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T Fukai

Publications and source records attributed to T Fukai.

70 records · Page 4Linked to original sources
PubMed1990

Liver abscess complicating intratumoral ethanol injection therapy for HCC.

We report a patient who developed multiple liver abscesses and sepsis caused by lactobacilli after the percutaneous intratumoral injection of ethanol for hepatocellular carcinoma. We diagnosed the liver abscess at an early stage because of a the finding of gas on ultrasound and computed tomography. Blood cultures grew Gram-positive rods, which were of the Lactobacillus species. The patient responded to the administration of antibiotics, and his hepatic tumors have not recurred in the 7 months since treatment. This is the first report of liver abscess following percutaneous ethanol injection therapy.

Aged↗
PubMedDate not supplied

Fokker-Planck approach to the pulse packet propagation in synfire chain.

We applied the Fokker-Planck method to the so-called 'synfire chain' network model and showed how a synchronous population spike (pulse packet) evolves to a narrow pulse packet (width < 1 ms) or fades away, depending on its initial size and width. The results of numerical integration of the Fokker-Planck equation are in good agreement with those of simulations on a network of leaky integrate-and-fire neurons. For a narrow input pulse packet, the integration of the Fokker-Planck equation requires careful numerical treatment. However, we can construct a precise analytical waveform of an output packet, which proves valid for narrow input pulse packets, from the stationary solution to the Fokker-Planck equation and a previously proposed approximate input-output relationship. Our methods enable us also to understand an essential role of the synaptic noise in the evolution, the peculiar temporal evolution of a broader pulse packets, and the irrelevance of the refractory period in determining the waveform of a pulse packet. Furthermore, we elucidate possible functional roles of multiple interactive pulse packets in spatiotemporal information processing, i.e. the association of information and the temporal competition.

Action Potentials↗
PubMedDate not supplied

Effects of phenolic constituents from the mulberry tree on arachidonate metabolism in rat platelets.

The effects of various phenolic compounds isolated from the rootbark of the mulberry tree on rat platelet cyclooxygenase and lipoxygenase products formed from (1-14C)arachiodonic acid were studied. Kuwanons G and H, sanggenon C, and mulberrofuran Q at concentrations of 10(-3) to 10(-4)M inhibited the formation of 12-hydroxy-5,8,10-heptadecatrienoic acid (HHT) and thromboxane B2 (cyclooxygenase products); however, they increased the formation of 12-hydroxy-5,8,10,14-eicosatetraenoic acid (12-HETE) (a lipoxygenase product). Sanggenon D and mulberrofuran J at concentration of 10(-3)M inhibited the formation of HHT, thromboxane B2, and 12-HETE. Mulberrofuran G at a concentration of 10(-3)M inhibited the formation of HHT, thromboxane B2, and 12-HETE, while at 10(-5)M, it inhibited the formation of 12-HETE without affecting the formations of HHT and thromboxane B2. Kuwanon M and mulberroside A did not affect arachidonate metabolism in rat platelets.

Animals↗
PubMedDate not supplied

Induction of apoptosis by flavones, flavonols (3-hydroxyflavones) and isoprenoid-substituted flavonoids in human oral tumor cell lines.

Various flavones, flavonols (3-hydroxyflavones) and isoprenoid-substituted flavones (flavonols) were investigated for their cytotoxic activity. Most of these compounds were more cytotoxic against human oral squamous cell carcinoma and salivary gland tumor cell lines than human gingival fibroblasts. The cytotoxic activity of flavonoids was generally higher than that of tannin-related compounds. Flavonoids induced apoptotic cell death characterized by DNA fragmentation (as identified by TUNEL method) and activation of caspase(s) (as identified by degradation products of cytokeratin 18 with M30 monoclonal antibody). ESR spectroscopy revealed that higher concentrations of flavonoids produced radicals under alkaline conditions. However, not all of them enhanced the radical intensity of sodium ascorbate, suggesting that the redox potential of flavonoids differs considerably from samples to samples. Catalase failed to eliminate the cytotoxic activity of flavonoids, reducing the possibility of the involvement of hydrogen peroxide for the cytotoxicity induction by them.

Apoptosis↗
PubMedDate not supplied

Cytotoxic activity of low molecular weight polyphenols against human oral tumor cell lines.

A total of 150 chemically-defined natural and synthetic polyphenols (flavonoids, dibenzoylmethanes, dihydrostilbenes, dihydrophenanthrenes and 3-phenylchromen-4-ones), with molecular weights ranging from 224 to 824, were investigated for cytotoxic activity against normal, tumor and human immunodeficiency virus (HIV)-infected cells. They showed higher cytotoxic activity against human oral squamous cell carcinoma HSC-2 and salivary gland tumor HSG cell lines than against normal human gingival fibroblasts HGF. Many of the active compounds had a hydrophilic group (hydroxyl group) in the vicinity of a hydrophobic group (prenyl, phenyl, methylcyclohexene or methylbenzene moiety), similar to isoprenoid-substituted flavones. Substitution of hydrophobic group (prenyl or geranyl group) did not significantly change the cytotoxic activity of flavanones, isoflavans, chalcones or 5-hydroxy-3-phenoxychromen-4-ones. However, the prenylation(s) of an isoflavone and a 2-arylbenzofuran significantly enhanced the cytotoxic activity. Agarose gel electrophoresis showed that active components induced internucleosomal DNA fragmentation in human promyelocytic leukemic HL-60 cells, but not in HSC-2 cells. Most of the polyphenols failed to reduce the cytophathic effect of HIV infection in MT-4 cells.

Anti-HIV Agents↗
PubMedDate not supplied

Cytotoxic and DNA damage-inducing activities of low molecular weight phenols from rhubarb.

Six new phenol (anthraquinone or stilbene) glycosides with an acyl group at 6-position of the glucopyranose moiety were isolated from rhubarb (the roots of Rheum palmatum) cultivated in Japan, together with 22 known compounds. Most of these compounds were evaluated for cytotoxic activity against tumor and normal cells and for induction of DNA damage by spore rec-assay. Among them, emodin and aloe-emodin showed higher cytotoxic activities against human oral squamous cell carcinoma (HSC-2) and salivary gland tumor (HSG) cell lines than against normal human gingival fibroblasts (HGF). Chrysophanol 8-O-beta-(6'-acetyl)glucopyranoside, 4-(4'-hydroxyphenyl)-2-butanone 4'-O-beta-D-(2"-O-galloyl-6"-O-cinnamoyl) glucopyranoside, and 6"-O-(4'''-hydroxybenzoyl) resveratroloside exhibited relatively higher cytotoxic activities against all these cells. The other glycosides of anthraquinone or stilbene showed weaker cytotoxic activity against these tumor cell lines, but may be considered as cancer chemopreventive agents. Spore rec-assay with a recombination deficient mutant of Bacillus subtilis M45 demonstrated the DNA damage-inducing activity of emodin and aloe-emodin 15-O-beta-D-glucopyranoside among, rhubarb phenols.

Bacillus subtilis↗