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H Fukumura

Publications and source records attributed to H Fukumura.

6 recordsLinked to original sources
PubMed1990

In vivo thrombus formation induced by complement activation on polymer surfaces.

To clarify involvement of complement activation in thrombus formation on polymer surfaces, in vitro complement activation was evaluated for polyethylene (PE) tubes radiation-graft copolymerized with acrylamide (AAm), acrylic acid (AC), 2-hydroxyethyl methacrylate (HEMA), N-vinylpyrrolidone (NVP), and vinyl alcohol (VOH), and compared to their in vivo antithrombogenicity and cell adherence in canine peripheral veins. The complement-activating surfaces (NVP and VOH) cause preferential adhesion of leukocytes and were more thrombogenic than the low complement-activating surfaces (AAm, PE, and HEMA). Infusion of naja haje cobra venom factor depressed leukocyte adhesion, followed by a marked decrease in thrombogenesis, for the strong classical-pathway-activating surface (NVP). Although estimation of in vitro activation for AC was inconclusive because of a large effect of adsorption, AC behaved like VOH in vivo. These results suggest that C5a(des Arg) mediated activation of leukocytes may play a role in thrombus formation by complement activation on polymer surfaces.

Animals↗
PubMed1989

Morphological change and Raman spectrum of rabbit lens irradiated with ultraviolet laser beam.

The effect of ultraviolet rays on eyes was studied. An ultraviolet laser beam (XeCl 308 nm) was irradiated to rabbit eyes to investigate morphological changes of the lens fibers and molecular structural changes of the lens proteins at immediately, 15 days and 32 days after irradiation. 1. Scanning electron microscopic findings of the lens The lens fibers in the control eye were regularly and densely arranged in neat layers of hexahedrons. In the irradiated eye, the fibers at areas that seemed injured were disrupted and the disrupted ends were spherical-shaped. 2. Raman spectra of the lens 1) The relative intensity ratio (I825/I850) of the Raman scattering for the tyrosine residue and the relative intensity ratio (I3390/I2960) of the OH stretching mode (3390 cm-1) of water contained in the lens cortex showed slight changes in the irradiated eye compared to the control eye. 2) The relative intensity ratio (I2572/I2721) of the SH stretching mode (2572 cm-1) for the cysteine residue was 1.05 in the irradiated eye at 32 days after irradiation. It was lower than that in the control eye (1.22 +/- 0.08). This suggested the synthesis of S-S binding by oxidization.

Animals↗
PubMed1987

Complement-induced thrombus formation on the surface of poly(N-vinylpyrrolidone)-grafted polyethylene.

The role of complement activation in thrombogenesis was investigated on the surface of hydrophilic monomer-graft copolymerized polyethylene (PE) tubes. N-vinylpyrrolidone (NVP)-grafted tubes activated in an in vitro complement system of canine serum; but no activation occurred in 2-hydroxyethyl methacrylate (HEMA)-grafted tubes. The relative patent time for NVP-grafted tubes implanted in canine peripheral veins was shorter than that for HEMA-grafted tubes and adhesion of numerous leucocytes was observed on the luminal surfaces of the NVP-grafted tubes. Decomplementation by prior administration of cobra venom factor elongated the relative patent time for NVP-grafted tubes only and also inhibited the adhesion of leucocytes onto them. These results suggest that the complement activation participates in thrombus formation on the polymer surfaces in canine veins.

Animals↗
PubMedDate not supplied

Three new lanostanoids from Ganoderma lucidum.

Three new lanostanoids--ganodermenonol (1), ganodermadiol (2), and ganodermatriol (3) [isolated as its triacetate derivative (3a)]--were isolated from the MeOH extract of Ganoderma lucidum, together with ergosterol and its peroxide. The new compounds were identified as 26-hydroxy-5 alpha-lanosta-7,9(11),24-trien-3-one (1), 5 alpha-lanosta-7,9(11),24-triene-3 beta, 26-diol (2), and 5 alpha-lanosta-7,9(11),24-triene-3 beta, 26,27-triol (3) by their respective spectral data.

Acetylation↗