Spin dependence of pp inelasticities at intermediate energies.
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Journal Article↗
Biomedical subjects
H Fujisawa
Publications and source records attributed to H Fujisawa.
Purification and characterization of aromatic L-amino acid decarboxylase from rat kidney and monoclonal antibody to the enzyme.
Aromatic L-amino acid decarboxylase was purified from rat kidney to homogeneity, as judged by polyacrylamide gel electrophoresis, in the presence and absence of sodium dodecyl sulfate (SDS). The final preparation showed an activity of 3,4-dihydroxyphenylalanine (dopa) decarboxylation of approximately 11,000 nmol/min/mg of protein at 37 degrees C. The purified enzyme also catalyzed the decarboxylation of 5-hydroxytryptophan, tyrosine, tryptophan, and phenylalanine. The enzyme appeared to be composed of two identical subunits, each possessing a molecular weight of 48,000. The isoelectric point of the enzyme was estimated to be 6.7 in the presence of 8 M urea and 5.60-5.85 in its absence. To examine the identity of aromatic L-amino acid decarboxylase from various tissues, a monoclonal antibody directed against the enzyme from rat kidney was prepared. Immunotitration and analysis by antibody-affinity chromatography followed by SDS-polyacrylamide gel electrophoresis revealed that the enzymes from the striatum, adrenal medulla, pineal gland, liver, and kidney were indistinguishable with respect to immunological cross-reactivity and molecular size.
Amino Acids↗
Effective preoperative irradiation of highly vascular cerebellopontine angle neurinomas.
Three cases of large cerebellopontine angle neurinoma with marked vascularity and tumor staining on the angiogram were treated with effective preoperative irradiation. The radiotherapy was given before the second operation in two cases and before the first operation in the other case. Irradiation doses administered with a linear accelerator were 2.34 to 3.0 Gy for 3 to 3.5 weeks, and radical operations were done 1.5 to 2 months after irradiation. After the irradiation, vertebral angiography showed moderate to marked decrease of the hypervascular capsular stain and disappearance of the early draining vein. Computed tomographic scan showed enlargement of the central necrotic area within the heterogeneously enhanced tumor, which was unchanged in size. Radical operations, which had been impossible because of uncontrollable massive bleeding, were successful without any intraoperative bleeding after radiotherapy. Postirradiation radiological findings corresponded well with those of histopathological examination, which showed decrease in cellularity and in vascularity and diffuse coagulation necrosis around the collapsed tumoral vessels as radiation effects. Preoperative irradiation of the hypervascular neurinoma was though to facilitate radical surgery by abolishing or diminishing the risk of intraoperative bleeding.
Adult↗
[Self-regulation of nerve function].
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Animals↗
Effect of a high-fat diet on resistance to Listeria monocytogenes.
Effects of a high-fat diet on macrophage (M phi) functions were investigated. Eight-week-old ddN mice were fed a high-fat diet and carbon clearance was tested. Remarkable suppression of phagocytic activity (K16) was observed in mice fed such a diet for 1 or 2 weeks. Resistance against Listeria monocytogenes inoculated intravenously (iv) with a lethal, a sublethal, or a non-pathogenic dose was observed in the liver of mice fed a high-fat diet. When mice were infected with a lethal dose of bacteria, the number of listeria increased progressively in the liver to kill both control and a high-fat diet fed mice by day 4. The number of listeria revealed no significant difference between the group in the case of low dose inoculation. High-fat diet fed mice given a sublethal dose of bacteria showed a rise in the number of viable bacteria during the first 3 days after infection while a decline in the number of bacteria was observed in control mice during such a period. Suppression of M phi activity induced by a high-fat diet may account for the reduced resistance.
Animals↗
Identification of serotonergic neurons in human brain by a monoclonal antibody binding to all three aromatic amino acid hydroxylases.
A monoclonal antibody, PH8, has been isolated and shown by immunocytochemistry to bind to serotonergic and catecholaminergic neurons in sections of the rat and human brain. In human brain, obtained at autopsy, particular fixation and embedding conditions eliminate the labelling of catecholaminergic neurons while leaving intact the labelling of serotonergic neurons. This property makes the antibody of potential use for structural studies of serotonergic neurons in the normal and diseased human brain. PH8 was raised to pure monkey phenylalanine hydroxylase and has been shown to bind to the 50,000 mol. wt. phenylalanine hydroxylase polypeptide. Immunocytochemical and immunochemical evidence is presented in support of the hypothesis that the labelling of serotonergic and catecholaminergic neurons results from the binding of PH8 to tryptophan and tyrosine hydroxylase, respectively.
Adrenal Medulla↗
Characterization of the bacteriophage T3 DNA packaging reaction in vitro in a defined system.
The bacteriophage T3 DNA packaging system in vitro defined here is composed of purified proheads and two non-capsid proteins, the products of genes 18 and 19 (gp18 and gp19). In this system, a precursor complex (50 S complex) accumulates in the presence of adenosine 5'-O-(3'-thiotriphosphate) (ATP-gamma-S), a non-hydrolyzable analog of ATP. The 50 S complex is converted to a filled head in the presence of ATP. The conversion of the 50 S complex, formed by preincubation with ATP-gamma-S, to the mature head proceeds in a synchronous manner after the addition of ATP. The lag time for formation of mature heads from the 50 S complex is 1.8, 4.5 and 6.8 minutes at 30, 25 and 20 degrees C, respectively. DNA is translocated into the capsid at a constant rate of 5.7 x 10(3) base-pairs per minute at 20 degrees C. The conversion of the 50 S complex to the mature head exhibits a sigmoidal relationship with respect to the concentration of ATP, the concentration for half-maximal activity being about 20 microM. The transition of the prohead to the expanded capsid occurs at 20 degrees C at one minute 40 seconds after the initiation of DNA translocation, when one-fourth of the genome has been packaged into a prohead. At the same time, the capsid-DNA complex becomes stable to high concentrations of salt. When DNA translocation is interrupted by the addition of ATP-gamma-S, packaged DNA exists at 0 degrees C as well as at 20 degrees C but the exit of DNA stops after one-third of the genome is inside the capsid. After exit, DNA is retranslocated into the expanded capsid by the addition of ATP at a rate of about 5.7 x 10(3) base-pairs per minute at 20 degrees C. The decrease in concentration of ATP interrupts DNA translocation into the capsid but does not induce DNA exit. Interrupted DNA translocation may be reinitiated by the addition of ATP. DNA exit is not induced by the addition of ATP-gamma-S to mature heads or partially filled heads pretreated with DNase.
Adenosine Triphosphate↗
Reversible conversion of tyrosine hydroxylase to an inactive form by antipain.
Tyrosine hydroxylase, the rate-limiting enzyme in the biosynthesis of catecholamines, was reversibly inactivated by incubation with antipain, which is known as a microbial protease inhibitor. The inactivation was a time-dependent reaction and it was prominent when the enzyme was assayed at a neutral pH but not when assayed at an acidic pH. The inactivated enzyme was markedly activated by cyclic AMP-dependent protein kinase. Other microbial protease inhibitors such as leupeptin, chymostatin, and pepstatin did not induce such as inactivation of the enzyme.
Animals↗
Brain 14-3-3 protein is an activator protein that activates tryptophan 5-monooxygenase and tyrosine 3-monooxygenase in the presence of Ca2+,calmodulin-dependent protein kinase II.
We have found that the 14-3-3 protein, an acidic neuronal protein, is substantially identical to the 'activator' protein [(1981) J. Biol. Chem. 256, 5404-5409] that activates tryptophan 5-monooxygenase and tyrosine 3-monooxygenase in the presence of Ca2+, calmodulin dependent protein kinase II. This finding is based on the remarkable similarity of both these proteins in physicochemical, biochemical and immunochemical properties, as well as on detection for the 14-3-3 protein of an activator activity towards tryptophan 5-monooxygenase. The result suggests that the 14-3-3 protein plays a role in the regulation of serotonin and noradrenaline biosynthesis in brain.
14-3-3 Proteins↗
Mode of growth of retinal axons within the tectum of Xenopus tadpoles, and implications in the ordered neuronal connection between the retina and the tectum.
Retinal axons of Xenopus tadpoles at various stages of larval development were filled with horseradish peroxidase (HRP), and their trajectories and the patterns of branching within the tectum were analyzed in wholemount preparations. To clarify temporal and spatial modes of growth of retinal axons during larval development, special attention was directed to labeling a restricted regional population of retinal axons with HRP, following reported procedures (H. Fujisawa, K. Watanabe, N. Tani, and Y. Ibata, Brain Res. 206:9-20, 1981; 206:21-26, 1981; H. Fujisawa, Dev. Growth Differ 26:545-553, 1984). In developing tadpoles, individual retinal axons arrived at the tectum, without clear sprouting. Axonal sprouting first began when growing tips of each retinal axon had arrived at the vicinity of its site of normal innervation within the tectum. Thus, the terminals of the newly added retinal axons were retinotopically aligned within the tectum. The retinotopic alignment of the terminals may be due to an active choice of topographically appropriate tectal regions by growth cones of individual retinal axons. The stereotyped alignment of the newly added retinal axons was followed by widespread axonal branching and preferential selection of those branches. Each retinal axon was sequentially bifurcated within the tectum, and old branches that had inevitably been left at ectopic parts of the tectum (owing to tectal growth) were retracted or degenerated in the following larval development. The above mode of axonal growth provides an adequate explanation of cellular mechanisms of terminal shifting of retinal axons within the tectum during development of retinotectal projection. Selection of appropriate branches may also lead to a reduction in the size of terminal arborization of retinal axons, resulting in a refinement in targeting.
Animals↗
First measurement of the real part of a pp double-spin-flip amplitude.
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Journal Article↗
Specific expression of the chicken delta-crystallin gene in the lens and the pyramidal neurons of the piriform cortex in transgenic mice.
Two transgenic mice, 5-8 and 7-5, carrying the chicken delta-crystallin gene were produced by microinjecting cloned genes into male pronuclei. The mice were analyzed at 8 weeks of age with respect to gene integration and expression by means of blotting techniques and immunohistochemistry. Southern blot analysis indicated that both mice carried, on average, 50 copies of intact delta-crystallin gene per cell. Histological analysis of the mice using DNA-DNA in situ hybridization indicated that mouse 5-8 carried the delta-crystallin gene in every cell while mouse 7-5 was mosaic, with 20-40% of the cells of various tissues carrying the gene. Western blot analysis indicated that in both mice delta-crystallin is expressed in the lens and the cerebrum, but not in any other tissue examined. Immunohistological analysis revealed that, in the cerebrum of the mice, delta-crystallin was expressed specifically in pyramidal neurons located in layer IIb of the anterior piriform cortex. Thus, our results with transgenic mice not only demonstrate the primary specificity of delta-crystallin gene expression in authentic lens tissue, but reveal the unexpected specificity of this chicken gene in the central nervous system of the mouse.
Animals↗
Spatial and temporal expression pattern of N-cadherin cell adhesion molecules correlated with morphogenetic processes of chicken embryos.
N-cadherin is a Ca2+-dependent cell-cell adhesion molecule, which was identified in brain cells of mouse and chicken. In the present study, we have determined the pattern of expression of N-cadherin in chicken embryos at various stages by means of immunohistochemistry. N-cadherin was expressed in cells derived from all three primary germ layers. Its expression was transient in many tissues but permanent in others. The transient expression occurred in nephric tubules, skeletal muscles, mesenchymal tissues, endodermal organs, and epidermis, while the permanent expression occurred in nervous systems, lens, and myocardiac cells. Appearance or disappearance of N-cadherin could be generally correlated with morphogenetic events, such as rearrangement, segregation, or association of cells. Comparison of the expression pattern of N-cadherin with that of L-CAM and N-CAM determined by other workers suggests that there is some mechanism controlling expression of multiple classes of adhesion molecules. The pattern of expression of N-cadherin was generally complementary to that of L-CAM; that is, if N-cadherin appeared, L-CAM disappeared or vice versa. We also found cases in which N-cadherin was expressed in the same local regions as L-CAM. The distribution of N-cadherin was similar to that of N-CAM with some exceptions. Thus, N-cadherin and other cell-cell adhesion molecules seem to be expressed under a precise spatial and temporal control so as to be associated with a variety of morphogenetic events during development.
Animals↗
Specific cell surface labels in the visual centers of Xenopus laevis tadpole identified using monoclonal antibodies.
Monoclonal antibodies (MAbs) against the optic tectum of Xenopus tadpoles were generated and screened by the immunofluorescent staining of frozen sections of tadpole brains. MAb-A5 stains the 8th and 9th plexiform layers of the optic tectum, whereas MAb-B2 stains all but the eighth and ninth plexiform layers of the optic tectum. MAb-A5 antigen is also detectable in the nucleus of Belonci, the corpus geniculatum thalamicum, the pretectal area, and the basal optic nucleus, all targets of the optic nerve, but is not detectable in the optic nerve or the optic tract. On the other hand, MAb-B2 does not stain any of these visual centers, though many fibers surrounding them are stained. Eye-enucleation experiments showed that MAb-A5 antigen is expressed in the optic tectum even when it is not innervated by optic nerves. Staining of viable brains with these MAbs indicates that these antigens are cell surface molecules. Immunoadsorption followed by SDS-PAGE suggests that proteins are constituents of these antigens. The MAb-A5 antigen in the diencephalon and the mesencephalon is not detectable at stage 35/36, but is detectable at stage 39 when the optic nerves begin to innervate the optic tectum. The spatial as well as the temporal patterns of the expression of the MAb-A5 antigen suggest that this molecule may be involved in the target recognition of optic nerve fibers.
Animals↗
On the molecular mechanism of DNA translocation during in vitro packaging of bacteriophage T3 DNA.
The process of packaging of bacteriophage T3 DNA in a defined in vitro system can be separated into two stages: formation of a precursor complex (50 S complex) in the presence of adenosine-5'-O-(3'-thiotriphosphate) (ATP-gamma-S) and subsequent translocation of DNA into the head by the addition of ATP. Packaged DNA exits when DNA translocation is interrupted by the addition of ATP-gamma-S (M. Shibata, H. Fujisawa, and T. Minagawa, 1987, Virology, in press; M. Shibata, H. Fujisawa, and T. Minagawa, 1987, J. Mol. Biol., in press). The in vitro system packaged nicked and cross-linked DNAs but did not package single-stranded DNA. DNA packaging was inhibited by intercalating reagents such as ethidium bromide, acridine orange, and 4',6-diamino-2-phenylindole dihydrochloride. The inhibitory effect was proportional to the ability of intercalating agents to unwind DNA. Ethidium bromide did not inhibit the formation of 50 S complex but blocked translocation of DNA into and out of the capsid. DNA packaging was inhibited by actinomycin D and distamycin A which bind to the minor groove of the DNA helix. From these results, we conclude that DNA packaging mechanism utilizes the exterior structure of duplex DNA for translocating the DNA into the capsid.
Capsid↗
Characterization of ATPase activity of a defined in vitro system for packaging of bacteriophage T3 DNA.
We have developed a defined in vitro system for packaging phage T3 DNA which is composed of purified proheads and the noncapsid proteins gp18 and gp19, products of genes 18 and 19 (K. Hamada, H. Fujisawa, and T. Minagawa, 1986, Virology 151, 119-123). The in vitro system displayed an ATPase activity. The requirements for ATPase activity were the same as those for DNA packaging. ATPase was inhibited by a nonhydrolyzable ATP analog, adenosine-5'-O-(3'-thiotriphosphate) (ATP-gamma-S). ATPase activity did not display specificity for T3 DNA. A reaction mixture containing 8- proheads, proheads deficient in gp8, a portal protein for DNA entrance, or mature heads had no gp18- gp19-dependent ATPase activity. gp8 itself had no ATPase activity and did not complement 8- proheads for ATPase activity. Photoaffinity labeling of proheads, gp18 and gp19 with 8-azidoadenosine-5'-[alpha-32P]triphosphate([32P]8-N3ATP) resulted in preferential labeling of gp19. Protection from incorporation of [32P]8-N3ATP was afforded by ATP but not by AMP and ADP. From these results, it is concluded that gp19 has an ATP binding site(s). A conserved sequence of ATP-binding site containing Gly-X-Gly-X-X-Gly-X-Val is found in gp19.
Adenosine Triphosphatases↗
Early events in DNA packaging in a defined in vitro system of bacteriophage T3.
We have developed a defined in vitro system for packaging phage T3 DNA which is composed of purified proheads and the noncapsid proteins gp18 and gp19, products of genes 18 and 19. The reaction requires Mg2+, ATP, and polyethylene glycol and is inhibited by a nonhydrolyzable ATP analog, adenosine-5'-O-(3'-thiotriphosphate) (ATP-gamma-S) (K. Hamada, H. Fujisawa, and T. Minagawa, 1986, Virology 151, 119-123). About 30% of added mature T3 DNA was packaged into heads in the defined system. A complex with a sedimentation coefficient of about 50 S (50 S complex) accumulated in the reaction mixture containing ATP-gamma-S. The 50 S complex was DNase sensitive and was converted to filled heads by a second reaction in the presence of ATP without addition of DNA, proheads, gp18, and gp19. These results indicate that during early stages of DNA packaging, formation of precursor complexes proceeds by an allosteric mechanism with ATP acting as effector. The movement of DNA into the head is driven by the energy released by hydrolysis of ATP. gp18 formed a complex with DNA without addition of ATP-gamma-S and gp19. gp18-DNA complex was DNase sensitive and did not bind gp19; it was converted to filled heads by way of a second reaction after addition of ATP, gp19, and proheads. gp19 formed a functional complex with prohead in the presence of ATP-gamma-S or ATP. The complex did not bind gp18 but was converted to filled heads by incubation with ATP, gp18, and DNA. In the absence of ATP-gamma-S, gp19 formed complexes with prohead that were abortive in DNA packaging. Formation of the 50 S complex occurred in a reaction mixture containing gp18-DNA and gp19-prohead complexes in the presence of ATP-gamma-S. From these results, we propose details of the molecular mechanism of DNA packaging in the defined in vitro system.
Adenosine Triphosphate↗
Phenylalanine 4-monooxygenase from Chromobacterium violaceum.
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Amino Acids↗