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Biomedical subjects

H Ono

Publications and source records attributed to H Ono.

At least 415 records · Page 23Linked to original sources
PubMed1990

Effects of a new analog of thyrotropin-releasing hormone, N alpha-[(S)-4-oxo-2-azetidinyl) carbonyl]-L-histidyl-L-prolinamide dehydrate (YM-14673) on spinal reflex potentials and flexor reflexes in spinalized rats.

Experiments were performed on spinalized rats, transected at the Cl level. The intravenous administration of TRH and its analog YM-14673 (N alpha-[(S)-4-oxo-2-azetidinyl) carbonyl]-L-histidyl-L-prolinamide dehydrate) produced marked increases in the amplitude of mono- and polysynaptic reflex potentials and those of the withdrawal flexor reflexes. The effects of YM-14673 were stronger and longer-lasting than those of TRH. The stimulant action of TRH and YM-14673 on the flexor reflexes was not antagonized by prazosin, chlorpromazine, haloperidol or cyproheptadine, suggesting no involvement of the release of catecholamines or serotonin in the stimulant effects of TRH and its analog. Therefore, YM-14673 may be beneficial for the treatment of several spinal motor neuron diseases.

Animals↗
PubMed1990

Effects of heparin dosage and sperm capacitation time on in vitro fertilization and cleavage of bovine oocytes matured in vitro.

The present study was conducted to clarify the effect of heparin dosage and sperm capacitation time on in vitro fertilization (Experiment 1) and cleavage (Experiment 2) rates of bovine oocytes matured in vitro. For in vitro fertilization, seven dosages of heparin (0, 5, 10, 25, 50, 100 and 200 microg/ml) and nine incubation periods (0, 5, 15, 30, 45, 60, 120, 180 and 240 min) in a capacitation medium were examined, using 6,634 oocytes. The mean proportions of fertilized oocytes in 25, 50 and 100 microg/ml of heparin were significantly (P<0.05) higher (53 to 59%) than in the other dosages (3 to 44%). Incubation with heparin for longer than 60 min lowered the frequencies of fertilization (20 to 36%) compared with the shorter incubation periods (38 to 49%). Higher proportions of fertilized oocytes were obtained by 5, 15, 30 or 45 min of incubation (42 to 49%) than by the other time periods (20 to 38%). Cleavage rates were found by using 2,098 oocytes in a factorial study (4x4x15: dosages -25, 50, 100 and 200 mug/ml; incubation periods -0, 15, 30 and 60 min; and replicates). The incubation periods and replicates resulted in highly significant differences (P<0.001) in development rates to eight-cell stage, but the four dosages of heparin showed no significant differences. The present results indicate that heparin dosage and sperm capacitation time are important factors influencing in vitro fertilization and cleavage rates. Optimal heparin dosages for the capacitation of bull spermatozoa ranged from 25 to 100 microg/ml; optimal incubation periods ranged from 5 to 60 min.

Journal Article↗
PubMed1990

Effects of culture systems on development of in vitro fertilized bovine ova into blastocysts.

We examined the effects of co-culture with oviductal epithelial cells, cumulus cells, trophoblastic vesicles or amniotic sac cells on the development of bovine eight-cell embryos derived from in vitro maturation and fertilization into blastocysts. Frozen-thawed spermatozoa were treated with caffeine plus Ca-ionophore A23187 for capacitation and were then co-incubated for 4 h with oocytes matured in vitro. Ova resulting from this in vitro fertilization were cultured in HEPES-buffered TCM-199 + 10% fetal calf serum(FCS) for 68 h and then removed from the cumulus cell mass. The eight-cell embryos were cultured using four co-culture systems either without cells(controls) or within rabbit oviducts. The co-culture of oviductal epithelial cells, trophoblastic vesicles or amniotic sac cells significantly (P<0.05) increased development into blastocysts (39.0 to 50.7%) when compared with co-culture with cumulus cells, control or rabbit oviducts(1.9 to 29.3%). Six of 16 recipients became pregnant with frozen embryos derived from co-culture with oviductal epithelial cells(1/2), trophoblastic vesicles(2/7) or amniotic sac cells(3/7). Eight calves, including two sets of twins, were obtained.

Journal Article↗
PubMed1990

Effect of cyclosporin A on suppressor T cells.

The effect of cyclosporin A (CsA) on suppressor T cells (Ts) was evaluated by in vitro incubation with afferent-phase Ts (Ts-aff) and efferent-phase Ts (Ts-eff). 2,4-Dinitro-1-fluorobenzene (DNFB) and hen egg-white lysozyme (HEL) were used as antigens. Both Ts-aff and Ts-eff were resistant to high- and low-dose CsA treatments. However, T cells associated with delayed type hypersensitivity (DTH) [TDTH] to DNFB or HEL were sensitive to these CsA treatments. These results indicate that the effect of CsA treatment on contact sensitivity and DTH influences TDTH and not Ts.

Animals↗
PubMed1990

The binocular representation of uniform motion.

In the model of motion perception proposed by Swanston, Wade, and Day (1987, Perception 16 143-159) it was suggested that retinocentric motion and eye movement information are combined independently for each eye, to give left and right orbitocentric representations of movement. The weighted orbitocentric values are then added, to give a single agocentric representation. It is shown that for a physical motion observed without pursuit eye movements this formulation predicts a reduction in the perceived extent of motion with monocular as opposed to binocular viewing. This prediction was tested, and shown to be incorrect. Accordingly, a modification of the model is proposed, in which the left and right retinocentric signals are weighted according to the presence or absence of stimulation, and combined to give a binocular retinocentric representation. In a similar way left-eye and right-eye position signals are combined to give a single binocular eye movement signal for version. This is then added to the binocular retinocentric signal to give the egocentric representation. This modification provides a unified account of both static visual direction and movement perception.

Attention↗
PubMed1990

Purification of the putative import-receptor for the precursor of the mitochondrial protein.

The receptor protein for the mitochondrial protein precursor synthesized in the cytosol was extensively purified from the mitochondrial membrane fraction by affinity column chromatography using a synthetic peptide containing the extrapeptide of ornithine aminotransferase as a ligand. The purified fraction contained two major proteins with molecular masses of 52 and 29 kDa. Of these proteins, only the 29 kDa protein bound to the extrapeptide of ornithine aminotransferase. Furthermore, anti-29 kDa protein Fab fragments inhibited the import of pre-ornithine aminotransferase into mitochondria, suggesting that the 29 kDa protein plays an essential role in the process of import of the mitochondrial protein precursor.

Amino Acid Sequence↗
PubMed1990

Structure and expression of cDNA for D-amino acid oxidase active against cephalosporin C from Fusarium solani.

D-Amino acid oxidase (DAO) was extracted and purified from cultured mycelia of Fusarium solani M-0718 (FERM P-2688). The enzyme was able to oxidatively deaminate cephalosporin C to 7-beta-(5-carboxy-5-oxopentanamido)cephalosporanic acid. Ninety-eight amino acid residues of the F. solani DAO were determined by sequence analysis of 9 peptides derived from Acromobacter protease I digests of the protein. Complementary DNAs encoding F. solani DAO were isolated from the F. solani cDNA library by hybridization with synthetic oligonucleotide probes corresponding to the partial amino acid sequences. Analysis of the nucleotide sequences of the clones revealed a 1,186-nucleotide sequence with a 5'-terminal untranslated region of 41 nucleotides, an open reading frame of 1,083 nucleotides that encoded 361 amino acids, and a 3'-terminal untranslated region of 62 nucleotides. The amino acid sequence of F. solani DAO had 25% homology to that of porcine kidney DAO [EC 1.4.3.3] and 37% homology to that of Trigonopsis variabilis DAO. The constructed plasmid overproduced F. solani DAO in Escherichia coli. The recombinant DAO had almost the same molecular activity as the native DAO against cephalosporin C.

Amino Acid Sequence↗
PubMed1990

Genetic control of nickel sulfate delayed-type hypersensitivity.

Genetic control of delayed-type hypersensitivity (DTH) to nickel sulfate antigen was studied using various strains on inbred mice. Mice with class II Ad,k,s haplotypes showed a high magnitude of response, whereas those with class II Ab,f were low responders. These results indicate that nickel sulfate DTH may be influenced by the I-A region of H-2. Transfer experiments revealed that these responses might be mediated by L3T4+, Lyt-2- T cells.

Animals↗
PubMed1990

A combined case of desmoplastic trichoepithelioma and nevus cell nevus.

A 41-year-old woman with desmoplastic trichoepithelioma associated with pigmented nevus presented. Pigmented nevus had been present on her face at birth. She had received cryotherapy and dermabrasion at a small part of the pigmented nevus. As a result of the therapy, the discoloration disappeared. The lesion lately increased and became hard. Histologically, the lesion was composed of two distinctive but intimately mixed cellular components; nevus cells and basaloid cells. In the pigmented lesion, basaloid cells were not present. To our knowledge, this is the first reported case of desmoplastic trichoepithelioma associated with nevocellular nevus in Japan.

Adult↗
PubMed1990

Spinal alpha 1- and alpha 2-adrenoceptors mediate facilitation and inhibition of spinal motor transmission, respectively.

The role of descending noradrenergic fibers in the spinal motor systems was investigated using spinal reflexes in acutely spinalized rats. In rats pretreated with the MAO inhibitor clorgyline-HCl (1 mg/kg, i.v.), L-3,4-dihydroxyphenylalanine (L-dopa) (5 mg/kg, i.v.), a precursor of dopamine and noradrenaline, markedly potentiated the mono- (MSR) and polysynaptic reflexes (PSR). Selective blockade of alpha 1-adrenoceptors by pretreatment with prazosin-HCl abolished these facilitatory effects on the MSR and the PSR and revealed the inhibitory effect of L-dopa on the PSR. The depression of PSR was antagonized by the alpha 2-antagonist piperoxan. Clonidine-HCl (0.05 mg/kg, i.v.), a so-called alpha 2-agonist, and tizanidine-HCl (0.1 mg/kg, i.v.) decreased the MSR and the PSR in rats pretreated with prazosin. These inhibitions were antagonized by piperoxan. These results suggest that alpha 1- and alpha 2-adrenoceptors mediate facilitation and attenuation of motor transmission in the rat spinal cord, respectively.

Animals↗
PubMed1990

Decreased VIP content in peripheral nerve from streptozocin-induced diabetic rats.

After induction of diabetes with streptozocin (STZ-D) in rats, we measured vasoactive intestinal polypeptide (VIP) content in sciatic nerve and spinal cord obtained from nondiabetic, untreated STZ-D, and insulin-treated STZ-D rats. Eight weeks after the onset of diabetes, caudal nerve conduction velocity (NCV) in the untreated STZ-D rats (n = 13) was slower than in the controls (n = 11; mean +/- SE 30.9 +/- 0.6 vs. 41.4 +/- 1.8 m/s, P less than 0.001). The decrease in NCV was less marked in the insulin-treated STZ-D rats (n = 11; 36.3 +/- 0.9 m/s, P less than 0.05 vs. control). VIP content in sciatic nerve decreased in the untreated STZ-D rats (1.33 +/- 0.23 ng/g wet wt) compared with the other groups (control, 3.10 +/- 0.44, P less than 0.01; insulin-treated STZ-D, 2.44 +/- 0.55, P less than 0.05). However, in spinal cord, VIP content was not significantly different among the three groups. The VIP levels in sciatic nerve showed a positive correlation with NCV (r = 0.430, P less than 0.01). In addition, an inverse correlation between VIP levels and blood glucose levels was observed (r = -0.5624, P less than 0.001). NCV was also inversely correlated with blood glucose levels (r = -0.7662, P less than 0.001). Together with a previous morphological study, these findings suggest a possible causal relationship between reduced VIP content and diabetic neuropathy.

Animals↗
PubMed1990

Monocular stereopsis with and without head movement.

Random dots moving with various velocity gradients were presented to observers; the motion was yoked to head movement in one condition and to no head movement in another. In Experiment 1, 12 observers were shown motion gradients with sine, triangle, sawtooth, and square waveforms with amplitudes (equivalent disparities) of 12' and 1 degrees 53'. In Experiment 2, 48 observers were shown only the sinewave or square-wave gradient of 1 degrees 53' disparity either with or without head movement so that the observers' expectation to see depth in one condition did not transfer to another. The main findings were: (1) with 12' disparity, the head-movement condition produced perceived depth but almost no perceived motion, whereas the no-head-movement condition produced both perceived depth and perceived motion; (2) with 1 degrees 53' disparity, both conditions produced perceived depth and perceived motion; and (3) when the expectation to see depth was removed, the no-head-movement condition with the square-wave gradient produced no perceived depth, only motion. We suggest that monocular stereopsis with head movement can be achieved without perception of motion but monocular stereopsis without head movement requires perception of motion.

Attention↗
PubMed1990

[Perceived depth produced by luminance differences in the two eyes with zero disparity].

We examined Kaufman, Bacon, and Barroso's (1973) finding that perceived depth covaries with relative luminance of the two half-fields of the stereogram. Five subjects were shown two sets of stereograms: one with three lines and another with random dots. In each trial, they reported the apparent depth plane produced by one of 15 different relative luminances of the lines or the mid portions of the random dots. The direction and the magnitude of perceived depth as a function of the relative luminance varied across subjects. It is argued that the stimulus should be considered as being Wheatstone-Panum's Limiting Case rather than that requires processing of binocular retinal disparity.

Adult↗
PubMed1990

Fosfadecin and fosfocytocin, new nucleotide antibiotics produced by bacteria.

Two new nucleotide antibiotics, fosfadecin and fosfocytocin, have been isolated from the culture filtrates of Pseudomonas viridiflava PK-5 and Pseudomonas fluorescens PK-52, respectively. These antibiotics were purified by column chromatographies using adsorption, gel filtration and ion exchange resins. On the basis of the spectroscopic and degradation studies, the chemical structures of fosfadecin and fosfocytocin were determined. These antibiotics were either enzymatically or chemically hydrolyzed to generate fosfomycin and a new antibiotic, fosfoxacin, which are also produced in the culture filtrates. They showed antibacterial activity against Gram-positive and Gram-negative bacteria. The antibacterial activity of these nucleotide antibiotics was weaker than that of fosfomycin and fosfoxacin.

Adenosine Diphosphate↗
PubMed1990

[Control of spinal motor system by descending noradrenergic neuron].

The physiological function of the descending noradrenergic system in the spinal ventral horn has not yet been fully elucidated. Here we describe our recent findings showing the motor function of the noradrenergic fibers. 1) alpha 1-Antagonists and alpha 2-agonists depressed the spinal mono- and polysynaptic reflex potentials in rats that have an intact connection between the spinal cord and the brain. In rats spinalized at the Cl level, the alpha 1-agonistic action of adrenergic agents increased the spinal reflexes. 2) In the radio frequency-lesioned decerebrate rigidity model of rats, alpha 1-antagonists and alpha 2-agonists reduced the rigidity by affecting the spinal and supraspinal levels, respectively. 3) alpha 2-Agonists but not alpha 1-antagonists reduced noradrenaline released into the subarachnoid space of anesthetized rats. 4) In a slice preparation isolated from adult rats, the alpha 1-agonistic action of adrenergic agents increased the excitatory synaptic transmission of the ventral horn. Thus, it was demonstrated that alpha 2-agonistic action at the brain stem inhibited spinal motor activity by reducing the release of noradrenaline in the spinal cord, and that the facilitatory action through alpha 1-adrenoceptors was dominant in descending noradrenergic transmission in the motor nuclei of the ventral horn.

Adrenergic alpha-Agonists↗
PubMed1990

[Malignant melanoma in children--case presentation and statistical analysis].

Malignant melanoma is a well documented but rare occurrence in children. We reported a case of a 10-month-old girl with malignant melanoma arising in a giant congenital nevocellular nevus. A giant mole on the lumbar and gluteal legion had been present since birth. Six month later, a nodular legion within the giant nevus started to growth slightly. The skin nodule were widely excised and grafted. Histological examination showed a malignant melanoma. The tumor located only in dermis. An enlarged lymph node of her left inguinal was removed. The histology revealed metastases from the melanoma. She died of metastases eight months after removal of the primary tumor. To our knowledge, only 37 documented cases of malignant melanoma in children under fifteen years of age have been previously reported, to which we add our case. In Japan, two-thirds of childhood melanomas arise de novo, which are clinically and biologically analogous to adult melanomas. The other third arises in large congenital nevocellular nevus which likely lead to death within two to three years of diagnosis. A majority of at least half of malignant melanoma in large congenital nevocellular nervus arise in children under 10 years of age. ALM types of malignant melanoma which are common in adult are rare in childhood melanomas.

Female↗
PubMed1990

Effects of the new centrally acting muscle relaxant 7-chloro-N,N,3-trimethylbenzo[b]furan-2-carboxamide on motor and central nervous systems in rats.

Effects of KW-6629 (7-chloro-N,N,3-trimethylbenzo[b]furan-2-carboxamide) were studied with special reference to the effect on motor and central nervous systems using rats. The drug effectively reduced the motor coordination (rotarod), the anemic decerebrate rigidity, the crossed extensor reflex, and the gamma-activity indirectly recorded from muscle afferent discharges without showing the direct inhibitory effect on muscle spindles. KW-6629 depressed the polysynaptic and dorsal root reflexes without showing marked effect on the monosynaptic reflex in intact spinal cord rats. KW-6629 produced high-amplitude slow wave in the cerebral cortex in electroencephalogram (EEG). KW-6629 did not reduce the EEG after-discharges and behavioral convulsion (amygdaloid kindling). KW-6629 had no effect on the neuromuscular junction. These results suggest that KW-6629 is a centrally acting muscle relaxant which has a site of action in supraspinal structures.

Animals↗