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Biomedical subjects

M Tabuchi

Publications and source records attributed to M Tabuchi.

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

[The role of magnetic resonance imaging in the diagnosis of Hallervorden-Spatz disease].

A mentally-retarded 21-year-old female with narrowing of the visual field was admitted to our hospital because of dystonia in the body and extremities which appeared 6 months before and was gradually exacerbating. On admission, torsion dystonia, pyramidal tract sign, and retinitis pigmentosa with optic atrophy, urinary incontinence, hyperhidrosis and insomnia were noted. On the Wechsler Adult Intelligence Scale, she achieved less than 60 for verbal-IQ. Laboratory tests including serum copper and ceruloplasmin, were all normal. A computed tomography of the brain showed small hyperdense spot in the globus pallidus on the both sides. There was neither cortical atropy nor ventricular dilatation. A Magnetic Resonance Imaging was obtained using both moderate-field (0.5 Tesla) and high-field (1.5 Tesla) superconducting MR systems. T2-weighted spin echo images demonstrated markedly decreased signal intensity area restricted in the globus pallidus and substantia nigra on both system. Moreover, in the center of the globus pallidus, a small high signal spot was seen ("eye-of the-tiger" sign coined by Sethi et al). There was no abnormal signal in the putamen, caudate nucleus, red nucleus, and dentate nucleus. On the other hand, T1-weighted inversion recovery images were not remarkable. These striking low attenuation on T2-weighted findings suggests an increased iron deposition limited to the globus pallidus and substantia nigra which is characteristic of Hallervorden-Spatz disease/syndrome (H-S). Moreover, "eye-of-the-tiger" sign on T2-weighted MR images in the globus pallidus is previously described in H-S.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

In vivo treatment with erythroid differentiation factor (EDF/activin A) increases erythroid precursors (CFU-E and BFU-E) in mice.

The in vivo effect of human EDF on erythroid precursors (CFU-E and BFU-E) was investigated in normal and bled mice. In anemic (bled) mice, EDF treatment led to significant dose-dependent rises in the CFU-E and BFU-E levels of bone marrow. An elevation in the level of CFU-E was also seen in the spleen. In normal mice, a significant elevation in the level of bone marrow BFU-E was observed. Thus, EDF has an effect on erythropoiesis in anemic and normal mice in vivo.

Activins↗
PubMed1989

Stimulation of insulin secretion by transforming growth factor-beta.

Effects of transforming growth factor-beta (TGF-beta) on insulin secretion were studied in rat pancreatic islets. When islets were incubated in a batch incubation system with various concentrations of TGF-beta in the presence of 2.8 mM glucose, TGF- beta increased insulin release in a concentration-dependent manner. Both TGF- beta 1 and TGF- beta 2 were equally effective. The stimulatory action of TGF- beta was greater in the presence of stimulatory concentration of glucose. In perifusion system, TGF- beta induced an immediate monotonic increase in insulin secretion. These results indicate that TGF- beta is a stimulator of insulin secretion.

Animals↗
PubMed1989

A case of primary malignant lymphoma of the brain with high uptake of 123I-IMP.

In general the 123I-IMP SPECT image of a brain tumor is visualized as a defect. Tumor cases with high IMP uptake have been rarely reported. We encountered a case of primary malignant lymphoma of the brain with high IMP uptake on both early and late scans corresponding to the CT lesions. Previously reported positive cases seemed to be confined to the early scan. For the present the exact behaviour of IMP is incompletely understood, but the mechanism of high uptake has been accounted for by increased extraction and increased amine receptors at the tumor sites. We need further information to establish whether these SPECT findings are specific for primary malignant lymphoma of the brain.

Aged↗
PubMed1988

A novel action of activin A: stimulation of insulin secretion in rat pancreatic islets.

The present study was conducted to examine an action of activin A on insulin secretion from rat pancreatic islets. In a batch incubation system, activin A stimulated insulin secretion in a dose-dependent manner at concentrations higher than 1 nM. Furthermore, activin A greatly potentiated glucose-induced insulin release. When islets were perifused with 1 nM activin A, insulin secretion was barely affected in this system. However, the insulin response to 16.7 mM glucose was greatly enhanced. Both the first and second phases of insulin response were enhanced by 1 nM activin A. These results indicate that, in addition to its known actions on pituitary-gonadal and hematopoietic systems, activin A modulates the function of pancreatic islets and stimulates insulin secretion.

Activins↗
PubMed1988

Intracarotid urokinase with thromboembolic occlusion of the middle cerebral artery.

Intracarotid urokinase infusion therapy was performed on 22 patients with evolving cerebral infarction due to acute thromboembolic occlusion of the middle cerebral artery. Mean time from onset of symptoms to start of infusion and mean dosage of urokinase were 4.5 hours and 927,000 units, respectively. Immediate recanalization was achieved in 10 patients (45%) after urokinase therapy. In patients with successful recanalization, rapid amelioration of symptoms followed the restoration of blood flow. Thrombolytic recanalization was associated with reduction of neurologic deficits and of computed tomography-demonstrable infarction volume. The reduction of infarction volume and functional outcome correlated highly with the degree of reflow. Hemorrhagic transformation of infarction occurred in four patients and controllable extracranial bleeding in three patients. These results support the safety and efficacy of urokinase therapy for acute thromboembolic occlusion of the middle cerebral artery.

Adult↗
PubMed1986

Hypergraphia: a right hemisphere syndrome.

A new right hemisphere symptom is reported. Five stroke patients with lesions in the perisylvian cortico-subcortical or thalamic region of the right hemisphere produced linguistically correct but semantically loose writing. The behaviour was initiated by subtle prompting and continued semiautomatically. A possible mechanism underlying this hypergraphia is discussed.

Aged↗
PubMed1986

[Analytical study of Xenopus hindlimb regenerate with special reference to muscle regeneration].

Amputated hindlimbs of Xenopus laevis, develop various types of regenerates in relation with amputation level as well as stage development. The present experiments is an attempt to study the histological characteristics of Xenopus regenerations, i.e., rational changes of tissue components along the length of the regenerated part with special emphasis on the degree of muscle regeneration. Four types of regenerates were studied viz; a 4th toe obtained from a completely restored regenerated limb at 126 days after amputation of limb at base level in stage 51. An amputated limb with no external sign of regeneration of limb at thigh level in stage 60. A spike-shaped regenerate at 96 days after amputation of limb at shank level in stage 63. A spike-shaped regenerate at about 2 years after amputation of limb at shank level in stage 60. Cross sectional areas of muscle, skin gland, epidermis and cartilage in each of the four types of regenerates were measured with Image Analyzing Apparatus (VIP 121 CH, Olympus Co.). The relative area of each tissue was expressed as a percentage of the cross sectional area of the limb. The obtained values were plotted along the length of the regenerate. Digitiform regenerates were found to be more or less similar to the control limbs, i.e., provided joints and muscle, while the heteromorphic spike or rod shaped regenerates were simply provided with cartilaginous axial core without joint formation. Muscle area were reduced rapidly near the amputation area of these heteromorphic regenerates with no more continuation in the regenerated tissue. It is interesting to mention that percentage cartilage area of about 2 years old spike regenerate was higher than that of similar 96 days regenerate. In addition muscle regeneration was completely absent even in such an aged regenerate. The area showed fairly similar ratio irrespective of the external appearance of the regenerate. In 32 regenerates of which limbs were amputated at various developmental stages ranging between stage 51 and adult stage, the histological condition of muscle at the amputation site, were well observed. In all digitated types of regenerates even in those with reduced number of toes, muscles were found grown well in the regenerates. In heteromorphic regenerates without toe formation muscle did not usually regenerate. In few cases, however, a small mass of myoblastic like cells or small aggregation of differentiated muscle cells without any structural continuation with the stump muscles, were seen to develop in the midst of the regenerate.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1984

Ataxic hemiparesis from small capsular hemorrhage. Computed tomography and somatosensory evoked potentials.

We studied three cases that fit the clinical syndrome of ataxic hemiparesis. Computed tomography revealed small hemorrhages of the posterior limb of the internal capsule in all the cases, and somatosensory evoked potential studies predicted a disturbance of the lemniscal pathway from the thalamus to the parietal sensory cortex without demonstrable sensory loss. These results suggested that ataxia of the contralateral limbs following capsular lesion might result from a disruption of the thalamocortical sensory projection. The site of the lesion, the pathologic cause, and the underlying mechanism of ataxia are not necessarily homogeneous within the syndrome.

Aged↗
PubMed1982

Selective loss of small myelinated and unmyelinated fibers in Shy-Drager syndrome.

The number and sizes of myelinated and unmyelinated fibers in biopsied sural nerves in cases with Shy-Drager syndrome were studied in comparison with cases with olivopontocerebellar degeneration not having autonomic dysfunction. In Shy-Drager syndrome there was a tendency for both small myelinated and unmyelinated fiber densities to be reduced in comparison with cases with olivopontocerebellar degeneration. Unmyelinated fibers more than 0.5 micrometers in diameter were significantly reduced in Shy-Drager syndrome, a fact suggesting myelinated fiber degeneration. Multilamellated Schwann cell processes, isolated Schwann cell processes, and collagen pockets were more numerous and conspicuous in cases with Shy-Drager syndrome. It was concluded that unmyelinated fibers and small myelinated fibers in the peripheral nerves were involved selectively in Shy-Drager syndrome. The significance of the findings was discussed in terms of autonomic dysfunction observed clinically.

Aged↗
PubMed1981

Renal cortex visualization and analysis of dynamic CT curves of the kidney.

Renal cortex visualization and dynamic renal computed tomography (CT) were carried out by bolus injection of contrast medium. In vivo renal cortex visualization showed that renal cortex volume and cortex thickness are both inversely correlated with age. The percentage volumes of cortex and columns of Bertin are correlated inversely in non renal-failure subjects. Percentage volumes of cortex tend toward low values in renal failure and status after renal transplantation. In analyzing dynamic renal CT curves, the corticomedullary junction time is a good index of mild impairment of renal function.

Acute Kidney Injury↗