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Biomedical subjects

S Terao

Publications and source records attributed to S Terao.

At least 55 records · Page 3Linked to original sources
PubMed1994

[The corticospinal tract lesion of amyotrophic lateral sclerosis--magnetic resonance imaging of the spinal cord].

Magnetic resonance imaging by gradient echo method demonstrated lesions of the lateral corticospinal tract at cervical cord levels in three ALS patients. Patient 1 was a 43-year-old woman with common form of ALS. She developed right-side predominant pyramidal signs, and right-side predominant prolongation of central motor conduction time. MRI showed hypersignal intensity areas in the dorsal region of the lateral column at the 4th and 5th cervical segments with right-side predominancy. Patient 2 was a 65-year-old man with pseudopolyneurtic form of ALS, who showed lower motor neuron signs without a pyramidal sign. MRI of the 3rd and 4th cervical cord segments demonstrated bilateral hypersignal intensity areas in the dorsal part of the lateral column. Patient 3 was a 62-year-old man with common form of ALS, who showed marked bilateral pyramidal signs with Babinski's sign. MRI of the 5th cervical spinal cord segment demonstrated bilateral hypersignal intensity areas in the dorsolateral column. Thus obtained MR images of the spinal cord corresponded well to the postmortem-confirmed degeneration of the spinal corticospinal tract. MRI of the spinal cord performed by gradient echo method would provide additional information on the upper motor neuron involvement in ALS.

Adult↗
PubMed1994

[Chronological changes in MR imaging of inferior olivary pseudohypertrophy--report of two cases].

Olivary pseudohypertrophy (OH) and its chronological change was examined by MR images in two patients with brainstem vascular disease. Patient 1 was a 63-year-old woman who developed an infarction in the red nuclei associated with "top of the basilar" syndrome. Two months later, she showed 2-4 c/s rhythmic myoclonus (rubral tremor) involving four extremities. Palatal myoclonus was absent. MR images of the inferior olives did not demonstrate a significant lesion in 10 days after the onset, but showed OH in 6 months, and then their size attained a maximum in 10 months after. On T2-weighted (T2) images and proton-density-weighted (PD) images obtained at 20 and 24 months, OH gradually became irregular but discrete in their intensity, and the intensity had also decreased to some extent. Rhythmic myoclonus had subsided to some extent after 20 to 24 months. Patient 2 was a 62-year-old woman who had a small hemorrhage in the pontine tegmentum. She developed 2.5 c/s vertical ocular myoclonus without palatal myoclonus two months after the onset. MR images showed OH in 6 and 8 months after the onset. On T2 and PD images obtained at 20 months, the image of OH gradually developed to become irregular in intensity and slightly atrophic in size. The ocular myoclonus somewhat reduced in their intensity 12 months after the onset. These serial changes in MR images were considered to correspond to the chronological changes of the pathology of OH. Appearance and subsidence of the myoclonic movement was also considered to correlate to the sequential changes of MR images of OH.

Cerebrovascular Disorders↗
PubMed1994

[Hemodynamic TIA associated with severe anemia--a case report].

A 62-year-old man developed recurrent TIAs presenting as mild unconsciousness, dysarthria and weakness of the right upper extremity lasting for 15 to 20 minutes. He was found to have severe iron deficiency anemia (hemoglobin: 5.5-5.9g/dl; hematocrit: 18.4-19.5%) which insidiously developed through the chronic bleeding from the gastric ulcer. He had slight hypertension (184/86mmHg), but no orthostatic hypotension. DSA and MR angiography showed severe stenosis at the origin of the bilateral internal carotid arteries and of the left vertebral artery. There was also hypoplasia of the right vertebral artery. Blood circulation detected by 123I-IMP-SPECT was markedly decreased in the whole brain and in the right hemisphere of the cerebellum. TIA was, however, completely disappeared following to the recovery of anemia. The present case suggested that the presence of severe anemia accelerated the occurrence of hemodynamic TIA (regional cerebral anemic hypoxia), which is probably the consequence of the reduced oxygen-transporting capacity of the blood.

Aged↗
PubMed1993

Modeling of human thromboxane A2 receptor and analysis of the receptor-ligand interaction.

In order to elucidate the mode of the thromboxane A2 (TXA2) receptor-ligand interaction at the molecular level, a model for the human TXA2 receptor, a member of the G protein-coupled receptor family with seven transmembrane segments, was constructed on the basis of its amino acid sequence, which was determined recently (Hirata, M.; et al. Nature 1991, 349, 617-620). First, we made a model for the human beta 2-adrenergic receptor using its amino acid sequence and the known helix arrangement of bacteriorhodopsin. Then, a TXA2 receptor model was constructed based on the beta 2 receptor model and was used to analyze the receptor-ligand interaction. The ligand-binding pocket of the TXA2 receptor includes a serine residue from segment V, an arginine residue from segment VII, and a large hydrophobic pocket between these two residues. These results are consistent with the known properties of TXA2 and TXA2 antagonists having a hydrogen-bonding group such as hydroxyl, a carboxyl group, and a hydrophobic moiety. This model should be helpful for rational design of potent TXA2 antagonists.

Amino Acid Sequence↗
PubMed1993

[A case of asymptomatic common carotid artery occlusion with the persistent proatlantal intersegmental artery].

A case of asymptomatic common carotid artery occlusion with direct vertebrocarotid anastomosis (proatlantal intersegmental artery) in a 70-year-old male is reported. Despite the acquired left common carotid artery occlusion, there was no demonstrable neurologic deficits that would occur by the involvement of the area supplied by the occluded carotid system. Cerebral angiography revealed, in addition to efficient collateral circulation from the contralateral carotid system through the anterior communicating artery, a collateral channel from the left vertebral artery to the ipsilateral external carotid artery via the proatlantal intersegmental artery. These collateral circulations were indicated to be important in prevention of possible grave neurologic consequences. The proatlantal intersegmental artery, though rarely visualized by ordinary cerebral angiographic procedures, was thus demonstrated to be capable of serving as a collateral channel of potential usefulness in the event of severe intracranial hemodynamic alterations, including acquired common carotid artery occlusion.

Aged↗
PubMed1992

Somatic motor efferents in multiple system atrophy with autonomic failure: a clinico-pathological study.

The myelinated fibers in the corticospinal tracts, ventral spinal roots, and the neurons in the ventral spinal horns were quantitatively examined in 8 autopsied cases of multiple system atrophy associated with autonomic failure. In these structures consisting of the somatic motor efferents, the main pathological feature was the size dependent-involvement of predominantly small-sized fibers and neurons. The small myelinated fibers were significantly depopulated, while the large myelinated fibers were well populated in the corticospinal tract. Neurons in the ventral horns were also involved, but those with a small diameter and located in the intermediate zone (Rexed's lamina VII, VIII) were markedly diminished. In the ventral spinal roots, in the fourth lumbar segments containing essentially no autonomic efferents, small myelinated fibers were also preferentially involved. These pathological changes in the small-sized fiber and neuron loss were examined in relation to the somatic and autonomic motor symptoms, particularly of pyramidal signs.

Aged↗
PubMed1992

[The corticospinal tract of amyotrophic lateral sclerosis--a morphometric analysis of the myelinated fibers].

The myelinated fibers in the lateral corticospinal tract at the C6, T7, L4 levels in amyotrophic lateral sclerosis (ALS) and control cases were morphometrically examined. ALS cases consisted of 6 males and 2 females with ages ranging between 48 and 85 years, and were all the common or bulbar form in clinical manifestation. As for controls, 10 cases who died of non-neurological diseases, with age ranging 36 to 90 years were served. The population and the diameter profile of the myelinated fibers in the corticospinal tract of the C6, T7, L4 levels were measured by the method previously described and expressed as number per mm2. In control subjects, fiber-size histograms of myelinated fibers showed a bimodal pattern with a sharp peak of small fibers (less than 7.28 microns) and a broad peak of large fibers (greater than or equal to 7.28 microns) in all the spinal levels. In ALS cases, large myelinated fibers were predominantly diminished in number, a small myelinated fibers were also decreased in some cases. The degree of fiber loss was extremely variable among cases; well populated in large fibers in some cases. As for the rostral caudal distribution of myelinated fiber loss, a caudally-accentuated fiber loss particularly in large fiber was seen in some of the cases. The topographical distribution of fiber loss in the horizontal plane of the corticospinal tract in ALS did not show a distinctive pattern.

Aged↗
PubMed1992

[Involvement of the ventral horn cells in Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuritis].

The lumbar ventral horn cells and myelinated fibers in the ventral spinal roots of Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyradiculoneuritis (CIDP) were morphometrically analyzed. In all six cases, central chromatolytic changes in the ventral horn cells were commonly observed. In addition, two out of four GBS cases and one of two CIDP cases showed a significant reduction in the ventral horn cell population, particularly in neurons with a large diameter. The cases with significant motoneuron loss also showed a remarkable reduction in the number of myelinated fibers in the ventral spinal roots, and severe axonal degeneration was observed in cases in acute phase. Astrogliosis of the ventral horn was also seen in some cases. The present study suggested that motoneuron loss in the primary demyelinating diseases like GBS and CIDP is the consequence of the axonal pathology of the motoneuron axons. These observations are helpful to understand motoneuron loss in certain motoneuron diseases with preferential involvement of lower motor neurons.

Adult↗
PubMed1991

Calmodulin-independent nitric oxide synthase from rat polymorphonuclear neutrophils.

Recently, the purification of nitric oxide synthase (EC 1.14.23) from rat cerebellum has been reported, and the enzyme is a calmodulin-requiring enzyme (Bredt, D. S., and Snyder, S. H. (1990) Proc. Natl. Acad. Sci. U. S. A. 87, 682-685). In this paper, nitric oxide synthase has been purified to near homogeneity from the cytosol fraction of rat polymorphonuclear neutrophils. The purification procedure involves affinity chromatography with adenosine 2',5'-diphosphate-agarose and an anion exchange column, DEAE-Bio-Gel A. On polyacrylamide gel electrophoresis in sodium dodecyl sulfate, the enzyme migrated as a single protein band with Mr = 150,000. The molecular weight was estimated to be 150,000 by gel filtration on a Superose 12 HR 10/30. The purified enzyme was unstable with a half-life of 3 h at pH 7.4 and 4 degrees C. The enzyme activity required the presence of Ca2+, NADPH, FAD, and (6R)-5,6,7,8-tetrahydro-L-biopterin. Calmodulin antagonists (W5, W7, W13, and trifluoperazine dihydrochloride) did not inhibit the enzyme activity, and the addition of calmodulin was also ineffective for the increase in the enzyme activity. The neutrophil enzyme appears to be a calmodulin-independent type of nitric oxide synthase.

Amino Acid Oxidoreductases↗
PubMed1991

Dual inhibitors of thromboxane A2 synthase and 5-lipoxygenase with scavenging activity of active oxygen species. Synthesis of a novel series of (3-pyridylmethyl)benzoquinone derivatives.

A novel series of (3-pyridylmethyl)benzoquinone derivatives was molecular designed and synthesized for the dual purpose of inhibiting thromboxane A2 and leukotriene biosynthesis enzymes and scavenging active oxygen species (AOS). They were evaluated for inhibition of TXA2 synthase, inhibition of 5-lipoxygenase, and for their scavenging activity of AOS using the thiobarbituric acid method. 2,3,5-Trimethyl-6-(3-pyridylmethyl)-1,4-benzoquinone (24, CV-6504) was the most promising derivative since it showed efficient AOS scavenging activity (inhibition of lipid peroxidation in rat brain homogenates: IC50 = 1.8 x 10(-6) M) as well as potent, specific, and well-balanced inhibitory effects on both enzymes (inhibitory effect on TXA2 synthase in human blood, IC50 = 3.3 x 10(-7) M; inhibitory effect on 5-lipoxygenase in human blood, IC50 = 3.6 x 10(-7) M). In adriamycin-induced proteinuria in a rat model, compound 24 at 10 mg/kg per day (po) suppressed proteinuria by more than 50%. The proteinuria, however, could not be reduced by single administration of an inhibitor specific for thromboxane A2 synthase [(E)-7-phenyl-7-(3-pyridyl)-6-heptenoic acid (2, CV-4151)] or for 5-lipoxygenase [2-(12-hydroxy-5,10-dodecadiynyl)-3,5,6-trimethyl-1,4-benzoquinone (1, AA-861)]. The proteinuria was also not reduced by administration of an AOS scavenger, 2-O-octadecylascorbic acid (4, CV-3611). Triple function compounds such as compound 24 that specifically inhibit both enzymes as well as scavenge AOS possess a variety of pharmacologically beneficial effects.

Animals↗
PubMed1991

[A clinicopathological study of familial amyotrophic lateral sclerosis with special reference to the mode of motoneuron loss in the spinal ventral horn].

The authors analyzed clinicopathologically eight patients with familial amyotrophic lateral sclerosis (F-ALS). We performed the morphometric analysis on size and topographical distribution of the fourth lumbar spinal ventral horn cells, and correlated thus obtained results with the clinical, genetic and neuropathological features of these cases. The patients were consisted of six men and two women with age ranged between 40 and 58 years old. Six cases among them were involved predominantly in the lower-legs with generalized hyporeflexia and no Babinski's sign, which were compatible with the "pseudopolyneuritic" as a clinical form. Two other cases were involved in the upper limbs as the initial symptom and were considered to be "common form". Pathologically, five cases showed multiple system degenerations including the middle root zone of the posterior columns, Clarke's nuclei and posterior spinocerebellar tracts as well as the ventral horns and pyramidal tracts, which were designated as the form of "multiple system degeneration". In addition, three in these five cases were also associated with an extensive neuron loss and marked gliosis in the Onuf's nuclei, subthalamic, red and cerebellar dentate nuclei, suggesting that the involvement in certain F-ALS cases with a form of multiple system degeneration is more extensive in topography than ever believed. In other three cases, the neuronal degenerations were considerably restricted in the somatic motor efferent system, which were consistent with the classical pathology of the sporadic ALS, and were designated as "classical form". Five of seven cases showed a severe motoneuron loss in both the large and small neurons in the ventral horn. These five cases were heterogeneous in the pathological forms "multiple system degeneration" or "classical", but all were "pseudopolyneuritic" in clinical form. Moreover, these extensive motor neuron loss including small ones in the spinal ventral horn was similarly observed in the sporadic pseudopolyneuritic form of ALS cases. In two cases of F-ALS with "common" in clinical form, large motoneurons were fairly well preserved as are in the common form of sporadic ALS cases. Our tentative conclusion is that mode of motoneuron loss in the spinal ventral horn of F-ALS is more correlated to the clinical manifestations rather than the pathological or genetic background.

Adult↗
PubMed1991

[Clinical study of amaurosis fugax].

Nineteen cases of amaurosis fugax (AF) were analyzed in clinical study undertaken to address the problem of its pathogenetic mechanism. This series comprised 10 male and 9 female with an age range of 26-77 years. In 8 cases, AF was the only clinical manifestation, while in the other 11, AF was accompanied by hemispheric TIA. The attack lasted for a few to 15 minutes on most occasions, occurring on the left side in 7 cases and on the right in 12 cases. On the basis of cerebral angiographic findings and findings on transcranial Doppler blood velocity measurements (TCD), these cases were classified into 4 types of different etiology, i.e. (Group A) micro-embolus via internal carotid artery origin--7 cases (5 with stenosis at the level of siphon, 2 with stenosis of the ophthalmic artery); on TCD the direction of blood flow in ophthalmic artery was normal (forward flow) in 5 cases and antiplatelet therapy proved effective in 4 cases, (Group B) micro-embolus derived via the external carotid artery--5 cases (3 with complete occlusion of internal carotid artery at its origin, 2 with severe stenosis there of); TCD showed blood flow in the ophthalmic artery to be in a direction opposite to the normal (away flow) in 3 cases and 3 cases responded favorably to antiplatelet therapy, (Group C) cerebral hemodynamic crisis--3 cases (severe cardiac hypofunction following myocardial infarction, orthostatic hypotension, and elongation of internal carotid artery), and (Group D) unknown etiology--4 cases; cerebral angiography revealed no abnormalities, suggesting involvement of other factors than cerebrovascular agents.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Clinicopathological study of midbrain corectopia].

A clinicopathological study was conducted in 19 cases (including 9 autopsied) of midbrain corectopia (oval pupil) occurring in the acute stage of cerebrovascular disorders. This ocular symptom manifested itself in conjunction with severe impairment of consciousness invariably in all instances, unilaterally in 11 and bilaterally in 8 cases, with the shape of the pupil and the direction of its displacement varying from case to case. In 17 cases, this patients died several hours to several days after the appearance of this sign. On autopsy were noted small hemorrhagic lesion of the upper mesencephalic tegmentum in 2 cases and conspicuous cerebral herniation in 7 cases. In this study, it was thought that all cases had diffuse lesions including nuclear, infra- and/or supra-nuclear parts of the midbrain. Clinicopathologically, it was difficult to define the corresponding lesion for corectopia. We suggested that this ocular symptom which appeared transiently was the sign of poor prognosis.

Adult↗
PubMed1991

[A clinicopathological study of the somatic motor efferents in the pseudopolyneuritic form of amyotrophic lateral sclerosis].

Histopathology of the somatic motor efferents of three cases with pseudopolyneuritic from of amyotrophic lateral sclerosis (ALS) was analyzed, and the results were correlated with the clinical symptoms. The population of myelinated fibers in the lateral corticospinal tract at the thoracic segment, and in the fourth ventral roots, and motor neurons in the fourth ventral horns were morphometrically quantified. The patients were two males and one female ranging in age from 43 to 67 years, and showed a clinical course of 1.8 to 9.5 years. All three cases did not show any pyramidal sign nor spasticity but showed an extensive leg involvement, particularly the distally accentuated muscular weakness with depressed deep tendon reflexes. The clinical manifestations were consistent with the pseudopolyneuritic form of ALS. Fiber size profile of the myelinated fibers in the lateral corticospinal tracts at T7 segments and L4 lumbar ventral roots were estimated on the epon-embedded transverse sections as previously described (Sobue et al, 1981). Number and size distribution of anterior horn cells in the L4 segments were measured on 300-500 consecutive 10 microns-thick paraffin sections stained with Klüver-Barrera technique, using a TGZ-3 particle size analyzer (Zeiss). The location of the remained anterior horn cells was also quantitatively estimated. Three cases with common form of ALS and three control cases were analyzed in the same manner. The large myelinated fibers in the lateral corticospinal tract were extensively and predominantly depleted in all three cases. The small myelinated fibers were also depopulated but in lesser degree. The mode of these myelinated fiber loss was almost compatible with those in common form of ALS.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Clinical investigation of 10 patient with amebic dysentery].

Data were obtained in 10 patients with amebic dysentery at Osaka Socio-Medical Center hospital during the period from April 1985, to April 1989. All of the patients were male, and their average age was 41 years old. In the past history, all of them had never gone to foreign country, and 7 patients had the habit of homosexual love. In the serological test, positive rate of antiamebic antibody was 100% (6/6) by agar gel diffusion, that of antibody of Toreponema pallidum was 60% (6/10) by TPHA, but anti AIDS antibody was not detected (0/3) by HIV. Detectability of Entoamoeba hystolitica was 70% (7/10) in stool, 50% (2/4) in liver abscess, 25% (1/4) in biopsied specimens of rectal mucosa. Then, we fund that the serological test for antiamebic antigen was useful for diagnosis of this disease, and suspected that homosexual contact contributed to the infection of E. hystolitica.

Adult↗
PubMed1989

Endothelin-induced mobilization of Ca2+ and the possible involvement of platelet activating factor and thromboxane A2.

Endothelin (ET) caused transient and sustained elevations of cytosolic free Ca2+ concentrations ([Ca2+]i) in cultured rat and rabbit vascular smooth muscle cells (VSMC). Specific platelet activating factor (PAF) antagonists (CV-6209 and WEB-2086) and arachidonic acid (AA) cascade blockers (chlorpromazine, indomethacin, CV-4151 and AA-2414) potently inhibited the ET-induced increase in [Ca2+]i. Additionally, these compounds inhibited the PAF-induced increase in [Ca2+]i. These results suggest that PAF and thromboxane A2 (TXA2) may be involved in the mechanism of ET-induced mobilization of Ca2+ in cultured rat and rabbit VSMC.

Animals↗