV in regions that are densely callosal in the adult (e.g., callosal regions at the 17/18a border, lateral border of area 18a, and in area 18b). The decrease in the number of callosal cells in the interiors of areas 17 and 18a is more severe in the upper than in the lower band of the immature labeling pattern, and our data from tangential sections indicate that this loss of callosal neurons occurs synchronously across the interiors of these areas. During this period there is also a localized invasion of labeled callosal axons into those regions of gray matter where they will be found in adult life.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Organization and postnatal development of callosal connections in the visual cortex of the rat. 404 27

The principal goal of the present study was to determine the thalamic connections of area 2 of postcentral somatosensory cortex of monkeys. The placement of injections of anatomical tracers (horseradish peroxidase, wheat germ agglutinin, or 3H-proline) was guided by extensive microelectrode maps of cortex in the region of the injection site. These maps identified the body parts represented in the cortex included in the injection site, and provided information about the physiological boundaries of area 2, which was related later to the cortical architecture. Most injections were placed in the representation of the hand in area 2, which was highly responsive to cutaneous stimuli and could be mapped in detail. Injections were also placed in other parts of area 2, area 1, or area 5, and some injections involved more than one area. As other investigators have determined, regions of retrograde and anterograde thalamic label overlapped, demonstrating that connections with cortex are reciprocal. Injections completely confined to area 2 consistently produced label in two locations: the anterior pulvinar (Pa) and a dorsal capping zone of the ventroposterior complex that we term the ventroposterior superior nucleus (VPS). Single restricted injection sites resulted in one region of label in VPS, and multiple foci of label in Pa. In some cases where the injection was confined to the representation of the hand in area 2, label was also found more ventrally in the ventroposterior complex in ventroposterior nucleus proper (VP). Thus, area 2 receives input from Pa, VPS, and, at least in some locations and individuals, VP. Injections of tracers into area 1 confirmed previous findings that area 1 is densely interconnected with VP. In addition, there appear to be sparse connections with VPS. There was no evidence of connections with Pa. Evidence from injection sites that extended from area 2 into areas 5 and 7, and from injection sites in area 5, indicates that the lateral posterior nucleus (LP) projects to rostral areas 5 and 7. The results support the conclusion that area 2 is a functionally distinct subdivision of somatosensory cortex, and indicate that area 2 has thalamic connections that are characteristic of both "sensory" (VP and VPS) and "association" (Pa) cortical fields.
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PMID:Connections of area 2 of somatosensory cortex with the anterior pulvinar and subdivisions of the ventroposterior complex in macaque monkeys. 405 3

The cytoarchitecture in the retinoreceptive zone of the pigeon optic tectum has been studied in Nissl-stained sections taken in four planes. As suggested by a previous study, two cytoarchitectural fields are present. Reconstructed views of the tectum show that the fields are separated by a narrow transition zone approximating to the tectal representation of the retina's horizontal meridian. In field 1 (which is upper and rostral), sublayer IIb is wide, IIc wide and trilaminate, IId narrow and IIe continuous; in field 2, IIb and c are narrow, IId wide and IIe discontinuous. The distribution of retinal terminals was investigated by the anterograde axonal transport of [3H]proline or horseradish peroxidase from intravitreal injections. The depth distribution of grains or reaction product throughout the entire tectum was quantified by scanning with a microdensitometer. Both autoradiography and horseradish peroxidase transport show two patterns of lamination separated by a narrow transition zone and these two terminal fields correspond closely to the cytoarchitectural fields. In field 1 optic terminals are concentrated in sublayer IIb, superficial c, d, and to a lesser extent in f; in field 2 concentrations are present at the IIb/c boundary, across deep IIc and d, and a small concentration is found IIf. The patterns of retinal termination with depth in the tectum found by axonal transport are compatible with those found by electron microscopy, and are discussed in relation to the optic termination found by other techniques. Study of the time course of axonal transport shows that both radioactive material and horseradish peroxidase are fast transported to all the bands of optic terminals at about 150 mm/day. Horseradish peroxidase gradually accumulates in the retinoreceptive zone, filling clusters of terminals and horizontal processes. At 12 days, it has begun to disappear from the zone and a few diffusely filled profiles, that may be transcellularly labelled, are present. Electron microscope autoradiography of fast transported material shows clusters of grains over optic terminals and preterminals and a percentage density analysis confirms that these profiles are specifically labelled. The two tectal fields each contain the projection from specialized areas of the retina, suggesting functional specialization in the tectum for the processing of different kinds of visual information.
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PMID:Cytoarchitectural fields and retinal termination: an axonal transport study of laminar organization in the avian optic tectum. 409 92

Four proteins, which have been designated A, B, C and D, have been purified from human parotid saliva. These proteins are the major constituents of parotid saliva which migrate rapidly to the anode in polyacrylamide electrophoresis at pH9.5. Gel filtration and polyacrylamide electrophoresis were employed in the purification procedures. After purification all four preparations were tested for homogeneity by electrophoresis at pH2.8 and 9.5, by isoelectric focusing in the pH range 3-10, by immunodiffusion, and by sedimentation in the analytical ultracentrifuge. None of the proteins showed significant activity in assays for amylase, acid and alkaline phosphatase, protease, lysozyme, ribonuclease, peroxidase, beta-glucuronidase, beta-galactosidase, iron-binding activity and esterase. No cross-reactions were detected with antisera specific for lactoferrin and 15 serum proteins. All four proteins were rich in glutamic acid, proline and glycine and were lacking completely the sulphur-containing amino acids. Proteins A and C contained no threonine or tyrosine. Carbohydrate could be demonstrated only in protein A at a concentration of 4% of the total protein.
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PMID:Purification and partial characterization of four proteins from human parotid saliva. 500 93

The effects of long-term monocular deprivation on the geniculostriate system in squirrel monkeys were studied with neuroanatomical methods. Four neonates were visually deprived by monocular eyelid suture during their first 10 days of life and survived from 9 to 40 months. In the lateral geniculate nucleus (LGN), deprivation resulted in severe cell size changes. Neurons in the deprived laminae were smaller compared to those in the undeprived laminae. Deprivation left the reciprocal connections between LGN and striate cortex intact: After horseradish peroxidase (HRP) injections into striate cortex, retrogradely transported enzyme labeled a wedge of neurons in deprived and undeprived LGN laminae; anterogradely transported HRP filled preterminal and terminal axons in this wedge. Following 3H-proline injections into the deprived eye for transneuronal transport, autoradiography showed in the ipsilateral striate cortex a silver grain distribution over most of layer IVc similar to that in normal squirrel monkeys, except for a small strip in the anterior calcarine fissure. Here, a few, irregularly spaced "patches" of higher grain density occurred deep in layer IVc. Layer IVc of contralateral area 17 was also uniformly labeled over most of its extent, except for a very few and inconspicuous accumulations of slightly increased silver grains. After visual stimulation of the deprived eye, the 14C-2-deoxyglucose method showed in the contralateral striate cortex some alternating "patches" of higher uptake superimposed on the heavy labeling in layer IVc. Layer IVc in the ipsilateral cortex was more uniformly labeled. Regularly spaced arrays of labeled "puffs" in layers II/III were present in both hemispheres. Cytochrome oxidase staining showed no change in the distribution pattern of the enzyme in the deprived monkeys from the basic pattern of normal adults. No changes in cell sizes were found in layer IVc in cresyl-violet-acetate-stained sections. These results lead to the conclusion that in area 17 of squirrel monkeys there is no distinct segregation of inputs from the two eyes into anatomically discrete ocular dominance columns and they support the view of a predominantly binocular organization of area 17.
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PMID:Anatomical consequences of long-term monocular eyelid closure on lateral geniculate nucleus and striate cortex in squirrel monkey. 608 93

Transneuronal retrograde degeneration of retinal ganglion cells was investigated following neonatal visual cortex ablation in the cat. After a survival time of at least 18 months, retinal ganglion cells projecting to the thalamus were labelled by retrograde transport of horseradish peroxidase. Filled ganglion cells were classified into alpha, beta and gamma types on the basis of dendritic morphology. In normal cats, alpha cells made up 8-10% of the total population in the sample area, beta cells made up 64-67% and gamma cells made up 23-27%. In retinae of visual cortex-ablated cats, normal numbers of alpha and gamma cells were present, but the beta cell population was depleted by 90% of normal. Thalamic projections of surviving retinal ganglion cells were investigated by anterograde transport of tritiated proline injected into the eye. In these animals, ablation of visual cortex resulted in almost complete degeneration of laminae A and A1 of the dorsal lateral geniculate nucleus. In the radioautographic material, projections from the retina to the degenerated parts of laminae A and A1 were barely detectable. Survival of some ganglion cell populations and death of others after neonatal visual cortex ablation may be explained in terms of the pattern of projections of the different cell types. We conclude that the majority of beta cells degenerate following visual cortex ablation because of removal of cells in the dorsal lateral geniculate nucleus which form their sole or principal target. Alpha and gamma cells and 10% of beta-cells survive because of extensive collateral projections to targets other than cells of the laminae A and A1 of dorsal lateral geniculate nucleus.
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PMID:Transneuronal degeneration of beta retinal ganglion cells in the cat. 614 55

The retinogeniculate pathways of normal and albino ferrets have been studied with horseradish peroxidase and tritiated proline used as axonal markers. The uncrossed retinogeniculate projection of adult albino ferrets is abnormally small and occupies only a fraction of the geniculate area normally occupied by uncrossed afferents. The crossed pathway is correspondingly expanded, occupying almost the entire nucleus. The geniculate laminae in the albino ferret are abnormal, showing abnormal fusions between layers receiving crossed input and abnormal discontinuities next to the small cell islands receiving uncrossed afferents. In early development, retinofugal fibres can be labelled within the optic tracts on the 28th intrauterine day and a few crossed fibres can be traced into the lateral geniculate nucleus. At this stage, the uncrossed component is extremely small in normal and albino animals and cannot be traced beyond the tract. By day 32 retinal fibres are invading the lateral geniculate nucleus bilaterally, the invasion by the crossed component being significantly more advanced than that by the uncrossed component. The uncrossed pathway of the albinos is already abnormal in terms of its size, in terms of the position it occupies in the optic tract, and in terms of its limited invasion of the lateral geniculate nucleus. The abnormally reduced size of the uncrossed component appears earlier than the abnormal segregation of the retinogeniculate terminals, suggesting that the primary action of the albino gene upon central visual pathways is prechiasmatic. At postnatal stages (41 days after conception and older) the normal, gradual withdrawal of the uncrossed fibres from the monocular segment, and the separation of crossed from uncrossed retinogeniculate terminal arbors is significantly delayed in the albinos. The uncrossed retinogeniculate terminals are abnormally sparse initially and become distributed in an abnormal, interrupted pattern as development proceeds. The abnormal pattern of geniculate lamination appears to be secondary to the abnormal distribution of retinogeniculate afferents.
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PMID:The development of the retinogeniculate pathways in normal and albino ferrets. 615 58


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