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Biomedical subjects

T Goto

Publications and source records attributed to T Goto.

At least 703 records · Page 39Linked to original sources
PubMed1986

The complete nucleotide sequence of the structural gene TOP2 of yeast DNA topoisomerase II.

The nucleotide sequence of the gene TOP2 encoding DNA topoisomerase II of the yeast Saccharomyces cerevisiae has been determined. The entire coding sequence of the gene lies within an open reading frame, and there are 1429 amino acids in the single polypeptide protein if translation is assumed to start at the first ATG in this frame. The calculated subunit and molecular mass of the enzyme is 164,000 and 328,000 daltons, respectively. The transcriptional starts of the gene and a polyadenylation site of the message have also been mapped.

Amino Acid Sequence↗
PubMed1986

A chemiluminescent probe with a Cypridina luciferin analog, 2-methyl-6-phenyl-3,7-dihydroimidazo[1,2-a]pyrazin-3-one, specific and sensitive for O2- production in phagocytizing macrophages.

When a Cypridina luciferin analog (the title compound) was added to a macrophage suspension in Hank's balanced salt solution (control), the system emitted a weak, but detectable light, which was not altered in the presence of superoxide dismutase. The same system, however, emitted a much stronger light, just after the addition of a trigger, opsonized zymosan. The luminescence was suppressed to the control level in the presence of superoxide dismutase, while it was only slightly influenced, if at all, by NaN3, a scavenger of singlet oxygen and an inhibitor of myeloperoxidase. Some other results obtained also indicate the participation of O2- in the luciferin analog-dependent luminescence in macrophages during phagocytosis.

Animals↗
PubMed1986

An evidence of the peroxidase-dependent oxygen transfer from hydrogen peroxide to sulfides.

Horseradish- and chloro-peroxidase catalyzed oxidation of sulfides have been investigated. Thioanisoles were oxygenated to the corresponding sulfoxides by such peroxidases at the expense of H2O2. Dealkylation was observed only in the chloroperoxidase-dependent oxidations of p-methoxy- and p-iso-propoxy-thioanisoles. The experiments with 18O-labeled H2O2 indicated that an oxygen atom of H2O2 is incorporated into the sulfoxides. These research lead to the conclusion that compound I or II is capable of acting as an oxygen donor as well as an electron acceptor.

Cytochrome P-450 Enzyme System↗
PubMed1986

Differentiation of parenchymal lung disorders with in vitro proton nuclear magnetic resonance.

We investigated in vitro NMR properties of bleomycin-induced alveolitis and pulmonary fibrosis in 18 Lewis rats (6 controls). When alveolitis or fibrosis had developed, animal lungs were excised and examined histologically and gravimetrically and their T1 and T2 were determined by a NMR spectrometer at 10.7 MHz and 37 degrees C. Clinical diagnosis was confirmed histologically in each case. The NMR signal intensities were significantly elevated in both disease states (P less than 0.001). Both T1 and T2 values of alveolitic lungs were about the same as in controls, but were significantly decreased in fibrotic lungs (P less than 0.01). Changes in T1 and T2 correlated well (P less than 0.001) with changes in water content of diseased lungs.

Animals↗
PubMed1986

Chemiluminescence probe with Cypridina luciferin analog, 2-methyl-6-phenyl-3,7-dihydroimidazo[1,2-a]pyrazin-3-one, for estimating the ability of human granulocytes to generate O2-.

The Cypridina luciferin analog, 2-methyl-6-phenyl-3,7-dihydroimidazo[1,2-a]pyrazin-3-one (CLA), in Hanks' balanced salt solution, emitted a weak luminescence which was not affected by superoxide dismutase or catalase and was not augmented by resting human granulocytes. In contrast, activated granulocytes caused a dramatic increase in the luminescence of CLA. The light emission by CLA in the presence of activated granulocytes was inhibited by superoxide dismutase, but not by catalase or benzoate. Azide at 0.5 mM did not inhibit light emission significantly. These results indicate that O2-, rather than H2O2, HO., singlet oxygen, or HOCl, was the agent responsible for eliciting the chemiluminescence of CLA. Moreover, the intensity of light emission by CLA correlated with the rate of production of O2- either by activated neutrophils or by the xanthine oxidase reaction.

Granulocytes↗
PubMed1986

Presence of TAN (tonically autoactive neuron) and its two analogous neurons, located in the right parietal ganglion of the suboesophageal ganglia of an African giant snail (Achatina fulica Ferussac). Morphological and electrophysiological studies.

Three identifiable giant neurons, which were morphologically and pharmacologically identical, named TAN (tonically autoactive neuron), TAN-2 and TAN-3, were found in line on the dorsal surface of the right parietal ganglion in the suboesophageal ganglia of an African giant snail (Achatina fulica Férussac). The diameters of these neurons were 150-200 microns. They showed regular spontaneous spike discharges at the rate of 30-40 per min. However, the spike discharges of the three neurons were not synchronized. For morphological studies of these neurons, Lucifer Yellow was injected into their somata by pressure. The axonal branches of the three neurons examined extended commonly into the following seven peripheral nerves: left anterior pallial, left posterior pallial, intestinal, anal, right posterior pallial, right anterior pallial and right anterior pallial accessory nerves. The sensitivities of the three neurons examined to the main neurotransmitter candidates and their derivatives were almost identical. These neurons were excited by 5-hydroxytryptamine [the minimum effective concentration (MEC): 10(-5)-10(-4) M] and histamine (MEC: 1-3 X 10(-4) M), and inhibited by dopamine (MEC: 1-3 X 10(-4) M), L-norepinephrine (MEC: 3 X 10(-4)-10(-3) M), L-epinephrine (MEC: 3 X 10(-4) M), GABA (MEC: 10(-5)-10(-4)), acetylcholine (MEC: 1-3 X 10(-4) M) and its derivatives.

Amino Acids↗
PubMed1986

Site-specific mutagenesis of the calcium-binding photoprotein aequorin.

The luminescent protein aequorin from the jellyfish Aequoria victoria emits light by an intramolecular reaction in the presence of a trace amount of Ca(2+). In order to understand the mechanism of the reaction, a study of structure-function relationships was undertaken with respect to modifying certain of its amino acid residues. This was done by carrying out oligonucleotide-directed site-specific mutagenesis of apoaequorin cDNA and expressing the mutagenized cDNA in Escherichia coli. Amino acid substitutions were made at the three Ca(2+)-binding sites, the three cysteines, and a histidine in one of the hydrophobic regions. Subsequent assay of the modified aequorin showed that the Ca(2+)-binding sites, the cysteines, and probably the histidine all play a role in the bioluminescence reaction of aequorin.

Journal Article↗
PubMed1986

Effect of age on the renin-angiotensin-aldosterone system in normal subjects: simultaneous measurement of active and inactive renin, renin substrate, and aldosterone in plasma.

To investigate the effect of aging on the renin-angiotensin-aldosterone system, plasma renin substrate concentrations (PRSC); plasma total, active, and inactive renin concentrations (TRC, ARC, and IRC); PRA; and plasma aldosterone concentrations (PAC) were measured simultaneously in 60 normal subjects, 18-84 yr old. PRSC was measured by the addition of excess human renal renin. ARC and TRC after trypsin activation were measured by adding sheep renin substrate; IRC was calculated by subtracting ARC from TRC. The active renin ratio was calculated as follows: ARC/TRC X 100%. PRA and PAC were measured by RIA. There were no significant changes in PRSC, TRC, IRC, and PRA to PAC ratio with aging. Both ARC and active renin ratio fell significantly with aging (r = 0.46 and P less than 0.01; and r = 0.54 and P less than 0.01, respectively). PRA and PAC also tended to decrease with aging (r = 0.35 and P less than 0.01; and r = 0.59 and P less than 0.01, respectively). A significant positive correlation was found between PRA and ARC (r = 0.72; P less than 0.001). PRA was also correlated with PAC. In conclusion, the age-related decrease in PRA is not due to the change in PRSC, but is mainly due to the fall in ARC. Decreased conversion of inactive to active renin might be responsible in part for the reduced ARC in the elderly.

Adolescent↗
PubMed1986

Twenty-four hour ambulatory ECG monitoring of junior high school students in Miki City.

To evaluate incidence of serious arrhythmias among school age youths, 24-hour ambulatory ECG monitoring was performed in 100 junior high school students, including 60 subjects with some ECG abnormalities and 40 without. With this monitoring 2 cases with multifocal VPCs and 2 cases with paired VPCs or nonsustained ventricular tachycardia were found; the case with VT died suddenly after having been lost during careful follow up. It is emphasized from these results that ambulatory ECG monitoring is quite useful in selected cases in this age group and careful follow up of students with advanced grade VPCs is very important.

Adolescent↗