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Biomedical subjects

K Katayama

Publications and source records attributed to K Katayama.

At least 433 records · Page 24Linked to original sources
PubMed1987

Effect of the novel non-steroidal antiinflammatory agent N-methoxy-3-(3,5-di-tert-butyl-4-hydroxybenzylidene)pyrrolidin-2-one on in vitro generation of some inflammatory mediators.

A newly synthesized compound, the non-steroidal antiinflammatory agent N-methoxy-3-(3,5-di-tert-butyl-4-hydroxybenzylidene)pyrrolidin-2-o ne (E-5110) was investigated. E-5110 inhibited prostaglandin E2 (PGE2) generation by cultured rat synovial cells upon stimulation with interleukin-1-like factor of rat polymorphonuclear leucocytes (PMN). The IC50 values (mumol/l) for PGE2 generation were 0.026 for E-5110, 0.008 for indometacin, 0.112 for piroxicam and 0.667 for the compound B (3-amino-1-(M-trifluoromethyl-phenyl-2-pyrazoline). Calcium ionophore A23187-stimulated leukotriene B4 generation by human PMN was inhibited by E-5110 with an IC50 value of 0.20 mumol/l; E-5110 was as inhibitory as nordihydroguaiaretic acid and was more potent than the compound B (IC50 of 2.58 mumol/l). E-5110 suppressed superoxide generation by human PMN stimulated with opsonized zymosan, f-Met-Leu-Phe and phorbol myristate acetate. E-5110 also inhibited the generation of leucocytic pyrogen and leucocyte factor(s) which stimulated collagenase production by cultured synovial cells.

Animals↗
PubMed1987

[On the mechanisms of human T cell proliferation induced by the 10B4 molecule].

The 10B4 system of human T cells seems to constitute a member of T cell receptor complex. We have analyzed the mechanisms by which a monoclonal antibody against the 10B4 molecule activates human peripheral T cells. The 10B4 antibody together with goat anti-mouse immunoglobulin antibody induced significant increase of DNA and RNA syntheses in T cells with peak responses on day 9 and on day 7, respectively. This activation process is mediated by interleukin 2 (IL-2) and its receptor (IL-2R), because (1) IL-2 activity was detected in the culture supernatants, (2) the percentage of IL-2R positive cells increased during the culture period, with a peak on day 9, and (3) the 10B4-induced T cell proliferation was inhibited by anti IL-2R antibody. Blocking studies with pharmacological agents showed that in the 10B4-induced system, a protein kinase C (PK-C) inhibitor, palmitoylcarnitine, blocked DNA synthesis, RNA synthesis, IL-2 production and IL-2R expression whereas a Ca ion channel blocker, verapamil, inhibited DNA synthesis, RNA synthesis, IL-2 production but not IL-2R expression. It is thus concluded that PK-C activation is required for IL-2 production and IL-2R expression and that channel-mediated Ca ion influx is important for IL-2 production but may not be needed for IL-2R expression.

Animals↗
PubMed1987

Pharmacological properties of the novel non-steroidal antiinflammatory agent N-methoxy-3-(3,5-di-tert-butyl-4-hydroxybenzylidene)pyrrolidin-2 -one.

The antiinflammatory activity of the novel pyrrolidin-2-one derivative N-methoxy-3-(3,5-di-tert-butyl-4-hydroxybenzylidene)pyrrolidin-2-o ne (E-5110) was investigated and compared with those of indomethacin and piroxicam in various antiinflammatory, analgesic and antipyretic animal models. The acute antiinflammatory activity of E-5110 on the carrageenin paw edema was similar to that of indomethacin, and half that of piroxicam. The chronic inflammatory responses in established adjuvant- and type II collagen-induced arthritis, which are widely used models of rheumatoid arthritis, were suppressed as effectively by E-5110 as by indomethacin and piroxicam. E-5110 decreased the pleural exudate volume and inhibited leucocyte infiltration in a reversed passive Arthus reaction more potently than indomethacin, suggesting that mediators other than prostaglandin E2 may play an important role in this inflammatory process. The analgesic potency of E-5110 against inflammatory pain was similar to that of indomethacin or piroxicam, but the antipyretic activity of E-5110 was more potent than that of the reference drugs. The ulcerogenic effect of E-5110 on rat gastric mucosa was less than those of indomethacin and piroxicam. In conclusion, E-5110 is a very potent antiinflammatory compound acting against various types of inflammation, and has a favorable therapeutic index.

Animals↗
PubMed1987

[Neuropsychological disturbance in Parkinson's disease--analysis of a new modified Wisconsin Card Sorting Test and of the P300 component evoked by auditory stimuli].

To clarify the neuropsychological disturbances in Parkinson's disease, we used the New Modified Wisconsin Card Sorting Test (WCST) which is simpler and less ambiguous than the other methods. We also examined P 300 components evoked by auditory stimuli. In the previous paper, we reported that the latencies of P 300 component evoked by the complex visual stimuli were prolonged. These two examination were administered to 25 parkinsonian patients with normal intelligence and 15 normal controls. In the New Modified WCST, parkinsonian patients had fewer categories achieved. And they made a higher proportion of total errors, preservation errors and difficulty of maintaining set than normal controls. In the latencies and the amplitudes of P 300 components, there were no significant differences between the two groups. In the group of parkinsonian patients, significant correlations were demonstrated between the P 300 latency and the scores of the New Modified WCST. These results show that the New Modified WCST is useful for the detection of neuropsychological disturbance in Parkinson's disease and that P 300 components evoked by simple task could not disclose it.

Aged↗
PubMed1986

An enzyme immunoassay for osteocalcin.

A sensitive and specific enzyme immunoassay for bovine osteocalcin was developed with the use of enzyme-labeled antigen. Bovine osteocalcin was conjugated with beta-D-galactosidase for use in the immunoassay. The minimum amount of osteocalcin detectable by this method was 5-10 pg/assay. The enzyme immunoassay could detect immunoreactive osteocalcin levels in normal human sera, giving a value of 6.58 +/- 0.72 ng/ml (mean +/- SE of 16 human subjects). The correlation coefficient between the levels measured by this method and radioimmunoassay was 0.94.

Animals↗
PubMed1986

A high-performance liquid chromatographic method for the assay of cholesterol 7 alpha-hydroxylase activity.

A high-performance liquid chromatographic method has been developed for the measurement of cholesterol 7 alpha-hydroxylase activity in liver microsomes. 7 alpha-Hydroxycholesterol generated from endogenous cholesterol was derivatized with anthroyl 1-carbonitrile, chromatographed on a reverse-phase column, and detected fluorometrically. The detection limit of 7 alpha-hydroxycholesterol was 1 ng/tube. The cholesterol 7 alpha-hydroxylase activity in rat liver microsomes was assayed by this method, and the effects of some detergents and of the addition of exogenous cholesterol together with detergents on the enzyme activity were investigated. The endogenous 7 alpha- and 7 beta-hydroxycholesterol could be also measured by this method.

Acetone↗
PubMed1986

A high-performance liquid chromatographic method for the determination of dolichyl phosphates in tissues.

A sensitive high-performance liquid chromatographic method has been developed for the determination of dolichyl phosphate homologs in tissues. Dolichyl phosphates were methylated and derivatized with 3-(9-anthryl)-diazo-2-propene to yield methyl 3-(9-anthryl)-2-propenyl dolichyl phosphates. As an internal standard, 2,2-didecaprenylethyl phosphate was used. The derivatives were separated on a reversed-phase column using isocratic elution, and detected fluorometrically. The method with fluorescence detection was sufficiently sensitive to measure the concentration of dolichyl phosphate homologs in tissues.

Animals↗
PubMed1986

A kinetic study on chlorpromazine disposition and hypothermic response in rats.

Pharmacokinetic relationships were developed to characterize a multi-exponential drug disposition and pharmacologic response time courses. The derived expressions were applied to serum and cerebral concentrations and the hypothermic response data, which were obtained after rapid intravenous administration of chlorpromazine hydrochloride to rats. The results of this study indicate that the magnitude of the pharmacologic effects of chlorpromazine such as decrease in metabolic heat production and increase in tail blood flow, at a given time, are logarithmic logistic functions of the cerebral chlorpromazine concentration at that time.

Animals↗
PubMed1986

OF4949, new inhibitors of aminopeptidase B. II. Elucidation of structure.

The structures of OF4949-I, II, III and IV were identified by analysis of the products of their chemical degradation and by 1H NMR, 13C NMR, and mass spectrometry. These compounds were new cyclic peptides containing diphenyl ether as a chromophore. OF4949-I had two amino acids, beta-hydroxy-L-asparagine and 4-methylisodityrosine. The structural differences between I and II and between III and IV lay solely in the diphenyl ether moiety; the phenolic hydroxyl group in II and IV was methylated in I and III. OF4949-III and IV contained L-asparagine instead of the beta-hydroxy-L-asparagine moiety of I and II.

Aminopeptidases↗
PubMed1986

OF4949, new inhibitors of aminopeptidase B. III. Biosynthesis.

To elevate production of OF4949 by Penicillium rugulosum OF4949 and to elucidate the pathway of its biosynthesis, mutants were selected on the basis of their resistance to growth inhibition by phenylalanine analogs. A mutant resistant to m-fluorophenylalanine, strain No. M414, had 3-fold the production of the parent. In a study of the biosynthesis of OF4949-I and II, several 14C-labeled compounds were examined as possible precursors of OF4949. L-[14C]Tyrosine and L-[14C]asparagine were incorporated efficiently. Most of the radioactivity of L-[14C]tyrosine was found in the 4-methylisodityrosine (B2) or isodityrosine (B1) moieties, and that of L-[14C]asparagine was in the beta-hydroxyasparagine moiety.

Aminopeptidases↗
PubMed1986

Effect of environmental temperature on thermal response to chlorpromazine. II. Simulation of hypothermia in rats.

Thermal response of rats to chlorpromazine (CPZ) was determined at low (15 degrees C) and high (28 degrees C) environmental temperature. Effects of CPZ at ambient temperature of 5-33 degrees C were estimated using a drug disposition-thermoregulation model reported previously. The simulation revealed that the hypothermic effect of CPZ is greater in cold environment and is suppressed in hot environment.

Animals↗