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Biomedical subjects

T Kubo

Publications and source records attributed to T Kubo.

At least 613 records · Page 34Linked to original sources
PubMed1993

A novel role of Periplaneta lectin as an opsonin to recognize 2-keto-3-deoxy octonate residues of bacterial lipopolysaccharides.

1. Periplaneta lectin of the American cockroach was shown to have affinity to bacterial lipopolysaccharides (LPS) of chemotypes Rb-Re, but not to lipid A. 2. 2-Keto-3-deoxy octonate (KDO) was the most effective sugar so far tested for inhibition of the hemagglutinating activity of Periplaneta lectin. 3. Periplaneta lectin was suggested to participate in the clearance of bacteria injected into the abdominal cavity of the cockroach.

Animals↗
PubMed1993

An investigation into the effects of apomorphine on the release of acetylcholine in the striatum of freely-moving rat using in vivo microdialysis.

1. Using in vivo microdialysis, we studied the effects of apomorphine on the release of acetylcholine (ACh) in the striatum of freely-moving rats. 2. Basal release of ACh was 3.01 +/- 0.51 pmol/15 min in 30 microliters (containing of 10 microM neostigmine) of the striatal perfusate. 3. Ringer containing tetrodotoxin (1 microM), hemicholinium-3 (5 mM), or Ca(2+)-free Ringer was perfused into the striatum. Each of these treatments produced a significant attenuation in release content of ACh. High K+ (30 mM) produced a significant increase in ACh release. 4. In normal rats, apomorphine (0.05 mg/kg, s.c.) increased striatal ACh release. A high dose (1.0 mg/kg) significantly attenuated release. 5. In 6-OHDA-pretreated rats, although the lower dose of apomorphine did not increase striatal ACh release, the high dose produced a more significant attenuation of release. 6. It is concluded that apomorphine enhanced or attenuated the striatal ACh release and that this effect was regulated by nigro-striatal dopaminergic system in the freely moving rats.

Acetylcholine↗
PubMed1993

Malignant osteopetrosis treated with high doses of 1 alpha-hydroxyvitamin D3 and interferon gamma.

A male infant with malignant osteopetrosis was treated with high doses of 1 alpha-hydroxyvitamin D3 and interferon gamma. Therapy with 1 alpha-hydroxyvitamin D3 increased the serum calcium level despite the markedly elevated serum level of 1 alpha, 25-dihydroxyvitamin D before treatment. Recombinant human interferon gamma increased neither the bone mineral nor matrix turnover, and was not tolerated because of bone marrow suppression.

Dose-Response Relationship, Drug↗
PubMed1993

Purification and characterization of the arylphorin gene specific binding protein from an embryonic cell line of Sarcophaga peregrina (flesh fly).

Previously, we purified a DNA binding protein from a nuclear extract of the fat body of Sarcophaga peregrina larvae that binds to the ACCACAACA motif in the 5'-upstream region of the arylphorin gene, and suggested that this protein is a transcriptional activator of the arylphorin gene. In this study, we detected and purified the same protein (ABP-1) from an embryonic cell line of Sarcophaga that does not express the arylphorin gene. Unlike the fat body, which synthesizes arylphorin actively, the embryonic cells were found to contain an additional DNA binding protein (ABP-2) that bound to the same DNA probe as ABP-1, suggesting a novel mechanism of regulation of the arylphorin gene.

Animals↗
PubMed1993

Purification of an AU-rich RNA binding protein from Sarcophaga peregrina (flesh fly) and its identification as a Thiolase.

A protein that binds to the AU-rich sequence in the 3'-untranslated region of sarcotoxin IIA mRNA was purified from a Sarcophaga pupal extract to near homogeneity. The molecular mass of this protein was estimated to be 39 kDa by SDS-polyacrylamide gel electrophoresis. The partial amino acid sequences of two peptides obtained from the 39 kDa protein showed striking similarities to partial amino acid sequences of rat and yeast 3-oxoacyl-CoA thiolase, suggesting that this protein is a Sarcophaga thiolase. In fact, the purified 39 kDa protein was found to have thiolase activity. Moreover, rat mitochondrial 3-oxoacyl-CoA thiolase showed affinity to the AU-rich RNA. These suggest that the RNA binding activity is an intrinsic character of thiolase.

Acetyl-CoA C-Acetyltransferase↗
PubMed1993

Effect of Desmodium styracifolium-triterpenoid on calcium oxalate renal stones.

We have studied the inhibitory effects of Desmodium styracifolium-triterpenoid (Ds-t) (extracted from Desmodium styracifolium (Osbeck) Merr, a herbal medicine) on the formation of calcium oxalate renal stones induced experimentally by ethylene glycol (EG) and 1 alpha(OH)D3 (1 alpha D3) in rats. The incidence of urinary stone formation was 81% in the control group, which received EG and 1 alpha D3, and 29% in the Ds-t group, which received EG and 1 alpha D3 supplemented by Ds-t. The serum calcium (Ca) concentration in the Ds-t group was significantly elevated and urinary Ca excretion was markedly reduced. Urinary excretion of citrate (Cit), a factor that prevents stone formation, was significantly increased in the Ds-t group. Excretion of urinary phosphorus (P), which was elevated to a significantly greater extent in the controls than in the Ds-t group, was increased in both groups. The increase in urine volume in the Ds-t group was significantly greater than in the control group. The 24-h creatinine clearance rate (Ccr) was significantly lower in the controls. These findings suggest that Ds-t inhibits the formation of Ca oxalate stones in rat kidneys by increasing the output of urine, decreasing the excretion of calcium and increasing the urinary excretion of citrate. Ds-t may be useful in preventing the recurrence of urinary Ca oxalate stones in the clinical setting.

Animals↗
PubMed1993

Mechanism of rat uterine smooth muscle contraction induced by endothelin-1.

1. Endothelin (ET)-1 has been demonstrated to cause contraction of uterine smooth muscle. We investigated the role of ET receptor subtypes (ETA and ETB receptors) in ET-1-induced contraction of rat uterine smooth muscle by using the ETA receptor antagonist BQ-123 and the ETB receptor agonist BQ-3020. 2. ET-1 caused a contraction with superimposed oscillations of the rat isolated uterus suspended in Krebs-Ringer solution; both the amplitude of contraction as well as the oscillation frequency increased in a dose-dependent manner (10(-11)-10(-7)M). 3. BQ-123 (10(-6)M) markedly shifted the dose-response curve of ET-1 for both contractile effects and oscillation frequency to the right. 4. BQ-3020 (10(-11)-3 x 10(-7) M) did not cause uterine contraction; neither did it affect the dose-response curve of ET-1 for either the contractile effect or the increase in oscillation frequency. Thus, stimulation of ETB receptors is not involved in these responses. 5. The present findings suggest that ET-1-induced contractile responses and the increase in oscillation frequency in rat uterine smooth muscle is mediated through ETA receptors, and that ETB receptors play no role in these responses.

Amino Acid Sequence↗
PubMed1993

Purification and characterization of a 59-kilodalton protein that specifically binds to NF-kappa B-binding motifs of the defense protein genes of Sarcophaga peregrina (the flesh fly).

Various Sarcophaga peregrina (flesh fly) defense protein genes were shown to be activated when NIH-Sape-4 cells were cultured with bacterial lipopolysaccharides or beta-1,3-glucan. The 5' upstream regions of the defense protein genes were found to have common motifs showing similarity to the mammalian NF-kappa B-binding consensus sequence. A protein with affinity to the NF-kappa B-binding motif of the Sarcophaga lectin promoter was identified and purified to near homogeneity. This 59-kDa protein also bound to the NF-kappa B-binding motifs of other defense protein genes, e.g., sarcotoxin I and sarcotoxin II genes. This protein was found in both the cytoplasmic and the nuclear fractions of the cells, and it appeared to migrate from the cytoplasm to the nucleus on treatment of the cells with lipopolysaccharides. This 59-kDa protein is probably a transcriptional regulator of the genes for defense proteins of S. peregrina.

Animals↗
PubMed1993

Neuropharmacology of motion sickness and emesis. A review.

Histamine H1-receptors are involved in the development of the symptoms and signs of motion sickness, including emesis. On provocative motion stimulus, a signal for sensory conflict activates the histaminergic neuron system, and the histaminergic descending impulse stimulates H1-receptors in the emetic center of the brain stem. The histaminergic input to the emetic center through H1-receptors is independent of dopamine D2-receptors in the chemoreceptor trigger zone and serotonin 5HT3-receptors in the visceral afferent, which are also involved in the emetic reflex. Antihistamines block emetic H1-receptors to prevent motion sickness. Acetylcholine muscarinic receptors are involved in the generation of signals for sensory conflict. Anti-cholinergic drugs prevent motion sickness by modifying the neural store to facilitate the acquisition of habituation to provocative motion.

Animals↗
PubMed1993

Analysis of head and body movements of elderly people during locomotion.

In order to elucidate the effect of aging on head and limb motions, 10 young and 8 elderly normal subjects were studied kinesiologically during i) walking, ii) stepping, and iii) hopping, with their eyes open or closed. For this study, a 16-mm high-speed cinecamera and accelerometers were used. Analysis of head movements showed that pitch rotation seemed to counteract the translational movement in the sagittal plane. Although this phenomenon was observed in both the young and elderly groups, the mean pitch position of the head, as measured by the cantho-meatal line relative to the horizontal line, was larger for the elderly group, while head acceleration of elderly people showed a higher frequency in the power spectrum. With eyes closed, the head tended to be tilted downward.

Acceleration↗
PubMed1993

Motion sickness induced by sinusoidal linear acceleration in rats.

The characteristics of linear acceleration to cause motion sickness of rats were examined using pica as a behavioral index of motion sickness. A vestibular sled was used to generate sinusoidal linear acceleration. At 0.4 Hz and with a peak acceleration of 0.15 G, the effectiveness of linear acceleration in inducing motion sickness was X-axis > Y-axis > Z-axis. At 0.4 Hz and along the X-axis, rats suffered from more severe motion sickness with a high peak G load (0.15 G) than with a low one (0.08 G). Along the X-axis and with a peak acceleration of 0.15 G, the severity of motion sickness was not related to frequency (0.4, 0.6 Hz).

Acceleration↗
PubMed1993

Nystagmus responses in normal subjects during eccentric sinusoidal rotation.

Earth vertical axis rotation provides a method of stimulating the horizontal semicircular canals. By placing subjects off from the axis of rotation, the otolith organs may also be stimulated by additional linear acceleration forces. In the present study, we compared the rotation with subjects placed on axis to those placed in an eccentric position, either facing outward or turned 90 degrees facing the direction of the rotation. When the subject was facing outward, sinusoidal eccentric rotation at 0.64 Hz produced a significantly higher vestibulo-ocular reflex (VOR) gain than did on-axis rotation. No increase in VOR gain was observed during eccentric rotation with the subject facing the direction of the rotation. These findings suggest that the gain enhancement due to eccentric rotation is a result of tangential linear acceleration, probably sensed by the utriculus. This study raises the possibility of using eccentric rotation for the diagnosis of the patients with otolith dysfunction.

Acceleration↗
PubMed1993

Effect of changes in blood pressure on per-rotational nystagmus in guinea pigs with obliterated endolymphatic sac.

The effect of blood pressure (BP) changes on per-rotational nystagmus (PRN) was compared between normal guinea pigs and guinea pigs with unilaterally obliterated endolymphatic sac. Eye movements were recorded 3 months postoperatively. When the animal was rotated sinusoidally, asymmetry of PRN was minimal in the control animals. In the operated guinea pigs, however, nystagmus oscillating toward the operated side was largely suppressed when BP was decreased (30-40 mmHg). Thus, directional preponderance of PRN toward the nonoperated side was established. Oxygen tension (pO2) was measured in the perilymphatic space of the lateral semicircular canal to investigate the mechanisms underlying the PRN asymmetry. When BP was reduced below normal, pO2 on the operated side decreased much more than that on the intact side. It is suggested that obliteration of the endolymphatic sac results in an autoregulatory dysfunction in the semicircular canal. Asymmetry of the vestibulo-oculomotor reflex at low BP may be the result of decreased blood flow to the semicircular canal.

Animals↗
PubMed1993

Hearing recovery following large and small fenestra stapes surgery for otosclerosis.

Fifty-five ear of 49 patients with otosclerosis were operated on with either large fenestra stapes (stapedectomy; SDE) or small fenestra stapes (stapedectomy; STO) surgery. Pre-operative average hearing levels for the speech frequency ranges (0.5, 1, 2 kHz) were 56.1 dBHL for SDE and 61.0 dBHL for STO. These improved to 39.0 dBHL and 35.0 dBHL. Statistically, significant hearing recovery was obtained for a frequency range from 0.125 to 2 kHz for SDE and from 0.125 to 4 kHz for STO (p < 0.05, Dunnett's multiple variance test). The degree of post-operative hearing improvement for STO was significantly higher at 0.5, 2 and 8 kHz than that for SDE (p < 0.05, Student's t-test). A pre-operative speech discrimination score of 80% was obtained at 68.9 dB for SDE and at 76.0 dB for STO. These values improved to 56.1 dB and 49.5 dB post-operatively. Thus, it was proved that STO results in better hearing than SDE does.

Adolescent↗
PubMed1993

Hearing recovery in sudden deafness patients using a modified defibrinogenation therapy.

Ninety-eight patients with idiopathic sudden deafness were treated with a modified defibrinogenation (DF) therapy including batroxobin, low molecular dextran, vasodilators and vitamins. Hearing improvement was evaluated with two methods: categorical judgement and improvement rate (%). By categorical judgement, 60 patients (61% of the total) were classified into recovery or good improvement categories. The improvement rate was calculated for each of the 93 patients, and the average value was 64%. Modified DF therapy was effective especially for patients with severe hearing loss of 70-90 dB with flat audiogram. Although serum fibrinogen significantly decreased after batroxobin administration there was no correlation between the concentration of fibrinogen and hearing recovery. When prognostic factors were studied, the interval between the onset of hearing loss and start of treatment, initial hearing level, and the existence of vertigo all had significant correlation with the degree of hearing recovery.

Adenosine Triphosphate↗
PubMed1993

Tinnitus suppression by electrical promontory stimulation in sensorineural deaf patients.

In 62 patients, whose hearing acuity was normal or profoundly impaired, tinnitus suppression was attempted through electrical promontory stimulation (EPS) with a Promontory Stimulator (Cochlear Co.). The causes of tinnitus were idiopathic sudden deafness, ototoxicity, noise induced hearing loss, labyrinthitis, Meniere's disease, acoustic neuroma and unknown origin. Reduction of tinnitus was achieved in 46 of 68 ears (67.6%). Of these, EPS was most effective in cases of noise induced hearing loss (100.0%; 3/3), followed by those of idiopathic sudden deafness (87.5%; 14/16), Meniere's disease (83.3%; 5/6), labyrinthitis (75.0%; 6/8), ototoxicity (66.6%; 4/6) and unknown origin (76.4%; 13/17). The treatment had hardly any effect on patients with acoustic neuroma (8.3%; 1/12). Twenty patients reported residual inhibition with a duration ranging from several hours to one week. Our results suggest that tinnitus due to cochlear lesions can be suppressed by EPS. This technique may also be useful for differentiation between tinnitus resulting from cochlear lesions and from retrocochlear lesions.

Adolescent↗
PubMed1993

Vagal and sympathetic nerve activities influenced by posterior cerebral circulation in rabbits.

Vagal and sympathetic nervous activities in the rabbit were recorded while vertebral blood flow was partially blocked by the injection of adenosine 5'-diphosphate (ADP; platelet aggregator). When a small dose of ADP (0.2 mg/kg) was administered into a unilateral vertebral artery, sympathetic nerve (SN) activity increased, and its magnitude was inversely correlated with the extent of the decrease in blood pressure (BP). A larger dose (2 mg/kg) of ADP suppressed SN activity on the injected side, whereas the change was small on the non-injected side. Vagal nerve (VN) activity showed a monophasic excitatory response on both sides, although the change was larger on the injected than on the non-injected side. As a result, asymmetry in autonomic nerve activity was more distinct in SN than in VN. The present study demonstrated that asymmetry of autonomic nervous function can result from changes in blood flow in the cerebellum and brainstem.

Adenosine Diphosphate↗