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Biomedical subjects

Y Hasebe

Publications and source records attributed to Y Hasebe.

At least 19 recordsLinked to original sources
PubMed2000

Pleasant odors attenuate the blood pressure increase during rhythmic handgrip in humans.

We have investigated the effects of inhaling odors of preference on physiological responses to physical exercise in college students. Rhythmic handgrip, maintaining a mercurial pressure by repetitive compression, increased blood pressure. In the participants exercised with inhaling odors of their choice, such as rose, jasmine and lavender, the increase in diastolic blood pressure during exercise was reduced by 24%. In contrast, the blood pressure increase during static handgrip, maintaining the power 30-40% of maximum, was not affected by the existence of favorite odors. Since the blood pressure increase during static handgrip is a lower brainstem reflex, the present result shows that the inhalation of favorite odors suppresses the muscle sympathetic vasoconstrictor activity and attenuates the blood pressure increase by affecting the central nervous system higher than the midbrain.

Adolescent↗
PubMed2000

A comparison of distilled water and normal saline as diluents for endobronchial administration of epinephrine in the dog.

UNLABELLED: We compared the effects of distilled water and normal saline as diluents for the endobronchial administration of epinephrine in anesthetized dogs by using a cross-over design. Six dogs received 2 mL of either normal saline or distilled water into the bronchus, and the other solution was administered 1 wk later. Eight dogs received 0.02 mg/kg epinephrine diluted in either distilled water (E + water) or normal saline (E + saline) to a total volume of 2 mL into the bronchus, and the other solution was administered 1 wk later. Normal saline or distilled water without epinephrine did not affect the plasma epinephrine concentration, mean arterial pressure (MAP), and PaO(2). The peak plasma epinephrine concentration was significantly larger after treatment with E + water (26.5 +/- 7.9 ng/mL) than after E + saline (2.1 +/- 0.7 ng/mL). E + water caused an increase in MAP of 91 +/- 24 mm Hg, whereas E + saline did not affect MAP. The maximal decrease in PaO(2) after the administration of E + water (14 +/- 5 mm Hg) was significantly greater than after E + saline (7 +/- 2 mm Hg). In conclusion, distilled water as the diluent for endobronchially administered epinephrine to a total volume of 2 mL allowed better absorption of epinephrine compared with normal saline without a serious detrimental effect on PaO(2). IMPLICATIONS: Using a small volume of distilled water as the diluent for endobronchial epinephrine administration significantly increased epinephrine absorption and arterial pressure in comparison with normal saline, without having a serious detrimental effect on PaO(2), in an anesthetized, noncardiopulmonary, resuscitation dog model.

Animals↗
PubMed2000

Pentoxifylline inhibition of vasculogenesis in the neonatal rat retina.

PURPOSE: The zeta isozyme of protein kinase C (PKC) is essential for activation of the transcription factor nuclear factor (NF)kappaB and transcription of vascular endothelial growth factor (VEGF). This study examined the antiangiogenic potential of an existing drug, pentoxifylline (PTX), which inhibits PKC-dependent activation of NFkappaB and is reported to prevent hypoxia-induced expression of VEGF. METHODS: Neovascularization was induced by maintaining neonatal rats for 10 full days in 80% oxygen, interrupted daily by 30 minutes in room air followed by a progressive return to 80% oxygen. On experimental day 11, they were placed in room air until they were killed on day 17. Daily intraperitoneal injections of PTX in saline (25 or 75 mg/kg per day), or saline alone, were administered from day 6 through day 16. Retinal neovascularization was scored, and avascular areas (AVAs) were measured in ADPase stained retinas. RESULTS: PTX inhibited radial extension of retinal vessels, causing increases in AVA of 65% (P < 0.01) and 33% (P < 0.15) at the lower and upper doses, respectively. A significant increase in mean neovascular score was seen at the lower dose (P < 0.0001), but analysis of variance indicated that neovascularization was strongly and positively influenced by the AVA (P < 0.0001) and only weakly stimulated by PTX (P < 0.05). CONCLUSIONS: Systemic PTX significantly inhibited VEGF-mediated retinal vasculogenesis, but was not effective in reducing neovascularization in the oxygen-exposed neonatal rat.

Animals↗
PubMed1999

Eicosapentaenoic acid release from the red alga Pachymeniopsis lanceolata by enzymatic degradation.

Forty-eight species of seaweeds from Japanese waters were screened for the valuable polyunsaturated fatty acids eicosapentaenoic acid (EPA). The eight species that contained the highest levels of these compounds were analyzed in detail. Of all species tested the red alga Pachymeniopsis lanceolata contained the highest EPA concentration, and it was present as both the free and bound forms. EPA constituted 38.7% of total fatty acids, and polar lipids were the main constituent of the total lipids in P. lanceolata. EPA was obtained from the marine algae P. lanceolata by enzymatic hydrolysis of the total lipids extract using phospholipase A2 (PLA2). The release of EPA reached a plateau after 10 min of enzymatic treatment. These results suggest that P. lanceolata is a useful natural source of EPA and that PLA2 treatment is a convenient method for obtaining EPA from the red alga.

Eicosapentaenoic Acid↗
PubMed1998

Highly sensitive flow detection of uric acid based on an intermediate regeneration of uricase.

The principle of the signal amplification of a uric acid sensor based on dithiothreitol (DTT)-mediated intermediate regeneration of uricase was applied to a flow-injection system with an immobilized uricase reactor and a DTT-containing carrier. Highly sensitive detection for nM to microM order of uric acid was achieved when 10 mM TRIS-HCl buffer (pH 10.0) containing 20 mM DTT was used as a carrier at 0.6 ml min-1 and 37 degrees C. The sensitivity of the uric acid was much improved over a batch method using a uricase membrane-coupling electrode, and the detection limit (ca. peak current 8 nA) of uric acid was found to be down to 3 x 10(-10) M (amplification factor; more than 10,000). This chemically amplified flow-system is very useful for the direct assay of uric acid in highly diluted biological fluids (urine and serum) without complicated pretreatment of the samples, because this sensor has the potential to detect trace amounts (nM to microM) of uric acid in highly diluted body fluids in which the concentration of interfering constituents was decreased to negligible levels. Good correlation was observed between this system and conventional spectrophotometry. The immobilized uricase reactor could be re-used for at least 4 months of repeated analysis without loss of activity and was stable if stored at 4 degrees C in 10 mM TRIS-HCl buffer, pH 9.0.

Dithiothreitol↗
PubMed1998

Dorsal specification in blastoderm at the blastula stage in the goldfish, Carassius auratus.

The teleost dorsoventral axis cannot be morphologically distinguished before gastrulation. Previous studies by the current authors have shown that localized dorsalizing activity in the yolk cell (YC) induces the dorsal tissues in the overlying blastoderm. In order to examine whether or not dorsal blastomeres are committed to their dorsal fate before the gastrula stage, a variety of transplant operations were performed in goldfish blastoderms at the mid- to late-blastula stages. When the blastoderm was cut from the YC, rotated horizontally at 180 degrees, and recombined with the YC, the blastoderm frequently developed two axes, indicating that dorsal blastomeres of the blastula had already acquired the ability to differentiate into the organizer in the absence of dorsalizing signals from the YC. This result was further confirmed by experiments using ventralized embryos in which no dorsal structures formed: the axis formation was frequently observed in the normal blastoderm combined with the ventralized YC at the blastula stage. However, the axes formed in the absence of dorsal information from the YC exhibited a lower dorso-anterior index. Furthermore, the dorsal specification was not stably maintained when the dorsal cells were located far from the YC. These results suggest that the inductive and permissive influence of the YC may be required for the blastoderm to undergo full dorsal differentiation.

Animals↗
PubMed1997

Specific and amplified current responses to histidine and histamine using immobilized copper-monoamine oxidase membrane electrode, based on novel ascorbate oxidase activity induced by exogenous ligands.

Upon the addition of histidine and histamine, the copper containing monoamine oxidase (MAO) catalyzes the oxidation of L-ascorbic acid (AsA) by dissolved oxygen, in which the consumed oxygen was finally converted to hydrogen peroxide, according to Michaelis-Menten kinetics (Km) = 1.97 mM, upon the addition of 5 x 10(-5) M L-histidine at 35 degrees C and pH 8.5). The amount of oxygen consumption depended on the amount of histidine and histamine added, and specific responses over other amines were observed when the oxygen electrode modified with immobilized MAO membrane was used in the 0.1 M Tris buffer containing AsA. The calibration curves of L-histidine and histamine at 4 mM AsA exhibit linearity in the concentration range from 5 x 10(-7) to 5 x 10(-5) M L-histidine and 5 x 10(-6) to 1 x 10(-8) M histamine, with detection limit of 3 x 10(-7) M L-histidine and 3 x 10(-6) M histamine, respectively. The ESR signal of copper(II) in active site of MAO at 77K was apparently changed upon the addition of L-histidine and histamine indicating that exogenous histidine and histamine bound to the copper site of enzyme and lead to the structural change in active site.

Animals↗
PubMed1997

Effects of skin surface temperature distribution of thermal manikin on clothing thermal insulation.

Effects of the distribution of skin surface temperature were investigated on thermal insulation of clothing for whole and each body part. The experiments were carried out with a thermal manikin in a climatic chamber. The two types of clothing ensemble were measured. The measurement with nude thermal manikin were also conducted. The three variations of skin temperature distribution were set with the thermal manikin. The values of the thermal insulation of nude skin surface (Ia), the total thermal insulation of clothing (It) and the basic thermal insulation of clothing (Icl) were measured with this thermal manikin under each skin temperature distribution. As a result, the values of Ia and It were not affected by skin temperature distributions of the range of typical experimental conditions. However, It is necessary to carefully use the values of the thermal insulation of clothing for the body parts, because these values were more influenced by the skin temperature distribution than those for the whole body.

Body Temperature Regulation↗
PubMed1996

Microbial cyanide sensor for monitoring river water.

A microbial cyanide sensor using Saccharomyces cerevisiae for monitoring a river water is described. This sensor is based on the inhibition of S. cerevisiae's respiration by cyanide. This sensor is a reactor type flow system and composed of two oxygen electrodes and a reactor which contains S. cerevisiae immobilized beads. The S. cerevisiae's respiration activity is measured using the oxygen electrodes. The sensor showed a linear response in the range from 0 to 15 microM and maintained stable response for 9 days at ambient temperature. The sensor was optimized for the monitoring of river water and was applied to river water analysis.

Biosensing Techniques↗
PubMed1995

Usefulness of R-R interval and its variability in evaluation of thermal comfort.

The use of R-R interval and the coefficient of variation in R-R intervals (CVR-R) for the evaluation of thermal comfort was investigated. The experiments were carried out with ten male subjects but data from one were excluded from the analysis. Thermal sensation, comfort, and tolerance of environmental conditions were reported and mean skin temperature, R-R interval and CVR-R were monitored during a 3 h period in a climatic chamber with the operative temperature set at 26, 20, or 30 degrees C. Relative humidity was maintained at ca. 50% in each case. At the operative temperature of 20 degrees C, the mean skin temperature was significantly lower, the cold sensation was significantly more intense, and discomfort was significantly greater than at 26 degrees C and R-R interval was increased significantly. Seven of the nine subjects were unable to tolerate this thermal environment. The R-R interval and CVR-R were increased in five and four of those seven subjects, respectively. At the operative temperature of 30 degrees C, the mean skin temperature was significantly higher, and the sensation of warmth was significantly more intense than at 26 degrees C. Seven of the nine subjects felt discomfort, and four of the seven reported an inability to tolerate this thermal environment. The R-R interval and CVR-R were decreased in four and three of these four subjects, respectively. At the operative temperature of 20 degrees C CVR-R was significantly greater than that at 30 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

Acclimatization↗
PubMed1994

[Thermal insulation of clothing for seated and standing postures].

The purpose of this study is to examine the effects of body posture on thermal insulation of clothing. Clothing ensembles including skirts were mainly investigated. A new thermal manikin was developed for this study. This manikin was able to change her body posture without increasing or decreasing her surface area. By changing posture from standing to seated, the total thermal insulation of clothing (It) was decreased by around 1.4%. The surface thermal resistance at nude (Ia) was increased by 8%. As a result, the basic thermal insulation of clothing (Icl) was decreased by 14%. The main reason for the decrease of basic thermal insulation (Icl) when the posture of thermal manikin changes from standing to seated was the increase of Ia at nude. The total thermal insulation of clothing for each body posture (Iti), when standing and seated, were compared. The parts affected by the changed posture were abdomen, hip and thighs, and especially under the skirt of 61cm length, the knees were most affected.

Adult↗
PubMed1992

[Intermittent intra-arterial chemotherapy using subcutaneously implanted reservoir for hepatocellular carcinoma and liver metastasis of colorectal carcinoma].

Hepatectomy has been performed as a treatment for hepatocellular carcinoma (HCC) and metastatic liver carcinoma. The prognosis has improved, but it is not sufficient. In our department hepatic arterial infusion chemotherapy using subcutaneous implanted reservoir has been undertaken in 21 of 66 patients who underwent hepatectomy in hepatocellular carcinoma and 13 of 30 in liver metastasis of colorectal carcinoma since 1986. There was no significant difference between the group with and without arterial infusion chemotherapy in HCC but there was a significant difference in metastasis of colorectal carcinoma. In unresectable cases, intra-arterial chemotherapy was undertaken, but there was no significant difference. On the other hand, 26 of 58 cases receiving arterial infusion chemotherapy have shown complications.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Amphetamine-antagonistic properties of 4-phenyl-1,2,3,4- tetrahydroisoquinoline: inhibition of spinal reflex-enhancing effects of methamphetamine, phenylethylamine and nomifensine.

The antagonistic effects of 4-phenyl-1,2,3,4-tetrahydroisoquinoline (4PTIQ) against S(+)-methamphetamine, phenylethylamine and nomifensine were studied by measurement of spinal monosynaptic reflex potential (MSR). S(+)-Methamphetamine, phenylethylamine and nomifensine enhanced the amplitude of MSR in C1-spinalized rats through release of noradrenaline from the terminals of descending fibers and consequent activation of alpha 1-adrenoceptors. Although 4PTIQ alone did not change the amplitude of the MSR, 4PTIQ inhibited the enhancement of MSR induced by S(+)-methamphetamine and related compounds. The MSR of rats with an intact spinal cord was enhanced by conditioning stimulation of the ipsilateral locus ceruleus. The MSR enhancement produced by the stimulation was blocked by prazosin but unaffected by 4PTIQ, showing that 4PTIQ does not have an alpha 1-blocking action. These results suggest that the antagonistic effects of 4PTIQ on MSR enhancement by S(+)-methamphetamine, phenylethylamine and nomifensine are due to its blocking of noradrenaline release produced by these amphetamine-like agents.

Amphetamine↗
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↗
PubMed1989

The most desirable conformation of phenylethylamine (PEA) moiety stimulating noradrenergic neurons: effects of PEA, methamphetamine, phenelzine, methylphenidate, nomifensine and mazindol on rat spinal reflexes.

1. The effects of phenylethylamine (PEA) and PEA-related substances on the rat spinal monosynaptic reflex (MSR) were examined. According to the flexibility of the PEA moiety in the molecule, these drugs were classified into three groups, i.e. non-rigid, rigid and semi-rigid groups. 2. PEA, methamphetamine and phenelzine (non-rigid group) showed opposite effects on the MSR, an increase at low doses and a decrease at high doses. The former effect was antagonized by pretreatment with the alpha 1-blocker, prazosin. 3. Nomifensine and mazindol (rigid group), which share the similar spatial relationships between the aromatic moiety and nitrogen, increased the MSR, and this effect was blocked by prazosin. 4. In the semi-rigid group the same result was obtained for methylphenidate but not for 1-methyl-2-benzylpiperidine, which might have difficulty in having the similar conformation of PEA moiety as methylphenidate because of its methyl group. 5. From these results, it appears that the effects of PEA and amphetamines on the MSR are determined by the spatial relationships between the amino group and the aromatic moiety and that the enhancement of the MSR might be induced through alpha 1-adrenergic transmission.

Animals↗
PubMed1989

Enhancement of spinal monosynaptic reflexes with phenylethylamine and related drugs through descending noradrenergic neurons.

The effects of phenylethylamine (PEA) and related drugs, such as methamphetamine, phenelzine, methylphenidate, nomifensine and mazindol on the spinal monosynaptic reflex (MSR) were investigated in rats treated with 6-hydroxydopamine (6-OHDA) or 5,6-dihydroxytryptamine (5,6-DHT). PEA (1 x 10(-5) mol/kg, i.v.) increased the amplitude of MSR in control rats, but decreased the amplitude in rats treated with 6-OHDA. Although PEA-related drugs increased the amplitude of MSR, they did not change the MSR amplitude in 6-OHDA-treated rats. In 5,6-DHT-treated rats, PEA-related drugs increased the amplitude of MSR, whereas PEA produced a decrease. These results support our previous suggestion that the enhancement of MSR by these drugs might be mediated through release of noradrenaline or inhibition of noradrenaline uptake at the noradrenergic synapses.

5,6-Dihydroxytryptamine↗
PubMed1989

Structure-activity relationships of phenylethylamine analogs in their serotonergic depressant effects on the spinal monosynaptic reflex in rats.

The effects of 2-phenylethylamine (PEA) and related compounds on the spinal monosynaptic reflex (MSR) were examined using C1-spinalized rats. At low doses, PEA, S(+)-amphetamine, S(+)-methamphetamine and phentermine increased the amplitude of the MSR, whereas high doses of these drugs reduced it. p-Substituted PEA analogs (p-C1-PEA, p-methoxy-PEA and (+/-)-p-C1-amphetamine) only reduced the MSR. Low doses of PEA-related rigid compounds, R(+)-2-aminotetralin, (+/-)-N-methyl-2-aminotetralin and (+/-)-N,N-dimethyl-2-aminotetralin only reduced the MSR. S(-)-2-Aminotetralin did not affect the MSR. Depressions of MSR produced by PEA, S(+)-methamphetamine and R(+)-2-aminotetralin were antagonized by ketanserin and haloperidol which have 5-hydroxytryptamine (5-HT) antagonistic activity, and the MSR depression caused by S(+)-methamphetamine but not PEA and R(+)-2-aminotetralin was abolished by intracisternal 5,6-dihydroxytryptamine treatment or chronic spinal transection. These results suggest that PEA-related compounds cause MSR depression by direct and indirect 5-HT agonistic mechanisms, and support the proposal that the PEA moiety which exists in R(+)-2-aminotetralin is important for the direct 5-HT agonistic activity of some hallucinogens.

Animals↗