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T Egashira

Publications and source records attributed to T Egashira.

At least 91 records · Page 5Linked to original sources
PubMed1990

[Stereotactic aspiration using coordinate software for hypertensive intracerebral hematomas].

Stereotactic aspiration for intracerebral hematoma has become widely used due to improvements in computed tomography (CT). CT-guided stereotactic aspiration for hypertensive intracranial hematomas was performed in 46 cases. Stereotactic aspiration with coordinate software was carried out among 16 cases. We compared the clinical results of conventional stereotactic aspiration with results of the new method using coordinate software. Using coordinate software, we can examine the route for the target point, as well as the target point of the hematoma before surgery. Therefore we can avoid obstacles such as ventricles and internal capsules. Further, we can aspirate hematoma by using only this one procedure. Mean hematoma aspiration percentage has risen from 44.9 to 87.2% by using coordinate software. Rate of drainage tube insertion after operation has decreased from 90 to 50%. The period of placement of the drainage tube and the frequency of infection due to the drainage tube has become lower, too. Therefore we can say that the outcome of treatment of hypertensive intracranial hematomas is improved by using coordinate software.

Cerebral Hemorrhage↗
PubMed1990

[Instrumentation surgery for tumor of the spine].

Spinal instrumentation surgery has come into wide use recently, especially for tumor of the spine. It is very effective for fixing the spine for relieving the patient from pain. But the decision about the indication of instrumentation surgery for tumor of the spine must be made carefully. In cases of double malignant tumors including spinal tumor, it is hard to decide how to treat tumor of the spine. We report a case of 78-year-old male with multiple myeloma of the cervical spine and cancer of the prostate. The patient had been in good health until one year previously, when he started to complain of nuchal pain. He became bedridden with loss of voluntary control of the right upper extremity for the last two months. Then he was admitted to our hospital and radiological examination was carried out. It revealed tumor of the cervical spine and it seemed to be bone metastasis. Further examination revealed that the patient was suffering from multiple myeloma and cancer of the prostate. The tumor of the spine was diagnosed as either multiple myeloma or metastasis of cancer of the prostate. Spinal instrumentation surgery using Luque-rod was carried out as one of the comprehensive treatment plans for double malignant tumors. The instrumentation surgery was effective for fixing the spine and improving the patient's quality of life. In operative procedures, intraoperative spinal cord monitoring was carried out. Intraoperative spinal cord monitoring was indispensable for preventing spinal cord injury. The tumor of the spine was diagnosed as multiple myeloma by pathological examination.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

Endogenous monoamine oxidase inhibitor-like substances in monkey brain.

The extraction and partial purification of endogenous "monoamine oxidase (MAO) inhibitor-like" material from the monkey brain are described. The endogenous material (F-1 and F-2) obtained after Bio-Gel P-2 gel filtration and silica column chromatography inhibited MAO in the monkey brain mitochondria toward 5-hydroxytryptamine (5-HT), beta-phenylethylamine (beta-PEA), tyramine and dopamine as substrates. The inhibitory effects of F-1 and F-2 were non-linear concentration dependent, and F-1 non-competitively inhibited A-form MAO, while F-2 inhibited A-form MAO competitively and inhibited B-form MAO non-competitively. These substances were more potent inhibitors of A-form than of B-form MAO. F-2 was heat stable but liable to the treatment with pepsin and trypsin. F-1 was not inactivated by heat treatment and digestion with pepsin and trypsin. F-1 may be a low molecular weight (less than 1350) compound, including certain monoamines or their metabolites or other unidentified compounds, while F-2 was a low molecular weight (about 2500) peptide.

Animals↗
PubMed1989

[Neurochemical studies on bifemelane, a new cerebral function improver. I. Effects of bifemelane on the function of neurotransmission-related enzymes and receptors in rat brain].

We examined neurochemically the effects of bifemelane (BF) on muscarinic ACh (mACh-R) and beta-adrenergic receptors (beta-AdR) and imipramine binding sites and the activities of acetylcholinesterase (AChE), choline acetyltransferase (CAT) and monoamine oxidase (MAO) in the P2 fractions of rat brain, ex vivo and in vitro. Male rats were given daily injections of 10, 30 mg/kg BF, p.o., for a period of 4 weeks. The Kd and Bmax values for mACh-R in the rat forebrain by administration of 10, 30 mg/kg BF decreased significantly compared with that of the control, although the Kd and Bmax values for beta-AdR and imipramine binding sites were almost identical. The Km and Vmax values of A- and B-form MAO decreased in rats that had been administered 30 mg/kg BF for 4 weeks. The binding of 3H-QNB (quinuclidinyl benzilate) on mACh-R, 125I-CYP (iodocyanopindolol) on beta-AdR and 3H-imipramine on imipramine binding sites decreased by 60, 20 and 70% in the presence of 1 microM BF, respectively, while the addition of 1 microM BF inhibited MAO activity by about 50%. However, CAT and AChE activities were not inhibited by BF.

Acetylcholinesterase↗
PubMed1989

Effect of diethylnitrosamine on monoamine oxidase in rat liver.

The effect of diethylnitrosamine (DEN), a well-known experimental carcinogen, toward MAO-A and MAO-B activity of rat liver was investigated. The oxidations of both beta-PEA (MAO-B) and 5-HT (MAO-A) were inhibited by DEN. The K1 values of DEN in the inhibition of rat liver MAO-A and MAO-B activity were determined. The kinetic data show that DEN is a competitive, MAO-B selective inhibitor and its inhibitory effect on MAO-B is about 4-fold more potent than that on MAO-A. DEN might change the proportions of the multiple forms of MAO activity in tumor cells.

Animals↗
PubMed1989

Effects of bifemelane hydrochloride on various cholinergic markers in cortical and subcortical regions of aged rats.

The effects of bifemelane hydrochloride (BF) upon various cholinergic markers, muscarinic receptors, acetylcholinesterase (AChE) and choline acetyltransferase (CAT), in the aged rat brain were examined. Marked reduction of the density of muscarinic receptors (Bmax) as well as AChE and CAT activity concomitant with aging was observed. Administration of BF in daily doses of 10 mg/kg for 4 weeks to aged rats significantly decreased the apparent dissociation constant (Kd) for QNB in muscarinic receptors in the forebrain, but did not affect the value of Bmax. CAT activity also increased significantly compared with that of control aged rats, but administration of BF did not alter AChE activity. These results indicate that long-term treatment with BF enhances the affinity of muscarinic receptors for QNB as well as CAT activity and that BF may have therapeutic application in the treatment of CNS cholinergic dysfunctions.

Acetylcholinesterase↗
PubMed1989

Amine oxidase released into plasma of rats treated with hepatotoxin allyl formate.

Amine oxidase activity in plasma of rats were investigated after pretreatment with the perilobular hepatotoxin allyl formate (AF). Amine oxidase activities in plasma elevated after administration of AF 0.1 ml/kg i.p. to male rats with 1 microM and 100 microM benzylamine (Bz), 10 microM beta-phenylethylamine (beta-PEA) and 100 microM serotonin (5-HT) as substrates. But the complete inhibition of amine oxidase activities with 5-HT and beta-PEA were not observed by clorgyline as A-form MAO inhibitor and deprenyl as beta-form MAO inhibitor. The deamination of 1 microM Bz was not inhibited at high concentrations of these MAO inhibitors, while it was inhibited at low concentrations of phenelzine and semicarbazide. On the other hand, the deamination of 100 microM Bz was highly sensitive with these MAO inhibitors, while it was less sensitive with phenelzine and semicarbazide as compared with 1 microM Bz. Then, the Km values of amine oxidase in plasma of AF-administered rats with Bz as substrate were determined from Lineweaver-Burk double reciprocal plots. Two Km values for Bz of high and low Bz concentration in amine oxidase in plasma of AF-administered rats were obtained. However, this Km value of low Bz concentration was not obtained from liver mitochondria and microsomes of control rat and AF-administered rats. The Km value for beta-PEA of MAO in plasma of AF-administered rats was the same as the values of rat liver mitochondrial MAO. These results indicate that native mitochondrial MAO was released from the liver, and two or more distinct amine oxidases were released from other organs in response to AF.

Animals↗
PubMed1988

Reversible inhibition of aromatic hydroxylation of methamphetamine in rat liver microsomal preparations pretreated with methamphetamine.

The effects of a single and repeated administration of methamphetamine (MP) in vivo in rats on its own metabolism in vitro were investigated. In both cases, the p-hydroxylation of MP to p-hydroxymethamphetamine by a microsomal fraction from rat liver was inhibited for a period of 16 hr after the last injection of MP. This inhibition was diminished by dialysis of the microsomal preparations. In contrast, the reduced level of cytochrome P-450 in hepatic microsomes from rats pretreated with the SKF 525-A did not revert to the control value after dialysis. When microsomes were preincubated with N-hydroxymethamphetamine, which is the metabolite of MP and a potent substrate for the formation of a metabolic intermediate (MI) complex with cytochrome P-450, the content of the MI was increased and the MP-hydroxylation activity decreased in direct proportion to the length of the preincubation. These results suggest that the inhibition of MP-hydroxylation may be due to reduction of the level of cytochrome P-450 that accompanies the formation of the MI complex. Furthermore, it appears that the complex can be dissociated by dialysis.

Animals↗
PubMed1988

Changes in amine oxidase in plasma of rats treated with hepatotoxins.

When allyl formate (AF) was administered to rats, the marked elevation of B-form MAO activity in plasma was found with beta-PEA as a substrate. In contrast, in the case of carbon tetrachloride (CCl4), A-form MAO activity elevated predominantly. The deaminations of 5-HT and beta-PEA in these plasma treated with AF or CCl4 were not inhibited completely by a high concentration of MAO inhibitor, deprenyl or clorgyline. These results indicate that there may be two or more distinct amine oxidases released from the liver and other organs in response to CCl4 or AF.

Animals↗
PubMed1987

Modulation of neuronal MAO activity, 5-HT uptake and imipramine binding by endogenous substances in dog cerebrospinal fluid.

Addition of small amounts of dog cerebrospinal fluid (CSF) inhibited both type A and type B monoamine oxidase (MAO) in dog brain mitochondria. The inhibition was competitive with 5-HT as substrate, but non-competitive with beta-phenylethylamine as substrate. Tricyclic antidepressants also exhibited competitive inhibition with type A MAO, but were non-competitive with type B MAO. The endogenous materials in CSF activate [3H]-imipramine specific, dose-dependent binding in dog brain preparations. The maximum number of binding sites (Bmax) increased, but the dissociation constant (Kd) was altered significantly in the presence of CSF. Addition of CSF induced a marked activation of uncompetitive [14C]-5-HT uptake in dog brain preparations. Moreover, there were reversibilities of the inhibition of MAO activity or of the activation of imipramine binding and 5-HT uptake by CSF substance after dilution experiment. These results indicate the possible presence of an endogenous psychotic drug-like substance in CSF.

Animals↗
PubMed1987

Ossification of the posterior longitudinal ligament: a clinico-radiological study of 74 cases.

A clinico-radiological analysis of 74 cases of ossification of the posterior longitudinal ligament is reported. Eighteen cases (24%) were asymptomatic or only had neck or shoulder pain; 16 cases (22%) showed signs of radiculopathy, and the remaining 40 cases (54%) had myelopathy. Ossification of the posterior longitudinal ligament developed most frequently at C5, and was rare in thoracic and lumbar regions. Ossification of the posterior longitudinal ligament led to stenosis of the spinal canal; more marked stenosis caused clinical myelopathy. The data showed that 30% of stenosis caused by ossification of the posterior longitudinal ligament was critical for the production of myelopathy.

Adult↗
PubMed1987

[Electrophoretic properties of mitochondrial monoamine oxidase in monkey liver].

Monkey liver monoamine oxidase (MAO) was predominantly the B-form enzyme from the observed differences in substrate specificities and differences in sensitivities to MAO inhibitors. It is known that a MAO inhibitor, pargyline, binds to MAO irreversibly in the molar ratio of 1:1. 3H-pargyline was used as a marker to determine the existence of MAO. The molecular weight of MAO in monkey liver mitochondria was investigated by SDS-polyacrylamide gel electrophoresis after solubilization of 3H-pargyline binding mitochondria with 6% sodium dodecyl sulphate (SDS). The subunit molecular weight was found to be 60,000. The molecular weight determined from the electrophoretic mobility on several concentrations of gels by disc gel electrophoresis in the absence of SDS was found to be 120,000. These results indicate that monkey liver mitochondrial MAO exists as a dimer. Isoelectric focusing of the enzyme after solubilization with 0.1% Triton X-100 and 0.75% Triton X-100 and 0.75% Lubrol showed that it had a pI value near 6.5. Similar pI values were obtained for enzyme preparations solubilized with 0.75% Triton X-100 after treatment with phospholipase A or methylethylketone. These results suggest that the pI value of MAO in monkey liver mitochondria does not depend on the properties of detergents used to solubilize the enzyme preparation.

Animals↗
PubMed1987

Evidence for existence of A and B form monoamine oxidase in mitochondria from dog platelets.

It is known that platelet MAO appears to behave more like the B-form enzyme than the A-form enzyme based on inhibitor sensitivity and substrate specificity. However, dog platelets showed a different substrate specificity such as high activity with 5-HT and beta-PEA as substrates. Moreover, dog platelet MAO was sensitive to the drugs clorgyline and harmaline with 5-HT as the substrate, while it was sensitive to the drug deprenyl with beta-PEA as the substrate. These results also indicate the existence of two forms of MAO in dog platelets unlike in other platelets such as those from humans. A-form MAO from dog platelets was more stable against heat treatment at 55 degrees C than A-form MAO from dog liver and brain. On the other hand, there was no difference in the heat resistance of the three enzymes with beta-PEA as the substrate. After digestion with trypsin at 37 degrees C for 30 min, it was found that MAO from dog platelets, brain and liver were mostly inhibited with 5-HT as the substrate. In contrast, MAO in brain and liver were inhibited about 10%, but platelet MAO was inhibited about 50% with beta-PEA as the substrate. From these results, it is considered that dog platelet MAO exists as the two forms of the enzyme and has different enzymic properties in comparison with those of MAO from dog liver and brain mitochondria.

Animals↗
PubMed1987

Changes in MAO activities in several organs of rats after administration of l-thyroxine.

Male rats were given daily injections of 200 micrograms/kg l-thyroxine, s.c., for a period of 10 days. Monoamine oxidase (MAO) activities in the heart, lung and liver mitochondria decreased rapidly to about 50% those of the control rats with 5-HT and beta-phenylethylamine (beta-PEA) as substrates on the first day. After that, heart MAO activity increased gradually and exceeded the control value after 10 days with 5-HT as the substrate. The level of liver MAO activity was maintained at about 50-70% during the same period of administration with 5-HT as the substrate. The thyroxine treated rats showed no marked change in brain MAO activity. In vitro, l-thyroxine and its metabolites had no discriminative actions on MAO activities in these organs of rats. The heart, lung and liver MAO have unaltered Km values for 5-HT and beta-PEA, but decreases in the Vmax for both substrates were observed between the control and l-thyroxine-treated rats. Addition of the brain, heart and liver cytosol fractions from l-thyroxine treated rats caused MAO activities of heart mitochondria to decrease with 5-HT as a substrate and caused them to increase with beta-PEA as a substrate. MAO activities in liver also were inhibited by adding all the cytosols when beta-PEA was the substrate, but on the contrary, lung MAO activities were increased when 5-HT was the substrate. These results indicate the possible presence of multiple modulators of MAO in the cytosol fractions of l-thyroxine treated rats.

Animals↗
PubMed1987

Effects of d-methamphetamine on monkey brain monoamine oxidase, in vivo and in vitro.

A and B form MAO activities in mitochondria and synaptosome were measured in the brain of monkeys administered d-methamphetamine (d-MP) 2 mg/kg, i.m., daily for 7 days. When mitochondria were used as an enzyme preparation, the Km and Vmax values decreased with 5-HT (serotonin for A-form MAO substrate) and beta-phenylethylamine (beta-PEA for B-form MAO substrate), while in the synaptosome, a significant increase of the Km and Vmax values was observed with 5-HT and dopamine as substrates. The mitochondrial MAO treated with d-MP was inhibited strongly by clorgyline and deprenyl with beta-PEA as a substrate, while synaptosomal MAO was highly sensitive to these MAO inhibitors with 5-HT as a substrate. MP and amphetamine (AP) were found in brain mitochondrial and synaptosomal preparations of monkeys administered 2 mg/kg d-MP, i.m. daily for 7 days; MP and AP contents were 5.05 +/- 0.22 pg/mg protein and 37.3 +/- 3.8 ng/mg protein in mitochondria and 2.35 +/- 0.35 pg/mg protein and 46.4 +/- 1.5 ng/mg protein in synaptosomes, respectively. MAO was inhibited by MP and its metabolites, AP p-hydroxymethamphetamine (OH-MP) and p-hydroxyamphetamine (OH-AP), with 5-HT, beta-PEA and dopamine as substrates, in vitro. MP and its metabolites were more potent inhibitors of A-form MAO than B-form MAO.

Animals↗
PubMed1986

Methamphetamine-induced behavioral alterations following repeated administration of methamphetamine.

Repeated administration of a large dose of methamphetamine (MA) (25 mg/kg, i.p. twice daily for 4 days) to mice enhanced locomotor activity and decreased stereotyped behavior following a subsequent injection of MA. Simultaneous determinations of catecholamines revealed a depletion of brain dopamine. The moderate doses of haloperidol significantly enhanced MA-induced locomotor activity in mice. A significant enhancement of MA-induced locomotor activity was observed in the rats pretreated with 6-hydroxydopamine into the striatum, and this effect correlated negatively with the striatal dopamine level. These results suggest that hypofunction of striatal dopaminergic neuron systems induced by repeated administration of MA may be one of possible mechanisms of the enhancement of MA-induced locomotor activity due to the decrease of stereotyped behavior.

Animals↗
PubMed1986

Demonstration of endogenous inhibitors of monoamine oxidase in dog cerebrospinal fluid.

Cerebrospinal fluid (CSF) from dogs competitively inhibited A-form MAO, but was non-competitive with B-form MAO. Heat treatment of CSF (90 degrees C, 20 min) had no effect on the inhibition. Digestion with trypsin and chymotrypsin reduced the MAO inhibitory activity. After ultrafiltration of the CSF through a membrane to remove substances of greater than 5,000 M.W., significant inhibitory activity persisted. These results suggest that CSF contains endogenous substances that act like MAO inhibitor to inhibit A and B-form MAO, and these substances are peptides of less than 5,000 M.W.

Animals↗