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Biomedical subjects

N Fujisawa

Publications and source records attributed to N Fujisawa.

52 records · Page 3Linked to original sources
PubMed1992

Isolation and characterization of delta-subspecies of protein kinase C from rat brain.

The delta-subspecies of protein kinase C (delta PKC) was purified to near homogeneity from the Triton X-100 extract of the rat brain particulate fraction by successive chromatographies on S-Sepharose fast flow, phenyl 5PW, heparin 5PW, hydroxyapatite, and Mono Q columns. The purified enzyme was a doublet with molecular masses of 78 and 76 kDa on SDS/PAGE. The doublet proteins were separated partially by Mono Q column chromatography; both were recognized by the antibodies raised against synthetic oligopeptides, parts of the deduced amino acid sequence of the rat delta PKC. Protein phosphatase 2A treatment suggested that the 78-kDa protein was a phosphorylated form of the 76-kDa protein. To confirm the structural and genetic identity of the doublet proteins, delta PKC was expressed in COS 7 cells by transfecting its cDNA-constructed plasmid and was purified for comparison. This recombinant enzyme was also a doublet. The enzymes isolated from the brain and COS 7 cells showed identical reactivities with delta PKC-specific antibodies, chromatographic behaviors, and V8 protease peptide mappings. In addition, these two enzyme preparations were indistinguishable from each other in their responses to phosphatidylserine, diacylglycerol, phorbol esters, free fatty acids, Ca2+, and enzyme inhibitors. Comparison was also made between the enzymologic properties of delta PKC and alpha PKC, which were distinctly different from each other.

Animals↗
PubMed1992

Catalytic properties of yeast protein kinase C: difference between the yeast and mammalian enzymes.

With bovine myelin basic protein as a model common substrate, protein kinases C (PKC) purified from yeast (Saccharomyces cerevisiae) and mammalian tissue (rat brain) were shown to exhibit clearly different catalytic properties. The major sites of phosphorylation in bovine myelin basic protein by the yeast PKC were identified: Thr-19, Thr-34, and Thr-65. These sites are distinctly different from those for the mammalian PKC: Ser-8, Ser-46, Ser-55, Ser-110, Ser-132, Ser-151, and Ser-161, which were previously identified [Kishimoto, A., Nishiyama, K., Nakanishi, H., Uratsuji, Y., Nomura, H., Takeyama, Y., & Nishizuka, Y. (1985) J. Biol. Chem. 160, 12492-12499]. The results suggest that the yeast and mammalian enzymes may play distinct roles in cellular regulation. No evidence is available, however, that a yeast-type PKC exists in mammalian tissues. An oligopeptide containing the sequence around Thr-19 of bovine myelin basic protein, Lys-Tyr-Leu-Ala-Ser-Ala-Ser-Thr(19)-Met-Asp-His-Ala, can be used as a substrate for selective assaying of the yeast PKC.

Amino Acid Sequence↗
PubMed1992

A method to eliminate odor from recirculating air in the animal house.

A new method to eliminate odors from air recirculating in an animal house is described. The new system consists of an ozonizer and titania silica ozone decomposition catalyst in the terminal of a recirculating ventilation system. The principle underlying the elimination of odors is the oxidative reaction of malodorous components on the surface of the catalyst caused by coupling with ozonolysis. This method appeared superior in terms of its durability, efficiency and lack of resistance to air flow.

Animals↗
PubMed1992

[A case of cardiac sarcoidosis associated with various clinical symptoms and thrombocytopenia].

A 29-year-old man presented with acute onset of high fever, chest pain and dyspnea. Chest X-ray film showed diffuse interstitial shadows, a cavitary lesion in the left upper lung field and cardiomegaly, but no lymphadenopathy. Abdominal CT scan showed hepatosplenomegaly and multiple small low density areas in the liver and spleen. Electrocardiogram demonstrated multifocal ventricular premature beats and ventricular tachycardia. Cardiac catheterization revealed left ventricular aneurysms. Sarcoidosis was confirmed by lung and liver biopsy. Drug therapy of prednisolone and mexiletine resulted in clinical improvement of symptoms, signs and chest X-ray film, but platelet count decreased gradually. It is suggested that an immune mechanism of sarcoidosis may have been the cause of this thrombocytopenia.

Adult↗
PubMed1992

Tumor dormancy and the effect of selected drugs on the tumor-dormant state.

An animal model for studying tumor dormancy was established by two-way selection of tumor-progressive and nonprogressive (tumor-dormant state) ddY mice in the same basal stock. In the tumor-progressive (prg) substrain of mice, Ehrlich ascites tumor cells (2 x 10(7)) subcutaneously inoculated into the dorsal skin formed a progressive solid tumor. In the tumor-dormant substrain (drm) of mice, the same tumor cells did not grow at all but formed a small caked nodule (1 to 3 mm in diameter) within 1 week. Some of the tumor cells persisted in the nodule at least 3 months without apparent mitotic figures. Such dormant tumor cells emerged and revealed outgrowth to overt solid tumors after they were transplanted into the dorsal skin of prg mice or into athymic mice (C57BL/6J nu/nu). To estimate the predisposition of drm mice to form tumors, the effect of certain drugs on the tumor-dormant state was examined. Estradiol, progesterone, dexamethasone, prostaglandin E2, Cyclosporin A, and collagenase all failed to promote the emergence of dormant tumor cells in drm mice.

Animals↗
PubMed1991

Establishment of clonal cell lines, with or without cartilage phenotypes, from a hamster mesenchymal chondrosarcoma.

A hamster mesenchymal chondrosarcoma was found in the soft tissues of the cheek pouch and has been successfully transplanted. The tumor was composed principally of two cell types: poorly differentiated mesenchymal cells and focal areas of cells in islands showing cartilaginous differentiation. The clonal cell lines, MCS-1 and MCS-8 which closely correspond to the respective cell types in the original tumor were also established. MCS-1 cells formed an undifferentiated sarcoma in the subcutaneous layer of nude mice and MCS-8 cells formed a chondrosarcoma of a common type.

Animals↗
PubMed1986

Characterization of vascular permeability-increasing component isolated from solid tumors and the effect of highly polymerized dextran sulfate on its activity.

Increase in vascular permeability is usually seen at the growth site of a tumor implant in murine dermal tissue. Increased vascular permeability was inducible by the subcutaneous injection of a solid tumor extract rich in protein precipitable at 20-50% saturation of ammonium sulfate. The vascular permeability-increasing activity of the tumor extract was reducible in the presence of highly polymerized dextran sulfate (DS-500) which showed a strong anticomplementary activity, but not by other substances such as dextran sulfate with a low molecular weight, non-sulfated dextran, chondroitin sulfate or heparin. As the tumor extract includes gamma-globulins in aggregated or bound form and adsorbs complements, it is probable that the aggregated gamma-globulins increase vascular permeability by triggering the complement activation system in the skin. DS-500 might antagonize the process.

Ammonium Sulfate↗
PubMed1986

Growth experiment of Hantaan virus in A549 cells: an attempt to improve the immunofluorescent antibody technique for hemorrhagic fever with renal syndrome.

An assay method for the infectivity of Hantaan virus, a causative agent of HFRS (hemorrhagic fever with renal syndrome), was developed by the use of IFA (immunofluorescent antibody technique). With the aid of this method, the growth characteristics of Hantaan virus, 76-118 strain, were followed in A549 cells. At a maximal MOI (multiplicity of infection) of 1.6 VAIU (viral antigen-inducing units) per cell, the conventionally available value, plateau level potencies of the viral antigen and virus infectivity were attained at eight and ten days postinfection, respectively, and most of the infective virus produced accumulated in the culture fluids of infected cells. When infections were defined with MOI values in terms of VAIU per cell, development of the viral antigen was highly consistent and followed a given pattern of kinetics. Based on these findings, a protocol for preparation of the viral antigen in IFA was presented, wherein spot culture and FBS treatment were emphasized as effective procedures to minimize non-specific staining.

Animals↗
PubMed1985

[Histochemical demonstration of proteins, lipids and polysaccharides in Japanese monkey oocytes].

A histochemical study of proteins, lipids and polysaccharides was carried out in the oocytes of Japanese monkey (Macaca fuscata) during development of follicles. There were a small number of protein granules reactive to acrolein-Schiff in the cytoplasm of oocytes from primordial, secondary and vesicular follicles, while there were no lipid droplets, granules of neutral polysaccharides or acid polysaccharides in the cytoplasm. Proteins reactive to acrolein-Schiff, neutral polysaccharides reactive to periodic acid-Schiff and acid polysaccharides stainable with alcian blue were observed in the zona pellucida of the oocytes of secondary and vesicular follicles. The zona pellucida contained sudanophilic lipids composed of neutral fats and lipoids, besides the proteins and polysaccharides.

Animals↗
PubMed1984

[Evaluation of amputation techniques for the study of limb regeneration in the newt and toad].

A comparison between forelimb amputations through the radius-ulna and the humerus was made in the adult newt, Cynops pyrrhogaster pyrrhogaster and the young toad, Xenopus laevis. Newts regenerated their forelimbs after the amputations and the new parts resembled the old in structure and function. Toads regenerated their forelimbs incompletely after the amputations. The new parts lacked joints and fingers showing a simply elongate pattern. The effect of re-amputation of exposed bone on the regeneration was evaluated in the adult newt. A left forelimb was amputated through the humerus and the exposed bone which protruded from the cut surface due to the relationships of the soft tissues, was then re-amputated a few minutes later. A right forelimb of the same individual was simply amputated without re-amputation of the exposed bone. Newts regenerated both forelimbs simultaneously. The new parts resembled the old in structure and function.

Amputation, Surgical↗
PubMed1980

Isolation and characterization of a composite plasmid Rms201 mutant temperature sensitive for replication.

A mutant temperature-sensitive for R-plasmid replication, Rms201ts14, was isolated from composite plasmid Rms201 after mutagenesis of P1 transducing lysate with 100 mM hydroxylamine for 40 h at 37 degrees C. When Escherichia coli ML1410(Rms201ts14)(+) was grown at temperatures between 40 and 42 degrees C in L broth, antibiotic-sensitive cells were segregated. When the incubation temperature of ML1410(Rms201ts14)(+) in L-broth was shifted to 42 from 30 degrees C, the increase in the number of antibiotic-resistant cells ceased 90 min after the temperature shift. However, the total number of cells continuously increased, and only 3% of the cells retained the plasmid at 5 h after the temperature shift to 42 degrees C. At 30 degrees C the amounts of covalently closed circular deoxyribonucleic acid per chromosome of Rms201ts14 and Rms201 were 3.8 and 6.3%, respectively. Incorporation of radioactive thymidine into the covalently closed circular deoxyribonucleic acid of Rms201ts14 did not take place at 42 degrees C, whereas radioactive thymidine was incorporated into the covalently closed circular deoxyribonucleic acid of Rms201 at a rate of 4%/chromosome even at 42 degrees C. The synthesis of plasmid covalently closed circular deoxyribonucleic acid in a cell harboring Rms201ts14 was almost completely blocked at 42 degrees C. These results indicated that the gene(s) responsible for plasmid deoxyribonucleic acid replication was affected in the mutant Rms201ts14. Temperature-sensitive miniplasmid pMSts214, which has a molecular weight of 5.3 x 10(6) and encodes ampicillin resistance, was isolated from Rms201ts14. Similarly, miniplasmid pMS201, which encodes single ampicillin resistance, was isolated from its parent, Rms201, and its molecular weight was 4.7 x 10(6). These results indicate that the gene(s) causing temperature sensitivity for replication of Rms201 resides on the miniplasmid.

Ampicillin↗
PubMedDate not supplied

Basal ganglia mass lesions in juvenile rheumatoid arthritis.

A 2-year-old boy suffered aphasia, hypotonia, dystonia, and loss of activity and spontaneous speech during an active stage of juvenile rheumatoid arthritis with pericarditis, fever, anemia, and a high antinuclear antibody titer. These neurologic signs slowly improved with corticosteroid treatment but fluctuated over 1 year. The neuroimaging studies revealed irregular mass lesions in the basal ganglia bilaterally mainly involving the globus pallidus. They gradually decreased in size and almost disappeared after 1 year. A stereotactic brain biopsy revealed a slight proliferation of astrocytes. Chorioretinitis was also observed during the clinical course. A chronic inflammatory process involving cerebral vessels was suspected, although angiography did not demonstrate cerebral vasculitis. The possibility of central nervous system lymphoma could not be eliminated. The type of aphasia and the relation to the lesion sites are discussed.

Arthritis, Juvenile↗