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H Inaba

Publications and source records attributed to H Inaba.

267 records · Page 15Linked to original sources
PubMed1980

Studies on the tryptophan-dependent light emission by prostaglandin hydroperoxidase reaction.

The chemiluminescence earlier observed upon the incubation of arachidonic acid with prostaglandin-synthesizing microsomes of sheep vesicular gland (Marnett et al. (1974) Biochem. Biophys. Res. Commun. 60, 1286-1294) was reinvestigated with prostaglandin endoperoxide synthetase purified from bovine vesicular gland microsomes. When the purified enzyme was incubated with arachidonic acid in the presence of hematin and tryptophan, a rapid light emission was observed. The fatty acid cyclo-oxygenase activity as demonstrated with manganese protoporphyrin was not responsible for the luminescence. When the hematin-requiring prostaglandin hydroperoxidase reaction (the conversion of prostaglandin G2 to H2) was carried out with tryptophan, skatole, or 3-indolepropionic acid, the light emission was observed, but not with either epinephrine or guaiacol in place of tryptophan. The light intensity was dependent on the concentration of enzyme, hematin, tryptophan, and prostaglandin G2. Various other hydroperoxides in addition to prostaglandin G2 were also active. The luminescence spectrum recorded by a spectrometer equipped with a filter spectral analyzer gave emission peaks around 500, 550, and 610 nm. The spectrum was distinguishable from that of singlet oxygen, and was similar to that reported for a photochemical reaction of tryptophan.

Animals↗
PubMed1975

Lymphocyte-increasing action and hypocalcemic action of parotid gland extract.

It has previously been shown in our laboratory that the hypocalcemic substances purified from the thymus have a potent lymphocyte-increasing action in mice. Then, lymphocyte-increasing activity was examined with bovine parotid gland extracts, which showed a hypocalcemic activity as potent as that of the thymus extracts. The lymphocyte-increasing activity was assayed in the littermates of neonatal mice of Swiss-Webster strain; the materials used for this experiment were purified preparations and several fractions obtained from the parotid gland extracts in the course of purification. It was found that the potency of lymphocyte-increasing activity rose approximately in parallel with the rise in hypocalcemic activity with progress in purification. The final product, which was purified from the gland by isoelectric precipitation at pH 5.4, fractional precipitation with ammonium sulfate, chromatography on DEAE-cellulose, gel filtration on Sepharose 6B and preparative disc electrophoresis, gave a single band in polyacrylamide gel electrophoresis. Its intravenous injection in rabbits, in a dose of 10 mug/kg, produced a significant lowering in serum calcium (percent decrease 10.24 +/- 1.06%) compared with control animals given an injection of physiological saline. Intraperitoneal injection of this purified product, in a dose of 0.5 mug/mouse, in the littermates of neonatal mice, also produced a significant increase (ratio of lymphocytes to polymorphs 2.47 +/- 0.07) in lymphocytes compared with control animals injected with physiological saline (L/P ratio 1.57 +/- 0.05). These facts suggest that this purified protein fraction inherently contains both activities, but the possibility cannot be ruled out of slight contamination by a substance having a high activity. On the other hand, a fraction having no activity for lowering serum calcium but which had activity for increasing the lymphocytes was obtained. This is the first paper to report the presence of lymphocyte-increasing substances in the bovine parotid gland and the purification of one of the substances from the gland.

Animals↗
PubMedDate not supplied

Analysis of synchronous photon emissions from the bacterium Photobacterium phosphoreum during colony formation from a single cell.

Light emission from Photobacterium phosphoreum was analysed during cell growth on an agar plate from a single cell to colony formation. Temporal analysis of image intensified light was set so that a quadratic window covered a single cell. Intensity of light emission from a single cell through colony formation showed an initial decrease, a prolonged lag phase, and then a rapid increase. These responses on an agar plate were similar to those from liquid cultures. The image analysis showed repeated bursts of light emission in the phases when light was increasing and decreasing. Statistical analysis of light emission also emphasized the presence of bursts of light emission, suggesting the metabolic synchronism of luciferase reactions in either a single cell or suggesting the metabolic synchronism of luciferase reactions in either a single cell or synchronously divided cells. The repetitive bursts of light occurred in a single cell and continued during the growth phase in which the cell population and the light emission was increasing. In a single cell, however, periodicity of light emission was not defined directly from fast Fourier transformation, although it was indicated on oscillation of mean level of fluctuated light emission, at initial phase of culture on agar plate.

Cell Division↗
PubMedDate not supplied

Measurement of rate constants for quenching singlet oxygen with a Cypridina luciferin analog (2-methyl-6-[p-methoxyphenyl]-3,7-dihydroimidazo [1,2-a]pyrazin-3-one) and sodium azide.

The rate constants for [1O2] [MCLA] and [1O2] [NaN3] were measured by quenching the near-infrared emission (1 delta g----3 sigma g) in steady state with MCLA and NaN3, respectively. 1O2 was constantly generated by energy transfer to O2 from Ar laser-excited Rose Bengal. The Stern-Volmer plots yielded the second-order rate constants of 2.94 x 10(9) M-1 S-1 and 3.83 x 10(8) M-1 S-1 for quenching 1O2 with MCLA and NaN3 in water at pH 5.4, respectively. The 1O2 + MCLA reaction emitted light with maximum at 465 nm at pD 4.5 identical to the O(2-) + MCLA reaction.

Azides↗
PubMedDate not supplied

Growth and behavioral changes in mice prenatally exposed to methylmercury and heat.

Postnatal and behavioral changes in mice exposed prenatally to methylmercury and heat were investigated. Pregnant ICR mice were immersed in water at 37 degrees C or 42 degrees C for 10 min once or twice daily from day 12 through day 15 of gestation. Two hours after the heat exposure on day 12 of age, mice were injected s.c. with 5 mg Hg/kg of methylmercury (MeHg, as chloride) or saline. Prenatal exposure to heat significantly induced inactivity in an open field test (OPF) in males and retarded walking ability in both males and females. Prenatal exposure to MeHg caused significant inactivity in the OPF in females. Although heat did not enhance the effect of MeHg on physical growth or the behavior of pups and vice versa, there were some interactions between the effects of these two agents. Thus, the difference in walking ability in both sexes caused by heat was more distinctive in the saline-treated groups than in the MeHg-treated groups; the difference in locomotion in OPF caused by MeHg in females was more distinctive in the normothermic group than among the hyperthermic groups. The mechanisms underlying these behavioral changes need to be further examined.

Analysis of Variance↗
PubMedDate not supplied

Ultra-weak chemiluminescence of smokers' blood.

An extremely sensitive single photon counter was developed that could quantitatively detect very weak, spontaneous light emission from human blood samples. Ultra-weak chemiluminescence intensities of cigarette smokers' blood plasma reached significantly higher levels than those of nonsmokers. Elevated levels of the chemiluminescence of the smokers' plasma returned to the nonsmokers' range within 12 hr after cessation of cigarette smoking. We propose that this higher chemiluminescent property of the smokers' plasma might be somehow related to cigarette smoking-associated health disorders, e.g., carcinogenesis.

Adult↗
PubMedDate not supplied

TNF-alpha and endotoxin serum levels in cancer patients undergoing intraperitoneal hyperthermic perfusion.

Intraperitoneal hyperthermic perfusion (IPHP) is performed as one treatment for patients with advanced gastrointestinal cancer complicated by peritoneal dissemination or carcinomatous peritonitis. However, the anticancer mechanism of IPHP and its safety have not yet been fully elucidated. It has been experimentally known that endotoxinemia occurs by high body temperature, and that endotoxin stimulates the macrophage, monocyte and endothelial cell to induce the production of TNF-alpha. TNF-alpha is one of cytokines to be induced at the initial phase as a host immune response and play an important role to initiate the systemic inflammatory response syndrome (SIRS). We have tested whether the serum concentrations of TNF-alpha and endotoxin are elevated following IPHP. Eleven patients with gastro-intestinal cancer underwent surgery combined with IPHP. Mixed venous blood obtained from pulmonary artery (PA-blood) was collected at four sampling points. TNF-alpha and endotoxin levels in the PA-blood were measured by ELISA and a limulus amoebocyte lysate assay respectively. In all patients the serum TNF-alpha levels in PA-blood were temporarily elevated following IPHP from less than 10 pg/ml before IPHP to 42.8 +/- 26.6 pg/ml; endotoxin levels were not altered. This study shows that IPHP has the ability to induce endogenous TNF-alpha not mediated by endotoxin.

Adult↗
PubMedDate not supplied

Functional significance of adhesion molecules in Fas-dependent apoptotic cell death induced by interleukin-2-activated T cells.

We investigated the functional significance of the adhesion molecules CD2 and lymphocyte function-associated antigen-1 (LFA-1: CD11a/CD18) in Fas-Fas ligand (FasL) death pathway. Interleukin-2-activated T cells expressed a large amount of FasL protein and could efficiently kill a Fas-sensitive leukemic cell line, MML-1. The major part (over 80%) of MML-1 cell death was Fas-dependent. Antibodies to CD2 and CD11a/CD18 completely inhibited MML-1 target cell lysis, whereas effector to target cell binding was partially reduced or not affected at all. These results suggest that effector/target interaction via CD2/CD58 and LFA-1/CD54 systems would be essential for triggering target cell death. More interestingly, there is the discordance in the ability of anti-CD2, and particularly anti-LFA-1 antibodies, to block Fas-dependent cell death versus effector to target conjugate formation. This suggests some non-adhesive role for CD2 and LFA-1 in induction of Fas-dependent cell death. Although these antibodies were capable of inhibiting T cell proliferative response, there was no significant reduction of FasL or granzyme B expression. Thus, the signaling pathway for growth inhibition via CD2 and LFA-1 could not be linked to signaling for FasL and granzyme B expression.

Antibodies, Monoclonal↗